The production of high-current and intense spin polarized electron beams is of great importance in electron-based facilities. Tests are planned to produce such beams in 2023 using GaAs-based photocathodes installed in the Brookhaven National Lab RHIC Coherent electron Cooling superconducting radiofrequency (SRF) photogun [1]. A fast and efficient electron polarimeter operating in the MeV...
Dielectric gratings are used in Dielectric Laser Acceleration due to their high damage thresholds in high acceleration gradients. When an electron bunch passes close to these gratings, it emits radiation, and the features of this radiation will be dependent on the beam position relative to the grating, the bunch charge, and the bunch length. A compact high-resolution diagnostic device will be...
Grid-controlled electron gun usually uses specially designed power supplies to supply power, the performance of the power supplies can directly affect the beam performance of the accelerator. In this paper, a nanosecond power supply for a grid-controlled electron gun is designed. It uses avalanche transistors and superimposes Marx generators to improve the power. Finally, its rise edge is less...
Beam monitoring for Ultra High Dose Rate (UHDR) radiation therapy using pulsed beams, i.e. Very High Energy Electrons (VHEE), is a major challenge. The lower pulse repetition of VHEE beams means a larger dose-per-pulse is necessary to achieve the mean dose rates required for UHDR therapy (so-called FLASH). The currently used transmission ion chambers suffer drastic recombination effects under...
A design study is currently underway at the University of Melbourne for a large energy acceptance beamline to enable future hadron therapy modalities. As part of the TURBO project, a beam delivery system demonstrator is being developed for a DC Pelletron accelerator, which will provide 3 MeV H+ beams. Fixed Field Accelerator optics will be used to maximise momentum acceptance, with dispersion...
Space charge forces represent main induced effects in an RF-injector that degrade the beam quality. In this scenario the laser distribution sent on the photocathode acquires an
important role in the emittance compensation process, as the slice analysis shows. A novel model of space charge forces is proposed for bunch with arbitrary charge distribution to derive expressions of self-induced...
Developments in current and future experiments in the SPS North Area (NA) and PS East Area (EA) fixed target beam lines at CERN, including the “Physics Beyond Colliders” (PBC) program, require accurate determination of the number of protons on target (POT). The re-calibration of Beam Secondary Emission Intensity monitors (BSI), recently completed in one of the NA branches, reduced the...
The development of high-power, attosecond methods at free-electron lasers has led to new possibilities in the probing and control of valence electron dynamics. Beyond simple observation of ultrafast processes, one of the longstanding goals of atomic physics is control of the electronic wavefunction on attosecond timescales. We present a scheme to generate sub-femtosecond pulse pairs from x-ray...
Boron Neutron Capture Therapy(BNCT) is useful for cancer therapy. To generate safe and efficient neutron beams, we accelerate 2.5 MeV protons and irradiate a lithium target. This is an endothermic reaction that avoids activation of the accelerator and produces neutrons of relatively low energy. We are designing a beamline to deliver such protons to a lithium target. Tokyo Institute of...
The Large Hadron Electron Collider (LHeC) is a study
at CERN to construct an energy recovery linear accelerator
(ERL) tangentially to the High Luminosity Large Hadron
Collider (HL-LHC). This would enable deep inelastic scat-
tering collisions between electrons and protons in the ALICE
interaction region (IR2). In this design, one of the two pro-
ton beams of the HL-LHC collides with the...
At EuPRAXIA@SPARC_LAB an X-ray FEL user facility is driven by a plasma accelerator in the particle-driven configuration where an ultra-relativistic beam, the driver, through a plasma generates a wake of charge density useful for accelerate a witness beam. The electron bunches are generated through the so-called comb technique in an RF injector that consist of a 1.6 cell S-band gun followed by...
Accelerating technology is evolving towards compactness and high intensity. In such a scenario, beam loading effects result in significant energy losses for long trains of bunches. To address these effects, we generalised the Beam Loading module of the tracking code RF-Track to allow the study of beam loading independently of the particle type and velocity or the accelerating cavity design....
In recent work, it has been shown that reinforcement learning (RL) is capable of outperforming existing methods on accelerator tuning tasks. However, RL algorithms are difficult and time-consuming to train and currently need to be retrained for every single task. This makes fast deployment in operation difficult and hinders collaborative efforts in this research area. At the same time, modern...
The understanding of beam-beam effects, which influence the choice of the FCC-ee design parameters for several aspects, require sophisticated and high-performance numerical simulations. The self-consistent study of the interplay of nonlinear dynamical phenomena resulting from collisions in the machine is key to accurately assess its potential performance. Although current simulation frameworks...
Laser-wake field accelerators (LWFAs) are potential candidates to produce intense relativistic electron beams to drive compact free electron lasers (FELs) in VUV and X-ray regions. In High-Field Physics and Ultrafast Technology Laboratory at National Central University (NCU), an LWFA is being developed to produce a 250 MeV high-brightness electron beam by their 100-TW laser system. An FEL...
A set of twelve Polycrystalline Chemical Vapour Deposition (pCVD) diamond detectors are installed in the beam injection, extraction and betatron collimation areas of the Large Hadron Collider (LHC) as fast beam loss monitoring detectors. Their high-radiation tolerance and time resolution in the order of a few ns makes them an ideal candidate to monitor bunch-by-bunch losses in the LHC beams,...
Novel particle accelerators based on plasma technology allow a drastic reduction in size, due to the high accelerating field established inside plasmas, which are created and confined by specific devices. Plasma Wakefield Acceleration experiments are performed at the SPARC_LAB test facility (Laboratori Nazionali di Frascati - INFN) by using gas-filled capillaries, in which the plasma formation...
The Compact Linear Collider (CLIC) is a proposed linear accelerator designed to collide electrons and positrons at energies up to 3 TeV. In order to explore new physics and to be more competitive with other collider projects, CLIC is exploring the increase of the center-of-mass energy to 7 TeV. The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to...
In the frame of ongoing initiatives for the design of a new generation of synchrotron-based accelerators for cancer therapy with ion beams, an analysis of linac designs has been started, to address a critical element with strong impact on performance and cost of the accelerator. The goal is to identify alternatives at lower cost and similar or possibly smaller footprint than the standard 217...
Laser wakefield acceleration (LWFA) using metal targets has been developed for high-vacuum and high-repetition rate operations compare to the gas targets[1-2]. However, the ionization effect due to high intensity fs laser should be considered as propagating through the plasma and the difference of LWFA mechanisms between aluminum plasma and helium plasma has been investigated with the...
The damage mechanisms and limits of superconducting accelerator magnets caused by the impact of high-intensity particle beams have been the subject of extensive studies at CERN in the recent years. Recently, an experiment with dedicated racetrack coils made of Nb-Ti and Nb3Sn strands was performed in CERN’s HiRadMat facility. In this paper, the design and construction of the sample coils as...
Dielectric wakefield acceleration (DWA) is a promising approach to particle acceleration, offering high gradients and compact sizes. However, beam instabilities can limit its effectiveness. In this work, we present the result of a DWA design that uses alternating gradients to counteract quadrupole-mode induced instabilities in the drive beam. Through simulation and experimental results, we...
LEAF (Low Energy heavy ion Accelerator Facility) is a low-energy high-intensity heavy-ion LINAC complex for multidiscipline research. At present, the beam repetition rate is the same as the LINAC frequency of 81.25 MHz. A lower frequency would be desirable for many types of experiments employing time of flight data acquisitions. A method of increasing the bunch spacing to 98 ns by combining a...
The Lanzhou Light Ion Cancer Therapy Facility (LLICTF) is a compact medical accelerator currently under construction. It is designed to treat cancer using a 230MeV, 30mA H+ beam and a 85MeV/u, 1mA 3He2+ beam. The facility comprises two ion sources, a low-energy beam-transport (LEBT), a Radio Frequency Quadrupole (RFQ), a medium-energy beam-transport (MEBT), and the main ring accelerating...
In modern accelerator facilities, femtosecond synchronisation between an optical master oscillator (OMO) that provides facility-wide timing pulses and an external experiment laser is needed to achieve the few-fs resolution required for experiments such as pump-probe spectroscopy. This can be achieved with a balanced optical cross-correlator (BOXC), which determines the timing delay between two...
Spin is one of the intrinsic properties of particles. However, there are many incomprehensible problems about it. High energy polarized electron-ion collisions will provide unprecedented conditions for the study of spin physics and lead us to the study on the inner structure of matter and fundamental laws of interactions, and other forefronts of natural science. As the Phase II of the HIAF...
Tokyo Institute of Technology is planning a linac facility to produce 211 astatine, an isotope for αemitter cancer therapy. To produce astatine, we aim to bombard a bismuth target with helium ion beam of sufficient intensity at 28 MeV. Unlike a cyclotron, this facility will be able to accelerate a milliampere class high intensity helium ion beam. In addition, the subsequent accelerator...
A Low Energy Branch is being built at Micro Analytical Centre * that will allow us to produce a variety of high current (up to 50 $\mu A$) ion beams, ranging from light (i.e. H, He, C, B, $^{15}N$), mid-mass (i.e. Si) to heavy (Ag, W, Pb, Bi) ion beams in the energy range of 100 eV up to 30 keV. Ions will be produced with the use of ion sources that are currently available at the facility....
Polarized beam is an effective tool in basic research. An Electron-ion collider in China (EicC)*, as a future high energy nuclear physics project, has been proposed. Eicc can provide good research conditions for precision measurements of the partonic structure of nucleon or nuclei and the study on the interactions between nucleons and so on. High quality polarized beam is helpful to the...
The muon-dedicated linear accelerator is being developed for the muon g-2/EDM experiment at J-PARC. To suppress the decay loss during acceleration, the alternative phase focusing (APF) method inter-digital H-mode drift tube linac (IH-DTL) is adopted in the low-velocity region following a radio-frequency quadrupole linac (RFQ). We are planning to accelerate muons in 2024 using the RFQ and the...
Standard methods of measuring the transverse beam profile are not adaptable for sufficiently high-intensity beams. Therefore, the development of non-invasive techniques for extracting beam parameters is necessary. Here we present experimental progress on developing a transverse profile diagnostic that reconstructs beam parameters based on images of an ion distribution generated by beam-induced...
For the purpose of indirect search of dark matter, we designed laterally driven Dielectric Laser Acceleration (DLA) structure that achieves 1.2 MeV energy gain in 6 mm length together with 6D confinement. The design originated from a relativistic DLA structure and was supplemented with non-homogeneous shapes following the APF segments and optimized using a genetic algorithm together with the...
Solid-state plasma wakefield acceleration might be an alternative to accelerate particles with ultra-high accelerating gradients, in the order of TV/m.
In addition, due to their thermodynamic properties, 2D carbon-based materials, such as graphene layers and/or carbon nanotubes (CNT) are good candidates to be used as the media to sustain such ultra-high gradients. In particular, due to...
The CLEAR facility at CERN allows users to receive an electron beam with energy up to 200 MeV, allowing flexibility in intensity, beam size and bunch structures. Separate from the main CERN accelerator complex, it is capable of hosting numerous experiments with rapid installations at two test stands.
It would be highly desirable for many applications, but particularly those of a medical...
Vertical orbit excursion Fixed Field Accelerators (vFFAs) feature highly non-linear magnetic fields and strong transverse motion coupling. The detailed study of their Dynamic Aperture (DA) requires computation codes allowing long-term tracking and advanced analysis tools to take the transverse motion linear and non-linear coupling into account. This coupling completely transforms the beam...
High temperature superconductor REBCO has the property of maintain a high critical current density under strong external magnetic field, which makes a promising material for electromagnets in cyclotron and ECR ion source. Therefore, an ECR ion source using iron-less REBCO coils as electromagnet is under development in Research Center for Nuclear Physics (RCNP), Osaka University. A coil system...
Optical Stochastic Cooling (OSC) is a feedback beam cooling technique that uses radiation produced by a beam to correct particles' own momentum deviation. This system is made up of two undulator magnets, the pickup and kicker, separated by a bypass chicane that introduces a momentum-dependent path length. The beam produces radiation in the pickup and arrives in the kicker with a delay...
Ultrafast electron probing techniques offer unique experimental tools for investigating the structural dynamics of ultrafast photo-induced processes in molecular and condensed phase systems. In this work, we propose using the SEALAB Photoinjector's exceptional and versatile electron beam parameters to develop a state-of-the-art facility for ultrafast electron diffraction and imaging (UED and...
Polarization levels in the Electron Storage Ring (ESR) of the Electron-Ion Collider (EIC) must be maintained for a sufficient time before depolarized bunches are replaced. The depolarizing effects of synchrotron radiation can be minimized with spin matching, however the optics requirements for the ring must still be satisfied. Furthermore, the robustness of the polarization in the presence of...
Limited dynamic aperture which is in the consequence of strong nonlinearities in a low emittance storage ring, is a challenging issue from beam dynamics point of view. In the present study, we have applied three families of focusing and defocusing octupoles to the storage ring lattice with the aim of increasing dynamic aperture and beam lifetime . We have discussed different methods to...
The beam screen for the Future Circular hadron-hadron Collider (FCC-hh) has a baseline design based on a copper (Cu) coating. Calculations have indicated that the resistive wall impedance will be the major contributor to the beam impedance for the FCC-hh at both injection and collision and that Cu might be on the limit to ensure beam stability. To increase the safety margin, it is desirable to...
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator [1]. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch...
The Hefei Advanced Light Facility (HALF) is a diffraction limited storage ring (DLSR) being constructed. As the main component of the storage ring vacuum system, the vacuum chamber transports the beam and withstands the thermal effect of synchrotron radiation simultaneously. The thermal and mechanical condition of the vacuum chamber of HALF were quantitatively analysed by means of ANSYS...
Within the framework of FLASH2020+, substantial parts of the injector of the FEL user facility FLASH have been upgraded during a nine-month shutdown in 2022 to improve the electron bunch properties in preparation for FEL operation with external seeding starting in 2025. As part of the injector upgrade, a laser heater has been installed upstream of the first bunch compression chicane to control...
For the first time, photoemission of spin-polarized electron beams from gallium nitride (GaN) photocathodes are observed and characterized. The spin polarizations of the emitted electrons from epitaxially grown hexagonal and cubic GaN photocathodes activated to Negative Electron Affinity (NEA) via cesium deposition are measured in a retarding-field Mott polarimeter.
Chromaticity up to the third order in the LHC has been well observed in the LHC’s first and second operational runs, with regular beam-based measurements performed during commissioning and machine development. In previous runs however, no higher-order chromaticity could be observed. In 2022, dedicated collimators setups meant optics measurements could benefit from an improved range of...
Upcoming projects requiring ~650 MHz medium-to-high-beta elliptical cavities such as Michigan State University’s Facility for Rare Isotope Beams’ energy upgrade and Fermilab’s Proton Improvement Project-II drive a need to understand magnetic RF loss mechanisms in greater detail. It remains to be seen whether flux trapping mitigation techniques used in 1.3 GHz cavities are as effective at ~650...
Energy recovery linacs (ERLs) possess bright prospect of the fully coherent x-ray generation. Recently, we designed a 600 MeV energy recovery linac capable of producing high power fully coherent radiation pulses at 13.5 nm with a relatively low-intensity 256.5 nm seed laser profited from the employment of angular-dispersion-induced microbunching (ADM) technology. We also designed a matched...
A periodic system of spirally arranged magnetized annular sectors creates near the axis a helical field, which is close in structure and magnitude to the field in the set of helical magnets. Such a system of relatively few available magnets can be easier to manufacture and assemble than a system containing magnetized helices made from a single piece. In this paper, we theoretically study the...
Charged particles moving through a carbon nanotube may be used to excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell that makes up a nanotube wall. This effect has recently been proposed as a potential novel method of short-wavelength-high-gradient particle acceleration. In this contribution, the existing theory based on a linearised hydrodynamic model...
Magnetic field errors pose a limitation in the performance of circular accelerators, as they excite non-systematic resonances, reduce dynamic aperture and may result in beam loss. Their effect can be compensated assuming knowledge of their location and strength. Procedures based on orbit response matrices or resonance driving terms build a field error model sequentially for different...
The LHC particle-physics program requires that the delivered luminosity be measured to an absolute accuracy in the 1% range. To this effect, the absolute luminosity scale at each interaction point (IP) is calibrated by scanning the beams across each other according to the van der Meer method. During such scans, the orbit and the shape of the colliding bunches are significantly distorted by...
Impedance-induced tune shifts and instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Calculation of these beam observables are obtained using both Vlasov solvers and macroparticle tracking simulations, and are compared with those observed during dedicated measurement campaigns. Thanks to improvements in the...
Free-electron lasers (FEL) producing ultra-short X-ray pulses with high brightness and continuously tunable wavelength have been playing an indispensable role in the field of materials, energy catalysis, biomedicine, and atomic physics. A core challenge is to maintain and improve the transverse overlap of the electron and laser beams. This requires high-dimensional, high-frequency, closed-loop...
The IBA ProteusOne (P1) system is suitable to treat ocular tumors and achieves efficient dose conformality using state-of-the-art pencil beam scanning. Nevertheless, with the limited cyclotron current of the P1 system, clinically relevant (> 15 Gy/min) dose rates can barely be achieved in eye tumors treatment cases with the baseline configuration of the system due to the significantly high...
The future AMBER experiment aims to measure the inner structure and the excitation spectra of kaons with a high intensity kaon beam at the CERN secondary beam line M2. One way to identify the small fraction of kaons in the available beam is tagging with the help of differential Cherenkov detectors (CEDARs), whose detection efficiency depends critically on the beam parallelism. In the framework...
Diffraction-limited light sources have garnered significant interest -- yet the smaller equilibrium size of their electron bunches also reduces the beam-lifetime. One remedy is to vertically excite the electron beam, for instance using a Multi Bunch Feedback (MBF) system. Previous work has demonstrated that this approach can safely increase the vertical emittance, thus beam-lifetime. However,...
Landau damping plays a crucial role in preserving single-bunch stability. In view of delivering the beam to the High-luminosity LHC (HL-LHC), the Super Proton Synchrotron (SPS) must double the intensity per bunch. In this intensity range, the loss of Landau damping (LLD) in the longitudinal plane can pose an important performance limitation. Observation of the beam response to a rigid-bunch...
The photon flux resulting from a high energy electron beam's interaction with a target, such as in the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, should yield, through its spectral and angular characteristics, information about the electron beam's underlying dynamics at the interaction point.
This project utilizes data from simulated plasma wakefield...
PERLE (Powerful Energy Recovery LINAC for Experiment) is a high-power Energy Recovery LINAC (ERL) facility with 20 mA beam current and beam energy from 250 MeV to 500 MeV featuring three passes through two cryomodules. It is a hub for validation of the ERL technology development towards future energy and intensity frontier machines. Design challenges of PERLE and its beam parameters make it a...
An 800 MHz, Radio Frequency Quadru-pole (RFQ) was designed to accelerate the proton beam to 2 MeV energy at a distance shorter than one meter in KAHVE-Lab, Turkey. A half-length test module was previously produced to investigate the local manufacturability of this RFQ cavity. The manufactured test module was subjected to mechanical, vacuum and electromagnetic tests to adjust the pressure, EM...
Nb3Sn superconducting radiofrequency (SRF) cavities have been an ongoing research topic for many years motivated by the potential for higher accelerating gradients and quality factors compared to niobium SRF cavities. The highest performing Nb3Sn cavities are manufactured using tin vapor-diffusion coating, which creates a Nb3Sn film with a surface roughness of around 100-200 nm. This is...
One of the most fundamental measurements since the Higgs boson discovery, is its Yukawa couplings. Such a measurement is only feasible, if the centre-of-mass (CM) energy spread of the e+e- collisions can be reduced from ~50 MeV to a level comparable to the Higgs boson’s natural width of ~4 MeV. To reach such desired collision energy spread and improve the CM energy resolution in...
IFMIF-DONES* is a key device in the EUROfusion roadmap for studying and licensing materials for future fusion reactors. It will be a unique neutron fusion-like irradiation facility equipped with a linear particle accelerator impinging an intense deuteron beam (125 mA, 40 MeV) onto a liquid lithium target. In terms of safety analysis of the facility, relevant accidental scenarios are related to...
Optical Transition Radiation (OTR) is commonly used in imaging systems of highly relativistic charged particle beams as the light yield and collection efficiency would increase with beam energy. For low beam energies, scintillating screens are typically preferred but would saturate or even get damaged when using high beam current. For such a beam, OTR screens can, therefore, still be an...
This paper proposes a new coupling slots design for the Pi-Mode structure high-frequency cavity in the China Spallation Neutron Source (CSNS) Phase II. Through simulation calculations and experimental verification, it was found that the new coupling slots design significantly improves the Q value and transmission efficiency of the high-frequency cavity. This study is of great significance...
One of the Grand Challenges in beam physics relates to the use of virtual particle accelerators for beam prediction and optimization. Useful virtual accelerators rely on efficient and effective methodologies grounded in theory, simulation, and experiment. This work extends the application of the Sparse Identification of Nonlinear Dynamical systems (SINDy) algorithm, which we have previously...
Electropolishing (EP) and buffered chemical polishing (BCP) are conventional surface preparation techniques for superconducting radiofrequency (SRF) cavities that remove damaged material from the cavity surface. One main issue with EP and BCP treated SRF cavities is high field Q-slope (HFQS), a drop in quality factor at high gradients that limits quench field. High gradient performance in EP...
The cryocooled DC electron gun at Arizona State University (ASU) is the first electron gun built to implement single-crystal, ordered surface and epitaxially grown photocathodes to produce cold and dense electron beams at the source. These high brightness electron sources are extremely desirable for ultrafast electron applications such as Xray Free Electron Lasers (XFELs), Ultrafast Electron...
Integrating the advances made in photonics with efficient electron emitters can result in the development of next generation photocathodes for various accelerator applications.
In such photonics-integrated photocathodes, light can be directed using waveguides and other photonic components on the substrate underneath a thin (<100 nm) photoemissive film to generate electron emission from...
We present the latest updates to the PLACET3 tracking package which focus on the impact of both transverse and longitudinal wakefields on a beam travelling through accelerating and decelerating structures. The main focus of this update was the first implementation of 6D tracking through Power Extraction and Transfer Structures (PETS) for the Compact Linear Collider (CLIC) which is described...
In this paper we will show the injection philosophy and the design of timing and filling scheme for high luminosity CEPC scheme under different energy modes. It is found that the RF frequency choice in CDR cannot meet the injection requirements for the bunch number at Z pole. A modified scheme was proposed to support the design luminosity,which basically meets our current design requirements and...
Recent studies showed significant improvement in quantum efficiency (QE) by negative electron affinity (NEA) GaAs nanopillar array (NPA) photocathodes over their flat surface peers, particularly at 500 ─ 800 nm waveband. However, the underlying physics is yet to be well understood for further improvement in its performance. In this report, NEA GaAs NPA photocathodes with different dimensions...
The Large Hadron Collider at CERN is equipped with instruments that exploit collisions between beam particles and gas targets, one of them being the Beam Gas Vertex monitor. By design, its operation generates secondary particle showers used to measure beam properties, that also result in radiation levels in the tunnel proportional to the beam intensity and gas pressure. In this work, the...
As a scientific system with many subsystems, particle accelerator system is getting more complex， due to rising demands on accelerator performance. Meanwhile, it is increasingly difficult to study such complex systems using traditional research methods based on physical models. At present, machine learning (ML) is mature enough to be applied in accelerator science such as beam diagnostics and...
As the precise sensor system for monitoring the rela-tive altitude changes among multiple points, the capacity hydrostatic leveling system (HLS) is widely used in particle accelerators. To expand its application in provid-ing the elevation constraint for the control network ad-justment, the research on the issue of the HLS for alti-tude difference measurement between multiple points is carried...
The CERN Super Proton Synchrotron (SPS) aims at providing stable proton spills of several seconds to the North Area (NA) fixed target experiments via third-integer resonant slow extraction. However, low-frequency power converter ripple (primarily at 50 and 100 Hz) and high-frequency structures (mainly at harmonics of the revolution frequency) modulate the extracted intensity, which can...
Externally seeded high-gain free electron lasers (FELs) are capable of providing fully coherent radiation with high shot-to-shot stability at wavelengths down to the soft X-ray range.
However, present seed laser sources are not suitable for the generation of short wavelength FEL radiation at high repetition rates. As a result, such setups have been unable to make use of the full repetition...
In the KIT storage ring KARA (Karlsruhe Research Accelerator), two parallel plates with periodic rectangular corrugations are planned to be installed. These plates will be used for impedance manipulation to study and eventually control the electron beam dynamics and the emitted coherent synchrotron radiation (CSR). In this contribution, we present simulation results showing the influence of...
The effect of radiation reaction is often negligible in inverse Compton scattering. However, in the nonlinear Compton regime, at high laser fields and high electron beam energies where electron recoil must be properly accounted for, there is experimental data which demonstrates the onset of radiation reaction * . We model the radiation reaction as a series of emissions from individual...
Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1--30s. This work is the first study of slow extraction from a scaling Fixed...
The high precision measurement of the centre-of-mass energy in the Future Circular Collider e+e- (FCC-ee) at Z and W energies can be realized through resonant spin depolarization utilizing transversely polarized beams. This requires a guaranteed sufficiently-high spin polarization in the presence of lattice imperfections. Investigations of the impact of misalignments on the equilibrium...
With the high beam current in storage ring, it is necessary to consider the instability problem caused by the heavy beam loading effect. It has been demonstrated that direct RF feedback (DRFB), autolevel control loop (ALC) and phase-lock loop (PLL) in the main cavity can lessen the impact of the beam effect. This paper regarded the beam, main cavity, harmonic cavity and feedback loops as...
In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to its potential advantages in compactness and beam dynamics compared to conventional focusing elements. A promising application could be optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures to...
Superconducting dipoles with a strong curvature (radius smaller than 2 meters, for an aperture of about 100 mm and a length of 1-3 meters) are required for applications where compactness is key, such as the synchrotron and gantry for Carbon-ion therapy developed within the European program HITRIplus.
Such magnets challenge several assumptions in the field description and put to the test the...
Modelling electron cloud driven instabilities using a Vlasov approach enables studying the beam stability on time scales not accessible to conventional Particle In Cell simulation methods. A linear description of electron cloud forces, including the betatron tune modulation along the bunch, is used in the Vlasov approach. This method is benchmarked against macroparticle simulations based on...
The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in the field of next-generation compact and cost affordable particle accelerators. Recent results obtained at SPARC_LAB show evidence of the FEL laser by a compact (3 cm) particle beam plasma accelerator. This work is carried out in the framework of the SPARC_LAB activities...
Slowly extracted beams from a synchrotron have temporal fluctuations, the so-called spill micro structure. The reason is related to power supply ripples that act on the quadrupole magnets, leading to unintended tune fluctuations during extraction. Related simulations regarding the dependency of spill quality on the power supply ripples are executed with varying excitation levels of the...
Surface annealing using intense nanosecond laser pulses is an emerging technique for SRF cavities. This technique can effectively reduce the cavities’ surface defects and improve their RF performance. However, previous studies in this field limited themselves on solid state lasers or gas lasers, which have very low average power and are not practical for processing actual SRF cavities with ~m2...
The performance of operating particle accelerators has been seriously affected by the electron cloud (e-cloud) effect. The secondary electron emission (SEE) and the e-cloud can be effectively suppressed through laser-etching the inner surface of the vacuum chamber. Oxygen-free copper (OFC) has become the first choice for the vacuum chambers of modern accelerators due to its high electric and...
Radiation resistance of materials is an important area of research, relevant to nuclear reactor technology. Various challenges are associated with this research; one of which is the selection of radiation resistant material for the plasma facing wall of the reactor due to its harsh operating environment.* Recent studies reveal that WC has the potential to be developed as radiation resistant...
The superconducting radio-frequency (SRF) community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity profile of niobium with a low residual resistance ratio (RRR) and correlate...
Particle Accelerators demand high particle transmission and reduced longitudinal emittance; hence, effective bunching systems are requested. The concept based on an efficient, compact design called “Double Drift Harmonic Buncher - DDHB” fulfills these two requirements for a c.w. or pulsed beam injection into an RFQ, a DTL, or a cyclotron. The proposal is associated with two buncher cavities...
A uniform distribution of nucleation tin sites is essential to the growth of high quality Nb3Sn thin film by vapor diffusion method. The less-nuclear zones were commonly observed in previous nucleation experiments. However, a fully understanding of the occurrence of less-nuclear zones has not yet been achieved. Here, the adsorption energy of nuclear agent SnCl2 on different crystal planes of...
Real-time dosimetry for ultra-high dose-rates (UHDR) and Very High Energy Electrons (VHEE) is a challenge which is currently being studied using the electron beam at CERN Linear Accelerator for Research (CLEAR). These studies are motivated by the demand for reliable dosimetry for FLASH radiotherapy. This mode of irradiation relies on UHDR, a dose rate regime where conventional dosimetry...
A new electron cooling experiment is being planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab for cooling ~2.5 MeV protons in the presence of intense space-charge. Electron cooling is integral to the study of beam dynamics and has valuable applications for producing high-intensity hadron beams in particle accelerators. For such goals, an electron lens to be placed in the IOTA...
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications*, is a proposed facility for the study of proton and ion radiation biology. The accelerator is designed to deliver a variety of ion species over a wide range of spatial and temporal profiles at ultra-high dose rates. The facility requires that the deposited dose distribution be measured in real-time. For this purpose, an...
The quest of laser plasma accelerators is of great interest for various applications such as light sources or high energy physics colliders. This research has led to numerous performance improvements, particularly in terms of beam energy versus compactness [1] and ultra-short bunch length [2]. However, these performances are often reached without the achievement of sufficient beam quality,...
Inverse Compton Scattering (ICS) is an ideal source of tunable monochromatic gamma rays. These gammas have uses for Nuclear Resonance Fluorescence, and production of novel medical radioisotopes. The gamma energy can be tuned by changing the electron energy. An ICS source can be made quasi-monochromatic by using low energy spread electron and laser beams, and using a collimator.
Currently...
In this proceeding, we demonstrate the synthesis of epitaxial Cs$_3$Sb films with a high degree of crystallinity on silicon carbide substrates. Films less than 10 nm thin are grown in vacuum and exhibit percent level quantum efficiencies at 532 nm. We find a positive correlation between quantum efficiency and improved crystallinity of the photocathode film, particularly in the longer...
The upgrade project for the LHC injectors is described in detail, highlighting the major improvements implemented in the injector chain. Lessons in technical progress, project management and planning are presented. The performance of the upgraded systems in intensity, average particle flux and beam brightness is described and compared to the upgrade goals and LHC`s original design parameters....
An overview of the project status of the future Italian 2.4 GeV 4th generation light source Elettra 2.0 that will replace the existing 3rd generation light source Elettra is presented, including challenges and perspectives in the design and construction of such light sources. Elettra 2.0 will be the ultra-low emittance light source that will provide ultra-high brilliance and coherence and...
LCLS-2 should be completed in 2022, producing first light from its new SC linac. The status of beam commissioning and the performance of the new SC CW linac should be shown in detail. Performance should be compared with the design values and an outlook to further steps should be shown.
The Linear IFMIF Prototype Accelerator (LIPAc) has been constructed in Rokkasho, Japan to demonstrate the validity of the low energy section of an IFMIF deuteron accelerator up to 9 MeV with a beam current of 125 mA in continuous wave (CW) under the joint collaboration between EU and Japan. The short-pulse 125-mA deuteron beam acceleration to 5 MeV was successfully demonstrated in 2019. Now...
Superconducting RF thin film (SRF-TF) technology for RF cavities has only recently began to achieve accelerator field gradients and Q-factors close to that of bulk niobium SRF cavities. These thin films (such as Nb3Sn, NbTiN, Mg2B and multilayer structures) offer the ability to operate at higher temperatures (4.2 K instead of 1.9 K) thereby increasing the operating efficiency of the RF system...
Delivering and tailoring high brightness electron beams for a wide range of novel applications is a challenging task in single pass accelerator test facilities. This paper will review beam dynamics challenges at single pass accelerator test facilities in Europe to generate, transport and tailor low- to medium-energy high brightness electron beams for a range of novel applications.
Laser-plasma acceleration is a technique for producing ultra-relativistic electrons that takes advantage of the ability of plasma to carry arbitrarily intense fields. In practice, fields of several hundred GV/m can be produced simply by focusing an ultra-intense laser pulse in a sub-critical plasma [1]. These fields, which are 3 orders of magnitude larger than those produced in conventional...
The European Eupraxia project has recently been included in the ESFRI roadmap. EuPRAXIA is a world-wide first, new kind of compact facility and will be constructed at two European sites. One of the two sites for Eupraxia will be the INFN LNF at Frascati. The facility will be integrated with the already planned 1GeV linear accelerator.
This talk will cover the status of the technical design of...
Next generation storage ring light sources will dramatically increase the electron beam brightness, thereby significantly increasing the X-ray brightness for science. Such intense electron beams exhibit numerous collective effects that potentially drive instabilities. Advanced numerical simulation methods are compared with theory and experimental measurements at different machines. One...
The Fermilab Linac delivers 400 MeV H- beam to the rest of the accelerator chain. We are exploring several machine learning (ML) techniques for automated RF tuning, with an emphasis on time-evolving modeling that can account for parameter drift. Providing stable intensity, energy, and emittance is key since it directly affects downstream machines. To operate high current beam, accelerators...
The Eupraxia@SPARC_LAB project, foreseen a 1GeV Linac based on a X-band booster composed by 16 accelerating structures working at the nominal gradient of 60MV/m. In this framework, an intense activity has started in the last years in order to prove the reliability and functionality of the X-band technology at very high peak power. The main step of this activity has been the implementation of a...
A systematic study of microbunching instability is being carried out in the FERMI free-electron laser linac driver. This talk will report about modelling and experiments related to the instability, including the development of an infrared (IR) spectrometer for the diagnostic of microbunching-induced coherent emission in the IR spectral range.
In the commissioning and operational stage of X-ray free-electron lasers (XFELs), it is a challenging problem to efficiently tune the large-scale scientific machines which consist of hundreds and thousands of components. Here we tried to introduce several tuning algorithms to achieve automatic tuning in XFELs and compared the performance. This also paves the way for further development of...
Particle accelerators, relevant to LANL’s mission spaces will rely on the use of copper based rf structure for charged particle acceleration. Additively manufactured (AM) copper structures offer the usual well-known advantages in terms of relaxation of physical design (shape) constraints, and thus hold the promise of making complex shaped rf structures. To rapidly demonstrate the potential to...
Although beam emittance is critical for the performance of high-brightness accelerators, optimization is often time limited as emittance calculations, commonly done via quadrupole scans, are typically slow. Such calculations are a type of multi-point queries, i.e. each query requires multiple secondary measurements. Traditional black-box optimizers such as Bayesian optimization are slow and...
An important part of the new accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) is the beamline connecting the pre-accelerator with the main accelerator. The setup includes a vertical parallel beam offset realized with two dipoles. These are designed in a way, that they can serve as steerer for the main accelerator and will be discussed in this contribution. Furthermore,...
The Large Hadron Collider (LHC) arcs have been designed for a FODO optics with roughly 90° betatron phase advance per arc cell, but not necessarily with exactly the same optics in the eight sectors of the ring. Measuring an optics with a significantly different arc cell phase advance, e.g. 60° which is at the limit for aperture at LHC injection, offers the possibility of understanding the LHC...
750 MHz IH-DTL with the capability to accelerate protons from 3 to 10 MeV was proposed for the compact therpy linac that now under development in IMP. Four drift tube sections were housed in a single vacuum chamber and coupled with three large drift tubes which housing focusing triplet lens inside. In each drift tube section, there were 9 to 10 drift tubes, supported by the separated ridges....
Acceleration of polarized electron and positron beams to ultra-high beam energies is of interests for polarized beam applications in future 100km-scale e+e- circular colliders. However, it was widely envisaged that crossing hundreds of spin depolarization resonances would lead to severe depolarization during the energy ramp in the booster synchrotron. In this work, we have studied the spin...
After the PIP-II linac is commissioned as a new start of the Fermilab Acclerator Complex, the Booster will become a bottleneck for future high intensity particle physics research at Fermilab. An SRF linac is proposed as a replacement for the booster to enable future higher power proton beams in the Fermilab complex - this would include neutrino-based and muon-based studies, dark matter...
Production of super heavy elements of which atomic number is larger than 118 can provide new prospects in the field of nuclear physics. Extremely low production rate of these elements makes the experiments time consuming. This difficulty can be solved by using the energy recovery internal target, so-called ERIT, because the number of interactions can be increased as a circulating beam hits...
To reach the desired energy for a muon collider, muons should be accelerated to 5 TeV. This acceleration must be rapid to avoid muon decays, while simultaneously having a high average bending field to minimize the the required RF voltage. One concern with high energy muons is radiation from neutrinos, produced from muon decay, interacting with matter far from the accelerator. While this is...
This study is motivated by the search for the electric dipole moment (EDM) of elementary particles. The most promising idea in that regard is the “Frozen Spin” concept first proposed by the BNL. This concept, however, requires the building of a brand-new facility devoted to the EDM-search. NICA is not such a facility, hence the need for a modification compatible with the existing optics; one...
I describe a fixed field alternating gradient (FFA) lattice design to accelerate muons final energy for a muon collider. Ideally the muons would be accelerated to 5 TeV to reach the desired energy for physics studies*. An FFA allows the acceleration of muons over a large energy range without changing magnetic fields. It is an alternative to a pulsed synchrotron in which magnet fields must be...
Many applications of synchrotron light sources such as imaging, lithography and angle-resolved photoemission spectroscopy can benefit from high photon flux, which, unlike the brightness, is almost independent of electron beam transverse emittance. To realize high photon flux, it is desired to increase the stored current or number of periods of insertion devices. To this end, a low energy...
Hefei Advanced Light Facility (HALF) was designed as fourth generation light source based on the diffraction-limited storage ring (DLSR). The pre-research has been completely done, due to the smaller beam dynamic aperture, about 10mm, beam inject could not completed by the traditional bump magnet. We purposed and designed a novel dual-channel kicker, with other two traditional kicker, they...
The High Energy Photon Source (HEPS) is a fourth generation photon source, including a storage ring, a booster ring and a Linac. Due to the small dynamic aperture of the storage ring， a novel on-axis swap-out injection scheme was chosen. Here, the 6GeV booster acts as an accumulating ring during that injection process. To extract 6 GeV beam from the booster before injection into the storage...
At MAXIV Laboratory we are continuing the efforts to reduce the emittance of 330 pm.rad of the larger storage ring (SR) operating at an energy of 3GeV. This paper details the techniques used to improve the characterization of the optics, and to optimize the injection into the SR with an emphasis on the difficulties encountered during the process and the strategies adopted to overcome them.
The far-infrared linac and test experiment (FLUTE) serves as an accelerator test facility for a variety of accelerator physics studies. FLUTE is foreseen to provide coherent radiation in ultra-short, very intense light pulses in the terahertz (THz) and far-infrared spectral range. A superconducting undulator in the accelerator structure after bunch compression offers the possibility to...
Betatron coupling resonance has been considered by many low emittance upgrade light sources as a candidate to produce round beams. Due to the limited literature on the topic, last year an experimental campaign was undertaken on the ALBA storage ring to establish limits and requirements to operate a light source in full coupling. The work highlighted how coupling can indeed produce a round beam...
Nowadays, Energy Recovery Linacs (ERLs) became really appealing thanks to their low environmental impact and high sustainability.
ERLs require a special low energy injector, usually named merger. The energy at merger exit is clearly the energy that can’t be recycled in the ERL machine and is the amount dumped at the end. The lower the injection energy is the more efficient is the energy...
Diamond Light Source has been operating in top-up mode for users since late 2008. To date, Diamond’s electron gun has operated in single-bunch mode for multiple-shot top-up of user beam, and multibunch mode for storage ring fill. The uneven bunch-to-bunch charge of the multibunch train is visible in the storage ring and so the fast multibunch fill must be followed by a slower single bunch...
New R\&D concepts for particle acceleration, generation, and focusing at ultra high acceleration gradients (GeV/m and beyond) have the potential to enable future e+e- and $\gamma - \gamma$ colliders to and beyond 15 TeV energies. In addition to proven high gradient and ultra-bright beam generation, these systems have the potential to increase luminosity per unit beam power via short beams, for...
The performance of the Low Energy Ion Ring (LEIR) at CERN is mainly determined by the number of charges extracted from the machine and transferred to the downstream chain of accelerators. While the required target of 9e10 charges has now been surpassed, a series of studies have been undertaken to further push the intensity reach of LEIR. In this work, we quantify the effect of the stray fields...
The nominal Diamond-II storage ring optics have been designed to produce a pseudo twenty-four-fold symmetry by maintaining equal phase advance across the long and standard straights [1]. In this paper, the impact of introducing a high beta section in the injection straight and reducing the ring symmetry to one have been extensively investigated. This solution does not require any additional...
An in-vacuum Hall probe measurement bench was designed, built, and used to measure four Cryogenic Permanent Magnet Undulators (CPMUs) at 77 K at Diamond Light Source. The devices were tuned to correct the phase error at cold temperatures based on the measurements from the in-vacuum bench. The in-vacuum bench consists of a stretched wire system supplied by Danfysik and the in-house Hall probe...
Electron beam central-axis percentage depth dose (PDD) curves in water phantom are routinely employed to evaluate the electron beam energy at the phantom surface, in particular the mean and most probable energies from the values of R50 (half-value range) and Rp (practical range). However, these two quantities are not enough to evaluate important details of the energy distribution, such as the...
The accelerator high-power system provides electromagnetic energy to the acceleration structure to establish a high-power acceleration field. In pace with the current intensity development of accelerator beam, heigtening RF system performance is put on a new agenda. Temperature is a momentous parameter of accelerator RF system, which will directly affect the mechanical, electromagnetic and...
The High Luminosity Large Hadron Collider (HL-LHC) project foresees the upgrade of a large fraction of primary and secondary collimators of the betatron cleaning system to reduce the collimation impedance. The new collimator design also includes the installation of in-jaw beam position monitors (BPMs) to align the collimators faster and to continuously monitor the beam orbit, ensuring an...
While large circular colliders rely upon analysis of turn-by-turn beam trajectory data to infer and correct magnetic lattice imperfection and beam optics parameters, historically storage-ring based light sources have been exploiting orbit distortion, via the orbit response matrix. However, even large collider usually benefit of the orbit analysis during the design phase, in order to evaluate...
Iterative learning control(ILC) is a effictive algorithm for transient beam loading compensation. However, considering the algorithm complexity and the hardware cost, the ILC algorithm is usually implemented outside FPGA. This practice would decrease the real-time ability of the control system. In this paper, a real-time ILC algrithm will be introduced. And the result is summarized.
A third family of sextupole magnets was recently in-corporated at the KIT storage ring KARA (Karlsruhe Research Accelerator). Computer studies of beam dy-namics were performed with an objective to estimate benefits of operation with three sextupole families and possibility of new configuration of ring lattice to con-trol slope and curvature of momentum compaction factor as function of energy...
A 7 MeV Alvarez-type drift tube linac (DTL) had been designed and machined in the past few years for Xi'an 200 MeV proton application facility (XiPAF). This paper presents the assembly, alignment, error analysis and tuning results of the DTL. After all these tasks were completed at Tsinghua University, the DTL cavity had been transported to Xi'an for repetition measurement and test. It has...
All high-energy beam dump events at the Large Hadron Collider (LHC) are analysed to verify correct functioning of the Machine Protection System and to allow early identification of potential issues. This includes the evaluation of particle losses before and during the beam dump event.
The paper describes a newly developed tool for the automated evaluation of beam losses during high energy...
RF-Conditioning of a room temperature cavity is a long and resource intensive process. The need for constant supervision by experienced personal to avoid damage to the cavity and used equipment makes it a very expansive endeavor. To reduce the workload of the experimentalist, it was decided to develop a program utilizing machine learning, which, once finished, should have the probabilities to...
A lattice of a storage ring for the future plan of UVSOR synchrotron facility, UVSOR-IV, is designed at 1 GeV electron energy. The lattice of 12 compact double achromat cells conducts to an emittance of 4.2 nm at 1 GeV electron energy and 2.3 nm at 750 MeV electron energy in achromat condition, 82.5 m circumference, and six straight sections of 4 m long and six of 1.5 m long. The lattice has...
We fabricated corrugated wakefield structures and did cold test of them. Since the wakefield frequency of our structure is about 0.2 THz, there are several technical issues in the bead-pull.
We present issues concerning to bead size and the wire. And issues concerning to mode converter are described as well. We manufacture a customized mode converter which change electromagnetic mode from...
The baseline beam parameters of the FCC-ee contemplate different operation modes, with beam energies ranging between 45.6 GeV and 182.5 GeV. The highest expected beam stored energy reaches 20 MJ for the so-called Z operation mode (45.6 GeV), i.e. two orders of magnitude above that found in previous and operating lepton colliders.
In order to protect sensitive equipment and to limit...
The Beijing Electron Positron Collider II will upgrade to achieve a higher beam energy and higher luminosity which need a higher beam current and smaller beam size. The consequent high beam background should be controlled within in a safety range. The beam related background at BEPCII is mainly from the Touschek effect and the beam gas effect. This paper presents the beam background study at...
The machine-detector interface (MDI) issues are one of the most complicated and challenging topics at the Circular Electron Positron Collider(CEPC). Comprehensive understandings of the MDI issues are decisive for achieving the optimal overall performance of the accelerator and detector. The CEPC machine will operate at different beam energies, from 45.5 GeV up to 180 GeV.
A flexible...
Due to various errors, the beam does not pass through the center of magnets in a storage ring. The beam orbit is affected by additional dipole fields since magnetic field feed-down. To obtain a reference orbit, on which the beam circulates along the quadrupole axes, the beam-based alignment (BBA) is performed in the ring. In this work, a novel method based on a neural network is proposed to...
After the successful conclusion of Run1 in 2018, the AWAKE experiment is presently undergoing its second phase (Run2), which aims to demonstrate the possibility of producing high quality electron beams for high energy physics applications.
Over the last year, a significant time-investment was made to study proton beam centroid modulation effects in plasma induced by a seeding electron bunch...
Heavy-ion single event effect (SEE) test facilities are critical in the development of microelectronic components that will be exposed to the ionizing particles present in the hostile environment of space. CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) and HEARTS have developed a high-energy ion beam capable of scanning a wide range of Linear Energy Transfer (LET)...
The Large Hadron Electron Collider (LHeC) is a study at CERN to construct an energy recovery linear accelerator (ERL) tangentially to the High Luminosity Large Hadron Collider (HL-LHC). This would enable deep inelastic scattering collisions between electrons and protons in the ALICE interaction region (IR2). In this design, one of the two proton beams of the HL-LHC collides with the electron...
The electron-positron Future Circular Collider (FCC-ee) foresees stored beam energies up to 20.7 MJ, a value almost two orders of magnitude higher than any previous lepton collider. Considering the intrinsic damage potential of the FCC-ee beams, a halo collimation system is under study to protect the most sensitive equipment from unavoidable losses. Beam dynamics and tracking studies are key...
A high-charge, low-emittance injection beam is essential for SuperKEKB. For its both rings, HER and LER, the injection efficiencies and detector backgrounds have not been good enough up to the recent run. There are many reasons for the issues. For example, serious emittance growths are observed through the beam transport lines between the injector linac and both rings. It is considered...
The single nonlinear kicker (NLK) injection has been adopted by several synchrotron radiation light source facil- ities or their upgrades. The injected beam receives a kick from an NLK and goes into the acceptance of the storage ring while the stored beam passes through the center of the NLK where the magnetic field is almost zero. Compared with the local-bump injection, NLK injection requires...
Compared to the conventional injection scheme, the three-kicker bump injection scheme with an anti-septum has two advantages. One is less requirement of dynamic aperture thanks to the thin blade of the anti-septum, the other is less installation space requirement of the injec-tion system. Both are beneficial to the beam injection for the fourth generation light sources. In this study, the...
In the electron-driven ILC positron source, the positron is generated a multi-bunch format with gaps, because it corresponds to a part of the damping ring fill pattern. The beam loading is compensated by amplitude modulation on the input RF (*). In this article, we derive the exact solution for the compensation with gaps. In addition, we evaluate the effect of the time constant (delay) of the...
The Insertion Region 2 (IR2) will accommodate a Pre-Cooler at injection energy ($24~\mathrm{GeV}$) and a Strong Hadron Cooling
(SHC) facility at top energy ($100~\mathrm{GeV}$ and $275~\mathrm{GeV}$) in the Hadron Storage Ring (HSR) of the Electron-Ion Collider
(EIC). This paper summarizes the lattice update in HSR-IR2 to meet the requirements from the Pre-cooling and the SHC. The layout...
The proposed REDTOP experiment is a $\eta$/$\eta'$ factory aiming to explore dark matter and physics beyond the Standard Model. The $\eta$ and $\eta'$ mesons are almost unique in the particle universe because of their quantum numbers and the dynamics of their decay are strongly constrained. This effect increases the branching ratio of rare decays which can be studied to probe physics BSM. The...
In the future 100 km-scale Circular Electron Positron Collider (CEPC), beam polarization is an important design aspect. Transverse beam polarization for resonant depolarization is essential for precision measurements of the beam energies at Z-pol and WW threshold. Longitudinally polarized colliding beams are also beneficial for expanding the capability of the physics program. This paper...
Wuhan Advanced Light Source (WALS) is a fourth generation diffraction limit synchrotron radiation facility, which is composed of a full energy 1.5 GeV LINAC, a 1.5 GeV Storage Ring and 10 beamlines for its phase I project. The LINAC is 6 meters lower than the storage ring, which is connected by a 46 meters beam transfer line. The beam transfer line includes three parts, one ver-tical line...
Large initial beam position monitor (BPM) offsets have to be reduced by one order of magnitude by means of beam-based calibration (alignment) (BBA) in order to match the element-to-element magnet alignment error. At SLS 2.0 the BBA will be performed with respect to adjacent auxiliary quadrupole magnets, which are also employed for optics and tune correction. Different static and dynamic...
Top-up operation at BESSY II is performed with average injection efficiencies of 98 %. However, the four-kicker bump and the septum, that form the present injection system, both contribute to a distortion of the stored beam with an amplitude of about two millimeters for several thousand turns after injection. A non-linear injection kicker (NLK) could be used to reduce the distortion due to the...
The understanding of beam-beam effects, which influence the choice of the FCC-ee design parameters for several aspects, require sophisticated and high-performance numerical simulations. The self-consistent study of the interplay of nonlinear dynamical phenomena resulting from collisions in the machine is key to accurately assess its potential performance. Although current simulation frameworks...
For the Future Circular Collider (FCC-ee), particular attention is drowned to the crucial role of the positron source. Two positron production schemes are considered for the FCC-ee: conventional and crystal-based (hybrid), implying the use of channeling radiation in the oriented crystals. To design and optimize the positron production and capture by considering the positron injector...
To harness the major advances that have been done in the field of synchrotron light research, Elettra synchrotron radiation facility is being updated. Presently in its design phase, the Elettra 2.0 project will allow new and better research to be performed at the facility. In the upgrade of the storage ring, the new 6BA lattice brings challenges in terms of available space and radiated power....
The “Pre-Conceptual Design Report” (preCDR) of the BESSY III facility (https://doi.org/10.5442/r0004) has been finalized at the end of August 2022 and reviewed by a Project Advisory Committee beginning of September 2022. In this paper, we give a status report of the BESSY III facility project and will discuss aspects of lattice design, technical specifications, initial developments and a first...
The measurement of Bhabha scattered leptons enables a direct estimate of luminosity in lepton colliders. Currently existing Monte Carlo event generators for this process are optimized for high precision detector background simulations. From a beam dynamics point of view, emitted photons will modify the bunch distribution and lead to beam losses
due to the limited momentum acceptance of the...
The Southern Advanced Photon Source is a diffraction-limited storage ring at middle energy. The popular injector which includes a low energy Linac and a full energy booster is proposal. The concept design of the booster is presented in the paper. The booster is a high intensity synchrotron accelerator. The impedance model is obtained and the instability threshold is predicted.
Due to the reduced diameters of the vacuum chambers and of the other equipment, the performance of the next generation light sources can be greatly affected resulting in a reduction of the intensity in both single and multi-bunch operations. This is particularly important for Elettra 2.0 since there are plans to incorporate bunch compression schemes for providing very short photon pulses. In...
At SPring-8, the injector was changed from the booster synchrotron to the XFEL linear accelerator. Accordingly, we have developed a new bunch cleaning system in the storage ring to ensure high bunch purities required by photon beam users since unwanted electrons were observed behind the injection bunch even after some countermeasures were taken in the injector to eliminate unwanted electrons....
We carried out the study of the beam lifetime at SuperKEKB to investigate beam instabilities. We analyzed the injection interval for individual bunches to evaluate their beam lifetime ratio. SuperKEKB performed the top-up operation with the equalized bunches currents. This particular condition enables us to evaluate the lifetime ratio among all operation bunches. This report introduces the...
Inverse Compton Scattering is a promising technique to deliver compact, high brightness and high rate sources of photons ranging from few keVs to several MeVs. Current projects either focus on producing high rates of photons thanks to high-power (up to 300kW) enhancement optical cavities and electron storage rings or on providing low bandwidth photon sources based on room-temperature linacs....
NICA is mainly designed for experiments with heavy ions and polarized proton and deuteron beams at an energy of the former about 13 GeV. For these purposes, appropriate SPD and MPD detectors, as well as other necessary implements, are installed in the straight sections. EDM experiment supposes use deuterons at an energy of about 240 MeV. To ensure the «Quasi-Frozen Spin» mode, E+B elements...
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is one of the most powerful accelerator-driven neutron sources in the world. The intense protons strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is...
I describe the method used for calibration the amplitudes and phases of the cavities in the Main Linac Cryomodule (MLC) for the CBETA energy recovery linac at Cornell University. The cavities are powered one at a time, and the phase of each cavity is set to a uniformly spaced set of values over a full 360 degree range, with cavity voltages set to one or more values. For each cavity, voltage,...
Optical enhancement cavity (OEC) provides the high intensity and high stability modulation laser field in steady-state microbunching (SSMB) light source. An SSMB extreme ultraviolet (EUV) light source targeted for lithography application is currently being developed at Tsinghua University, which demands for megawatt scale intra-cavity power for OEC. Cavity mirrors are the key components of the...
Extending the energy reach of CEBAF by increasing the number of recirculations, while using the existing linacs is explored. This energy upgrade is based on the multi-pass acceleration of electrons in a single non-scaling Fixed Field Alternating Gradient (FFA) beam line, using Halbach-style permanent magnets. Encouraged by the recent successful demonstration of CBETA, a proposal was formulated...
The CEPC is a proposed high luminosity Higgs/Z factory, with the potential to be upgraded to top factory at center-of-mass energy of 360GeV. We perform an optimization study on the circumference of CEPC. We calculate the instant luminosity, the construction and operation cost for different circumferences. With respect to the total cost and average cost per particle, we conclude that the...
A damping ring system which includes a small 1.1 GeV ring and two transport lines is introduced in CEPC linac in order to reduce the transverse emittance of positron beam at the end of linac and hence reduce the beam loss in the booster. The repetition rate of Linac is 100 Hz and one-bunch-per-pulse is considered. The double-bunch scheme of Linac is only considered for the high luminosity mode...
The future upgrade to the High-Luminosity Large Hadron Collider (HL-LHC) will impose tight tolerances on IP optics measurements. k-modulation is currently the preferred method in the LHC for IP optics measurements and will play a critical role in the HL-LHC. As such, Run 3 of the LHC provides an ideal test-bench for addressing challenges in k-modulation. In the first commissioning year of Run...
I describe a method for finding a set of cavity voltages and phases for the CBETA multi-pass energy recovery linac. The beam in CBETA makes up to 8 passes through its 6 cavity linac. The voltage and phase for each cavity can be set individually, and the path length for each arc energy can be set as well. I show that solutions can be found where each cavity has energy gains and losses balanced...
The Electron-Ion Collider (EIC) uses the local crab crossing scheme to compensate the geometric luminosity loss of the $25 ~\mathrm{mrad}$
crossing angle in the interaction point. Due to space limitations and other optics constraints, the beam optics at the crab cavities in
the Hadron Storage Ring (HSR) is not perfectly matched to fully compensate the crab dispersion.
This paper...
The fourth generation of synchrotron radiation sources will be constructed in Wuhan. The RF system of the storage ring provides 600kV voltage to the beam through a 500MHz normal conducting cavity. A coaxial coupler is designed for the 500 MHz cavity to input 150kW power. The coupler was modified from KEK-B. We use a high-power ceramic disk window design and under over cut window structure....
The High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) aims to achieve stored beam energies of 680 MJ. One possible limit to the achievable intensity is the quench limit of the superconducting magnets downstream of the betatron collimation insertion. At HL-LHC beam intensities, even a tiny amount of particles leaking out of the collimation system may be sufficient to quench...
For the Future Circular Collider (FCC) Conceptual Design Report (CDR), the FCC-hh collimation system was studied and optimized for proton and heavy-ion operation with up to 8.3 GJ stored beam energy. There are currently studies ongoing for an updated design baseline, including a new ring layout, compatible with the FCC-ee, and optics, where the collimation insertions have undergone major...
Magnetic fields in the 12-16 T range are needed to bend the beams in future hadron colliders, such as the CERN FCC-hh. For these magnets, made with Nb3Sn superconducting cable, a small reduction of the field brings a non-negligible reduction of cost and complexity. Increasing the dipole filling factor is hence a priority to provide higher energies for the same magnetic fields - or the same...
The RF system of the ThomX storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state amplifier, and its associated Low-Level RF feedback and control loops. The low operating energy of 50 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam...
We will report on the ongoing ThomX ring commissioning, its status, its main challenges, our results and our planning.
ThomX is a compact Compton-based X-ray source under commissioning at IJCLab in Orsay (France). This facility is composed of a 50-70 MeV linac, a transfer line and a storage ring whose closed orbit is 18 m long. Compton scattering between the 50 MeV electron bunch of 1 nC...
Storage ring commissioning-like simulations are necessary to assess the feasibility of proposed future lattice designs. This paper proposes a python package for commissioning-like simulations based on python accelerator toolbox (pyAT). The software includes: 1) errors definition, 2) correction routines from open trajectory to optics and coupling correction and 3) the evaluation of the relevant...
Hollow electron lenses (HELs) could be used in the HL-LHC to selectively remove halo particles from the circulating beams. While the ideal design should leave particles in the beam core unaffected, in reality, the core particles will be exposed to a small residual kick that could induce transverse emittance blowup if not properly compensated while the HEL is operated in pulsed mode. One...
The interaction of particle beams with materials is important for muon colliders, as it causes particle scattering, energy loss and energy-straggling processes. Such interactions are also relevant in high-precision applications such as radiation oncology treatment planning, where the beam travels through air before reaching the patient, and are also the crucial mechanism for ionization cooling...
Modern synchrotron light sources are competing intensively to increase X-ray brightness and, eventually, approach the diffraction limit, which sets the final goal of lattice emittance. Recently, we propose a new optics solution aimed at reaching low emittance, using a lattice element “Complex Bend”. The Complex Bend is a sequence of dipole poles interleaved with strong alternate focusing so as...
We presented a novel concept of longitudinal bunch train compression capable of manipulating relativistic electron beam in range of hundreds of meters. It has potential to compress electron beam with high ratio, and raise its power to ultrahigh level within compressed duration of nanoseconds. Electron’s spiral motion in uniform magnetic field is utilized to fold the hundreds of meters long...
The SHADOWS experiment is a proposed beam dump experiment in the CERN North Area, aiming to search for feebly interacting particles (FIPs) created in 400 GeV/c proton interactions. Due to its intended off-axis location alongside the K12 beam line, the SHADOWS detector can be placed potentially very close to the dump, enabling it to look for FIPs in non-covered parts of the parameter space. To...
The Configuration Management of the LHC and its injectors ensures a clear and coherent representation of the CERN accelerators at a given point in time. It has been evolving steadily. The methodology has been continuously improved, incorporating best practices and was also extended to the injectors to face the Long Shutdown 2 (LS2) with a set of rigorous and homogenised processes for the...
The current injector complex design of the FCC-e+e− project consists of e+/e− linacs, which accelerate the beams up to 6 GeV, a damping ring at 1.54 GeV, a pre-booster ring, accelerating the beam up to 16 GeV and a booster synchrotron ring integrated in the collider tunnel accelerating the beams up to the collision energies. The purpose of the damping ring is to accept the 1.54 GeV beam coming...
Commissioning a test beamline in KEK Photon Factory Advanced Ring (PF-AR, 6.5GeV and 5.0GeV) is proceeded under cooperation with the KEK Institute for Particle and Nuclear Studies (IPNS) to use electron beams in the GeV-range for the development of detectors in particle physics experiments. The inauguration of the project which was mainly directed by the IPNS was launched back in 2014, but the...
Coordinate conversion is used in many aspects, such as laser tracker transfer problem, the conversion between WGS84 coordinate system and local coordinate system and so on. The high precision of coordinate conversion model is beneficial to improve the accuracy index of the network. The dual quaternion can integrate rotation and translation, which effectively simplifies the complexity of the...
In this paper we present the first results of full 6D multi-bunch tracking through the new Drive-Beam decelerator lattice for the first-stage of the Compact Linear Collider (CLIC). Using the new PLACET3 tracking code, we evaluate the coupling between transverse and longitudinal dynamics in the lattice finding an indirect impact of the Drive-Beam's transverse emittance in the Main-Beam performance.
Over the last three years (2020-2022) Diamond Light Source has installed four in-house designed, built, and measured Cryogenic Permanent Magnet Undulators (CPMUs). All four are 2 m long with a 17.6 mm period and have a minimum operating gap of 4 mm. These have replaced existing 2 m long in-vacuum pure permanent magnet (PPM) devices to improve the flux to several of Diamond’s MX (Macromolecular...
Crystal collimation is studied to improve the collimation efficiency with ion beams at the High-Luminosity Large Hadron Collider (HL-LHC). Bent crystals are used instead of conventional primary collimators to deflect high-energy halo particles at angles orders of magnitude larger than what can be achieved with scattering by conventional materials. Following the promising results obtained...
DAFNE, the Frascati electron-positron collider, based on the Crab-Waist collision scheme, has successfully completed the preliminary phase with the SIDDHARTA-2 detector aimed at testing and optimizing the performances of the machine and the experimental apparatus.
In this configuration the collider has delivered to the experiment, using gaseous 4He targets, a data sample suitable to perform...
The Future Circular Collider project is built around two main pillars: the construction of 100 km lepton collider running at increasing energies from the Z-pole to the t-tbar threshold (FCC-ee) followed by a hadron collider in the same tunnel (FCC-hh) to explore unprecedented energy frontier.
The realization of FCC-ee relies on a very challenging injector complex that should provide the...
We discuss the beam requirements for indirect searches of dark matter and feebly coupled particles using advanced accelerator concepts. A parameter comparison reveals dielectric laser acceleration as a promising candidate for delivering the needed single-electron beams in the 5-100 GeV energy range or beyond. We suggest a parameter set for a baseline DLA-based dark sector accelerator....
After the discovery of the Higgs boson at the LHC, particle physics community is exploring and proposing next accelerators, to address the remaining open questions on the underlying mechanisms and constituents of the present universe. One of the studied possibilities is FCC (Future Circular Collider), a 100-km-long collider at CERN. The feasibility study of this future proposed accelerator...
A degrader device is being built at the CEBAF injector to degrade the electron beam phase space for machine acceptance studies. The electron beam is degraded through multiple scattering in a thin target before further transport in the injector beamline for injection into CEBAF. The degraded electron beam will approximate phase space distributions expected from a bremsstrahlung-based polarized...
Within the Standard Model the electric dipole moment (EDM) of the muon is heavily suppressed. Observation of a non-zero EDM value would be an additional source of CP violation that would aid in answering the many open questions about the universe and the Standard Model. As part of an investigation into the feasibility of measuring the muon EDM at the g-2 storage ring at Fermilab, a study on...
The main SPS users are the experiments installed in North
experimental Area (NA) which are served with a continuous 4.8 s long
spill of protons and heavy ions. A third-integer resonant slow extraction is used to provide a uniform, long spill. Such a technique
comes at the cost of particles directly hitting the electrostatic septum
wires and activating the surrounding of the extraction...
In the J-PARC Muon g-2/EDM experiment, to measure muon g-2 and EDM, it is necessary to accumulate 300 MeV/c muon beams with a 66 cm diameter region with a 3 T solenoid-type magnetic field. A new three-dimensional spiral injection scheme has been invented to achieve this target. Since this is the first instance to employ this injection scheme, a scale-down experiment with an electron beam of...
Nb3Sn, NbTiN and NbN are superconductors with a critical temperatures of 18.3, 12.6-17, 11.6-17.5 K, respectively, that are higher than that of Nb (9.3 K). Hence, at 4 K they have an RF resistance of an order of magni-tude lower than that of Nb, which leads to quality factors above those of Nb. In recent years, there has been an extensive effort converting Nb cavities into Nb3Sn by alloying...
CNAO is one the six hadrontherapy centers all around the world that produce
both proton and carbon
ions beams.
It is based on a synchrotron in which the beams are extracted by a slow extraction mechanism that uses a betatron core.
In the last years an electrostatic exciter has been installed along the ring in order to allow
beam extraction using the RF-KO method.
The system has been...
The Spallation Neutron Source (SNS) employs six cavities in the Drift Tube Linac (DTL) section to accelerate the H- ion beam to 87MeV. Each cavity is energized by a 2.5MW peak power klystron at 402.5MHz using rapid tapered waveguide iris couplers. All six original iris couplers have been in operation without replacement for over two decades. The increased RF power demands of the Proton Power...
A test station for the THALES 300kW transmitter PSM has been successfully constructed in NSRRC. Integrating the modules of power supply, control interface, interlock protection, and accessories into a single rack simplifies the examination procedure and makes signal observation easier. The layout and hardware realization of this test station, as well as important considerations and proper...
The Future Circular electron-positron Collider (FCC-ee) is planned to operate with beam energies from 45.6 to 182.5 GeV and beam currents from 5 to 1400 mA. This will enable precision physics at the four operational points, Z, W and Higgs boson and the top and anti-top quarks. This work will focus on the RF structure design for the ttbar operation point to reach a beam energy and current of...
**The baseline scheme for hadron beam cooling in the Electron Ion Collider (EIC) calls for Coherent electron Cooling (CeC) of the hadrons with non-magnetized electrons at high energy (150 MeV electrons), and additional cooling via conventional bunched beam cooling using a precooler system. The electron beam parameters for these concepts are at or beyond the current state of the art, with...
this paper briefly introduces the layout theory and analysis basis of the first-level control network, calculates the accuracy index of the first-level control network of Hefei Advanced Light Source, designs the basic scheme of the first-level control network, and analyzes the absolute precision and relative precision of the control network in detail through the simulated adjustment...
In the Electron Ion Collider (EIC), to be built at Brookhaven National Lab, the beams collide with a crossing angle of 25 mrad and an aspect ratio of 12 to 1. The orbit control in the interaction region is critical to achieve and to maintain the design luminosity and polarization, and to control synchrotron radiation induced detector background. In his report, the authors will introduce the IR...
High brightness beams are desired for application to Inverse Compton Scattering (ICS) systems for generation of high-quality x- and γ-rays. It opens new opportunities for nuclear physics research in fields such as nuclear photonics, nuclear astrophysics, photo-fission, production of exotic nuclei, applications in medicine, industry and space science. In ICS mechanism high energy electron is...
LEAF (Low Energy heavy ion Accelerator Facility) is a low-energy high-intensity heavy-ion LINAC complex for multidiscipline research. At present, the beam repetition rate is the same as the LINAC frequency of 81.25 MHz. A lower frequency would be desirable for many types of experiments employing time of flight data acquisitions. A method of increasing the bunch spacing to 98 ns by combining a...
The Southern Advanced Photon Source (SAPS) is a 4th generation storage ring based light source under design started several years ago, which is planned to be constructed
at Guangdong province at China. The equilibrium emittance of the storage ring will be below 100 pm.rad and the beam energy is determined to be 3.5 GeV. During the past two years, the nominal current of the storage ring was...
We propose to develop a compact superconducting cyclotron to accelerate H2+ ions for isotope production since using H2+ allows the use of a stripper foil after extraction from the cyclotron to remove the binding electron, thereby doubling the electrical beam current. An RFQ, partially embedded in the cyclotron yoke, will be used to bunch and axially inject the H2+ beam into the cyclotron’s...
Super Tau Charm Facility (STCF) proposed in China, is a future electron-positron collider project with symmetric double ring. It’s designed to be operated in the center of mass energy (CME) range between 2 GeV and 7 GeV. The goal luminosity is beyond $0.5\times 10^{35} cm^{-2} s^{-1}$. Hybrid multi-bend-achromat (HMBA) concept, proposed to develop low emittance lattices with large dynamic...
The Super Proton Synchrotron (SPS) injection system plays a fundamental role to preserve the quality of injected high-brightness beams for the Large Hadron Collider (LHC) physics program and to maintain the maximum storable intensity. The present system is the result of years of upgrades and patches of a system not conceived for such intensities and beam qualities. In this study, we propose...
As compared to traditional magnets, permanent magnets can effectively reduce energy consumption and eliminate the impact of current ripple and the wa-ter cooling system on beam current. The use of perma-nent magnets in accelerators has become a new trend as permanent magnet technology has advanced. In HALF, we have designed a permanent magnet based on the quadrupole magnet, and the central...
A S band high power klystron for BEPCII operating at frequency of 2856 MHz has been designed and simulated at Institute of High Energy Physics, Chinese Academy of Sciences. A thermionic electron gun have been designed. A beam current of 379 A is obtained at operating voltage of 325 kV with cathode current density of 6.6 A/cm2. Then, the full 3-dimensional particle-in-cell simulation of the...
High power input often leads to frequency deviation that cannot meet the high-precision frequency control requirements of keV Ultrafast Electron Diffraction (UED) compression cavities. In this paper, we propose new solu-tions for reducing heat generation and frequency devia-tion based on modifications to the cavity design and power input method, building upon the design of the orig-inal...
The Compact Linear Collider (CLIC) is a proposed linear accelerator designed to collide electrons and positrons at energies up to 3 TeV. In order to explore new physics and to be more competitive with other collider projects, CLIC is exploring the increase of the center-of-mass energy to 7 TeV. The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to...
With the growing interests and new experimental development in time-resolved studies at Stanford Synchrotron Radiation Light Source (SSRL), we are motivated to develop the Pseudo Single Bunch (PSB) operational mode to address the requirements from time-resolved and regular user experiments simultaneously. In this paper, we will present the physics design for this new mode. Beam line...
The High Energy Photon Source is a 6 GeV synchrotron radiation light source being built in Beijing, China. The electron beam inside the storage ring is designed to run with ultra-low emittance. To ensure high beam quality, the coupled bunch instabilities must be carefully investigated and controlled, therefore an effective feedback system is essential. Stripline kickers are designed for...
A Boron Neutron Capture Therapy facility requires a high flux of neutrons (approx. 10^9 thermal or epithermal n/s*cm^2) with low contamination content (gamma and off energy neutrons). The core of such a facility is a low energy high intensity proton linac, coupled with a high power beryllium neutron production target, followed by a proper Beam Shaping System. In this paper we shall discuss...
Based on the key scientific questions in the frontier of particle physics field, the current status and future development trend globally and domestically of accelerator-based particle physics experiments, a Super Tau-Charm Facility (STCF) is proposed by taking into account the advantages in the relevant fields in China. The STCF is a new-generation electron-positron collider facility that has...
A new fourth-generation synchrotron radiation source(4GSR) will be built in Ochang, South Korea by 2027. A technical design review for the Korea 4GSR is currently in progress and is expected to be completed in mid-2023.
The storage ring has a circumference of 800 m. It has been designed for a maximum current of 400 mA at 4 GeV electron beam energy. A target emittance is 58 pm-rad, 100 times...
The Electron-Ion Collider is gearing up for "Critical Decision 2", the
project baseline with defined scope, cost and schedule.
Lattice designs are being
finalized, and preliminary component design is being carried out. Beam dynamics
studies such as dynamic aperture optimization, instability and polarization
studies, and beam-beam simulations are continuing in parallel. We report on
the...
In order to produce a high luminosity at the interaction point, the Compact Linear Collider (CLIC) accelerators must preserve low emittance beams along both the main 22km linacs. A key factor in preserving a low emittance beam is the mechanical alignment and stability of the accelerator components.
The CLIC accelerators are divided into `Two Beam Modules’ (TBMs) which integrate a section of...
The FFA@CEBAF energy upgrade study aims to approximately double the final energy of the electron beam at the Continuous Electron Beam Accelerator Facility (CEBAF). It will do this by replacing the highest-energy recirculating arcs with fixed-field alternating gradient (FFA) arcs, allowing for several more passes to circulate through the machine. This upgrade necessitates the re-design of the...
MYRRHA will be a research infrastructure focussed on the construction of a first prototype of an accelerator driven sub-critical nuclear reactor (ADS). The driver ac-celerator will deliver a 600 MeV, 4 mA Proton beam to the reactor core. The first phase called MINERVA aims for the construction of a 100 MeV, 4 mA proton linear accel-erator with a focus on reliability. Attached to this 100 MeV...
The Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBL) is going through an upgrade (ALS-U), where the ALS triple-bend achromat is replaced by a nine-bend achromat storage ring (SR) with on-axis injection using beam swapping from a triple-bend achromat accumulator ring (AR). The small beam size at the straight sections of the ALS-U has opened the possibility to use...
With the high accelerating gradient, radiofrequency (rf) gun has a significant feature of suppressing the growth of transverse emittance caused by space charge. Field emission cathodes were first used in vacuum electronic devices, which do not require the high electron beam intensity, but the cathode size and integrality. A new X-band (11.424 GHz) rf electron gun has been proposed with the...
Manipulating high energy beams with bent crystals has applications ranging from beam collimation to slow or direct beam extraction. These systems are now integrated parts of accelerators and studied for future experimental set-ups.
With growing achievements and expectations of crystal beam manipulation, requirements for the devices that operate the crystals become more stringent. They must...
Beam-based alignment (BBA) is a standard tool at accelerators for aligning particle beams to the centre of quadrupole magnets. Traditional BBA measurements have been slow, potentially taking many hours for a whole machine. We have developed a tool, based on results previously reported at the ALBA synchrotron, that uses fast excitation of magnets to greatly speed up measurements. We show...
Southern Advanced Photon Source (SAPS) is a 3.5GeV fourth-generation storage ring light source, considered to construction in Guangdong province of china, adjacent to the China Spallation Neutron Source(CSNS). Its natural emittance of the beam is close to the diffraction limit. Since the dynamic aperture of SAPS is far smaller than the physical aperture in the low emittance storage ring,...
The PETRA IV storage ring currently under development at DESY will require a third harmonic 1.5 GHz RF-system to prevent negative effects on both, lifetime and emittance, caused by Touschek effect and Intrabeam scattering. These cavities lengthen the bunches and thereby reduce their charge density.
For this 3rd harmonic system, a one-cell single-mode cavity with a simple mechanical and...
The muon-dedicated linear accelerator is being developed for the muon g-2/EDM experiment at J-PARC. To suppress the decay loss during acceleration, the alternative phase focusing (APF) method inter-digital H-mode drift tube linac (IH-DTL) is adopted in the low-velocity region following a radio-frequency quadrupole linac (RFQ). We are planning to accelerate muons in 2024 using the RFQ and the...
MINERVA (MYRRHA phase 1) aims at demonstrating the requirements related to the reliability and the fault tolerances of the MYRRHA accelerator-driven system (ADS) by the realization of a superconducting linac for 100 MeV/4 mA proton beams. The design and the performance of the Medium Energy Beam Transfer section (referred to as MEBT-3) of the accelerator are critical for reaching the goals of...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. Besides high luminosity and high polarization, it is also recommended for the EIC design to incorporate a possible second interaction region...
The Electron-Ion Collider (EIC) will be constructed at Brookhaven National Laboratory with the goal of providing high luminosity, high average beam polarization, and a wide range of colliding beam energies. One critical requirement is a large dynamic aperture (DA) of the collider rings, in both transverse and momentum dimensions. The ring lattices have been continually optimized to improve the...
The PETRA IV project will have a storage ring with an ultra-low natural emittance of 20 pm rad [1]. For an off-axis injection scheme with working points at the difference resonance it is important to assure the vertical excursion arising due to transversal coupling such, that injection efficiency is not compromised. In this contribution we present simulations results of an off-axis injection...
We frequently experience earthquakes in Japan. Even though countermeasures against earthquake is deeply considered and well carried out, sometime troubles are occurred on facilities or experimental devices. When we focus on the relative displacement due to an earthquake, it is possible to cause damage of a beam pipe bellows or interference by disappearing tolerance between the sub-detectors....
Proton bunches will collide with electron bunches in the Electron-Ion Collider (EIC) to produce a luminosity of up to $10^{34}~\mathrm{cm}^{-2}\mathrm{s}^{-1}$. Various sources can lead to electron orbit ripple at the interaction point (IP). This ripple will cause emittance growth of the proton beam via beam-beam interaction. This paper presents weak-strong simulations for the case where a...
The FEL performance strongly correlates with the undulator field quality. The definition of mechanical tolerances for the undulator magnets allows us to achieve the wished field quality. These mechanical tolerances should be defined both on short and long-range errors. With long-range errors, we address problems like deformations of the yoke caused by the support structures or unwanted...
The Electron Ion Collider is adopting a crabbing scheme of 25 mrad crossing angle. The local crab cavity system designed to kick the bunches in the first interaction region (IR) also introduces higher order multipoles com-ponents in electric field which affect the dynamic aperture. We have studied the strength of each multipole up to n = 4, or octupole, with respect to the main dipole field in...
A scheme for electron acceleration by self focused -Gaussian laser pulses in under dense plasma has been presented. The relativistic increase in the mass of plasma electrons gives nonlinear response of plasma to the incident laser pulse resulting in its self focusing. Under the combined effects of saturation nature of relativistic nonlinearity of plasma, self focusing and diffraction...
Polarization levels in the Electron Storage Ring (ESR) of the Electron-Ion Collider (EIC) must be maintained for a sufficient time before depolarized bunches are replaced. The depolarizing effects of synchrotron radiation can be minimized with spin matching, however the optics requirements for the ring must still be satisfied. Furthermore, the robustness of the polarization in the presence of...
The EIC electron beam parameters will feature 320 kJ stored kinetic energy and beam sizes leading to the melting of most metals in case of normal impact of a single bunch. In order to protect the aperture, focusing magnets and experimental detectors from beam losses and backgrounds a dedicated collimation system will be included in IR2 and IR4. Additionally, to protect against accidental...
Dust particles interacting with the proton beams have caused many thousand beam-loss events at CERN's Large Hadron Collider (LHC), some of which led to premature beam dumps and even magnet quenches. It has been hypothesized that dust particles on the vacuum chamber wall of the LHC are negatively charged due to electron clouds and can detach from the chamber wall by the electric field of the...
Elettra will be upgraded between 2025 and 2026 and the storage ring lattice will be totally different to enhance the emittance and improve the coherence of the machine.
The storage ring design requires a stiff support system to reduce the impact of vibrations on the electron orbits, a high thermal stability as well as low static deformations. The magnets support system must be easy to...
Elettra 2.0 is the name of the upgrade project of the existing Elettra Storage Ring (SR) and its ancillary systems. The project comprises also new beamlines (BLs) and the re-allocation of some of the currently operational ones.
Consequently, the “Experimental Hall” (EH) of Elettra, i.e. where the beamlines are installed, is another working area with activities that have started well before...
The LHC beam dump system has the task of safely and reliably disposing of the extracted beams from 450 GeV to 7 TeV. The present dump assembly consists of a multi-segment graphite core, which is contained in a duplex stainless steel vessel with titanium windows. To reduce the energy deposition density in the core and windows, the extracted beams are swept across the dump front face with...
Circular Electron-Positron Collider (CEPC) is a 100 km circumference double-ring Collider, the high luminosity lattice in CEPC TDR is half lower emittance compared with the lattice in CEPC CDR. The dynamic aperture is strongly sensitive to the magnet misalignments and field errors. We present the study of the error correction for the CEPC TDR lattice and the dynamic aperture tracking after...
We discuss the beam power loss related to the heating of the beam pipe walls of the FCC-ee interaction region. We analyse the excitation of trapped modes, which can accumulate electromagnetic energy and determine the locations of these modes. We study the unavoidable resistive-wall wake field, which is responsible for the direct beam pipe walls heating. We show the distribution of the heat...
The European X-ray Free Electron Laser (EuXFEL) is a user facility delivering soft and hard X-ray FEL radiation. It provides X-rays with high brilliance and intensities in the photon energy range of 0.5 keV to 25 keV. 2700 pulses at 10 Hz with femtosecond up to 4.5 MHz pulse repetition rate. The FEL radiation which is created by the Self Amplified Spontaneous Emission (SASE) process, whose...
The Interaction Regions (IR) of many colliders benefit from the application of leading-edge technologies to ensure the highest possible luminosity delivered to the experiments. Leading-edge low-beta focusing magnets and crab cavities to handle individual bunches are critically important to increase the instantaneous and integrated luminosity in future Colliders.
The High-Luminosity LHC...
The BEPCII has already realized the collision luminosity target of $1.0\times10^{33}cm^{-2}s^{-1}$ in April 2016. However, in the past six years of practical operation, the collision luminosity usually remains between $6.0\times10^{32}cm^{-2}s^{-1}$ and $8.5\times10^{32}cm^{-2}s^{-1}$. In the operation with high beam current, the BEPCⅡ displayed serious beam instabilities, which greatly limits...
The FCC-ee project takes a step forward towards the discovery of new physical phenomena beyond the frontier of the standard model, by aiming at unprecedented center of mass energies and luminosities in a double-ring lepton collider. In order to explore potential improvements to the current lattice design, this paper looks at the use of combined function magnets within the short straight...
Steady-state microbunching (SSMB) is envisioned to enable the generation of high-power coherent synchrotron radiation at an electron storage ring for wavelengths up to the extreme ultraviolet. The underlying mechanism has been shown to be viable in a proof-of-principle (PoP) experiment at the Metrology Light Source (MLS) in Berlin*.
An enhanced detection scheme allows systematic studies of...
A new collaboration between ESRF and DESY within the EURIZON project is aiming at building tools and concepts that can be used for the next generation light sources. The developed tools will be applied to the ESRF-EBS and the PETRA IV lattice models to validate concepts to improve the injection efficiency or the lifetime of storage rings.
In this project framework, the bounded Extremum...
Sharing of emittances between transverse planes has potential benefits in storage ring light sources. The larger vertical emittance significantly increases the Touschek lifetime, while the smaller horizontal emittance helps to mitigate the loss in brightness at high photon energies due to the larger vertical beam size and divergence. A fully coupled beam is considered as an optional operation...
To improve the performance of beam orbit correction, it is necessary to perform beam-based alignment in modern storage ring light sources. For the High Energy Photon Source (HEPS), a 4th generation storage ring light source being built in China, because of the large number of BPMs in storage ring, it may take dozens of hours to complete the alignment with a conventional BBA algorithm. To...
The Fermilab Muon Campus, repurposed Tevatron-era Antiproton Source facilities, is currently the home to the g-2 and Mu2e muon experiments. Collecting data since 2017, the g-2 experiment is wrapping up a final run before the Muon Campus transitions to Mu2e operation. Currently in the commissioning process, the Mu2e experiment is expected to begin calibration and data collection in fiscal year...
The SuperKEKB accelerator, a collider consisting of 7 GeV electron and 4 GeV positron rings, is ongoing in order to supply a great number of interaction events of electrons and positrons to the Belle II detector which explores the new physics beyond the standard model.
The important milestone is to obtain integrated luminosity of 15 /ab in the next decade,
so that the luminosity should...
The PERLE (Powerful Energy Recovery Linac for Experiments) project relies on superconducting RF (SRF) cavities to reach its goals. The installation of coaxial couplers on the cutoff tubes of SRF cavities is foreseen for damping cavity’s Higher Order Modes (HOMs). The prototyping and fabrication of 3D-printed HOM couplers for the PERLE cavity have recently started in collaboration with JLab and...
The design of a muon collider complex requires to overcome challenges associated with muons short lifetime. To reach the expected luminosity for a multi TeV muon collider ring an interaction region with beta values of the order of a few millimetres is required. Resulting challenges are the development of a chromatic compensation section that is not degrading the physical and dynamical...
At LNL (Laboratori Nazionali di Legnaro), the vacuum system of ALPI (Acceleratore Lineare Per Ioni) accelerator includes about 40 pumping groups installed in the 90s. Obsolescence and rigidity of the used hardware and deficit of spare parts required a complete renovation of the system and relative controls. In 2022 we made the first steps of the system renovation with the development and...
Chromaticity up to the third order in the LHC has been well observed in the LHC’s first and second operational runs, with regular beam-based measurements performed during commissioning and machine development. In previous runs however, no higher-order chromaticity could be observed. In 2022, dedicated collimators setups meant optics measurements could benefit from an improved range of...
A two-day test of operation with Pb ion beams was carried out in the CERN Large Hadron Collider (LHC) in 2022, with the aim of gaining experience in view of the future high luminosity heavy-ion physics runs from 2023 onwards. The LHC experiments received the first Pb-Pb collisions at a record energy of 5.36 TeV centre-of-mass energy per colliding nucleon pair (beam energy 6.8 Z TeV). Bunch...
A Multipole Injection Kicker (MIK) has been successfully designed, constructed, installed and commissioned with beam in the MAX IV 1.5 GeV ring. This device allowed reaching injection efficiencies as high as those obtained with the previously used conventional dipole injection kicker scheme, while at the same time providing an order of magnitude reduction in the perturbations to the stored...
The proposed FCC-ee machine is a high-energy, high-intensity and high-precision lepton collider which will require to reduce as much as possible the differential motions of its two beams at the interaction points. In this prospect, the vibration impacts of the quadrupoles in the region close to the interaction point are investigated. Considering the z-pole optics design and its dedicated...
Superconducting undulators provide a possible means of broadening the range of wavelengths that can be covered by an XFEL facility by generating larger magnetic fields at shorter periods than can be achieved using permanent magnet undulators.
As part of ongoing prototyping work at STFC to develop a superconducting helical undulator with 13 mm period and 5 mm magnetic gap, a test cryostat has...
The High Energy Photon Source (HEPS) is a 4th generation synchrotron radiation source being built in China. An APPLE-Knot undulator with a new configuration is designed for the XCMD beamline of the HEPS. It is the first time to apply four-row APPLE-Knot undulator in storage ring based light sources. The main differences between the novel design and the conventional design of the APPLE-Knot...
GaAs cathode is a unique device generating a spin-polarized electron beam by photo-electron effect with a circularly polarized laser illumination. Negative Electron Affinity (NEA) surface which is artificially made has an essential role in spin polarization, but the NEA surface has limited vitality. In this study, we activated GaAs as NEA cathode by evaporating Cs, K, and Sb metal on its...
We are developing gamma-ray-induced positron annihilation spectroscopy (GiPAS) using ultra-short pulsed gamma rays at the UVSOR synchrotron facility in Japan. The gamma rays with the pulse width of picosecond range are generated by 90-degree inverse Compton scattering between a 750 MeV electron beam and an 800 nm laser. As the energy of the gamma rays is 6.6 MeV, gamma-ray irradiation produces...
A laser-driven storage ring is proposed to generate steady-state, nanometer-long electron bunches. A ring of this type can produce coherent EUV radiation with greatly enhanced power and photon flux, benefiting a wide range of scientific and industrial communities, including condensed matter physics and computer chip fabrication. The underlying mechanism is called generalized longitudinal...
One of the design requirements to reach a high luminosity in the Electron Ion Collider (EIC) is the collision of matched spot sizes of hadron and electron beams at the IP, with a horizontal to vertical emittance ratio of up to almost 20. However, the natural vertical emittance of electron beams in the Electron Storage Ring (ESR) in EIC is a few orders of magnitude smaller than the horizontal...
Iranian light source facility (ILSF) is a 4th generation synchrotron with a nominal horizontal emittance of 270 pm.rad. Storage ring magnet-girder support stability is essential for beam stability. The support system of storage ring girders is essential to achieve the accuracy of adjustment and vibration stability. After studying different girder support systems and considering the stability...
The Mu2e Experiment has stringent beam structure requirements; namely, its proton bunches with a time structure of 1.7µs in the Fermilab Delivery Ring. This beam structure will be delivered using the Fermilab 8-GeV Booster, the 8-GeV Recycler Ring, and the Delivery Ring. The 1.7-µs period of the Delivery Ring will generate the required beam structure by means of a third order resonant...
The longitudinal distribution of the electron beam in the electron storage ring of the Electron-Ion Collider will be modified by the machine impedance. The modified distribution, combined with crab cavities may have an impact on the quality of the hadron beam during the collision. In this paper, we will explore the possible impact on the hadron beam quality with strong-strong and...
Studies of the beam spectrum of the Large Hadron Collider (LHC) have revealed the existence of harmonics of the mains frequency (50~Hz), ranging from 50~Hz to 8~kHz, in the form of transverse dipolar excitations. The restart of the LHC operation in Run 3 was accompanied by substantial improvements in the beam instrumentation. In particular, the upgrade of the transverse damper’s observation...
Travelling wave (TW) SRF accelerating structures offer several advantages over the traditional standing wave structures: substantially lower Hpk/Eacc and lower Epk/Eacc, ratios of peak magnetic field and peak electric field to the accelerating gradient, respectively, together with substantially higher R/Q. In this paper we discuss how a linear collider Higgs factory HELEN can be built using...
Energy recovery of residual ions may be needed to increase the energy efficiency of Neutral Beam (NB) injectors for fusion plants as DEMO while a deflection-based system has been proposed. A compact beam energy recovery system, composed of 2 Farady Cups (FC) with holes for D0 passage, based on space charge effects, very effective to recover ions with low residual energy, has been proposed...
Inverse Compton scattering (ICS) is a method used for X-ray production that has been possible in recent years due to the rapid development of ultra-fast, short, and stable oscillators. In addition, the research and development of high Finesse Fabry-Perot Cavities to store high average power inside it. ThomX is a new generation of compact X-ray source which implements the ICS method. It will...
Run 4 will be the first operational run of the LHC with full deployment of the upgrades from the High Luminosity (HL-LHC) project planned for 2026-2028 (Long Shutdown 3). The commissioning goals for the first run were defined to approach steadily the design beam current, while already fulfilling significant luminosity goals. Despite extensive operational experience already gained, intensity...
Energy Recovery linear accelerator (ERL) light source facilities based on superconducting radiofrequency (SRF) are deemed of the most resplendent techniques in the future of accelerator physics. Running in a continuous waves mode with a high repetition rate for a long timescale, we discuss High order modes (HOMs) analysis in a two-pass two-way ERL scheme where acceleration and deceleration of...
The Spallation Neutron Source (SNS) recently took delivery of a third Radiofrequency Quadrupole (RFQ03) that will ultimately be installed on the front-end (FE) of the SNS Linac. The first RFQ (RFQ01) operated in the SNS FE for more than a decade before being replaced with the second RFQ (RFQ02). RFQ01 was relocated to the Beam Test Facility (BTF) where it operated for five more years. The...
FCC-ee performance is challenged by magnetic errors and imperfections. Magnetic design simulations predict a systematic quadrupolar component in the arc dipoles significantly impacting the machine optics. This paper studies the impact of this component in the beta-beating and explores potential mitigations.
The new EBS machine was commissioned in 2020 with a targeted nominal beam emittance of 139pm.rad in the horizontal plane. The radiated energy in the 70 insertion devices present from the restart was expected to change the equilibrium emittance. This paper presents the prevision and the measurements performed as a function of the total radiated power in the machine. The comparison shows that...
The concept of steady-state microbunching (SSMB) as a new scheme for the production of high power synchrotron radiation has been demonstrated at the Metrology Light Source in Berlin-Adlershof (MLS) [1].
At the MLS the same undulator section is used for the generation of the micro-structures onto the electron bunch as well as for the detection of the resulting coherent radiation from the...
The 7-GeV low-emittance electron beam is essential to be delivered to the SuperKEKB double-ring collider. One of the issues at the complicated beam transport between the linear accelerator and the High-Energy Ring (HER) is significant transverse emittance growth. In general, both incoherent and coherent synchrotron radiation effects play crucial roles in beam behavior. In this paper, we...
The layout of Elettra 2.0 preserves the useful length of the long straight sections so that all the existing insertion devices (IDs) could in principle be maintained in the upgraded machine. However, new high-performance beamlines are planned that will take advantage of the much lower electron beam emittance. Therefore new undulators are being designed and constructed for these beamlines....
The Future Circular Electron-Positron Collider (FCC-ee) aims to achieve unprecedented energies and luminosities. This can only be achieved using complex insertion region optics that set high challenges for commissioning and operating the machine. In the following we discuss some of the optics correction methods anticipated to be used to achieve the targets of the FCC-ee.
CNAO is one the six centers all around the world able to treat patients affected from cancer by proton and carbon
ions beams. Beams are produced by a synchrotron equipped with two sources. A third source has been recently
installed in order to produce new species that will be interesting both for clinical and R&D purposes.
A new low energy line has been designed, installed and...
The Electron-Ion Collider, to be constructed at Brookhaven National Laboratory, requires a large dynamic aperture (DA) of the electron storage ring (ESR) for stable operation of 10 beam sigma for the transverse aperture and 10 times the RMS momentum spread in the longitudinal plane. In particular for operations at the top energy of 18 GeV this has not been easy to achieve, and the DA has...
Initiated through the Physics Beyond Colliders (PBC) Study Group there is a strong interest from the scientific community to exploit the full intensity potential of the Super Proton Synchrotron (SPS) at CERN for Fixed Target physics experiments before the end of this decade. With the ECN3 cavern in the North Area (NA) identified as a suitable candidate location for a future high-intensity...
As preparation for the upcoming Diamond-II upgrade, provisions for timing-users (those who predominantly care about the timing characteristics of the synchrotron radiation) are being investigated. Although ‘Hybrid bunch’ modes are currently employed at Diamond, such operation presents challenges for Diamond-II that merit investigating alternative approaches. PPRE, one such approach, involves...
Ion instabilities are a major concern in diffraction-limited storage rings. ELEGANT offers a `strong-strong' model for ion simulations that describes both the beam and ions using multi-particles. To balance accuracy and computing resources, a simplified model using ILMATRIX and one IONEFFECTS element per turn is employed to study the ion effects of the Diamond-II storage ring. After...
The team at LANL continues efforts for the LANSCE Accelerator Modernization. This paper summarizes the progress in developing of the proposed concept of the modernization, and the major technical challenges that are expected in this concept. Separate subsystems are designed on the conceptual level, and the computer models for beam dynamics simulations are established and presented here. The...
In this paper, we present our thinking on how to keep the modulation laser and electrons phase-locked in a steady-state microbunching storage ring.
The Southern Advanced Photon Source (SAPS) is a 3.5 GeV, kilometer-scale, ultra-low emittance storage ring to be built next to the CSNS(China Spallation Neutron Source) in Guangdong Dongguan, China. A preliminary lattice design for SAPS storage ring with an emittance of 32 pm.rad has been proposed before. Now, the SAPS lattice is continuously under extensive design and optimization. In this...
Among the possible future lepton colliders under study, circular muon colliders have the largest potential of reaching center-of-mass energies of 10+ TeV. Being more massive than electrons and positrons, muons are much less affected by synchrotron radiation emission, but they suffer from the drawback of having a limited lifetime. As a consequence of their decay, intense secondary radiation...
The electron-ion collider will utilize a major portion of the existing RHIC rings for its hadron storage ring (HSR). This paper describes the lattice design of the HSR. Presently, RHIC consists of two rings, each of which contains 6 straight sections, and between those straights are arcs, each consisting of 11 FODO cells. The HSR uses 7 of the existing RHIC arcs which are unmodified, other...
We present the lattice design for the interaction region (IR) for the Electron-Ion Collider. We specify the requirements that the IR must meet, both for the hadron and electron beams themselves and for the collision products and radiation that must be transmitted through the magnet apertures. We align the hadron magnets downstream of the detector to pass the collision products while minimizing...
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will utilize the Relativistic Heavy Ion Collider (RHIC) arcs and modified straight sections. Due to these modifications in the straight section of the on project electron Proton Ion Collider (ePIC) experiment, a new injection system needed to be built one arc downstream of the existing RHIC injection system. The new injection system...
The Metrology Light Source (MLS) is a 630 MeV electron storage ring as a synchrotron radiation source for the terahertz (THz) to the extreme UV spectral range. Its upgrade project MLS II is defined as a compact 0.8 GeV storage ring with multiple operation modes, which pursues lower emittance (<50 nm) in standard user mode and preserves
the strong capability of MLS to manipulate the momentum...
The Electron-Ion Collider (EIC) at Brookhaven National Laboratory will feature an electron storage ring that will circulate polarized beams with energies up to 18 GeV. Recently a study has been undertaken to extend the minimum energy from 6 GeV to 5 GeV. As the solenoid-based spin rotators around the interaction point require specific bending angles that depend on the energy range, this change...
The first year of Run 3 of the Large Hadron Collider (LHC) revealed significant changes in both linear and nonlinear optics errors with respect to Run 2. Several iterations of optics corrections were required to successfully bring the linear optics within operational tolerances. This paper presents the current status of optics corrections in the LHC and the challenges experienced in...
Diffraction-limited light sources have garnered significant interest -- yet the smaller equilibrium size of their electron bunches also reduces the beam-lifetime. One remedy is to vertically excite the electron beam, for instance using a Multi Bunch Feedback (MBF) system. Previous work has demonstrated that this approach can safely increase the vertical emittance, thus beam-lifetime. However,...
UVSOR, a low energy synchrotron light source, has been operational for about 40 years. It has been providing high brightness VUV radiation to users but also providing a research environment for light source technology developments. In this paper, first, we briefly review the history of the light source developments at UVSOR. Then, we describe a beamline BL1U, which is currently used for...
X-ray beamlines—essential components of all synchrotron light sources—transport emitted radiation from the stored electron beam to an experimental station. One may describe the linear optics of the beamline via an ABCD matrix computed using a ray-tracing code. Furthermore, one may then include diffraction effects and arbitrary wavefront structure by using that same information in a Linear...
Local coupling correction in Interaction Regions (IRs) and global coupling correction based on Base-Band Tune (BBQ) measurement have been performed routinely for RHIC operation. However, one still observes significant residual local coupling measured by beam position data. For the Electron-Ion Collider (EIC) project, betatron decoupling for the hadron beam needs to be improved to maintain a...
In the fourth-generation storage ring light sources, the dynamic acceptance is usually small related to the extremely strong nonlinearity inherent in the multi-bend achromat design, making it difficult to implement traditional off-axis local-bump injection. It was found that a double-frequency rf system can be used for longitudinal injection with the help of rf gymnastics. However, such...
For a reliable determination of the single bunch stability threshold, the broadband impedance budget needs to be analyzed for all resistive and inductive contributions. The completely new design of the arc vacuum chamber of SLS 2.0 with respect to SLS - now with a reduced beam pipe diameter, and coated with layers of copper and NEG - requires special focus on the resistive wall impedance....
The Advanced Sources and Detectors project is building an advanced multi-pulse linear induction accelerator capable of generating a 1.4 kA electron beam at energies up to 24 MeV. The accelerator, named Scorpius after the brightest known x-ray source in the sky, will be unique in its use of solid-state pulsed power (SSPP) to generate the voltage pulse for the injector and accelerating gaps...
We’ll introduce a high precision active motion controller based on machine learning (ML) technology and electric piezo actuator. The controller will be used for srf cavity active resonance control, where a data-driven model for system motion dynamics will be developed first, and a model predictive controller (MPC) will be built accordingly. Simulation results as well as initial test results...
In 2022, the Large Hadron Collider started its third operational run. Following the three-year Long Shutdown 2, a careful re-commissioning of the machine protection system (MPS) took place. The initial hardware and beam commissioning period was followed by a 30-day-long intensity ramp-up, during which the number of circulating bunches was successively increased to 2460 bunches per beam. After...
The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to the Interaction Point (IP). The Final Focus System (FFS) is the last part of the BDS and its role is to focus the beam to the required size at the IP and to cancel the chromaticity of the Final Doublet (FD). MAD-X and MAD-NG are simulation codes for beam dynamics and optics that are used for...
The Shenzhen Innovation Light-source Facility (SILF) is a 4th generation diffraction limited storage ring project with an operating energy of 3 GeV, which is prosed by the Institute of Advanced Science Facilities, Shenzhen. For the storage ring, hybrid seven-bend achromat (H7BA) lattice is used in order to achieve a low electron beam emittance. There are longitudinal gradient bends (LGB),...
PERLE (Powerful Energy Recovery LINAC for Experiment) is a high-power Energy Recovery LINAC (ERL) facility with 20 mA beam current and beam energy from 250 MeV to 500 MeV featuring three passes through two cryomodules. It is a hub for validation of the ERL technology development towards future energy and intensity frontier machines. Design challenges of PERLE and its beam parameters make it a...
The diffraction-limited storage ring (DLSR) of the Southern Advanced Photon Source (SAPS) use a large number of ultra-high gradient quadrupoles and sextupoles, which leads to the tight tolerance of beam parameters to magnetic errors. We showed the results of the magnetic error effects in previous published article. On this foundation, the magnetic error corrections are finished, including the...
One of the design challenges of Superconducting undulators (SCUs) is the fulfilment of tight mechanical tolerances. Simulations show that to guarantee high quality of the emitted radiation local mechanical errors must be below a few tens of micrometres. Such requirements are at the limit of the most precise machines and techniques for mechanical manufacturing. In addition, once the SCU is...
The project of PolFEL free electron laser comprises 185 MeV cw-linac furnished with ASG electron gun and 4 Rossendorf-like cryomodules. Magnetic lattice has been designed applying alike air cooled quadrupole magnets. FODO quadrupoles in undulator section differ with trimmed coils. A variety of dipoles has been designed: 14 – degrees air and water cooled rectangular dipoles are used for low...
The Tapered undulator provides interesting possibilities for keeping the undulator in resonance with the electron beam along the length of the undulator. The U50-II [1,2] undulator at Laser and Insertion Device Application Laboratory of DAVV, India is a 1000mm length, 50mm period length undulator. The four heavy-duty precise lead screw attached to the mechanical girder allows its gap to be...
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. In the HEPS storage ring, a proportion of quadrupoles and sextupoles are equipped with trim coils for horizontal and vertical orbit correction. For these magnets, the main field and corrector fields may have non-ignorable impact on each other. We have carried out...
An 800 MHz, Radio Frequency Quadrupole (RFQ) was designed to accelerate the proton beam to 2 MeV energy at a distance shorter than one meter in KAHVE-Lab, Turkey. A half-length test module was previously produced to investigate the local manufacturability of this RFQ cavity. The manufactured test module was subjected to mechanical, vacuum and electromagnetic tests to adjust the pressure, EM...
Gaussian lasers with temporal or spatial chirp have been used in the manipulation of the electron beam in the high-gain harmonic generation or echo-enabled harmonic generation in free-electron lasers. This paper presents the Mathematica expressions of these lasers. This work is a first step for novel laser-electron manipulation technique in presence of temporal or spatial chirp.
Studies of third-order chromaticity in the LHC during its initial two runs have consistently demonstrated a substantial discrepancy between the expected Q''' at injection and that observed in beam-based measurements. In 2022 during Run 3, for the first time, studies of Q''' have been complemented by measurements of chromatic detuning, being the momentum-dependence of amplitude detuning, and...
Numerical simulations of the beam dynamics with the Coherent Wiggle Radiation (CWR) impedance for the preliminary EIC back-up ring cooler parameters and positive and negative momentum compaction are discussed in detail. We show the microwave instability threshold dependence on low-frequency CWR impedance in free space and for parallel plates. The numerically simulated results performed by the...
During loss maps performed with beam at injection energy in the LHC with the high octupole and chromaticity settings used for multi-train operation, large beam losses were observed at an injection protection device (TDIS). Although these losses did not present a threat to machine operation or protection, reducing them is of high importance to improve machine performance. Various strategies...
The largest current obstacle to SuperKEKB's luminosity goals is currently beam-related backgrounds occurring during accelerator operation. Thus, understanding the level of these backgrounds is of crucial importance for the future of the facility. In this work, we take advantage of the Belle II Electromagnetic Calorimeter's near-total coverage of the interaction region to create a spatial model...
Modernization of the NESTOR hard X-ray generator storage ring for switching to the operating frequency of the accelerator of 2.856 GHz requires corresponding changes in the design of the high-frequency system, and this, in turn, leads to the need to modernize the laser-optical system. The necessary calculations were carried out to determine the new characteristics of the pulsed laser, the...
To satisfy up-to-date technical requirements NSC KIPT hard X-ray source on the base of Compton scattering NESTOR should be modified. Essential modernization should be done in accelerator-injector, lattice of the storage ring, RF and optical systems.
In the paper the technical proposals of the facility modernizations and results of beam dynamic simulations in the modified facility are...
KEK has two light sources: Photon Factory (PF, 2.5 GeV) and Photon Factory Advanced Ring (PF-AR, 6.5 GeV). In 2017, the use of a new beam transport line (BT) of PF-AR was started, and the simultaneous top-up injection for both PF and PF-AR was realized. These days, there have been strong demands for the reduction of the operating cost of accelerators, and its importance is greater in PF-AR...
One of the most fundamental measurements since the Higgs boson discovery, is its Yukawa couplings. Such a measurement is only feasible, if the centre-of-mass (CM) energy spread of the e+e- collisions can be reduced from ~50 MeV to a level comparable to the Higgs boson’s natural width of ~4 MeV. To reach such desired collision energy spread and improve the CM energy resolution in...
The system in place for remote alignment of the girders, which carry the storage ring elements of the PETRA III light source in the Max von Laue experimental hall, were never used to perform re-alignments after the initial installation of the storage ring in 2009. Since the planned upgrade, PETRA IV, can benefit from the fine control of the girder position to achieve the design beam...
Ultra-high brightness and ultra-low emittance electron beams can great enhance the radiation power in light sources, but the electron beams are prone to nonlinear effects in the velocity compression, which leads to the asymmetry of the beam. In this paper, a multi-objective optimization method based on NSGA-III is proposed to achieve a good symmetry in the C-band photocathode injector with an...
In beamline design, there are many floating parameters that need to be tuned; manual optimization is time-consuming and laborious work, and it is also difficult to obtain well optimized results. Moreover, there are always several objectives that need to be considered and optimized at the same time, making the problem more complicated. For example, asking for both the flux and energy to be as...
Transverse multibunch instabilities are of significant interest in accelerators with strong wakes and large bunch trains. In such cases, wakes that do not damp sufficiently from bunch to bunch can drive instability along the entire bunch train. Simulations are useful for understanding such instabilities, but the multiscale nature of the system and numerical noise can make results uncertain. A...
Utilizing short RF pulses ($\sim$9 ns) with Dielectric Disk Accelerators (DDA) is a way to improve the energy efficiency of a linear accelerator and decrease the required footprint while still achieving large energies. A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance while still achieving large accelerating gradients. A single cell clamped DDA...
A method to reconstruct the momentum distribution of the injected muon beam in the Muon g-2 Storage Ring at Fermilab has been developed, which is based on beam profile measurements from the Muon g-2 straw tracking detectors as input. Extending a spectrometric perspective to the muons injected into the Muon g-2 storage ring, a direct transformation of the beam radial coordinates when the...
Muons circulating in a muon collider decay and generate neutrinos within a small solid angle, which reach the earth’s surface. One of the challenges of a high energy muon collider is to ensure that showers created by such neutrinos interacting close to the earth’s surface result in very low radiation levels. The neutrino radiation cone from a muon beam without divergence is estimated through a...
The Nuclotron-based Ion Collider fAcility (NICA) is under construction at JINR. The NICA project goal is to provide colliding beams for studies of hot and dense strongly interacting baryonic matter and spin physics. The NICA Collider includes two rings with 503 m circumference each and the injection complex. For the heavy ion mode, the injection complex consists of following accelerators: 3.2...
To maintain polarization in a polarized proton collider, it is important to know the spin tune of the polarized proton beam, which is defined as the number of full spin precessions per revolution. A nine-magnet spin flipper has demonstrated high spin-flip efficiency in the presence
of two Siberian snakes. The spin flipper drives a spin resonance with a given frequency (or tune) and strength....
The 18 GeV Electron Storage Ring (ESR) lattice of the Electron-Ion Collider (EIC) showed various undesirable effects in nonlinear Monte Carlo tracking, including a vertical core emittance exceeding radiation-integral predictions and a low asymptotic polarization. These problems were resolved in a newer lattice where dispersion in the solenoidal spin rotators was set to zero. Here we identify...
As an energy frontier machine, the proposed Super Proton-Proton Collider (SPPC) will have the capability to explore a much larger region of new physics models with center of energy around 125 TeV and circumference 100 km.
The nonlinearity optimization of the SPPC collider ring lattice is essential to get a high peak luminosity and lifetime of the beams. In this paper, a collider ring lattice...
The booster ring of High Energy Photon Source is responsible for ramping the beam energy from 500 MeV to 6 GeV. Six 5-cell copper cavities of PETRA-type were chosen to provide a total accelerating voltage of 8 MV. To fulfill the specific requirements of the HEPS booster, several modifications were made on the original design from Research Instruments (RI). Six cavities manufactured by RI...
Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014. Installation of 16 beamlines of the first and second phases of TPS beamline project was completed. The third phase project also had been launched in 2021. To confront the situation that the experimental hall is more compact, we per-formed Computational Fluid Dynamic (CFD) simulation to analyse the...
We have developed numerical method to calculate temporal structure of synchrotron radiation in arbitrary magnetic field. Using this method, spectral phase of synchrotron radiation can be calculated, which is important in the reconstruction of temporal structure of radiation. It is also interesting that it reflects the symmetric property of magnetic field from which radiation is generated....
The electron storage ring DELTA which is operated by TU Dortmund University can be run at a reduced beam energy down to 500 MeV instead of 1.5 GeV. If a single bunch at low energy is stored, the bunch charge threshold for the emission of THz bursts is exceeded. Using a fast Schottky-barrier detector, coherent synchrotron radiation bursts of THz radiation were detected. Turn-by-turn data of the...
SuperKEKB suffers from sudden beam loss(SBL) during operation. It causes collimator damage, QCS quench and large beam background to the Bell-II detector. Beam aborts triggered by SBL hinder us from storing large beam current. Since cause of SLB is unclear, we launched an effort to investigate it and consider measures to be taken. In this paper, we discuss phenomena of SBL and various...
In this study we investigate the advantages and challenges of applying the two frequency crab cavity short pulse scheme to multi-bend achromat (MBA) lattice based fourth generation synchrotron light sources. Using the Advanced Photon Source Upgrade (APS-U) lattice as a concrete example, we show that short pulses with duration of 1~10 ps (FWHM) can be generated with modest deflecting voltages....
The ESRF-EBS is the first 4th generation source making use of the Hybrid Multi-Bend Achromat (HMBA) lattice cell, reaching an equilibrium horizontal emittance of 140 pm.rad in user mode (insertion devices (ID) gaps open). An off-energy operation was proposed to further reduce the equilibrium emittance by about 20 pm.rad. A first proposal rematched the HMBA optics at an energy deviation of -1\%...
The application of HTS coils as a matching device and a large-aperture L-band linac make it possible to transport a substantial part of positrons generated in a positron production target through a capture linac. It raises a question of how to manage their large phase space to provide bunches matched to the damping ring acceptance. This paper presents the beam dynamics studies of the FCC-ee...
The European Synchrotron Radiation Facility - Ex-tremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation storage ring light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. On 25th August...
A non-negligible risk of magnet quenches occurring due to the reduced cleaning performance of the original LHC collimation system with lead ion beams was expected at an energy of 6.8 Z TeV beams. Crystal collimation has therefore been integrated into the HL-LHC upgrade baseline to overcome present limitations. The upgrade scope involves the installation of 4 new crystal primary collimators....
In addition to the physics program with proton beams, the Large Hadron Collider (LHC) also provides collisions of fully-stripped Pb beams for about one month per year. When colliding Pb-Pb nuclei, electromagnetic interactions are the dominating processes because of the intense Coulomb field produced by the ions. These 'ultra-peripheral' interactions give rise to special losses in the machine...
In this paper, we present the possible use of laser Compton back scattering (CBS) to adjust and tune the bunch intensity. In the future circular electron-positron collider “FCC-ee”, the intensity of the colliding bunches should be tightly controlled, with a maximum charge imbalance between collision partner bunches of less than 3–5%. The control of such tolerance is necessary due to the strong...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. Preliminary beam-beam simulations resulted in an optimum working point of (.08, .06) in the Electron Storage Ring (ESR). However, during the...
MINERVA entails the first phase of the MYRRHA programme, which aims at driving a nuclear reactor with a high-power proton accelerator, commonly referred to as an Accelerator Driven System(ADS). The purpose of MINERVA is to demonstrate the reliability requirements that are needed for a stable ADS, by the realization of a 100 MeV, 4mA proton beam.
In order to transport the proton beam with...
The Swiss Light Source (SLS) will shut down in October 2023, entering the dark time period for installation of the upgraded SLS 2.0 synchrotron. The commissioning of the new electron storage ring is planned for early 2025. The upgraded storage ring features a lattice based on modern 7-bend achromats with lower momentum compaction factor, NEG coated vacuum pipes of smaller aperture and an...
The prototyping accelerator based on laser-plasma technology (PALLAS) project aims to build a laser-plasma injector accelerator (LPI) test facility to deliver within a few years electron beams of 150-250 MeV, >30 pC, <1 mm.mrad emittance beam at 10 Hz with control and stability comparable with RF accelerator. The project is, among others, built in the framework of the technical preparatory...
A facility for a muon collider brings the big advantages of a compact lepton collider and a collision energy up to several TeV, well above the energy reach of conventional electron circular accelerators.
However, the short lifetime of muons drives the design of the accelerator complex and collider, which makes this complex unique. A high muon survival rate and luminosity requires an extremely...
The observation of the Higgs boson by the LHC (2012), and the direct observation of gravitational waves (GW) from a collapsing binary systems by LIGO (2016) marked the successful end of long-standing efforts, and hopefully the dawn of a new era where both fields, Particle Accelerators (PA) and GW Physics, may benefit from knowledge/technologies developed by the other party. CERN recently...
NSLS-II is a 3 GeV third generation synchrotron light source at BNL. The storage ring was commissioned in 2014 and began its routine operations in the December of the same year. Since then, we have progressed steadily upwards in beam current and reached 500 mA in five years while increasing new insertion devices. Along this path, we report various challenges and the improvements to reach high current.
The Physics Beyond Colliders (PBC) studies at CERN address the possibility to utilise protons in the Large Hadron Collider (LHC) for a fixed-target program beyond the colliding-beam physics. As part of PBC, a double-crystal test stand is considered for installation in the LHC off-momentum collimation Insertion Region (IR) 3. In this PBC experiment, a first silicon crystal deflects beam-halo...
Undulators containing magnetized rare-earth helices can provide a significantly higher oscillatory electron velocity than the widely used planar Halbach undulators. Using Wire Electrical Discharge Machining (WEDM) and combining planar tool with rotary work piece motion, it is possible to manufacture NdFeB helices with a period of 1 mm or less with high accuracy. In this work, we describe the...
The Synchrotron Light Source PETRA III is one of the core facilities at DESY offering each year more than 2000 users unique opportunities for experiments with hard X-rays of a very high brilliance. The light source is operated mainly in two operation modes with 480 and 40 bunches at a beam energy of 6 GeV. The availability and failure statistics is reviewed for the year 2022 in comparison with...
Research and development of an accelerator-based THz source prototype for pump-probe experiments at the European XFEL are ongoing at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). Proof-of-principle experiments have been performed to generate a high-gain THz Free-electron Laser (FEL) based on the Self-Amplified Spontaneous Emission scheme. The FEL radiation pulses with a central...
A series of power outages during setup for RHIC Run 23 damaged two of the four helical dipole modules that comprised one of the full Siberian Snakes in RHIC’s Blue ring. The remaining two helical dipoles were reconfigured as a “partial” snake, one which rotates the spin by an angle less than 180 degrees. This partial snake configuration has a rotation angle and axis which both deviate from...
Positron beams would provide a new and meaningful probe for the experimental program at the Thomas Jefferson National Accelerator Facility (JLab). The JLab Positron Working Group, formed in 2018 and now with over 250 members from 75 institutions, continues to develop an experimental program with high duty-cycle positron beams including but not limited to future hadronic physics and dark...
The Large Hadron Collider (LHC) is equipped with a betatron halo collimation system designed to prevent magnet quenches during periods of reduced beam lifetime. Protons subject to single diffractive scattering in collimators can nevertheless leak into the adjacent dispersion suppressors (DS). In view of the future high-luminosity (HL) upgrade of the LHC, a better understanding of the quench...
To explore the beyond standard model of elementary physics, we proceed a new fundamental physics experiment, J-PARC muon g-2/EDM experiment. To realize very precise measurement of the muon spin precession frequency in the level of sub-ppm, a relativistic energy of muon beam is injected into a precisely adjusted storage magnet of sub-ppm uniformity by applying medical MRI magnet technologies....
The Korea 4th Generation Storage Ring(Korea-4GSR) project has been launched in 2022. The Korea 4GSR aims to generate the ultra-low emittance beam with the beam current of 400 mA and the beam energy of 4 GeV. In order to accelerate and store the beam to desired parameter, the Storage Ring RF(SRRF) is composed of 10 or more RF Stations and each RF Station includes LLRF(Low Level RF), HPRF(High...
Hefei Advance Light Facility (HALF) is a 2.2 GeV diffraction-limited storage ring, which is developed by National Synchrotron Radiation Laboratory in China. It has 20 long straight sections and 20 middle straight sections. All the experimental stations in the first stage will employ undulator as the light source. In this paper, we introduce the preliminary design of insertion devices of HALF,...
In the FCC-ee study, it is proposed that electron and positron beams circulate at high current and high energy in a 92-km circumference ring. The present operational scenario foresees a first running step at an energy of 45.6 GeV and around 1.4 A current, which would generate copious amounts of synchrotron radiation (SR) power and flux. To guarantee a quick decrease of the photon desorption...
The Steady-State Microbunching (SSMB) mechanism, which combines the benefits of high repetition rate of a storage ring and coherent radiation, has the potential to produce high average power short wavelength light. In order to generate kilowatt level radiation, the electron injector should have the ability to provide a 1 A average current, 100 ns long DC beam, with the requirements of small...
Rapid cycling synchrotron (p-RCS) is the first synchrotron of the accelerator chain in the proposed Super Proton-Proton collider (SPPC) project. It will provide high-energy and high-power beams for the injection to the downstream accelerators for SPPC collision with the required beam characteristics such as bunch spacing, bunch population and emittance, but also serve independent application...
In this paper we will show the injection philosophy and the design of timing and filling scheme for high luminosity CEPC scheme under different energy modes. It is found that the RF frequency choice in CDR cannot meet the injection requirements for the bunch number at Z pole. A modified scheme was proposed to support the design luminosity,which basically meets our current design requirements and...
Since the upgrade and renovation of the East Experimental Area at CERN during Long Shutdown 2 (LS2: 2019 - 2021), demand has increased for slowly extracted beam from the CERN Proton Synchrotron (PS). The East Area is a multi-user facility carrying out a diverse experimental physics programme. It requires a wide range of slowly extracted beams to be delivered by the PS. This contribution...
The potential future Soft X-ray (SXL) FEL beamline at the linear accelerator at MAX IV will require a series of undulators with distinct properties: It must be cost-effective and compact. Furthermore, it needs to have a small and round magnetic gap and provide elliptically polarized light under full polarization control. This undulator of a compact APPLE X type is currently being prototyped...
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The construction of HEPS started in mid-2019. Later, to deal with challenges emerging from the technical and engineering designs, the HEPS accelerator physics design was modified and had been finalized in 2020. Afterwards, studies on related physics issues were updated...
We report on progress developing the Energy and RF ramp for the EIC’s Rapid Cycling Synchrotron (RCS). The development of the RF voltage and phase ramp from injection energy at 400 MeV to 5, 10 and 18 GeV extraction energy requires control of the bunch’s longitudinal aspect ratio to avoid both collective instabilities, RF bucket height and width as well as lattice dynamic aperture limits....
The Hefei Advanced Light Facility (HALF) is a soft X-ray and VUV diffraction-limited storage ring to be built in the Hefei city of China. This paper reports the recent progress on the physics design of the HALF storage ring, including lattice modification and optimization, error and insertion device effects, collective effects, injection scheme and collimation.
In the Large Hadron Collider (LHC), corrections of local Interaction Region (IR) linear coupling are of importance to control beam sizes at Interaction Points (IPs) and hence the luminosity performance, as well as to prevent a significant impact on the beam dynamics. During the LHC Run 3, the skew quadrupole corrector magnets used on either side of IPs are expected to exceed their radiation...
The LHC beam dump system was developed to safely and reliably dispose of the LHC beams at the end of physics fills or in case of emergency aborts. The beams are extracted by means of kicker magnets, deflecting the beams horizontally, and septa, which provide a vertical kick. The system must be able to cope with rare failure scenarios, such as an asynchronous beam dump, where the rise time of...
The user service mode of ESRF started in August 2020 after the installation of the new EBS machine, replacing the original ESRF DBA storage ring. All the insertion devices (IDs) were stored and re-installed to be available from day-1 of the accelerator commissioning. A major concern was, and still is, to preserve them as much as possible from demagnetization, both low gap in-vacuum devices and...
We describe optics designs of the key components of proton and electron Recirculating Linear Accelerators (RLAs). They are presented in the context of a high-power hadron accelerator being considered at ORNL and a CEBAF electron energy doubling study, FFA@CEBAF, being developed at Jefferson Lab. Both concepts rely on the Fixed-Field Alternating gradient (FFA) arc optics designs where multiple...
The muon linear accelerator is under development at J-PARC for precise measurement of muon anomalous magnetic moment and electric dipole moment. Four 2592 MHz disk-loaded structures (DLSs) operating in the TM01-2pi/3 mode take charge of the acceleration of high-velocity muon from 70% to 94% of the speed of light. They have disk-iris apertures tapered to generate a quasi-constant gradient of 20...
An in-vacuum undulator is important for synchrotron radiation. An in-vacuum undulator with a permanent-magnet is used by the Taiwan Photon Source (TPS) in the National Synchrotron Radiation Research Center (NSRRC). Before installation in the storage ring, the magnetic field of the undulator is measured at the oper-ational gaps. The magnetic-field for an in-vacuum un-dulator is measured using a...
The user community of the Angle-Resolved Photoemission Spectroscopy (ARPES) beamline in Diamond Light Source (DLS) is strongly interested to use the lower photon energies down to 10 eV compared to the current 18 eV in both Diamond and the future 3.5 GeV machine Diamond-II. The high level of the heat load on the first optic as well as the undesired higher harmonics contamination are two major...
The European Spallation Source (ESS) project currently enters the final stage of installation. Since 2017, a group of engineers and technicians from The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Science (IFJ PAN) are involved in the project. The contribution to the project can be divided into three main tasks: Radio Frequency Distribution System (RFDS), RF (Radio...
Shanghai Laser Electron Gamma Source (SLEGS) beamline, based on laser Compton scattering (LCS), as one of beamlines of Shanghai Synchrotron Radiation Facility (SSRF) in phase II project, has been construct-ed and started test commissioning from July 2021. The results of the commissioning already show a steady experimental proof that SLEGS can produce gamma rays with adjustable maximum energy...
The design of Southern Advanced Photon Source (SAPS), which is a 3.5 GeV storage ring based light source, has been actively updated in the past two years. In addition, many relevant research activities such as the development of an electron source, high gradient accelerating structures, RF cavities and power supplies for fast injection kickers have already been started. The updated overall...
The Future Circular Collider (FCC) study comprises two accelerators, namely a high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh). Both rings share the same tunnel infrastructure, analogous to LEP and LHC. We present the current design status of FCC-hh, updated from the Conceptual Design Report (CDR) and with recent developments including the new designs of the...
The Taiwan Photon Source (TPS) experimental facility has experienced vibration interference at approximately 16.8 Hz during experiments at the end station of the TPS 23A beamline, which was traced back to the air handling units (AHUs) located on the second floor of the outer ring area of TPS. The vibration of the AHUs not only affects the TPS beamline 23A end station but also all experimental...
The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source being built in China. Basic accelerator physical design and vacuum design have been completed. Interactions between the accelerated particles and the residual-gas molecules will lead to a reduction in the beam lifetime. The residual gas lifetime includes contributions from elastic gas scattering and...
10Hz horizontal orbit oscillation due to helium flow was observed in the routine operation of the Relativistic Heavy Ion Collider (RHIC). Without compensation by 10Hz orbit feedback, this will cause sizeable luminosity variation and reduce the beam lifetime during physics stores. In this article, we revisit the effects of this beam oscillation with weak-strong beam-beam simulation and dynamic...
The Diamond-II storage ring will utilise normal conducting main cavities and a passive superconducting harmonic cavity in its RF system. To evaluate the effects of bunch lengthening and lifetime gain from the harmonic cavity for different filling patterns, transient beam loading effects need to be studied. When simulating these effects with ELEGANT, RF feedback for the main cavities must be...
The CERN Super Proton Synchrotron (SPS) aims at providing stable proton spills of several seconds to the North Area (NA) fixed target experiments via third-integer resonant slow extraction. However, low-frequency power converter ripple (primarily at 50 and 100 Hz) and high-frequency structures (mainly at harmonics of the revolution frequency) modulate the extracted intensity, which can...
The hybrid multi bend (HMBA) lattice has been introduced to the accelerator community with the ESRF-EBS storage ring. Scaling an HMBA storage ring (SR) to different number of cells or cell length may lead to loss of performances, in terms of dynamic aperture (DA), momentum acceptance (MA) and natural horizontal emittance of the resulting SR. In this article we present several (non-exhaustive)...
The Siam Photon Source, a synchrotron light source in Thailand, has undergone multiple improvements in recent years, including the installation of up to four insertion devices in the storage ring. The machine has operated at maximum capacity for a significant period of time. This study presents a statistical analysis of the machine's operation over the past seven years, including the number of...
The feasibility of performing sextupole injection at TPS (Taiwan Photon Source) storage ring has been demonstrated in November 2021 with 300 mA stored electron beam. In order to carry out the experiment, a sextupole and its associated pulser were fabricated according to the specifications required. The sextupole was installed during a short break in September 2021 by making use of a ceramic...
China Spallation Neutron Source (CSNS) is a high density complex with a high repetion rate of 25Hz. The Rapid Cycling Synchrotron is the key part of the CSNS. By adopting the sextupoles with pulsed beam power system, CSNS has been operating steadily at 140kW. The CSNSII is aim to deliever above 500kW with the upgrations of many aspects of the accelerator. The sextupoles upgration is very...
The Proton Storage Ring (PSR) of LANSCE compresses the pulse of a linac-produced beam by a factor of more than 2000 into an ultra-short high intensity beam, making the Lujan Center a leading facilities in the delivery of instantaneous beam power. This short-pulse feature allows a variety of experiments from neutron science to fundamental nuclear physics. Further shortening the beam pulse by...
Short pulsed proton beams of 8 ns has been extracted from FFAG accelerator in KURNS. Bunch rotation after adiabatic debunching was used at highest energy orbit.
A new in-vacuum undulator (IVU) with varying gap width is being developed for the new X-Ray source, PETRA IV at DESY. Its electromagnetic properties need to be investigated. These include, especially, the losses in the flexible taper transitions between the beam pipes and in the magnet array, as well as the impact of the IVU's impedance on beam stability. To assess the impedance of the...
The AAC community proposed linear collider concepts with energies extending to 15 TeV center-of-mass and luminosities up to 50E34 cm^-2 s^-1 as part of the Snowmass process. The beam power required to reach these energies and luminosities is prohibitive. We discuss the results of initial investigations of strategies to increase luminosity per beam power, a key figure-of-merit for linear...
We propose a computationally efficient algorithm to calculate a single statistical realization of partially coherent synchrotron radiation fields at a given frequency. The proposed algorithm relies on a method for simulating Gaussian random fields. We cross-checked the algorithm’s consistency with other well-established approaches, and, in addition, we show its advantage in terms of...
The strong field of the experimental solenoid around the interaction point has a considerable effect on the beam optics. Moreover, if the beams traverse the solenoid at an angle, as it is typically the case in a collider, the solenoid will also affect the closed orbit within and beyond the solenoid. Simulating these effects is not trivial. In the following we outline different philosophies of...
The High Energy Photon Source (HEPS), is an ultra-low emittance storage ring (USR) light source beingto be built in Beijing, China. Due to the characteristics of the compact 7BA structure with strong focusing, beam accumulation in an USR is expected to be very challenging. Our simulations confirmed the difficulty in the HEPS storage ring. This paper introduces the preparations made for the...
The High Energy Photon Source (HEPS) is a 6 GeV, 1.3 km storage ring light source being built in Beijing, China. To get an ultralow emittance, high-gradient quadrupoles, combined-function magnets and longitudinal gradient dipoles (BLG) are adopted in the design of the storage ring. The impact of fringe field effects is of interest. To this end, several methods based on one-dimensional and...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. To compensate the geometric luminosity loss due to a large crossing angle in the EIC, crab cavities are to be installed on both sides of...
During about one month in every operational year, the Large Hadron Collider (LHC) works as a heavy-ion collider. Four one-month Pb-Pb runs have been executed so far, as well as two p-Pb runs. The LHC heavy-ion programme is scheduled to continue in the future, featuring increased luminosity and beam energy. Beam losses caused by ions fragmenting in the collision process risk introducing...
Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1--30s. This work is the first study of slow extraction from a scaling Fixed...
The periodic orbit change caused by the temperature fluctuation of the cooling water at the SAGA-LS storage ring was suppressed by the slow orbit feedback correction system using newly equipped extra-windings on 8 steering magnets.
In recent years, the amplitude growth of temperature fluctuation of the cooling water caused maximally 40 micrometer periodic orbit change at the SAGA-LS storage...
The beam abort system for the current Swiss Light Source (SLS) is based on inverting the RF phase to decelerate the stored beam. The losses are localised at longitudinal positions where the dispersive orbit encounters the machine aperture. For the SLS, these losses mainly occur at the septum and in the arcs. For the SLS 2.0* with its multi-bend-achromat lattice and thus much lower dispersion...
The Swiss Light Source SLS will have a 15 months long shutdown starting in October 2023 in order to install the new storage ring SLS 2.0. While the procurement of large series of components like magnets, power supplies, RF, vacuum chambers, … has started, the design of more specific components like the thin septum, undulators or collimators, is close to completion. The main difficulties and...
There has been a recent explosion of interest for a Muon Collider (MuC) as evident by the number of journal publications, related workshops and white papers submitted for the 2021 Snowmass Study. In light of this strong interest and in order to provide input for Snowmass, a MuC Forum has created in 2020. It facilitated a strong bond and exchange of new ideas between the particle physics...
The synchrotron SOLEIL is both a 2.75 GeV third-generation synchrotron light source and a research laboratory at the forefront of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. We present the performance of the accelerators delivering extremely stable photon beams to 29 beamlines....
The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which started construction in 2019. The sextupole and octupole magnets in the storage ring of HEPS are divided into several groups, and each group of magnets shares one power supply. In the lattice design, magnets in the same group are identical, but the real magnets have errors, which violate the...
At DELTA, a 1.5-GeV synchrotron radiation source at TU Dortmund University, ultrashort radiation pulses are generated using CHG (coherent harmonic generation), where the interaction with laser pulses in an undulator (modulator) causes a periodic electron energy modulation within a 50-fs slice of a 2000-times longer electron bunch. A dispersive chicane creates a density modulation giving rise...
The possibility of spin control for dEDM experiment can be done by setting Wien Filters in straight section, which ensure that the particles spin retains mean direction in accordance with «Quasi-Frozen Spin» mode. However, the spin of different particles, due to their different motion in 3D space, in any case rotates with slightly different frequencies around the invariant axis, which one...
The high precision measurement of the centre-of-mass energy in the Future Circular Collider e+e- (FCC-ee) at Z and W energies can be realized through resonant spin depolarization utilizing transversely polarized beams. This requires a guaranteed sufficiently-high spin polarization in the presence of lattice imperfections. Investigations of the impact of misalignments on the equilibrium...
We describe methods for measuring the three-dimensional stable spin vector for RHIC stores at two locations in the ring, namely the proton-Carbon (pC) polarimeters and the interaction point at the STAR detector. Both the pC and STAR local polarimetry can only measure the two transverse components of the stable spin direction. Measuring the full spin vector requires making a local spin...
The Drift Tube Linac (DTL) for the ESS Linac will accelerate H+ beams of up to 62.5 mA peak current from 3.62 to 90 MeV. The structure consists of five cavities. The first cavity (DTL1, 21 MeV) has been commissioned with beam in summer 2022. DTL2, 3 and 4 are installed in the tunnel since the end of 2022, ready for the conditioning and commissioning starting in 2023. DTL5 is under assembly and...
In the context of the FCC IS European study, which investigates the feasibility of a 100 km circular $e^{+}e^{-}$ collider for the future high energy physics research, we present the status of the High Energy Booster (HEB) ring. The HEB will be located in the same tunnel as the collider and should have the same circumference. The main difference is to have a bypass near the experiments to...
High Energy Photon Source (HEPS), a 6 GeV diffraction-limited synchrotron light source, is currently under construction in Beijing. The double-frequency RF system is being developed to deliver 6 MV of RF voltage and 850 kW of beam power with an active third harmonic system. The prototypes of the higher-order-mode damped 166.6 MHz quarter-wave superconducting cavities, as well as the 499.8 MHz...
Building new experimental facilities to house experiments is an expensive and time-consuming activity. Although usually less expensive, repurposing old experimental facilities to accommodate new ones has its own set of challenges with regard to obsolete equipment, adequacy of electrical power, radioactive shielding and cooling capacity. At Los Alamos National Laboratory (LANL), one such...
In this work, we examine the beam correction requirements for the FFA@CEBAF energy upgrade. Both hardware and software diagnostic and corrector components are under investigation; in particular the relationship between hardware and software optimization will be developed. To generate a representative sample of errors---from the machine lattice and other beam properties---we construct a Markov...
The International Linear Collider is a proposed electron-positron linear collider, where the positron beam is generated by undulator radiation hitting a target. The resulting, highly divergent positron beam requires immediate optical matching to improve the luminosity and ensure the success of the intended collision experiments. Here, optical matching refers to the process of capturing...
In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to its potential advantages in compactness and beam dynamics compared to conventional focusing elements. A promising application could be optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures to...
The ALS-U project is an upgrade to the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory that aims to deliver diffraction-limited x-ray beams with an increased beam brightness of two orders of magnitude for soft x-rays compared to the current ALS facility. A nine-bend achromat lattice Storage Ring (SR) and a three-bend achromat Accumulator Ring (AR) will be installed...
Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing
purposes. A first partially successful attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity
by means of beam-based techniques has been carried out in 2018.
The large orbit distortion produced by the crab cavity dipolar field...
High intensity heavy ion beams are a main constituent of the FAIR research program. They will be provided by the UNILAC via the high current injector HSI. Generated in high current sources, these ions originally have low charge states. To allow for efficient acceleration in the UNILAC and SIS18, a gas stripper is located at the end of the HSI to reduce the mass-to-charge ratio below 8.5. An...
Provisions are being made in the Electron Ion Collider (EIC) design for future installation of a second Interaction Region (IR), in addition to the day-one primary IR [1]. The envisioned location for the second IR is the existing experi- mental hall at RHIC IP8. It is designed to work with the same beam energy combinations as the first IR, covering a full range of the center-of-mass energy of...
The implementation and further improvements of superconducting undulators is part of the European XFEL facility development program. Within this program, a magnetic field test facility is being developed. Named SUNDAE2 (Superconducting UNDulAtor Experiment 2), it aims to perform in-vacuum magnetic field measurements of superconducting undulators (SCUs) with three techniques: Hall probe, moving...
Wakefields kick the electron bunch to a non-linear tilt causing emittance growth. Any additional correlation like an energy chirp (energy vs z dependence) will filament the disturbance further causing a nearly unrecoverable bigger emittance. For C3 (Cool Copper Collider) the emittance preservation numbers seems to be about 1000 times more stringent than achieved. It is actually "only" about 30...
The Electron Ion Collier (EIC) will utilize highly polarized electron and ion beams. To preserve polarization through numerous depolarizing resonances over the whole EIC hadron accelerator chain, harmonic orbit correction, partial snakes,horizontal tune jump system and full snakes have been used. A new scheme using skew quadrupoles to compensate horizontal intrinsic resonances is under...
RadiaBeam, in collaboration with UCLA and Fermilab, is developing a strongly tapered helical undulator system for the Tapering Enhanced Stimulated Superradiant Amplification experiment at 515 nm (TESSA-515). The experiment will be carried out at the FAST facility at Fermilab as a Gamma-Ray high Efficiency ENhanced Source (FAST-GREENS). The undulator system was designed by UCLA, engineered by...
The collimation system of the electron-positron Future Circular Collider (FCC-ee) will have two main tasks: protect equipment from the multi-MJ beams and mitigate detector backgrounds. An integrated collimation system layout is presented, including beam halo collimation system in one insertion and synchrotron radiation collimation around the experimental interaction points. The Z-production...
Wuhan Advanced Light Source (WALS) is the low-energy 4th generation advanced light source, which is proposed by Wuhan, China. WALS includes a 1.5 GeV full-energy LINAC injector, a 180 m circumference, 1.5 GeV low-emittance storage ring, and a series of start-of-the-art beam lines. The standard 7BA magnetic focusing structure is adopted for the storage ring to lower the beam natural emittance...
The South Advanced Photon Source (SAPS) is a newly proposed storage ring (SR) based photon source project operating at the beam energy of 3.5GeV. To achieve X-ray diffraction-limited in the SR with high density bunch, larger coupling impedance brought by more compact beam pipe structure is inevitable, which makes the beam collective effects be one of the major challenges to the physical...
To further enhance the accelerating gradient of accelerators, we designed a cryogenic C-band standing wave bi-periodic accelerating structure for the Shanghai Soft X-ray Free Electron Laser Facility (SXFEL). According to the low-temperature environment, material characteristics and technological conditions, the design is completed and it is decided to design the accelerating structure into a...
A SLED (SLac Energy Doubler) RF pulse compressor is a passive RF component which increases the peak RF power level at the cost of reducing the pulse length. The Canadian Light Source (CLS) plans to replace the current 250 MeV Linac with a new one in mid-2024 by RI Research Instruments GmbH. The new Linac has a similar energy and two of its three 5.3 m TW constant-gradient accelerating...
The Diamond-II storage ring has been designed to increase photon brightness by up to two orders of magnitude compared to the existing Diamond facility. A single-bunch aperture sharing injection scheme using short stripline kickers applied with high-voltage nano-second pulsers was proposed to provide both high injection efficiency and high photon beam stability in top-up mode [1]. The...
A fourth generation storage ring with an energy of 3 GeV is proposed by Institute of Advanced Science Facilities, Shenzhen. After repeated optimization, the storage ring achieved a dynamic aperture of 15mm. With a relatively large dynamic aperture, Off-axis injection scheme is possible for SILF storage ring. We first considered conventional local bump injection as a candidate. The nonlinear...
SIRIUS is the 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). SIRIUS is currently operating with six beamlines and eight others are at different stages of deployment. In this work we report on the development of simulation tools to analyze the impact of insertion devices (IDs) on SIRIUS beam orbit, optics and dynamic aperture...
Optimization and realistic estimates of the sensitivity of the measurement of charged particle Electric Dipole Moment (EDM) in storage rings require a good understanding of systematic errors that can contribute to a vertical spin build-up mimicking the EDM signal to be detected. A specific case of systematic effect due to offsets of electrostatic bendings and longitudinal magnetic fields is...
The Korea fourth generation storage ring (Korea-4GSR) is a 4GeV, low emittance light source to be built in Ochang, Korea. The booster ring, which consists of 26 FODO standard cells and 2 dispersion-free cells, ramps the beam energy up from 200 MeV to 4 GeV as part of the injector. The circumference and repetition rate of the booster ring is 772.9 m and 2 Hz, respectively. In this paper, the...
Laser Compton Scattering (LCS) is a technique to produce quasi-monochromatic X-rays and gamma rays by colliding a laser with a high-energy electron beam produced by an accelerator. Although LCS light sources are expected to produce photons of the same quality in a small (6m x 8m) device as those from large synchrotron radiation facilities , the low number of scattered photons is an issue for...
The High Energy Photon Source (HEPS) is a 1360.4-m, 6-GeV, ultralow-emittance light source, being built in the suburb of Beijing, China. The HEPS booster contains 128 dipoles,148 quadrupoles and 68 sextupoles, which are divided into several groups. The magnets in one group are connected in series, and powered by a single power supply. To minimize the impact on beam dynamics, magnets sorting...
In this paper,we combines the problems in the determination of the adjustment weight of the current control network and the increasingly updated information processing model, taking the typical level network and making rational use of the function of MATLAB to systematically study the determination of the weight in the adjustment of control network.A variety of objective weighting methods are...
One of the main characteristics of the future light sources like Elettra 2.0 is the small vacuum chamber cross section. In fact, the resistive-wall (RW) impedance due to the small vacuum chambers cross section enhances transverse coupled-bunch instabilities. In this study, the effect of the RW in the multi-bunch case is investigated versus chromaticity. The threshold currents in the presence...
The Superconducting Electron Accelerator Lab (SEALab)* is the SRF-accelerator physics research facility at HZB created in 2021 following official completion of the bERLinPro project. It provides opportunities for SRF-accelerator related research beyond the ERL program, yet ERL-related research continues in this facility (“bERLinPro@SEALab”).
The first stage of commissioning and operation...
The Electron-Ion Collider has an electron storage ring (ESR) and a hadron storage ring (HSR) with beams traveling in opposite directions that collide initially at one but eventually at two interaction points. Our desired machine configurations require a wide range of energies for both rings: 5 to 18 GeV in the ESR, and 41 to 275 GeV/u in the HSR. The range of velocities in the HSR requires...
Previous TDR studies for the SOLEIL II Upgrade project have converged towards a lattice alternating 7BA and 4BA HOA type cells providing a low natural horizontal emittance value in the 80 pm.rad range at an energy of 2.75 GeV. This lattice adapts to the current tunnel geometry as well as to preserve as much as possible the present beamline positions. The new TDR lattice is an evolution...
High-intensity, monochromatic X and 𝛾-rays are a powerful tool for applied science in all fields. Free-Electrons Lasers can generate soft X-rays. A magnetic undulator's shortest possible oscillation period is ~1 cm, which restricts the photon energy to hundreds of keV at GeV-range electron energies. Inverse Compton Scattering, which needs powerful lasers, may provide hard X-rays and...
SIS100 is a new superconducting heavy ion synchrotron optimized for the acceleration of high intensity heavy ion beams. Most crucial intensity limitation for heavy ion beams in SIS100 is the dynamic vacuum and corresponding beam loss by projectile ionization. Ionization loss and ion induced desorption drive the residual gas pressure into an instability, generating an intensity barrier at much...
Recently, we completed a performance upgrade of Test Lab klystron-modulator system for PLS-II RF Linac as well as new developed S-Band 80-MW klystron test. PLS-II main linac system are under an operation of 17 RF stations including S-Band 80-MW klystron. It will be used as a test station for a performance test of RF components for PLS-II RF Linac. Klystron as RF sources is one of critical...
In the Advanced Photon Source Upgrade storage ring, the horizontal collimators protect the rest of the machine from whole beam aborts; however, as shown in previous experiments, the collimators themselves must also be protected from the full intensity of the lost store. The suitability of a vertically-deflecting fan-out kicker was evaluated experimentally. Aborted beam strikes the surface of...
The CERN Linear Accelerator for Research (CLEAR) is a test facility delivering an electron beam in the 30-220 MeV energy range to a diverse user community. In 2022, several hardware and software upgrades were done to the main installation, and procedures and methods were developed to address specific user requirements, including a further extension of the beam parameter ranges. In the paper,...
The Electron-Ion Collider polarized pre-injector is designed to generate a 7 nC with eight bunches every second to inject into the Rapid Cycling Synchrotron. The pre-injector includes the polarized electron source, bunching section, traveling wave plate (TWP) LINAC, and longitudinal phase space manipulation. A compact zig-zag chicane, and dechirp cavity are used to rotate the bunch in...
The ultimate goal of studying spin-radial motion in a ring with "Quasi-Frozen Spin" is to develop a procedure for measuring the deuteron electric dipole moment. For a ring with a "Frozen Spin", the authors developed the Frequency Domain Method. A distinctive feature of a ring with a "Quasi-Frozen Spin" is spin oscillation with a small amplitude around the direction of motion. In this work, we...
The European Spallation Source neutrino Super Beam plus (ESSνSB+) project has recently been approved by the EU for a 4-year design study. It aims at measuring the neutrino-nucleus cross-section, which represents the dominant systematic uncertainty in the measurement, in the energy range of 0.2 – 0.6 GeV, as well as perform searches for sterile neutrinos using a Low Energy nuSTORM (LEnuSTORM)...
The Frascati linear accelerator was used as electron and positron source for the DAFNE collider and the Beam Test Facility (BTF) where the fixed target experiments as PADME or irradiation test for space components are ongoing.
Builded in 1996 an upgrade of the L-C traditional resonant charging system is started in 2018 and today 3 of the 4 RF power stations modulator are upgraded from the...
High Energy Photon Source is a 6 GeV diffraction-limited synchrotron light source currently under construction in Beijing. To provide the required 6 MV of RF voltage and 850 kW of beam power, five 166.6 MHz superconducting quarter-wave beta=1 cavities have been chosen for the fundamental RF system of the storage ring. Each cavity will be equipped with one fundamental power coupler (FPC)...
The IFMIF RFQ has to accelerate a D+ beam of 125 mA
from the source energy of 100 keV to its final energy of 5
MeV. For such a purpose, the needed RF power
(approximately 600 kW dissipated power and 600 kW beam
power) is injected in the RFQ from 8 amplifier chains with
8 coupling loops. In order to quantitatively understand the
different circumstances which can occur, an...
The Beijing Electron-Positron Collider II (BEPC-II) is a 1.89 GeV two-ring e+/e- collider. It consists of two superconducting (SC) cavities in the ring and the design of the cavity is the same as the ones used in HEPS (High Energy Photo source) storage ring. During operation of the SC cavities of BEPC-II, sideband close to 46 Hz and 100 Hz were found, which decreased the controlling accuracy...
Following a 3-year long shutdown for upgrade and consolidation work, the LHC was re-commissioned in spring 2022, achieving a new record of 6.8 TeV per beam. This paper will describe the beam commissioning phase, the electron cloud conditioning, and the intensity ramp-up bringing the machine to a steady production state. The main issues and achievements will be presented, including the fully...
The Elettra 2.0 upgrade project requires the realization of a new storage ring that will replace the existing one of Elettra. The Elettra 2.0 optic, developed on the basis of the magnet feasibility studies, include a total of 552 iron-dominated electro magnets, with all sextupoles and octupoles equipped with additional coils to achieve the combined fields of corrector and skew quadrupoles....
The existing post-stripper Drift Tube LINAC (DTL) of the GSI UNILAC will be replaced with the new Alvarez 2.0 DTL to serve within the injector chain for the Facility for Antiproton and Ion Research (FAIR). The 108.4 MHz Alvarez 2.0 DTL accelerates intense ion beams along five individual cavities with a total length of 55 meters from 1.36 MeV/u to 11.32 MeV/u. The design of the Alvarez 2.0 DTL...
A new linear induction accelerator named Scorpius is being designed for multi-pulse flash radiography. The solid-state pulsed power system offers a technological breakthrough by delivering multiple independent pulses to accommodate a wide variety of pulse formats. The design provides pulse modulation capabilities which will mitigate reflected waves and reduce voltage variations across a...
The Future Circular electron-positron Collider, FCC- ee, is designed for unprecedented precision for particle physics experiments from the Z-pole up to above the top-pair-threshold, corresponding to a beam energy range from 45.6 to 182.5 GeV. Performing collisions at various particle-physics resonances requires precise knowledge of the centre-of-mass energy (ECM) and collision boosts at all...
We present the latest development for the FCC-ee interaction region. It represents a major challenge for the FCC-ee collider, which has to achieve extremely high luminosity over a wide range of centre-of-mass energies. The FCC-ee will host two or four high-precision experiments. The machine parameters have to be well controlled and the design of the machine-detector-interface has to be...
Polarization control of undulator radiation attracts a great attention due to its application prospects in material and biology. Various undulators have been developed to obtain radiation of specific polarization states. In the electron storage ring light source, different methods have been proposed to realize a specific polarization switching. However, there is still a strong demanding to...
The Korea-4GSR with low emittance of 60 pm-rad provides the photon beam that is 100 times brighter and 100 times more coherent than PLS-II. Despite these powerful advantages, the new source imposes high power density on beamline optics. In particular, the first mirror M1 receiving broadband white beam will be directly affected. To check this, we calculated the power density by introducing a...
A new electron cooling experiment is being planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab for cooling ~2.5 MeV protons in the presence of intense space-charge. Electron cooling is integral to the study of beam dynamics and has valuable applications for producing high-intensity hadron beams in particle accelerators. For such goals, an electron lens to be placed in the IOTA...
Ionization cooling is the only suitable approach to reduce the phase space volume occupied by a muon beam on a timescale compatible with the muon lifetime. Small normalized transversal emittances can be achieved by using hydrogen (H) as an absorber and high solenoid fields at low beam energy. The strong focusing suppresses emittance growth due to scattering occurring from muon beam interaction...
The SuperKEKB accelerator is currently in operation in Tsukuba, Japan, with a planned long shutdown in 2026. Among the possible upgrades being considered during this period is the change to a polarized electron beam in the High Energy Ring. Such a change would require modifications in the source generation and transport, geometrical and lattice variations to provide spin rotation, and...
During the injection phase of the Higgs mode of CEPC, the stored energy of the cavity is low and beam loading is relatively high. The synchrotron radiation damping is weak compared to the growth rate of the untidamped mode. This will cause two types of trouble. Firstly, the transient beam loading caused phase-shift between the head and the tail of the beam will be too much. Secondly, the...
During the on-axis injection process under the Higgs model, the transient beam loading in the CEPC storage ring will cause a phase shift between the head and the tail of one beam. Since the missing bunches are only extracted from one of the beams at a time, there will be a misalignment between the colliding bunches at the IP. In this paper, we presented the results of the study on this...
Matched first order transition crossing in the Relativistic Heavy Ion Collider (RHIC) is performed by using two families of jump quadrupoles when ramping species through transition to storage energy. The jump quadrupole families control $\gamma$ transition and the working point of the accelerator by compensating for the tune shift from the jump and minimizing optical distortions. After...
We investigate the upgrade of Elettra 2.0 to radio-frequency transverse deflecting cavities generating a steady-state vertical deflection of selected electron bunches. The study demonstrates the feasibility of 1 to few ps-long x-ray pulses at MHz repetition rate provided simultaneously to several beamlines, and transparent to the standard multi-bunch operation. The short pulse exhibits total...
Transverse Resonant Island Buckets (TRIBs*) can be established by moving the horizontal tune close to a third order resonance. In this case the TRIBs correspond to a second stable orbit, longitudinally winding around the core orbit in the transverse x-x’-phasespace and closing after three revolutions. TRIBs provide many potential application possibilities ranging amongst others from simple...
The concept of Transverse Resonance Island Buckets (TRIBs) has recently gained attention in the storage ring light source community, and has found usage to, e.g., serve timing users and can enable fast polarity switching of the light in undulators.
This contribution introduces two options for creating TRIBs in SLS 2.0 using either 3Qx or 4Qx resonances. Options for control of the islands...
Inverse Compton Scattering (ICS) is an ideal source of tunable monochromatic gamma rays. These gammas have uses for Nuclear Resonance Fluorescence, and production of novel medical radioisotopes. The gamma energy can be tuned by changing the electron energy. An ICS source can be made quasi-monochromatic by using low energy spread electron and laser beams, and using a collimator.
Currently...
We report on experimental investigations of a single electron, circulating in the Fermilab IOTA storage ring, focusing on two-photon undulator emissions. We employ a Mach-Zehnder (MZ) interferometer for the undulator radiation to determine the photon coherence length as well as to measure its statistical properties. In this experiment, the pulse of radiation in one arm of the interferometer...
The performance requirements for next generation electron accelerators put ever increasing demand on the photocathode performance, where it fundamentally limits the achievable beam quality. Metal photocathodes are limited by their high work function and relatively low quantum efficiency, necessitating the use of high powered deep UV lasers. Metal oxide thin film interfaces have been shown to...
HZB is in the process of developing a concept for a successor to the BESSY II synchrotron facility. The new facility will build on the strengths developed in Berlin over the last twenty years in delivering flexibly polarised soft X-Rays to dozens of beamlines. The successor facility BESSY III is planned to operate at 2.5GeV, in comparison to the 1.7GeV operation of BESSY II. This makes it...
The codes UNDUMAG and WAVE have been developed at HZB/BESSY. They are used
intensively to design undulators, and to understand their magnetic and
synchrotron radiation properties, as well as their impact on the storage ring.
Recent extensions will be presented. A more intuitive input file to define
undulator geometry has been developed, as well as a Python based GUI that
allows the...
The studies and R&D on the high-intensity positron source for the FCC-ee have been initiated for a while. The positrons are produced by a 6 GeV electron drive-beam incident on a target-converter at 200 Hz. The drive beam comes in 2 bunches spaced by 25 ns with a maximum charge of ~5 nC per bunch. Two scenarios using conventional and hybrid targets are being studied for positron production....
This publication builds on previous studies that explore the use of MAD-X and SAD to simulate FCC-ee. In particular, we examine further optics properties as well as single particle tracking. Compared to previous iterations, this work also introduces a comparison to XSuite and discusses how the different codes fit in a cohesive FCC-ee strategy.
The Diamond-II storage ring lattice has continued to be developed after publication of the Diamond-II’s technical design report. This study provides the updated information needed for the commissioning simulation. Firstly, changes to the reference lattice and phase-one insertion devices are briefly described. Then the error specifications are amended to be consistent with the magnet...
Siam Photon Source (SPS) is an existing synchrotron light source in Thailand, which has been operated and provided synchrotron radiation for user beam service for more than 20 years. The SPS accelerator system con-sists of a 40-MeV linac, a 1.2-GeV booster synchrotron and a storage ring with double bend achromat (DBA) lattice. The linac is one of the most critical parts of the SPS machine in...
Located between the Delivery Ring and the Mu2e experiment in the Muon campus, the M4 beamline serves as the transport line for a resonantly extracted, 8kW, 8GeV pulsed proton beam to the Mu2e production target. In addition to challenges posed by elevation and directional changes, the M4 line is tasked with removing beam halo from resonant extraction and ensuring adequate inter-pulse beam...
A matching device with a strong magnetic field is used to capture positrons in the positron source of future e+e- colliders such as the Compact LInear Collider (CLIC) and the Future Circular Collider (FCC-ee). Compared to conventional matching devices such as flux concentrators, superconducting (SC) solenoids can have a much higher peak field, improving the capture efficiency and the positron...
V3Si is an A-15 SC that has a relatively higher Critical Temperature Tc (17 K), compared to niobium (Nb) and can maintain a higher critical field than Nb [1]. These properties would in theory allow thin film V3Si superconducting RF-accelerator (SRF) cavities to operate at higher temperatures and with greater accelerator voltages, compared to Niobium cavities. However, this would require the...
The main accelerator of WALS (Wuhan Advanced Light Source) is a 1.5 GeV, 180 m storage ring with emittance 222.8 pm.rad, which reaches soft X-Ray diffraction limit. To achieve such low emittance, the magnet system is designed very compact with very small aperture. And this results in a narrow transition structure and a low flow conductivity vacuum chamber. In consideration of the beam...
The future Electron-Ion Collider (EIC) adopts a horizontal crab crossing scheme to compensate for the geometric luminosity loss from a 25 mrad crossing angle. The crab cavity noise-induced emittance growth in the deflecting plane (horizontal for EIC) has been well studied and a feedback system is effective to suppress the growth. However, simulations also showed emittance growth in the...
The SuperKEKB accelerator, a 7 GeV electron and a 4 GeV positron double-ring collider, is in progress in order to explore the new physics beyond the standard model.
The next milestone is to obtain integrated luminosity of 15 /ab data in the next decade,
so that the luminosity should exceed 2 x 10^35 /cm^2/s in several years.
One of the essential issues is the injection performances for both...
Alongside the new LCLS-II facility, a new electron beamline known as Linac to End Station A (LESA) is under construction at SLAC. LESA will use field-emitted dark current from the new superconducting accelerator to search for MeV- to GeV-scale dark matter. To predict the behavior of the dark current in LESA, we must account for the effects of wakefields. In the conventional analysis of...
The material for this paper/poster has been merged with WEPL037:
Robust design of modern Chasman-Green lattices – a geometric control theory approach
In intraoperative radiation therapy (IORT), accelerators typically consist of two or more tubes to achieve adjusta-ble electron energy. To simplify the accelerator structure and meet the demand for convenient adjustment of elec-tron energy, we propose an X-band electron linear accel-erator for IORT, composed of 102 cavities. This accelera-tor can adjust the output electron energy over a large...
A method is described whereby any desired longitudinal electron bunch profile may be generated in a storage ring by tailoring the wake potential. The required wake function is found by implicitly solving the Haïssinski equation through the usage of a regularization parameter. For two coveted longitudinal profiles—a lengthened profile and a triangular profile—the required solutions are...
The main ring synchrotron (MR) of the Japan Proton Accelerator Research Complex (J-PARC) has provided high-intensity proton beams to the T2K long-baseline neutrino experiment, which requires high statistics to confirm the existence of CP violation. We plan to increase the beam power from 0.5 MW in 2021 operation to 1.3 MW by 2028 in the fast extraction mode of the MR. This upgrade supports...
We propose a novel method to suppress the emittance variation caused by the opening and closing of the gap of insertion devices (IDs) in extremely low emittance light source storage rings. The core idea is to leak a small amount of dispersion into the straight section where IDs are installed and optimize its value so that the radiation excitation and damping caused by IDs are balanced [1]. A...
A realistic laser assisted charge exchange (LACE) scheme for 1.3~GeV H- beam injection into the Ring for Spallation Neutron Source is under development. The design considered here is supposed to demonstrate the possibility of H$^-$ charge exchange injection into the SNS ring as an alternative to carbon foil stripping. A realistic stripping magnet design is considered as an integrated part of...
Measurements of the very long single bunch spectrum with RF off, were started in the SPS in 2012 to identify the main impedance sources responsible for both single and multi-bunch beam instabilities observed during operation. The impedance of the vacuum flanges with a strong peak at 1.4 GHz was identified and proven from simulations to limit the beam intensities required for the...
Recent storage ring experiments have demonstrated the power and the potential of laser cooling of bunched relativistic ion beams. Encouraged by this, the heavy-ion synchrotron SIS100 at FAIR (Darmstadt, Germany) will be equipped with a truly unique laser cooling facility. A sophisticated combination of 3 newly developed UV (257 nm) laser systems and modest rf-bunching will allow for fast...
In high intensity proton synchrotrons, space charges effects will cause tune shift of the beam. When the betatron tune spreads over a resonance line, the betatron oscillation amplitude will get larger, causing large beam loss. Through the quadrupolar beam transfer function, the coherent space-charge tune shift of quadrupolar beam oscillations can be derived with quadrupole oscillating...
The superconductive quarter wave cavities hadron Linac ALPI is the final acceleration stage at the Legnaro National Laboratories. It can accelerate heavy ions from carbon to uranium up to 10 MeV/u for nuclear and applied physics experiments. It is also planned to use it for re-acceleration of the radioactive ion beams for the SPES (Selective Production of Exotic Species) project. The linac...
Cylindrical corrugated waveguides (CWGs) for accelerators and light sources have actively been studied in the past decade theoretically and experimentally. CWGs with a planar geometry have been successfully employed to cancel linear energy correlation in the electron bunch and thus to enhance the performance of free electron lasers (FELs). Cylindrical CWG have been proposed as a passive...
The High-Luminosity LHC project aims at increasing the LHC luminosity by an order of magnitude, and support LHC operation till the early 2040s. This presentation will review the overall HL-LHC project status. Many HL-LHC achievements will be available for reporting by mid 2023, starting with the finalisation of the Civil Engineering and extending up to the triplet magnet prototype demonstration.
Dielectric wakefield acceleration (DWA) is a high gradient novel acceleration concept. To realise this concept for future high energy facilities, scalable models of the transverse and longitudinal beam dynamics from these wakefields must be created and experimentally verified. We present a summary of results from the recent experimental run at the CLARA facility. This study used both circular...
SuperKEKB is a positron-electron collider with a nano-beam scheme and continues to achieve the world’s highest luminosity for the production of B meson pairs. The luminosity performance has been improved by the adoption of the crab-waist scheme. The nano-beam scheme allows the vertical beta function at the interaction point (IP) to be much smaller than the bunch length. The vertical beta...
For the purpose of indirect search of dark matter, we designed laterally driven Dielectric Laser Acceleration (DLA) structure that achieves 1.2 MeV energy gain in 6 mm length together with 6D confinement. The design originated from a relativistic DLA structure and was supplemented with non-homogeneous shapes following the APF segments and optimized using a genetic algorithm together with the...
The environmental credential of future colliders are increasingly in the spotlight, because of their size and complexity, and will be under scrutiny for their impact on the climate. Therefore, sustainability has become a prioritized goal in the design, planning and implementation of future accelerators; approaches to improved sustainability range from overall system design, optimization of...
For the first time, photoemission of spin-polarized electron beams from gallium nitride (GaN) photocathodes are observed and characterized. The spin polarizations of the emitted electrons from epitaxially grown hexagonal and cubic GaN photocathodes activated to Negative Electron Affinity (NEA) via cesium deposition are measured in a retarding-field Mott polarimeter.
A novel technique, called a spin transparency mode, for preservation and control of electron and ion spin polarization in colliders and storage rings has been proposed. The beam polarization can then be fully controlled by small adjustments of the snake axis orientations and snake strengths. An experiment has been carried out recently to test the concept. One of the RHIC rings is set to be...
Superconducting undulators (SCUs) can produce higher photon flux and can cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length. The operational experience of SCUs in accelerators as well as future plans of deploying SCUs in free electron lasers, diffraction limited storage rings and compact light sources will be presented.
SASE studies in the sub-ångström regime, using optimized electron beams, are carried out at varied energy levels according to the present state of the facility, that is, a pulsed mode operating with a 10 Hz repetition 0.6 ms-long bunch train with beam energies between 14 GeV and 17.5 GeV. From simulations nearly Millijoule-level SASE intensity is obtained at a photon energy of 30 keV at 16.3...
Aberration correction electron optics and cold field-emission electron source made the transmission electron microscope (TEM) a popular tool to image atomic and nano-scale objects. Cryogenic electron microscopy (Cryo-EM) revolutionized the bio-structure science, and recently it is explored to investigate radiation-sensitive battery and energy materials. But non- physiological environments,...
Business association for large supplies
The company D-Beam Ltd was established in 2015 to capitalize on the beam diagnostics R&D carried out in the QUASAR Group at the University of Liverpool/Cockcroft Institute. The start-up was one of the first companies to join the STFC CERN Business Incubation Centre (BIC) at Sci-Tech Daresbury. D-Beam has since become the partner of choice in a number of national and European projects.
The...
FERMI is the seeded Free Electron Laser (FEL) user facility at Elettra laboratory in Trieste, operating in the VUV to soft X-rays spectral range. In order to extend the FEL spectral range to shorter wavelengths, an upgrade plan for increasing the Linac energy from 1.5 GeV to 2.0 GeV is actually going on. After the successful testing of the short prototype of the new high gradient (HG) S-band...
Spin-off company – the main challenges
Innovative approaches in procurement procedures
The Hard X-ray Self-seeding system at the European XFEL started to be available for user delivery in summer 2021. A large number of user requests of HXRSS showed the interest and the importance of longitudinally coherent X-ray FEL pulses with narrow bandwidth for different applications. In this paper, we will summarize user requirements, tuning procedures and performance we achieved during...
The Ion Beam Centre at Kurukshetra University is the first facility established by Department of Science and Technology, Govt. of India by funding and supporting Accelerator based research programs in university system. The facility has been providing accelerator-based research facilities to researchers of host university as well as researchers from all over India. The air insulated high...
A Structured Laser Beam (SLB) is a type of optical beam with spatially inhomogeneous 3D polarisation structures. Generating SLBs from vector beams allows the creation of Hollow Structured Laser Beams (HSLB) with a dark central core. In this way, atypical electric and magnetic field vectors, which are purely longitudinally polarized in the dark zones of the beam, are obtained. The SLB spatial...
A 1–2 GHz stochastic cooling system is being de-veloped to provide fast 3D cooling of hot secondary beams (antiprotons at 3 GeV and rare isotope ions at 740 MeV/u) at intensities up to 10^8 particles per cycle. For antiproton cooling, cryogenic plunging pick-up electrodes will be used to improve the ratio of Schott-ky signals to thermal noise. To cool hot rare isotope beams quickly, a...
The FLASH2020+ project will open up new excellent opportunities for science on the highest level. The FLASH facility will not only produce soft x-ray SASE photon beams at full MHz repetition rate in a burst mode in FLASH2, but will also provide in FLASH1 several thousand fully coherent pulses per second using the HGHG and EEHG external seeding schemes. New types of experiments are enabled by...
In order to promote the studies of low emittance RF photo cathode and high gradient accelerating structures, a C-band test platform has been initialized since late 2021. In this paper, an overview of the present status and future plans of this platform is given, including a 3.6-cell C-band RF photo cathode and a C-band RF traveling-wave accelerating structure. In addition, other on-going...
Terahertz (THz) radiation sources are increasingly significant for many scientific frontiers, while the generation of THz radiation with high-power at wide-tunable frequencies is still a limitation for most existing methods. In this paper, a compact accelerator-based light source is proposed to produce coherent THz radiation with high pulse energy and tunable frequency from 0.1 THz to 60 THz....
Purpose: In the effort to develop a compact dielectric wall accelerator (DWA) system for proton radiotherapy, this work aims to demonstrate the feasibility of a drift step recovery diode (DSRD) based pulse forming network (PFN) to generate high magnitude, nanosecond scale voltage pulses at high repetition rates.
Methods: An initial numerical feasibility study was conducted in order to...
The magnetic and mechanical designs of a force-neutral adjustable phase undulator (FNAPU) are pre-sented. The FNAPU combines two magnetic assemblies with equal periods, one with an undulator magnetic structure and one with a force compensation magnet structure. The latter is used to neutralize the magnetic force affecting the undulator magnetic structure and vice versa in all undulator phases....
A High Brightness Beams Test Facility has been recently funded at the INFN-LASA laboratory in Segrate (Milan- Italy). The Test Facility will allow to perform developments in ERL construction and design and to carry out experiments with the high current CW electron beam in frontier areas of accelerator physics. The Test Facility setup will comprise a high-performance laser driven DC Gun...
In this paper we report on the status and performance of a newly commissioned high brightness electron beamline at Tsinghua University. The beamline is dedicated to research on the physics and technologies of multi-MeV, low charge, high brightness electron beams, as well as applications including MeV ultrafast electron diffraction and imaging. The layout, simulation and measurement results of...
J-PARC has three accelerators, 400MeV linear accelerator (LINAC), 3GeV rapid cycling synchrotron (RCS), and 50GeV (currently 30GeV) main ring (MR), which are connected by beam transport lines. The proton beam is delivered from the RCS to muon and neutron targets in the materials and life science experimental facility (MLF) via a beam transport line called 3NBT. A pulsed bending magnet in the...
Angular dispersion-induced microbunching (ADM) scheme was proposed to generate high harmonic coherent radiation in the storage ring with weak energy modulation amplitude. However, it is still difficult to convert the external UV seed laser into the sub-nanometer wavelength. In this paper, we proposed a novel scheme based on ADM mechanism. By properly choosing the parameters, theory and one...
Regarding high current e+ sources, the almost universal usage of target-based production schemes combined with conventional capture technology has led to poor transmission efficiencies. This long-standing difficulty to handle the extreme e+ transverse emittance and energy spread has been a major impediment for future, high luminosity lepton collider designs. The PSI Positron Production...
X-ray free electron lasers, especially fully coherent femtosecond free-electron laser (FEL) pulses, are widely used in numerous fields. This study aims to propose a new principle for generating fully coherent femtosecond X-ray pulse based on the Shanghai soft X-ray Free Electron Laser User Facility (SXFEL-UF). The principle was based on fresh-slice technique. First of all, the electron beam...
Muons have been playing an important and unique role in both fundamental physics and applied sciences; Recent results of the muon magnetic anomaly hint at physics beyond the Standard Model; Muon spin rotation techniques have been widely applied to the study of superconductivity and magnetic materials. A typical muon experiment measurement time of 10 muon lifetimes means that an ideal muon...
In order for the new ATLAS Materials Irradiation Station (AMIS) to take advantage of the future multi-user capabilities at ATLAS, a pulsed kicker is needed to switch 1 MeV/u heavy-ion beams. At this energy and due to space limitations, a pulsed electric kicker is very challenging due to very high voltage requirement, and a magnetic kicker is also very challenging due to the high magnetic field...
The China Spallation Neutron Source (CSNS) is a large scientific facility for frontier research by using the medium energy protons bombardment of tungsten target to produce a large number of scattered neutrons. The rapid cycling synchrotron (RCS) adopts the single-turn fast extraction scheme to extract the proton beam with the energy of 1.6GeV, and the extraction repetition frequency is 25Hz....
The CERN Linear Electron Accelerator for Research (CLEAR) has been operating since 2017 as a user facility providing beams for various experiments. We created a start-to-end model of the CLEAR setup in RF-Track, aiming to optimise the CLEAR accelerator as a driver for an X-ray source based on inverse-Compton scattering. RF-Track, a CERN-developed particle tracking code, can simulate the...
In a subcritical assembly, heavy metals are used to generate additional photo-neutrons using high-energy electrons. One of the options for a neutron-generating target is a set of tungsten plates coated with tantalum. It is promising due to the high neutron yield upon irradiation with high-energy electrons.
The operating conditions of a tungsten target exposed to electron beams with an energy...
High gradient radio-frequency structures are of considerable interest in ongoing structure wakefield acceleration research. The prospect of economical accelerators with a small footprint in the sub-terahertz regime shows promise in achieving high gradient and high efficiency, and in that vein, we present a design for a metallic corrugated waveguide designed at 110 GHz. This W-band structure...
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped, and reaccelerated rare isotope beams, started operation in May 2022. Since then, five nuclear physics experiments have been successfully accomplished. The experiments with rare isotope beams typically last within 1-2 weeks. Each experiment requires a different primary beam and its...
The superconducting radio-frequency photoelectron injector (SRF photoinjector), now under commissioning at the SEALab accelerator test facility, has the potential to cover a fast area of beam parameters. Electron bunches from fs to ps length, with fC to nC charge can be accelerated to a couple of MeV beam energy. The legacy from the energy-recovery linac (ERL) test facility bERLinPro, the...
The spectro-temporal characteristics of free-electron laser (FEL) radiation emerging from external seeding schemes such as high-gain harmonic generation are shaped by the properties of the initial seed laser. Accurate control of the seed laser envelope and phase is essential to allow for precise manipulation of the FEL output. Based on experimental data obtained at the seeded FEL user facility...
Beam-driven plasma-wakefield acceleration has the potential to reduce the size and construction cost of large-scale accelerator facilities, by providing accelerating fields orders of magnitude greater than that of conventional accelerating structures. To keep the running costs affordable, high energy-transfer efficiency from the wall-plug to the accelerated bunch has to be demonstrated. For...
To complete the Italian In-Kind contribution to the ESS SRF Linac, we are working on the qualification of the last eight missing cavities. To achieve this, we are proceeding with reprocessing of not yet qualified cavities and, as a mitigation, we are constructing at the vendor four more cavities. In this paper, we report on the actual status of both of these activities with the most recent results.
The design and construction of continuous wave (cw) superconducting (sc) high intensity linacs is a crucial goal of worldwide accelerator technology development. The standalone sc cw heavy ion HElmholtz LInear ACcelerator (HELIAC) is a common project of GSI Helmholtz Centre for Heavy Ion Research and Helmholtz Institute Mainz (HIM) under key support of Goethe University Frankfurt (IAP). In...
The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim to produce multiply charged ion beams with low ripple, high stability and reproducibility, low maintenance. Due to its unique peculiarity, it is a suitable choice for medical applications, but also to nuclear-physics and material experiments.
Two AISHa sources have been realized...
The high Quantum Efficiency (QE) and low Mean Transverse Energy (MTE) of alkali antimonide photocathodes enable the production of bright electron beams for a variety of accelerator applications. Growing alkali antimonide photocathodes requires an elaborate growth chamber and an operator with considerable expertise. Moreover, their sensitivity to chemical poisoning requires storage in an...
A first beam dynamics and RF design of an Alvarez-type drift tube linac (DTL) has been defined in the framework of the EU project, HITRIplus. Its main application is to be exploited as a carbon (12C4+) and helium (4He2+) ion injector into a compact synchrotron for patient treatment. As a second implementation, helium particle acceleration with a higher duty cycle of 10% enables the possibility...
We describe active Q-switched X-ray regenerative amplifier FEL scheme to produce fully-coherent, high-brightness hard X-rays. In this scheme, a moderate energy chirp is introduced to the electron beams to shift the Free Electron Laser (FEL) radiation frequency outside the reflectivity bandwidth of the Bragg crystal. By actively controlling the chirp of the electron beam, the ratio of the...
A new type of accelerator called Harmonytron has been proposed. The Harmonytron is based on a scheme of vertical Fixed-Field Alternating gradient (vFFA) focusing with harmonic number jump beam acceleration. An electron model of vFFA accelerator is under development at Kyushu University. The current status of the vFFA accelerator will be discussed.
Energy matching between two hadron synchrotrons is the adjustment of the magnetic bending fields and beam momentum to obtain a correct transfer between the two. Conventionally, energy matching is achieved by turning off the RF system and measuring the revolution frequency of the de-bunching beam in the receiving accelerator. For an ideal circumference ratio, the orbits would then be centred in...
In October 2022, the UK XFEL project entered a new phase to explore how best to deliver the advanced XFEL capabilities identified in the project's Science Case. This phase includes developing a conceptual design for a unique new machine to fulfil the required capabilities and more. It also examines the possibility of investment opportunities at existing XFELs to deliver the same aims, and a...
The synchrotron SIS18 at GSI uses resonant extraction for slow beam extraction. Recently it was discovered that about 50% of the anode wires of the electrostatic extraction septum were broken during beam operation. In this paper, we present the analysis of the possible loss scenario that led to the anode wire damage and suggest machine protection measures to prevent future damage. The...
The self-seeded free-electron laser (FEL) is developing towards advanced FEL modes such as ultra-short pulse, multi-color and high intensity, and the influence of thermal loading instantaneously loaded on monochromatic elements will not be ignored. Therefore, it is necessary to quantitatively describe the changes in X-ray optical properties of crystals caused by transient thermal loading...
The ESS cavity operation is challenging due to long RF pulse, high gradient, high beam power and high demands for energy efficiency and availability. These require a better understanding of RF-cavity dynamics and insight into RF-cavity interaction. RF and cavity dynamics identification relies heavily on high precision measuring and characterizing basic cavity parameters (Ql, dynamic detuning,...
The development of high-power, attosecond methods at free-electron lasers has led to new possibilities in the probing and control of valence electron dynamics. Beyond simple observation of ultrafast processes, one of the longstanding goals of atomic physics is control of the electronic wavefunction on attosecond timescales. We present a scheme to generate sub-femtosecond pulse pairs from x-ray...
AWAKE is the first proof-of-concept proton-driven plasma wakefield acceleration experiment. AWAKE’s first phase concluded in 2018, with controlled acceleration of electrons to energies of 2 GeV in a 10-m long plasma cell. AWAKE’s second phase operates since 2021. It has been divided into four stages (Run 2a, Run 2b, Run 2c and Run 2d) to prove step by step good that the required electron beam...
High-energy proton bunches offer the potential to drive wakefields over very long distances in plasma. An externally-injected electron bunch can thus in principle experience very large energy gain (hundreds of GeVs to TeVs) in a single plasma with GeV/m accelerating gradient. AWAKE explores this potential with 400GeV proton bunches from the CERN SPS. Based on the succesful demonstration of...
A cavity based free-electron laser (CBXFEL) is a next generation X-ray source promising radiation with full three-dimensional coherence, nearly constant pulse to pulse stability and more than an order of magnitude higher spectral flux compared to SASE FELs. In this contribution, an R&D project for installation of a CBXFEL demonstrator experiment at the European XFEL facility is conceptually...
X-ray beams with orbital angular momentum (OAM) have emerged as a powerful tool for investigating matter. Traditional optical elements, such as spiral phase plates and zone plates, have been employed to generate OAM light. However, applying these elements in x-ray free-electron lasers (XFELs) remains challenging due to high impinging intensities and efficiency concerns. The self-seeded FEL...
ARES is an electron linear accelerator at the SINBAD facility at DESY. It aims to deliver reliable high-brightness beams with energy in the range of 100 to 150 MeV having fs to sub-fs bunch lengths. This is ideal for injection into novel high-gradient acceleration devices such as dielectric laser accelerators and laser-plasma accelerators which feature fields with fs to ps period. The ARES...
The High Energy Photon Source (HEPS) is a synchrotron radiation source of ultrahigh brightness being built in China. Its accelerator complex is composed of a 6-GeV storage ring, a full energy booster, a 500-MeV Linac, and three transfer lines. The Linac is an S-band normal conducting electron linear accelerator with available bunch charge from 0.5 nC up to about 10 nC. The Linac installation...
For the high power spallation neutron sources,
RUEDI is a proposed relativistic ultrafast electron diffraction and imaging facility for the UK. It will deliver single-shot time-resolved imaging with MeV electrons, as well as ultrafast electron diffraction at 10 fs timescales. The few-MeV-scale imaging and microscopy line aims to deliver high charge (up to 108 electrons), ultra-low emittance electron bunches to a 10µm sample with...
RUEDI is a proposed relativistic ultrafast electron diffraction and imaging facility. It will have two beamlines: a diffraction beamline and an imaging beamline. This proceeding discusses the beam dynamics design of the diffraction beamline. The diffraction beamline needs to have the best temporal resolution possible which requires short bunch length and minimal time of arrival jitter at the...
In the framework of a collaboration between Sapienza University of Rome, the Italian Institute for Nuclear Research (INFN) and the Curie Institute, the proposal of a new facility dedicated to the Very High Electron Energy (VHEE) FLASH irradiation is in progress. The aim is to exploit the promising VHEE regime for the translation of electron FLASH radiotherapy into clinical practice in order to...
A beam dynamics optimization study of an electron injector linear accelerator including an RF photoinjector gun was performed using MOGA (Multi-Objective Genetic Algorithm). To meet the requirements of electron beam characteristics at the linac end, the optimization goal was to minimize transverse beam emittance and energy spread. The transverse and longitudinal beam sizes were constrained to...
Neutrons are an essential tool for studying the structure and dynamics of matter. The High Brilliance neutron Source (HBS) project aims to develop a scalable Compact Accelerator-driven Neutron Source that will enable neutron fluxes at the corresponding instruments comparable to existing fission-based or spallation neutron sources. The full-scale HBS facility is characterized by the...
Beam intensities and powers being increasingly strong, installations increasingly large, the need to reduce losses and costs (i.e. dimensions) becomes essential. Improvements are possible by increasing the acceptance in the two transverse planes. For example for LEBT lines and radioactive beams, a large geometric acceptance allows efficient transport of reaction products that have large phase...
The injectors for the LHC at CERN underwent a major upgrade during a recent two-year long shutdown in the framework of the LHC Injectors Upgrade (LIU) project. Following this upgrade, the Proton Synchrotron (PS) was restarted in 2021, with the same beam quality as before the upgrade quickly achieved or surpassed. This contribution details the current beam performance for fixed-target and...
The ALBA and BESSY II Linacs consist of a thermionic Pierce-type electron gun that delivers e- at 90 keV in pulses of 1 ns with a maximum charge of 0.25 nC/bunch. The gun is followed by a set of standing wave bunching cavities and traveling wave accelerating structures to further increase the beam energy, up to 50 MeV at BESSY II and up to 100 MeV at ALBA, while keeping the energy spread below...
The RAON accelerator has been constructed for various fields of science programs since 2011. The installation of the low-energy superconducting accelerator section (SCL3) had finished at the end of 2021, and the cooling of the cryogenics system started in early 2022. Prior to the SCL3, the beam commissioning has been carried out at the injector section of the RAON accelerator since 2020, and...
The new generation BNCT facilities require the management of high intensity proton beams (tens of mA). As a matter of fact, the total beam power can easily overcome hundreds of kW. Consequently, it is not only important to keep under control the losses but also to manipulate the beam distribution to decrease the power deposited along the accelerator and on the target. In this paper we will...
Plasma wakefields can produce broadband electron spectrums that can mirror the characteristics of the electron fluxes that exist in the planetary radiation belts. The SAMURAI RF facility which is currently being constructed and commissioned at UCLA, will be capable of producing beams with 100s pC of charge with bunch lengths in the 100s of fs range with low transverse emittances in the 3-80...
HPSim, the GPU-powered multi-particle simulation code developed for LANSCE, can provide critical 6-D beam distributions in near real-time to LANSCE user facilities. We will present the benchmarking results for HPSim to the LANSCE linac and our effort to provide a real-time distribution to the Isotope Production Facility.
Resonant slow extraction is a beam extraction method which provides a continuous spill over a longer duration than can be achieved with fast single-turn or non-resonant multi-turn extraction. By using transverse excitation to drive the circulating particles onto the resonance, a beam can be delivered to stationary target experiments which require low intensity, long-duration beams.
In order...
We present the conceptual design of a compact light source named BriXSinO. BriXSinO was born as a demonstrator of the Marix project, but contains also a dual high flux radiation source Inverse Compton Source (ICS) of X-ray and a Free-Electron Laser Oscillator of THz spectral range radiation conceived for medica applications and general applied research. The accelerator is a push-pull CW-SC...
In the first prototype of the AXSIS light source, electrons sourced from a 55 keV DC gun are first compressed by a THz-powered buncher, then accelerated in a THz-driven “booster” to 430 keV kinetic energy and finally accelerated to 20 MeV in a THz-powered LINAC. Guided by simulations, a booster prototype was developed employing three layer segmented structures and requires 400-µJ single-cycle...
The HL-LHC project covers the upgrade of the LHC, aiming at collecting an integrated luminosity of 3000 fb-1 equal to a 10-fold increase of the nominal LHC performance. Approved in 2016 for a 950 MCHF budget, the project is shaped by 19 work-packages, covering all expertise areas, from beam dynamics to technical infrastructures. A truly international effort is deployed, where 38 institutes...
The PolFEL free electron laser project comprises 185 MeV cw-linac furnished with ASG electron gun and 4 Rossendorf-like cryomodules. The beam diagnostics system, besides bringing the beam to undulators, inverse Compton scattering interaction point, and finally to the dump, system is dedicated to metallic superconducting photocathodes development, in particular to gun performance...
We present our 1.6-cell radiofrequency cavity design for a photoinjector under development for producing intense electron bunches with 250-pC beam charge and normalized emittance below 100 nm rad for cryogenic temperature operation. The cavity cell profile was designed by SLAC and UCLA, optimized for maximal shunt impedance and minimal peak magnitude of the electric and magnetic field. The...
Laser-wake field accelerators (LWFAs) are potential candidates to produce intense relativistic electron beams to drive compact free electron lasers (FELs) in VUV and X-ray regions. In High-Field Physics and Ultrafast Technology Laboratory at National Central University (NCU), an LWFA is being developed to produce a 250 MeV high-brightness electron beam by their 100-TW laser system. An FEL...
FEL oscillators can produce few-cycle optical pulses with a high-extraction efficiency when the oscillators are operated in the superradiant regime*. Such FEL oscillators are unique light sources to explore intense light field science, especially in mid-infrared and longwave infrared where ultrashort pulses are difficult to produce from conventional lasers. Since the laser-matter interaction...
The heavy ion synchrotron SIS100 is the flagship accelerator of the Facility for Antiproton and Ion Research (FAIR) currently under construction at GSI, Darmstadt. It will provide high intensity beams of particles ranging from protons to uranium ions at beam rigidities up to 100 Tm. Part of the machine protection system is an emergency beam dump that is partly inside the vacuum system and...
The generation of high--brightness electron beams is a crucial area of particle accelerator research and development. Photocathodes which offer high levels of quantum efficiency when illuminated at visible wavelengths are attractive as the drive laser technology is greatly simplified. The higher laser power levels available at longer wavelengths create headroom allowing use of manipulation...
Novel particle accelerators based on plasma technology allow a drastic reduction in size, due to the high accelerating field established inside plasmas, which are created and confined by specific devices. Plasma Wakefield Acceleration experiments are performed at the SPARC_LAB test facility (Laboratori Nazionali di Frascati - INFN) by using gas-filled capillaries, in which the plasma formation...
Xi’an 200 MeV proton application facility (XiPAF) upgrading project is now in the design phase. For the synchrotron of the project, the influence of the dipole and quadrupole errors on the closed-orbit distortion(COD) is a matter we must pay attention to. However, Before the synchrotron assembly is complete, we do not know the actual errors of magnets. So we set certain distribution for...
Variable polarization is a required feature of light sources employed to investigate the properties of matter. The possibility to select light polarization is, in particular, attractive for those experiments, which aim at exploring the local symmetry of the sample under scrutiny, e.g., the chirality of a molecule, or the presence of a net atomic magnetic moment. Moreover, several...
During the third operational run of the Large Hadron Collider at CERN, starting in 2022, the beam energy was increased to 6.8 TeV and the bunch population is planned to be pushed to unprecedented levels. Already in the first year of operation, beam stored energies up to 400 MJ were achieved. An improvement in cleaning performance of the LHC collimation system is hence required. In this paper...
A 70 MeV H- cyclotron system has been installed at the Institute for Basic Science (IBS) from Nov. 2021 as a driver for ISOL system. Internal beam was first accelerated in May 2022 and utilized to highly isochronize the magnetic field using Smith-Garren method. In June, a beam of 70 MeV was extracted to two beam lines and beam emittance was measured by variations of quadrupole strengths and...
LCLSII 1-MeV CW electron source was successfully commissioned 2018-2020. 100MeV injector system is being commissioned since summer 2022. CW RF operations for injector system is routinely established and e-beam is being ramped to very high rate. Ultra-low emittance has been achieved for desired charges. Dark current along the injector beam line is systematically characterized and mitigations...
The Offline 2 mass separator laboratory is part of the CERN-ISOLDE Offline facilities - a suite of installations required to perform essential quality control on target and ion source units before irradiation at CERN-ISOLDE. The facility is also used for offline studies as a prerequisite before conducting any beam development on-line, especially establishing systematic effects. The Offline 2...
Dalian Coherent Light Source (DCLS) is an extreme ultraviolet free-electron laser (FEL). The measurement of the longitudinal phase space (LPS) of electron bunch is vital to a FEL facility. In order to measure the LPS, a S-band RF transverse deflecting cavity (TDS) has been installed and commissioned at DCLS facility. This paper will introduce the TDS physical layout and commissioning results...
Phase shifter collocated with undulator is an efficient way to enhance lasing of free-electron laser
(FEL), especially for seeded FEL. Dalian Coherent Light Source (DCLS) is a seeded FEL operating on
high-gain harmonic-generation (HGHG) mode. In order to achieve highly performance of FEL
lasing, five phase shifters are interspersed between six undulators. This paper will present...
The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)^7Be reaction with a 2 MeV proton beam. Recent comissioning efforts showed succesful proton beam operation at the targeted RFQ injection energy of 60 keV up until the point of RFQ injection. The RFQ was retrofitted with new electrodes for the injection energy of 60 keV. We report on the...
The Rare isotope Accelerator Complex for ON-line experiments (RAON) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from hydrogen (proton) to uranium. Protons and uranium ions are accelerated up to 600 MeV and 200 MeV/u respectively. It can provide various rare isotope beams which are produced by...
Due to the limitations of Laser Produced Plasma (LPP) Extreme Ultraviolet(EUV) sources, semiconductor industry is seeking the next generation EUV source for sub-nm scale lithography processes. Various accelerator-based light sources have been already proposed as EUV lithography light sources. We investigated the design of a compact high-power EUV light source using laser Compton scattering....
In AXSIS project, we are developing compact, THz-based electron accelerators, which represent a promising technology for the development of next-generation compact electron accelerators that significantly downsize x-ray sources. A key aspect in such a design is transport and focusing of an electron bunch accelerated to 20 MeV kinetic energy to inverse-Compton scattering (ICS) like interaction...
Recent demonstrations of terahertz (THz) powered accelerators and beam manipulators have opened a pathway towards miniaturized accelerators that promise to enable new science due to unique features such as reduced timing-jitter and reduced space-charge broadening of the electron bunches. Here, we present on the development of a matchbox sized multi-layered accelerator structure powered by a...
In the frame of ongoing initiatives for the design of a new generation of synchrotron-based accelerators for cancer therapy with ion beams, an analysis of linac designs has been started, to address a critical element with strong impact on performance and cost of the accelerator. The goal is to identify alternatives at lower cost and similar or possibly smaller footprint than the standard 217...
The beam optics in the SNS normal conducting linac is analyzed for the 1.4 MW beam-on-target operation settings. The first section is a room temperature copper linac which include Medium Energy Beam Transport (MEBT) section with four re-bunching radio-frequency (RF) cavities, Drift Tube Linac (DTL), and Coupled Cavity Linac (CCL). The Radio Frequency (RF) cavities in this section accelerate H-...
The electron source is a critical component of the RUEDI (Relativistic Ultrafast Electron Diffraction & Imaging) facility, which needs to provide beam to match the re-quirements for performing both electron microscopy and ultrafast electron diffraction. To meet these demands, different operational modes are needed, to deliver ultra-short, ultra-bright and highly temporally and energy stable...
The IFMIF-DONES facility (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is currently under design and being prepared for the construction phase within the framework of a EUROfusion Consortium work package. Its location will be in Escúzar, Granada and it will be the largest science and technology infrastructure project developed in Spain. Its objective is...
The SPES RFQ is designed in order to accelerate beams
in CW with A/q ratios from 3 to 7 from the Charge Breeder
through the MRMS and the selection and injection lines up
to the MEBT (Medium Energy Beam Transport). The RFQ
is composed of 6 modules about 1.2 m long each, made of a Stainless Steel Tank and
four OFE Copper Electrodes. A copper layer is plated on
the tank inner surface and a...
Laser wakefield acceleration (LWFA) using metal targets has been developed for high-vacuum and high-repetition rate operations compare to the gas targets[1-2]. However, the ionization effect due to high intensity fs laser should be considered as propagating through the plasma and the difference of LWFA mechanisms between aluminum plasma and helium plasma has been investigated with the...
The demand for muon facilities has been continuously increasing since surface muons play a significant role in particle and solid-state physics. The installation of a refurbished muon target station and two new High-Intensity Muon Beam lines (HIMB) in the framework of the Isotope and Muon Production using Advanced Cyclotron and Target technology project (IMPACT) at PSI will pave the way to...
The Isotope and Muon Production using Advanced Cyclotron and Target technology (IMPACT) project at the Paul Scherrer Institut aims to produce and fully exploit unprecedented quantities of muons and radionuclides for further progress in particle physics, material science and life science. The proposed Targeted Alpha Tumor Therapy and Other Oncological Solutions (TATTOOS) facility will provide,...
During the last run, the CLARA accelerator ran with a 2.5 cell 10 Hz S-band RF gun which had a modified back plate to allow the use of INFN-style photocathode pucks. Previously this gun had used a solid wall back plate that also acted as the photocathode*.
This presentation describes the different photocathodes that were used during the run and the various methods employed to prepare them...
Surface nanostructuring is a promising approach when it comes to improving the quantum efficiency (QE) of materials for electron accelerator purposes at CERN. This is due to the plasmonic effect taking place in metallic materials at the nanoscale, when an electromagnetic wave interacts with a sub-wavelength feature. Ultrafast laser surface nanopatterning can be an efficient and times saving...
Alkali antimonide photocathodes are promising candidates for many high-brightness electron sources due to their low-emittance and high quantum efficiency. However, these materials require ultra-high vacuum (UHV) storage and transport to avoid oxidation, which affects their performance. In this proceeding, we report the synthesis of cesium antimonide cathodes with different stoichiometric...
The so-called “green photocathodes”, based on alkali antimonide compounds, are characterized by high efficiency at green light wavelengths (1-10% at 500-550 nm) and excellent charge lifetime, but are easily poisoned in poor vacuum and are usually grown in form of disordered polycrystalline layers. Surface disorder is an extrinsic factor significantly contributing to reduce the transverse beam...
The compact ERL has been built as a test machine of energy recovery linac (ERL) at KEK in 2013. It has been succeeded to operate with 1 mA beam current with energy recovery mode in 2016. Recently, two undulators have been integrated into it to produce an infrared free-electron laser (FEL) light and the light amplification has been successfully observed with a burst mode and without energy...
Abstract: Electron Cyclotron Resonance Accelerator (eCRA) simulation results are presented for realistic TE111 cavity geometry and finite space-charge beams that confirm the single-particle idealized solutions. The simulations include cavity openings for RF inputs, beam injection, and pumping; RF input couplings that maximize efficiency; a thin window for exit of the accelerated beam;...
In high-gradient accelerator structures, field emission produces dark current that behaves much differently than the main photobeam current. This dark current can damage accelerator components and increase the radiation dose in the surrounding area. Thus it is important to analyze its behavior when designing a new accelerator or subsystem, such as the superconducting low-emittance injector...
An electron beam test stand was designed and constructed at CERN, under the umbrella of the Hi-Lumi project, to tests components for the Hollow Electron Lens (HEL), and in collaboration with the ARIES project for testing the Space Charge Compensation gun. The test facility features normal conductive magnets providing solenoid fields of the order of fractions of Tesla, beam diagnostics...
The Southern European Thomson back-scattering source for Applied Research (STAR) project, based on a collaboration among University of Calabria (UniCal), CNISM, INFN and Sincrotrone Trieste, has the goal to install and test at UniCal a short linear accelerator for high brightness electron beams that will drive a unique advanced X-ray Thomson source. In 2021 INFN was committed to install, test...
Dielectric wakefield acceleration (DWA) is a promising approach to particle acceleration, offering high gradients and compact sizes. However, beam instabilities can limit its effectiveness. In this work, we present the result of a DWA design that uses alternating gradients to counteract quadrupole-mode induced instabilities in the drive beam. Through simulation and experimental results, we...
We report our recent results on the project (XLO) to build, characterize and operate a population inversion x-ray laser at the copper $K{\alpha_1}$ line, using LCLS x-ray pulses as a pump. The results include: gain measurement; design, alignment and focusing elements for the optical bow-tie cavity; copper target measurement of damage caused by the pump pulses; development of a fast system to...
A planned experiment at the Argonne Wakefield Accelerator (AWA) facility will demonstrate the plasma photocathode concept, wherein precise laser-based ionization of neutral gas within the wakefield driven by a relativistic particle beam generates a high brightness witness beam, which is accelerated in the wakefield. Replacing the plasma wakefield acceleration component with a dielectric...
The Japan Atomic Energy Agency (JAEA) is designing a 30 MW continuous wave (cw) superconducting proton linear accelerator (linac) for the Accelerator Driven Subcritical System (ADS) proposal. The JAEA-ADS linac's source must provide a proton beam over 20 mA with an energy of 35 keV and a normalized rms emittance of less than 0.1 π mm mrad. As the extraction system determines the beam...
Structure-based wakefield acceleration with nanosecond-long RF pulses is a promising advanced accelerator concept to mitigate the risks of RF breakdown. Advanced structures are required to satisfy the need of a high transient gradient with a short pulse length. A metamaterial (MTM) structure, as a subwavelength periodic structure exhibiting a negative group velocity, could have a higher shunt...
Accelerators operating in the mm-wave regime can reach much higher gradients than conventional accelerators due to the favorable scaling of the breakdown threshold with frequency. These structures also have the potential to achieve a much higher shunt impedance, enabling the efficient use of RF power that is critical given the current limitations on high power RF sources in this regime. We...
The energy contained in the LHC's two beams must be safely absorbed in external beam dumps (TDE). High Luminosity (HL) is a future upgrade which will increase this stored energy to 700 MJ, compared to 150 MJ in Run 1. The TDE design has changed little since Run 1; it is a cylindrical stainless-steel vessel with a core made of graphite. During long shutdown 2 (LS2), upgrades were made to the...
The High Intensity and Energy ISOLDE facility (HIE-ISOLDE) at CERN has unprecedentedly expanded the research capabilities to investigate the structure of the atomic nucleus and the nuclear interaction. In this context, to meet the high-resolution mass spectroscopy required by the HIE-ISOLDE physics program, an innovative spectrometer is currently being designed, the ISOLDE Superconducting...
The generation of electron sources by high gradient laser wakefield acceleration (LWFA) has already demonstrated its feasibility. This acceleration technique is on the way to be implemented for practical uses by well-defined user communities. However, obtaining the required outstanding high-quality beams is a difficult challenge. Several key parameters, such as the laser distribution...
For the Linac travelling wave S-band injector at ELSA a new electron gun is being designed, to enhance the beam parameters of the old gun. Furthermore, a new single bunch injection mode is to be realized alongside the standard long pulse (multi bunch) mode, allowing to use the gun for normal operation for the experimental program as well as enabling single bunch operations for accelerator...
RI Research Instruments (RI) in partnership with The Canadian Light Source (CLS) have designed a new 250 MeV electron linac to inject into the 0.25-2.9 GeV booster synchrotron. The RF frequency is 3000.24 MHz, the sixth harmonic of the 500.04 MHz booster and storage ring RF cavity frequency, and the main accelerating sections consists of three 5 m constant gradient accelerating structures. The...
The quarter wave resonator (QWR, a.k.a. λ/4 resonator) for the new ISIS MEBT is a bunching cavity that longitudinally compresses the H- beam into smaller bunches. It has 2 gaps with a distance of βλ/2 between mid-gaps, and works in π mode at the resonant frequency of 202.5 MHz, with a phase angle of -90 degrees. The maximum voltage per gap (E0L) is set to 55 kV. A detailed RF model has been...
Chopper systems are typically used to provide beam time structure and ensure the safety of accelerator operations by deflecting the beam away. The reliability of conventional chopper is entirely based on high-voltage (HV) pulsed power supplies, and when it fails to charge the electrostatic deflection plate, the beam cannot be cut off and will enters the downstream accelerator. To meet the...
The electrostatic chopper for the new ISIS medium-energy beam transport (MEBT) is a fast deflecting device to create gaps in the beam coming out of the RFQ, which will improve the trapping efficiency when injecting the beam into the ISIS synchrotron. Due to the stabilization time required by the ion source, it is expected that the first 100 μs of the 400 μs pulse need to be removed in order to...
Proton FLASH, which combines the advantages of a better spatial dose distribution of protons with the unique temporal effect of FLASH radiotherapy, is currently a hot topic of international research. Proton FLASH radiotherapy is technically demanding and currently lacks equipment support. There are only a few devices that have been modified to achieve small target section, fixed-energy...
This poster will describe the design of the photocathode plug for CARIE. Photocathodes are used to produce beams for a variety of accelerator applications, including colliders, UED, and FELs. Thin film semiconductors offer ways to increase QE, reduce MTE, and increase beam brightness, but are very sensitive to chemical contamination and have never been tested under high gradients or...
X-band high gradient accelerating technology is a challenging and important technology in advanced electron linear accelerator facilities. The X-band accelerating structure can provide harmonic compensation to eliminate non-linear energy spread and realize linear compression of bunch in linac. In this paper, a special X-band traveling-wave accelerating structure is designed for linearizer,...
The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole Moment) of elementary charged particles. A permanent EDM of a subatomic particle violates time reversal and parity symmetry at the same time and would be, with the currently achievable experimental accuracy, an indication for further CP violation than established in the Standard Model.
The...
A novel 704.4 MHz CH structure is under develop-ment. Due to its relatively small spatial dimensions (22 cm in diameter and 33.7 cm in length), the additive manufacturing (AM) technology is an attractive choice for the construction. For a proof of concept, a simplified model with one stem, one drift tube, and a small part of another stem was printed with copper. This structure was also...
We have been developing a backside laser-heated thermionic electron gun with a tripolar tube structure for a compact electron accelerator driven neutron source. A lanthanum hexaboride (LaB6) emitter is heated by irradiating a near-infrared laser light transported by an optical fiber to the back of it in this electron gun even though there was no heater wire. The LaB6 electron source with a...
Ultrafast electron diffraction (UED) is a powerful tool for the direct visualization of structural dynamic process-es in matter on atomic length and time scales. Observa-tions on a femtosecond time scale with atomic resolution spatially have long been a goal in science and are current-ly achieved with large photo injectors developed for FEL frontends. Here we demonstrate a compact 180 keV...
Two new eddy-current-type septum magnets were installed at the fast extraction section of J-PARC main ring in April 2022. Eddy septum magnets (EDDYs) are energized pulse currents; thus, it is necessary to consider the possibility of misfires. Based on simulation results, if one of the EDDY misfires, the extraction beam will be irradiated to the ducts of the superconducting magnets (SCs) on the...
Non-destructive beam diagnostics as well as experiments and light sources that have a low impact on the beam are important for the operation and applications of an Energy-Recovery LINAC (ERL). Compton backscattering can provide a quasi-monochromatic highly polarized X-ray or gamma-ray beam without strongly affecting the electron beam due to the small cross- section of the Compton scattering....
Spin is one of the intrinsic properties of particles. However, there are many incomprehensible problems about it. High energy polarized electron-ion collisions will provide unprecedented conditions for the study of spin physics and lead us to the study on the inner structure of matter and fundamental laws of interactions, and other forefronts of natural science. As the Phase II of the HIAF...
An ultrahigh dose rate (UHDR) MV-level X-ray radiation platform for FLASH radiotherapy (RT) research based on a normal conducting linear accelerator is presented in this work. A S-band backward traveling-wave linear accelerator powered by a commercial klystron produces electron beams with 11 MeV energy, 300 mA pulse current, and 2.6 mA mean current at 0.88% beam duty ratio. The radiation...
Short bunch electron beam from linear accelerators can produce broad band and Carrier Envelope Phase fixed coherent radiation in THz spectrum range via various schemes, such as Coherent Synchrotron Radiation and Coherent Transition/Diffraction Radiation. Especially in the high-repetition (or multi-bunch) linac, a CEP-fixed mono-cycle THz pulse train will be available. In order to realize a...
A ultra-low emittance electron source utilizing laser-cooled neutral gas as the photo-ionization source has been developed in several laboratories in the accelerator community. We have started the development aiming for using the electron source for the injector of a THz accelerator which has a small aperture and requires a high quality beam.
As the first stage of the development work, we...
Tokyo Institute of Technology is planning a linac facility to produce 211 astatine, an isotope for αemitter cancer therapy. To produce astatine, we aim to bombard a bismuth target with helium ion beam of sufficient intensity at 28 MeV. Unlike a cyclotron, this facility will be able to accelerate a milliampere class high intensity helium ion beam. In addition, the subsequent accelerator...
Polarized beam is an effective tool in basic research. An Electron-ion collider in China (EicC)*, as a future high energy nuclear physics project, has been proposed. Eicc can provide good research conditions for precision measurements of the partonic structure of nucleon or nuclei and the study on the interactions between nucleons and so on. High quality polarized beam is helpful to the...
The proposed Targeted Alpha Tumor Therapy and Other Oncological Solutions (TATTOOS) facility at the Paul Scherrer Institute aims to produce radionuclides, especially alpha-emitters, via proton-induced spallation for potential clinical studies of advanced cancer treatments. This new 100 microA / 590 MeV proton beamline delivers in the best-case scenario 26 kW to the target.
In this study, a...
The natural time scale of quantum mechanical motion of electrons in molecules is usually on the order of hundreds of attoseconds. Probing time-dependent dynamics with atomic-site specificity on such timescales requires the generation of soft X-ray attosecond pulses pairs with variable delay and synchronization down to the sub-femtosecond level. We report the generation of GW-level attosecond...
Beam uniformity is an important factor that must be considered in slow extraction optimization, and the tune ripple caused by the power supply ripple is an important factor
that causes beam uniformity to deteriorate. In this study, based on the beam excitation concept for two regions (extraction and diffusion regions), a differential equation of
beam spill under the influence of a mono...
Linear induction accelerators such as the DARHT at Los Alamos National Laboratory are used as sources for flash x-ray diagnosis of dynamic events. The source characteristics of primary interest are the source intensity, the source spot-size, and the illumination uniformity which are determined by the electron beam parameters. We utilize self-developing x-ray film to characterize the x-ray...
Background and aim: The potential of a compact, laser-based ion accelerator for radiobiological and medical applications relies heavily on the control of the laser-target source and on the use of custom beam transport and delivery to the final target. Here we show the results of an experimental campaign dedicated to the dosimetry of the beam at the crosswire and the first radiobiological...
Solid-state plasma wakefield acceleration might be an alternative to accelerate particles with ultra-high accelerating gradients, in the order of TV/m.
In addition, due to their thermodynamic properties, 2D carbon-based materials, such as graphene layers and/or carbon nanotubes (CNT) are good candidates to be used as the media to sustain such ultra-high gradients. In particular, due to...
Vertical orbit excursion Fixed Field Accelerators (vFFAs) feature highly non-linear magnetic fields and strong transverse motion coupling. The detailed study of their Dynamic Aperture (DA) requires computation codes allowing long-term tracking and advanced analysis tools to take the transverse motion linear and non-linear coupling into account. This coupling completely transforms the beam...
Following the successful Run 1 experiment, AWAKE has developed a program for Run2 that requires designing and implementing a compact electron source (150 MeV, >= 100 pC) for external injection. The baseline design uses a S- and X-band RF photo-injector gun system. The project EARLI investigates the feasibility of an alternative electron source system using a laser wakefield accelerator (LWFA)...
High temperature superconductor REBCO has the property of maintain a high critical current density under strong external magnetic field, which makes a promising material for electromagnets in cyclotron and ECR ion source. Therefore, an ECR ion source using iron-less REBCO coils as electromagnet is under development in Research Center for Nuclear Physics (RCNP), Osaka University. A coil system...
Several concepts for future linear colliders are dependent on very high gradient normal conducting RF cavities achieved by operation at cryogenic temperatures in order to reduce breakdown rates (BDR). These maximum fields are intended to be in excess of 200 MV/m. The concepts include the ultra compact Xray free electron laser and the C$^3$ collider. The theory involved with the complex physics...
Plasma accelerators can sustain accelerating gradients of up to ~100 GeV/m.
However, reaching the high energies required for future particle colliders requires the acceleration to be performed in multiple plasma stages.
Solving the challenges posed by multistage acceleration, such a beam quality preservation, requires the capability of simulating large chains of accelerating stages,...
In this paper, we present the benchmark results of Bmad space charge tracking on the Electron-Ion Collider cooler injector lattice. Bmad, GPT, and Impact-T are compared in terms of accuracy and performance. We highlight the importance of space charge algorithm and demonstrate that the adaptive step size control improves the performance of Bmad space charge tracking.
The 800-MeV proton linac at the Los Alamos Neutron Science Center (LANSCE) includes a drift-tube linac, which brings the beam to 100 MeV, followed by a coupled-cavity linac (CCL) consisting of 44 modules. Each CCL module contains multiple tanks, and it is fed by a single 805-MHz klystron. CCL tanks are multi-cell blocks of identical re-entrant side-coupled cavities, which are followed by...
The interest in plasma-based accelerators as drivers of user facilities is growing worldwide thanks to their compactness and reduced costs. The EuPRAXIA@SPARC_LAB collaboration is preparing a technical design report for a multi-GeV plasma-based accelerator with outstanding electron beam quality to pilot an X-ray FEL, the most demanding in terms of beam brightness. The beam dynamics has been...
Ultrafast electron probing techniques offer unique experimental tools for investigating the structural dynamics of ultrafast photo-induced processes in molecular and condensed phase systems. In this work, we propose using the SEALAB Photoinjector's exceptional and versatile electron beam parameters to develop a state-of-the-art facility for ultrafast electron diffraction and imaging (UED and...
Laser-generated terahertz frequency pulses have been used to manipulate the phase-space of electron beams at the CLARA test facility.
Acceleration gradients of 20 MeV.m$^{-1}$ were achieved in dielectric lined waveguides with narrow-band 400 GHz sources with MW peak powers, and with bunch charge from 2pC to 100pC.
The high-frequency of the acceleration field provided an extremely fast...
An Inverse Compton Scattering (ICS) X-ray source is under development at the ELSA electron RF linac of CEA DIF. The X-rays are emitted by the interaction of a 30-MeV electron bunch with a visible (532nm) or infrared (1064nm) Nd:YAG laser pulse. The radiation spectrum lies in a 10-100 keV range. The electron bunches duration is 30 ps after compression in double-alpha magnets. In such a system,...
Blow-out beam generation is an established method to generate uniformly-filled ellipsoidal electron bunches by illuminating the cathode by an ultrashort laser pulse having a parabolic-like transverse profile of laser intensity. A theoretical study of blow-out generation in an APEX-like ultrahigh frequency RF gun revealed emittance oscillations and self-compensation at the gun exit without any...
The high-voltage modulators of the 26 klystrons in the XFEL represent the largest power consumer of the accelerator facility. The beam energy is usually 14 GeV, but a few weeks a year, lower and higher beam energies are also produced. For example, 11.5 and 16.3 GeV. Until mid-2022, the modulator voltages were set so that enough RF power for 16.3 GeV beam energy could be provided at all times....
Recently, RadiaBeam has designed, manufactured, high power tested and delivered a robust production ready S-Band thermionic RF gun with optimized electromagnetic performance, improved thermal engineering and robust yet precise cathode mounting technique. This gun will facilitate performance improvements of existing and future light sources, industrial accelerators, and electron beam driven...
Externally seeded free-electron lasers are promising for generating intense, stable, and fully coherent soft X-ray pulses. An earlier study demonstrates that high brightness and coherent soft X-ray radiation can be produced based on coherent harmonic generation and superradiant principles, termed high-brightness high-gain harmonic generation (HB-HGHG). However, due to the limitations of...
RUEDI (Relativistic Ultrafast Electron Diffraction & Imaging) is a proposed facility which will deliver single-shot, time-resolved, imaging with MeV electrons, and ultrafast electron diffraction down to 10 fs timescales. RUEDI is being designed to enable the following science themes: dynamics of chemical change; materials in ex-treme conditions; quantum materials; energy generation, storage,...
The J-PARC Main Ring (MR) delivers high-intensity proton beams for
the neutrino experiment.
The beam intensity delivered to the neutrino experiment reached 520kW with a cycle time of 2.48 seconds in 2021.
We chose to shorten the MR cycle time to 1.36 seconds to achieve higher beam intensity.
An anode power supply feeds a high-voltage DC current to the tetrode vacuum tubes, which drive...
EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe. It was accepted onto the ESFRI roadmap...
At the University of Melbourne X-LAB we are investigating the use of a low (\beta) acceptance X-band accelerating structure as part of the design of an all X-band RF electron preinjector optimised for the production of low emittance electron bunches for medical physics applications and compact light source development.
In this work we will elaborate on the estimated performance, design...
Electron beams with a flat-top transverse distribution are highly desired for uniform dose delivery in irradiation applications, like studies of radiation damage to electronics and radiotherapy, as well as for potential applications in the improvement of light sources. In this work, we report on the optimization of the electron photocathode injector parameters which allow such uniform...
In the high gradient rf photoinjectors, dark current is the “unwanted beam” not produced by the cathode drive laser. It is a part of field emission from the cavity and photocathode, which is accelerated through the gun. Dark current can cause beam loss, increase the risk of damage to accelerator components, and create additional background for beam users. Furthermore, during operation of the...
Typically, in Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) based short-pulse schemes, pulse duration is limited by FEL coherence time. A method, proposed in [1], allows to overcome the coherence time barrier and to get much shorter pulses. When lasing part of an electron bunch is much shorter than coherence time, one can suppress the radiation in the long main undulator...
At iThemba Laboratory for Accelerator Based Sciences (LABS), particle beams are pre-accelerated in a K8 injector cyclotron and further accelerated in a K200 Separated Sector Cyclotron. The accelerated beams are transported to various target stations, including targets stations used for radionuclide production and fundamental subatomic physics research. All along the trajectory of the beam...
D-Pace has a self-heated hot-cathode Penning ion source test stand at their Ion Source Test Facility (ISTF). High-charge state production of boron, arsenic, and phosphorous is interesting to the ion implantation industry, as it allows for higher energy implants of these dopants using the same accelerating gradient in a given accelerator system. We use Neon and Krypton as proxy gases to...
Our laboratory has been studying about polymer electrolyte membrane (PEM) for polymer electrolyte fuel cell (PEFC) by irradiation graft polymerization using electron beam accelerator. Irradiation graft polymerization can reduce the production cost of the PEM compared with the current product, perfluoro-sulfonic acid (PFSA) ionomer such as Nafion®︎ by DuPont. We have two methods to fabricate...
The Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven system (ADS) as a future nuclear system to efficiently reduce high-level radioactive waste generated in nuclear power plants. As a first step toward the full-scale design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. The actual cavity fabrication started...
The future Accelerator Facility for Antiproton and Ion Research (FAIR) belongs to the category of international mega-projects and is under construction in Darmstadt, Germany. The FAIR project includes the construction of 24 accelerator and experimental buildings with a total area of about 150,000 m2, as well as 12 sub-projects in the areas of accelerators (pLINAC, SIS100, SuperFRS, p-bar, CR,...
A fast neutron facility, called NDPS (Nuclear Data Production System), has been constructed for nuclear science and applications at RAON (Rare Isotope Accelerator complex for ON-line experiments) in Korea. The installation of NDPS and transport beamline from SuperConducting LINAC 3 (SCL3) to NDPS was finished in 2022. The NDPS is designed to provide both white and mono-energetic neutrons,...
The 3.2 GeV electron stretcher facility ELSA at the University of Bonn provides electron beams for fundamental research in hadron, detector and medical physics. The beam is extracted from a storage ring, whose injector consists of a 26 MeV linear accelerator and a 1.2 GeV booster synchrotron. The advent of functional plasma-based electron injectors in the MeV energy range raise the opportunity...
We study the feasibility for a hard x-ray FEL oscillator (XFELO) at 3 GeV based on harmonic lasing and transverse gradient undulator (TGU) with strong focusing. We carry out optimization of parameters using the formula developed in 2021 [1] for harmonic lasing XFELO with TGU and strong focusing. From previously assumed x-ray cavity loss of 30-20%, we lowered the assumed cavity loss to 5%...
One of the limitations in structure wakefield acceleration is large transverse emittances of high-charge wakefield drivers. The simplest idea to avoid this issue would be to prepare multiple lower-charge drivers and apply RF power from all drivers to a single accelerating tube. However, the method has two significant drawbacks; cost and timing control. We propose a single high-charge beamline...
The photon energy in the soft X-ray range corresponds to the fundamental absorption edges of matter. Ultrashort X-ray pulses can be used to observe the breaking of chemical bonds in biochemical reactions and capture the transfer process of electrons in ultrafast physical phenomena, which is of great significance for the research of the next generation of semiconductor materials, such as...
We present an overview of the FERMI seeded free electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy. FERMI, in operation with both FEL lines FEL-1 and FEL-2 since 2012, covers the spectral range between 100 nm and 4 nm with light characterized by variable polarization, narrow spectral width, stable intensity and central wavelength. A series of infrastructure...
The upgrade of the single cascade FEL-1 of the FERMI free-electron laser, aiming at implementing operation either in Echo Enabled Harmonic Generation (EEHG) or in High Gain Harmonic Generation (HGHG) mode, has started. We have recently modified the layout in order to crate the space required for the installation of the large dispersive section needed for the EEHG scheme. As a result, the...
As an option for the proton driver for the next generation spallation neutron source (ISIS-II) at the Rutherford Appleton Laboratory (RAL), a Fixed Field Alternating Gradient Accelerator (FFA) is being considered. A prototype accelerator has been designed, referred to as FETS-FFA, to demonstrate flexible handling of beam repetition for users and high intensity operation with minimum beam loss....
Fixed field Alternating gradient (FFA) accelerator is an option as a proton driver for the next generation spallation neutron source (ISIS-II). To demonstrate FFA suitability for high intensity operation, a 3 to 12 MeV proton prototype ring is planned at RAL, called FETS-FFA. The main magnets are a critical part of the machine, and several characteristics of these magnets require development....
The cyclotron C70XP of the Interest Public Group ARRONAX is regularly producing radio-isotopes for medical and research purposes. To support these productions an internal data network based on EPICS has been deployed, extending the collection of data on the accelerator components and, beam and technical diagnostics. With the accumulation of the new data, a study program is being addressed...
Within the framework of FLASH2020+, substantial parts of the injector of the FEL user facility FLASH have been upgraded during a nine-month shutdown in 2022 to improve the electron bunch properties in preparation for FEL operation with external seeding starting in 2025. As part of the injector upgrade, a laser heater has been installed upstream of the first bunch compression chicane to control...
We report a first observation of terahertz super radiant emission from the Israeli Free Electron Laser. This is the first demonstration of a THz source based on the scheme of coherent spontaneous superradiant emission by an ultra-short e-beam bunch [1].
The FEL is driven by a compact (64 cm long) Hybrid photo-cathode RF gun, emitting a beam of electron with kinetic energy of 3.5 to 8.5 MeV...
X-rays production through betatron radiation emission from electron bunches is a promising resource for several research fields. In the framework of EuPRAXIA project, EuAPS (EuPRAXIA Advanced Photon Sources) project has the purpose to provide a compact, plasma based line designed to exploit internal injection processes occurring in laser-plasma interaction to drive electron betatron...
The importance of coherent brilliant light sources for research and industry makes free electron laser (FEL) facilities a cornerstone of today’s science. The improvements of such facilities are of great importance. Here I present the first steps to enhance the undulator sections in FEL facilities by adding a plasma inside the undulator [1]. Instead of propagating the electron beam in vacuum...
A research project was initiated at HZB to develop a new E-Gun control system for the Linac Gun to realize the advanced demands from the BESSY II injection scheme. The Flexi-Gun system will allow significantly higher flexibility in both pulse load and pulse timing structure. The purpose built gun test stand is equipped with a diagnostic beamline. Developed and manufactured in-house, the...
A Gabor-lens is an ion optical device using the electric self-field of a stable confined electron column providing the focusing strength. This lens type was investigated in detail and it was shown that it is possible to use it in a LEBT for intense heavy ion beams. The homogeneous electron density results in linear focusing forces and provides space charge compensation of the beam. On the...
The lateral position deviation between the electron beam and undulators will lead to an interaction area decrease in practical high-gain free electron laser (FEL) equipment. Corrector magnets can be modified in the FEL control system to regulate the electron beam trajectory and promote laser power. Tuning tasks are time-varying, drifting, and multi-dimensional, and manual tuning by operators...
Energy recovery linacs (ERLs) possess bright prospect of the fully coherent x-ray generation. Recently, we designed a 600 MeV energy recovery linac capable of producing high power fully coherent radiation pulses at 13.5 nm with a relatively low-intensity 256.5 nm seed laser profited from the employment of angular-dispersion-induced microbunching (ADM) technology. We also designed a matched...
The Los Alamos Neutron Science Center (LANSCE) is a MW-class H-/H+ 800-MeV proton linear accelerator and storage ring that serves five distinct user facilities in support of LANL’s national security mission and DOE’s Office of Science medical isotope program. We will describe future directions of LANSCE over the next two decades, which includes revitalization and modernization of existing...
Attosecond soft x-ray pulses is of great importance for the study of ultrafast electronic phenomena. In this paper, a feasible scheme is proposed to generate isolated fully coherent attosecond soft x-ray free electron laser via optical frequency beating. Two optical lasers with the opposite chirp are used to induce a gradient frequency energy modulation, which helps to generate a gradually...
This article presents a study on the H11(0) end cell of an IH-DTL prototype for accelerating carbon ion beams from 5 to 5.5 MeV/u, which is designed for a hadron therapy linac injector. The voltage across the first and last gap in a drift tube linac tends to drop from a typical uniform voltage distribution along the inner cells. In the case of an IH cavity, the power cost to supply the...
A periodic system of spirally arranged magnetized annular sectors creates near the axis a helical field, which is close in structure and magnitude to the field in the set of helical magnets. Such a system of relatively few available magnets can be easier to manufacture and assemble than a system containing magnetized helices made from a single piece. In this paper, we theoretically study the...
With the best of modern standard lasers, high-energy gamma gamma (gg) colliders from electron beams of E > 250 GeV are only possible at the expense of photon luminosity, i.e. 10 times lower than for photon colliders at c.m. energies below 0.5 TeV. For existing state-of-the art lasers, an optimistic upper energy limit for x=4.8 is an electron beam of less than 250 GeV. We show how a single FEL...
The 3-GeV RCS at J-PARC at present operates at a relatively high intensity beam of nearly 1 MW for the spallation neutron source. The beam loss and the corresponding residual radiation, which is the key limitation against beam intensity ramp up, has been well mitigated to a minimum level in a recent series of beam studies and feedback from realistic numerical simulations. The residual beam...
Varex Imaging High Energy Sources Group has developed, built, and tested a Diode Electron Gun (DEG) based 6 MeV Accelerator Beam Centerline ABC-6-S-X-D, which showed excellent performance results, and has been entered into a serial production. The ABC is very similar in performance to its Varian-produced counterpart and may be used as its drop-in replacement in the existing installed Varex...
The high-intensity, polarized electron source is a critical component for the electron-ion collider which requires a polarized electron gun with higher voltage and higher bunch charge compared to any existing polarized electron source. At Brookhaven National Laboratory, we have built and successfully conditioned the inverted HVDC photoemission gun up to 350 kV. We report on the performance of...
A typical commercially available thermionic triode e-gun operates in 10-15 kV range. Certain linac accelerating structures may benefit from higher voltage injection. Based on commercially available low voltage e-guns Varex Imaging High Energy Sources Group has developed an e-gun that could be operated in extended range of voltages of 10-40 kV, provides high adjustability of injecting beam...
A unique feature of the current LANSCE accelerator facility is acceleration of four H- beams (differing in time structure) and one H+ beam. This is achieved by utilization of an injector system based on two ion sources (H+/H-), and a combination of chopper and RF bunchers in the Low Energy Beam Transports. Since the end of 1990’s, the large LANSCE experimental, Area-A, has been largely unused....
Novel accelerator concepts such as all-optical terahertz (THz) based compact accelerators demand high-power THz sources that are robust in order to enable reliable testing. THz sources based on the tilted-pulse front scheme have become the method of choice for table-top, high-energy, single-cycle (SC) THz generation due to both their versatility and scalability. However, due to the...
Cavity-based FELs, including x-ray free electron laser oscillators (XFELO) and x-ray regenerative amplifiers (RAFEL), have been proposed to generate fully coherent x-rays at high repetition rates. Among them, the oscillator-amplifier scheme can be used to generate high-brightness x-ray beams. Motivated by this technique, we propose a promising scheme to generate a fully coherent x-ray seed...
Increasing energy of proton beam at the Los Alamos Neutron Science Center (LANSCE) from 800 MeV to 3 GeV will improve radiography resolution ten-fold. This energy boost can be achieved with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual booster is feasible for proton radiography (pRad), which operates with short beam...
Ultrafast science has developed rapidly nowadays thanks to the development of optical and laser technologies, like chirped pulse amplification and high-harmonic generation. In this work, a simulation has been performed to generate high-power femtosecond free-electron laser pulses with chirp pulse amplification in echo-enable harmonic generation. Numerical modeling shows that the peak power...
The C-band electron gun is an attractive option for lower emittance with compactness. In this paper, a new C-band photocathode gun has been developed. The electron gun experienced a high-power test and had preliminary reached the designed gradient on the cathode. The high-power test results are the basis of the beam dynamics design and beam testing.
Charged particles moving through a carbon nanotube may be used to excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell that makes up a nanotube wall. This effect has recently been proposed as a potential novel method of short-wavelength-high-gradient particle acceleration. In this contribution, the existing theory based on a linearised hydrodynamic model...
Within the EU-funded activity IFAST, the task REX (Resonance Extraction Improvement) was launched in 2021 as WP 5.3. The IFAST-REX consortium comprises European hadron synchrotron facilities CERN and GSI, the hadron therapy centres CNAO, HIT, MedAustron, MIT and SEEIIST, as well as the companies Barthel HF-Technik and Bergoz Instrumentation. It deals with the crucial challenge of slow...
Insertion devices may be also very detrimental for the dynamic aperture of storage rings, since they introduce linear and higher order perturbations on the optics of synchrotrons. It is essential to study these effects to adjust the lattice to compensate for these terms when possible (high order multipole magnets are present in the lattice of the machine), or optimize the design of the IDs to...
J-PARC Main Ring delivers 65 kW (7x10^13 ppp) slow-extracted beam over 2 sec. at 30GeV to the hadron experimental hall to drive various nuclear and particle physics (hadron) experiments. Unexpected behavior of the high-intensity beam caused by the accelerator trip could cause serious machine damage. In March 2021, the first electrostatic septum (ESS1) was broken by a bump orbit distortion...
Many experiments in biomedicine, security imaging, and condensed matter physics require high brilliance and moderate electron beams. The properties of the photo electron source is defined by the photocathode quality such as low thermal emittance, fast response time, high quantum efficiency (QE) and the photocathodes’ robustness.
Metal cathodes are commonly used in RF Guns because they work...
As the intensity and power quest continue to increase in several physics experiments, collective effects become more limiting, and curing them becomes more involved. Therefore, an accurate description of the machine components is required to investigate such effects. In this work, we present an impedance model for the Fermilab Recycler Ring. We quantify the impedance of several elements in the...
Acceleration grids of the Neutral Beam Injector in nuclear fusion reactors must be extremely accurate and satisfy specific geometrical requirements to work properly. The implementation of the additive manufacturing technology was proposed since 2017 starting the characterization of pure copper up to the recent excellent results in terms of density, process reliability and repeatability. To...
Requirement of availability of CiADS (China Initiative Accelerator Driven System) is greater than 0.8. As a part of CiADS, high power RF system, including SSA (solid-state amplifier), high power transmission line, which availability should greater than 0.999. And hot-plug technology is a significant way to improve availability of SSA. But in the process of hot-plug, there will exist high power...
Antiprotons are generated at CERN by extracting a high-intensity proton beam
from the Proton Synchrotron (PS) onto a target. The resulting antiprotons are
captured in the Antiproton Decelerator (AD) ring. As the AD is about three
times shorter than the PS, the entire primary proton beam must be compressed
to less than one third of the PS circumference. The previous batch...
Transfer lines provide the beam transport from accelerators to experimental areas. In the study presented in this paper, commonly used beam optics are supplemented by Gabor-lenses (GL) to investigate their effect on the luminosity for fixed-target experiments.
With GLs it is possible to confine a pure electron plasma with densities up to 10E15 m-3. The self-field of the homogeneous electron...
The oscillator-type mid-infrared free-electron laser (FEL) at Kyoto University named Kyoto University FEL (KU-FEL) has achieved the extraction efficiency of 9.4%. A 1-D simulation predicted that the extraction efficiency can be further increased by reducing the optical cavity loss or increasing FEL gain*. A new photocathode RF gun is installed for increasing the FEL gain by increasing the...
Free-electron lasers (FEL) producing ultra-short X-ray pulses with high brightness and continuously tunable wavelength have been playing an indispensable role in the field of materials, energy catalysis, biomedicine, and atomic physics. A core challenge is to maintain and improve the transverse overlap of the electron and laser beams. This requires high-dimensional, high-frequency, closed-loop...
The minimum emittance of ion beams achieved using electron cooling is limited by the heating processes of Intra Beam Scattering and diffusion driven by resonance crossing of particles due to space-charge. We describe a new experiment to explore the intense space-charge regime with a transverse tune shift approaching -0.5 using 2.5 MeV protons at the Integrable Optics Test Accelerator (IOTA) at...
Thomson/Compton scattering is a method to produce high energy photons through the collision of low energy photons in a laser pulse onto relativistic electrons. In the linear (incoherent) Thomson/Compton regime, the flux scales linearly with the number of primary particles and the bandwidth of the produced photons depend, amongst other factors, on the energy spread of them. In general, an...
It has been known for decades that the intensity fluctuations of free-electron laser radiation conceal some information about the temporal characteristics of the light. In particular, by measuring the ensemble-averaged spectral intensity correlation function, one can reconstruct the average length of the x-ray pulse [1]. This method in its original form starts to break down once the electron...
MedAustron is a synchrotron-based ion cancer therapy facility located in Austria. Patients are treated with proton and carbon ion beams in an energy range of 62-252 MeV and 120-402 MeV/u, respectively. The facility features three clinical irradiation rooms, among which horizontal and vertical beam lines as well as a proton gantry are available for treatment. A fourth irradiation room is...
MedAustron is an ion therapy facility for protons and carbon ions located in Wiener Neustadt, Austria. The beam is presently extracted for clinical operation from the synchrotron with third-order resonant slow extraction via acceleration with a betatron core. However, due to the flexibility of the synchrotron operation for Non Clinical Research (NCR) purposes, other extraction methods can be...
Intra-atomic dynamics are fundamental to organic processes such as photosynthesis. X-Ray spectroscopy, using pulses of tens of femtoseconds durations generated by Free Electron Lasers (FELs), has enabled great progress in understanding this field. Sub-femtosecond pulses would enable new discoveries in the ultrafast timescales of reactions and transitions. In this paper, attosecond pulse...
Radio Frequency Knock Out (RF KO) extraction is used to extract stored particle beams from synchrotrons through transverse excitation, delivering spills of particles for experiments and medical therapy. Minimizing the fluctuations of spill intensity is vital to prevent detector pile-up and interlocks while making most efficient use of the extracted beam. To improve the spill quality, different...
Hard X-ray Self-seeding (HXRSS) is a well-know scheme to obtain longitudinally coherent FEL pulses with single SASE mode selected by a crystal. However, multi-modes can also be produced if the electron beam contains lasing parts with different energy chirp slopes (i.e. nonlinear chirp). At the European XFEL we have observed HXRSS with multi-modes and investigated its origin both in simulation...
The Fermilab 750keV injector sends 25mA H- beam for 30µs at a rep-rate of 15Hz. The beam transmission through the FNAL injector is currently less than 50% from the ion source to the entrance of the drift tube linac. Recently it was uncovered that the primary loss point is within the region prior to the RFQ which houses the solenoid focal elements that match the beam to the RFQ. With recent...
The muonium is the bound state of the positive muon and the electron. The muoium can be ionized using a dedicated laser to produce the ultra-slow muon beam. It is one idea that the dense electrons may be used as a substitute of the ionization laser for the muonium. The preliminary study is reported for the ionization of the muonium using the electron.
The IOTA Proton Injector (IPI), currently under installation at the Fermilab Accelerator Science and Technology facility, is a beamline capable of delivering 20-mA pulses of protons at 2.5 MeV to the Integrable Optics Test Accelerator (IOTA) ring. First beam in the IPI beamline is anticipated in 2023, when it will operate alongside the existing electron injector beamline to facilitate further...
CLARA at STFC Daresbury Laboratory is a test facility for FEL research and novel accelerator technologies, providing high-quality electron bunches with charges up to 250 pC. Phase two of CLARA, which will bring the accelerator to its design energy (250 MeV) and repetition rate (100 Hz), is expected to begin commissioning in 2024. To maximise exploitation of the upgraded accelerator, a...
The future AMBER experiment aims to measure the inner structure and the excitation spectra of kaons with a high intensity kaon beam at the CERN secondary beam line M2. One way to identify the small fraction of kaons in the available beam is tagging with the help of differential Cherenkov detectors (CEDARs), whose detection efficiency depends critically on the beam parallelism. In the framework...
Modern linac-based free electron lasers (FEL) opened a new area of scientific research in physics, chemistry, biology and material sciences. In recent years laser plasma accelerator (LPA) technology has made great progress towards compact electron ‘GeV-energy scale’ accelerators. Combination of compact LPA accelerator with well-established technologies to build dedicated electron beam...
The ‘Laser-hybrid Accelerator for Radiobiological Applications’, LhARA*, facility is conceived to study the biological response to ionising radiation, specifically focussing upon the co-called ‘FLASH’ (>40 Gy/min) regime. A high repetition laser, directed at a thin target, will generate high intensity, ultra-short, particle bunches, at up to 15 MeV/u (and subsequent acceleration up to 127...
Electron Cyclotron Resonance Ion Sources (ECRIS) are commonly used as injectors in many accelerator laboratories and industries and therefore, pushing its limit towards very high charge state and intense ions for nuclear and elementary particle physics and low charge state ions for surface treatments & medical purposes. For these applications, several models of ECRIS were designed and...
JSPEC (JLab Simulation Package on Electron Cooling) is an open-source C++ program developed at Jefferson Lab, which simulates the evolution of the ion beam under the influence of both IBS and electron cooling effects. In this paper, we will report the latest updates to JSPEC. Firstly, we have added theoretical and numerical models that simulate the effect of the electron beam dispersion on...
The PERLE (Powerful Energy Recovery LINAC for Experiment) collaboration is developing a high power energy recuperation linac facility with three acceleration (up to 500 MeV) and three deceleration passes through two cryo-modules at an injection current of 20 mA. Here we present the lattice design of the first stage of this machine with one cryo-module that would demonstrate the six-passes...
In the next heavy ion runs at the LHC, the cleaning of the beam halo will rely on crystal collimation. A test system installed in the collimation cleaning insertion is being upgraded for the operational challenges of the ion runs. Therefore, it is crucial to experimentally test the performance of the newly installed crystal primary collimators. During a dedicated short Pb ion beam test in...
A CeB6 thermionic gun is presently operating for the X-ray free-electron laser (XFEL) facility SACLA. The gun emits high-intensity stable electron beams with a low-emittance of 0.6 µm, however, the emission lifetime of CeB6 cathode was unexpectedly limited to only one year or less at the SACLA injector. Recently, it was predicted by a particle tracking simulation and measurements that a cause...
We propose a linear accelerator concept for a Next Generation Nuclear Physics Accelerator Facility - a versatile User Facility with a wide variety and high availability of its instruments and beam time.
The concept is based on the simultaneous acceleration of light and heavy ion primary beams. It improves the utilization of the superconducting driver-accelerator capabilities and allows for...
A facility for the collision of muons offers a unique path to a compact lepton collider with an energy reach in the multi-TeV regime, well beyond the possibilities of conventional electron accelerators. However, due to the short lifetime of muons, the constraints for acceleration and collisions are very different. An extremely fast energy increase in combination with intense and ultra-short...
The FAST Injector at Fermilab has been the focus of a number of recent experimental efforts as 1) the driver of a novel FEL experiment, 2) as the injector for IOTA, and 3) as a test-bed for novel machine learning algorithms to reconstruct phase space measurements. Here we present our recent work to simulate the FAST injector and perform realistic comparisons of simulated beam distributions to...
Dalian Coherent Light Source (DCLS) is a free-electron laser (FEL) user facility. As a user facility, it is vital to provide the long-term stable FEL light, namely drift suppression. DCLS is a comprehensive integration of various devices, any key part of perturbation will result in drift of FEL lasing. Beam-based feedback (BBF) is an effective method to suppress the drift. This paper will...
Intra-beam scattering and other mechanisms can degrade the beam quality in the EIC Hadron Storage Ring. Strong hadron cooling will maintain the beam brightness and high luminosity during long collision experiments. An Energy Recovery Linac is used to deliver the high-current high-brightness electron beam for cooling. The best cooling rate is realized when the electron beam has low emittance,...
The ever-enriching beam application scenarios have put forward more demands on accelerators. With the research and application of multiple energy extraction technology in synchrotrons, how to extract multiple energy bunches in a shorter time has become the next problem to be solved, and it is expected to be applied in tumor radiotherapy. This paper provides three methods for generating short...
The vast majority of nuclear physics simulations are dependent on the National Nuclear Database, maintained at Brookhaven National Lab, and these in turn are all based on published experimental measurements. Even today, there are gaps in this database in low energy ranges, which can be filled even by older machines. In addition to the scientific output, these measurements provide a unique...
The high-energy upgrade of the Linac Coherent Light Source II (LCLS-II-HE) will extend the X-ray energy range up to 20 keV. The goal is to produce low emittance (0.1 mm∙mrad) electron bunches (100 pC/bunch) and accelerate 30 μA beams through the superconducting linac to 8 GeV. A low-frequency superconducting radio-frequency photo-injector (SRF-PI) will be a key aspect of the upgrade. An...
A new secondary beamline was recently installed in the MeV Test Area (MTA) with the objective of enhancing mu+/mu- production by factors of 3/8 by using a tungsten target versus the conventional graphite production target using the 400 MeV Fermilab proton Linac beam. Ultra-low energy muon beams can support world-class physics experiments for fundamental muon measurements, sensitive searches...
The photon flux resulting from a high energy electron beam's interaction with a target, such as in the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, should yield, through its spectral and angular characteristics, information about the electron beam's underlying dynamics at the interaction point.
This project utilizes data from simulated plasma wakefield...
Fourth generation light sources require high brightness electron beams. To achieve this a cathode with a high quantum efficiency and low intrinsic emittance is required while also being robust with a long lifetime and low dark current. Alkali-metal photocathodes have the potential to fulfil these requirements and, as such, are an important area of research for the accelerator physics...
The China Spallation Neutron Source (CSNS) has been operated with 100kW beam power on target since 2020. The Linac consists of an H- ion source, a low-energy beam transport line (LEBT), a 3 MeV Radio Frequency Quadrupole (RFQ), a Medium Energy Beam Transport line (MEBT) and a Drift Tube Linear (DTL) accelerator to boost the beam energy to 80 MeV with a beam intensity of 10 mA. A power upgrade...
Cavity-based XFEL, or CBXFEL, is a future highly-coherent photon source under construction at LCLS. In the first phase of the CBXFEL project, we will demonstrate the regenerative amplifier mode of operation with 7 LCLS Hard X-ray Undulators (HXUs). In this paper, we report on the recent measurement of the FEL gain in 7 LCLS HXUs, and hard x-ray self-seeding (HXRSS) under e-beam conditions...
Resistive oven technique is used to inject vapours of metallic species in plasma traps, where plasma sustained by the electron cyclotron resonance (ECR) mechanism provides step-wise ionisation of neutral metals, producing charged ion beams for accelerators. We present a numerical survey of metallic species suitable for oven injection in ECR ion sources to explore neutrals diffusion and...
The photocathodes used as electron sources in high-performance electron accelerators today are largely one of only a handful of materials. While there has been an increased understanding of the properties of the electron beams produced by these cathodes, there has been little change in the overall selection of materials used at accelerator facilities. In fact, nearly all of the photocathodes...
Hollow-core dielectric Electromagnetic Band Gap (EBG) microstructures powered by lasers represent a new and promising area of accelerator research since, thanks to the short optical wavelength and to the dielectric's high damage threshold greater accelerating gradients, with respect to the metallic counterparts, can be achieved.
In this paper, we present MeV-scale beam-dynamics simulations...
The electromagnetic Particle-In-Cell (PIC) code WarpX has been developed by the U.S. Department of Energy’s Exascale Computing Project, in collaboration with international partners, toward the modeling of plasma accelerators on Exascale Supercomputers. We will give an overview of the code and its latest features, such as collision and QED physics modules. We will also report on the latest...
Short bunches, high current and multiple linac pass are all characteristics of Energy Recovery Linacs (ERLs), which may result in collective effects. They in turn, may affect the beam, degrading its quality, or even yield to instabilities causing a beam loss. To study and mitigate these effects one needs a numerical simulation code, that can take into account both the collective effects, as...
High-quality electron beams are critical for generation of
intense X-ray pulses from free electron lasers. It was proposed
that complex thin films and heterostructures with semiconductor
photoemissive layers may be used in photocathodes to produce
electron beams with better quality. New developments in material
science allow designing alkali-antimonide photocathodes with
specific...
Modern free-electron laser (FEL) facilities are designed to simultaneously serve multiple undulator lines to pro-vide x-ray pulses with high peak power and tunable wavelengths. To satisfy different scientific demands, it is preferred to make the separate undulator lines work under different FEL schemes, such as the self-amplified sponta-neous emission (SASE) scheme and the echo-enabled...
We demonstrate a simple method to generate two-color or multi-color soft x-ray FEL pulses. This method mainly uses a chirped electron beam working together with an EEHG alike modulator and chicane setup to produce wide electron beam bunch train. And this bunch train can be used to generate multi-color FEL pulses. By tuning the configurations and parameters of the method, we can easily adjust...
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator [1]. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch...
Time-varying fluctuations of the intensity sharing between the islands and the core of the beam extracted via the CERN Proton Synchrotron (PS) Multi-Turn Extraction are the main effects that require manual adjustment for this beam type. To mitigate this, the application of an online controller is explored to further enhance both operational autonomy of the accelerator and physics performance....
Unprecedented electron beam brightness can potentially be achieved by exploiting high gradients in cryo-cooled RF cavities functionalized with high QE semiconductor photocathode materials. However, strong electric fields and thermal stresses from associated emission currents could potentially affect material stability, leading to breakdown events which may shorten device lifetime or degrade...
XiPAF (Xi'an 200MeV proton application Facility) synchrotron is using H^- stripping injection and phase space painting scheme. With the demand of more particle species for single event effect study, XiPAF synchrotron has been upgraded to multiturn injection from stripping injection, the injection system must be redesigned. This paper report XiPAF synchrotron multiturn injection scheme, a...
The K12 beam line and NA62 experiment in the North Area at CERN in beam dump mode exploits the interactions of 400 GeV protons with a movable dump-collimator, the so-called XTAX. Such interactions are theorised to generate potential light dark matter candidates such as the axion. Any rare process search requires precise knowledge and experimental reduction of the predominant muon background. A...
A new, high-efficiency source of a Muonium beam will be useful for fundamental muon measurements, sensitive searches for symmetry violation, and precision tests of theory. In the PIP-II era, Fermilab has the potential to provide the world's highest-intensity Muonium beam, by a considerable margin. Moreover, with the advent of a muon beam at Fermilab's existing 400 MeV linac, the necessary R&D...
Gabor-lens 2000 (GL2000) is an hadron optic device which confines a 2m long electron cloud. This opens up new possibilities in research with very long confined static electron ensembles. Due to the optimization of technical design it was possible to successfully complete the conditioning process creating a stable confinement of electrons. Also, the diagnostic tools were extended and the...
State-of-the-art spin-polarized photo-electron sources use GaAs-based photocathodes to provide electron beams with high degrees of spin-polarization. Such photo-guns are required to operate with both quantum efficiency and cathode lifetime as high as possible in order to meet the requirements of high-current applications such as energy-recovery linacs and colliders. Both quantum efficiency and...
A new project, NEWGAIN (NEW GAnil Injector), is under development at GANIL, and aims to build a second injector for heavier beams with A/q up to 7, as an extension of the SPIRAL2 accelerator. With this upgrade, SPIRAL2 will provide high intensity beams, from proton to uranium, thus increasing GANIL international competitiveness both in fundamental science and associated applications.
This...
Noise and density fluctuations in relativistic electron bunches, accelerated in a linac, are of critical importance to various Coherent Electron Cooling (CEC) concepts as well as to free-electron lasers (FELs). For CEC, the beam noise results in additional diffusion that counteracts cooling. In SASE FELs, a microbunching instability starts from the initial noise in the beam and eventually...
Recent studies by Dejan Trbojevic have confirmed that Non-Scaling Fixed Field Accelerators (NS-FFAs) can have their tune dependence on momentum flattened by adding non-linear components to the magnet fields, although not necessarily for an unlimited momentum range. This paper presents such a cell suitable for the proposed 3-12MeV FETS-FFA proton R&D ring at RAL.
The nonlinear magnetic field...
Electron beams serve many important roles from free electron lasers to medical imaging. Every time beam brightness is improved, a wide variety of fields take another step forward. Nanopatterned field emission cathodes serve as an excellent opportunity to continue to push the envelope on extreme high brightness beams. Their fabrication is thus of crucial importance to this objective. In the...
The LANSCE accelerator facility has been in operation for 50 years performing important scientific support for national security. The unique feature of the LANSCE accelerator facility is multi-beam operation, delivering beams to five experimental areas. To reduce long-term operational risks and to realize future beam performance goals in support of the laboratory missions, we develop a novel...
Development of advanced intense and reliable sources of charged particle beams is a direction within accelerator physics on its own right. By changing the temperature of Lithium Tantalate (LiTaO3) single crystal at moderate vacuum conditions leads to generation of strong electric field. The uncompensated polarization during the heating or cooling of the crystal causes the ejection of electrons...
In the J-PARC Main Ring, a project to upgrade the beam power to 1.3 MW is currently underway. The most important issues in realizing such a high-power beam operation are controlling and minimizing beam loss, which are essential for sustainable beam operation allowing hands-on maintenance. In this paper, we report on our recent efforts to understand the mechanism of beam loss and to reduce it.
Dielectric-lined waveguides have been extensively studied to potentially support high-gradient acceleration in beam-driven dielectric wakefield acceleration (DWFA) and beam manipulations. In this paper, we investigate the beam dynamics in the alternating-symmetry slab-based dielectric wakefield accelerator proposed and discussed in Ref.[1]. We use the first principle electromagnetic...
The realization of a plasma based user facility on the model of EuPRAXIA@SPARC_LAB requires to design a working point for the operation that allows to get an high accelerating gradient preserving a low emittance and low energy spread of the accelerated beam. Such beam is supposed to pilot a soft x-ray free electron laser, a device with very challenging requirements in terms of brightness and...
Generation of attosecond XFEL pulses has drawn great attention in a wide range of research fields over the past decade. Adaptation and combination of state-of-the-art FEL techniques have led to advanced working schemes capable of producing the required ultra-short X-ray pulses. At the European XFEL, an R&D project, the AttoSecond Pulses with eSASE and Chirp-Taper schemes (ASPECT), has been...
The Mainz Energy-recovering Superconducting Accelerator (MESA), currently under construction at the Johannes Gutenberg University (JGU) in Mainz, will offer two modes of operation, one of which is an energy-recovering (ER) mode in order to deliver electron beams of up to 155 MeV to two experiments. As an ERL, MESA, with it's high brightness electron beam, is a promising accelerator for...
A THz free electron laser (FEL) prototype has been developed at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) for obtaining high intensity radiation for THz-pump-X-ray-probe experiments at the European XFEL. In this development, a magnetic chicane was recently installed to optimize the THz FEL performance. The aim of this study was to investigate the beam dynamics in the chicane...
The relativistic interaction of short pulsed lasers or electrons with plasma has recently led to the birth of a new generation of femtosecond X-ray sources. Radiations with properties similar to those that can be observed from a wiggler or undulator, can be generated by the oscillations induced in the exited plasma by electrons (PWFA) or by lasers (LWFA), making plasma an interesting medium...
This work is focused on the anomalous skin effect in copper and how it affects the efficiency of copper-cavities in the temperature range 40-50 K. The quality factor Q of three coaxial cavities was measured over the temperature range from 10 K to room temperature in the experiment. The three coaxial cavities have the same structure, but different lengths, which correspond to resonant...
Protection of free-electron sources has been technically challenging due to lack of materials that transmit electrons while preventing corrosive gas molecules. Two-dimensional (2D) materials uniquely possess both of required properties. Here, we report three orders of magnitude increase in operation pressure and factor of two to four enhancement in the lifetime of high quantum efficiency (QE)...
CRYRING@ESR is a low-energy heavy-ion storage ring recently recommissioned at GSI, Darmstadt, as part of the FAIR project. With its standard working point lying on the lowest-order difference resonance, the ring contains a compensation solenoid to counter coupling of betatron motion introduced by the electron cooler magnetic field. That solenoid largely occupies one of the drift sections of...
The Los Alamos Neutron Science Center (LANSCE) is a very flexible H-/H+ 800-MeV proton linear accelerator and storage ring that serves five distinct user facilities in support of LANL’s national security mission and commercial applications. It is unique because of the intensity and energy spectrum of the neutrons produced. The Isotope Production Facility (IPF) operates using an H+ beam line at...
This poster will report the progress on optical optimization of Cs2Te photocathodes using simulations and preliminary experimental results. Thin film semiconductor photocathodes are often used in high brightness electron sources. These sources are particularly bright when the cathodes are operated “near threshold”, i.e., with a laser energy close to the sum of the band gap and electron...
The MYRRHA project (Multi-purpose hYbrid Re-search Reactor for High-tech Applications) is a planned accelerator-driven system (ADS) that will be realised at Mol in Belgium and will demonstrate the feasibility of transmutation of radioactive waste on an industrial scale.
The planned accelerator, which is to provide the 600 MeV proton beam, consists of a normal-conducting 17 MeV injector that...
As part of the EuPRAXIA project[1], the objective of the PALLAS project is to produce an electron beam at 200 MeV, 30 pC with less than 5% energy spread and lower than 2μm normalised emittance using the IJCLAB-LaseriX laser driver at 10 Hz, 1.5 J and 35 fs. Based on available publications[2,3], we propose a two-chamber gas plasma target with a dopant...
For storage-ring-based free-electron lasers (FELs), prebunching via echo-enabled harmonic generation (EEHG) is an efficient way to reduce the radiator length and improve the longitudinal coherence as well as output stability. We propose a conceptual design, which uses two straight sections of a synchrotron to seed coherent soft X-ray emission. This scheme requires no change of the storage ring...
Currently 26 RF stations are in operation at the European X-ray Free Electron Laser (XFEL) and all RF stations can deliver sufficient power to support 600 µs beam pulse with an energy up to 17 GeV. These beam parameters require a power consumption of about 4.9 MW for high-power RF. Of course, the simplest way to save power is to reduce the XFEL repetition rate, but with some additional work...
Xi'an Proton Application Facility (XiPAF) synchrotron provides 10~200MeV proton beam for the experimental simulation of the space radiation environment. Due to the space charge effect, the slow extraction of 10 MeV proton beam is a work full of challenges. In a past experiment, the total extraction efficiency was over 65% with 4.5 ~ 6.5×1010 protons stored before extraction but decreased to...
The JEDI experiment is dedicated to the search for the electric dipole moment (EDM) of charged particles using storage rings, which can be a very sensitive probe of physics beyond the Standard Model. In order to reach the highest possible sensitivity, a fundamental parameter to be optimized is the Spin Coherence Time (SCT), i.e., the time interval within which the particles of the stored beam...
In this proceeding, we will examine the designs of cavity-based XFEL (CBXFEL) and X-ray laser oscillator (XLO) currently under construction at SLAC. We will point out the possible improvements in the optical design, and propose new schemes. We especially focus of rectangular and bow-tie geometries.
A THz SASE FEL is currently under operation at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a prototype THz source for pump-probe experiments at the European XFEL.This prototype should provide tunable (3-5 THz) narrowband THz radiation with THz pulse energies up to several hundred μJ from 17-20MeV electron beams with a beam charge of several nC and a peak current up to 200 A...
MeV-ultrafast electron diffraction (MeV-UED) has enabled broad scientific opportunities for the studies of structural dynamics, ultrafast chemical processes and coupling of electronic and atomic motions in a variety of gas, liquid and solid state systems. The growing demand of future scientific needs calls for relativistic electron probes with ultra-short bunch length(10 fs) and ultra-low...
Cooling of secondary beams is often critical to accelerator based nuclear and sub-nuclear physics, with beams ranging from positrons e+ to muons μ+/- to hadrons (for the respective collider facilities) to exotic nuclei ions (like 132Sn1+) as in the SPES (Selective Production of Exotic Species) project at LNL. A prototype of a radiofrequency quadrupole (RFQ) cooler (RFQC) was developed at LNL...
Particle-in-cell simulation plays an important role in optimization of today’s plasma-based acceleration research and experiments. Due to many variables involved, the computational cost is usually very high, especially when the experiment includes several different beams, e.g., the AWAKE experiment. AWAKE Run2 uses the proton bunch to drive plasma wakefield and accelerate electron bunch in 10...
This paper proposes a new coupling slots design for the Pi-Mode structure high-frequency cavity in the China Spallation Neutron Source (CSNS) Phase II. Through simulation calculations and experimental verification, it was found that the new coupling slots design significantly improves the Q value and transmission efficiency of the high-frequency cavity. This study is of great significance...
The problem of standing wave formation by superposing two counter-propagating whistler waves in
an overdense plasma, studied recently by Sano et al (2019 Phys. Rev. E 100, 053 205 and 2020 Phys. Rev.
E 101, 013 206), has been revisited in the relativistic limit. A detailed theory along with simulation has
been performed to study the standing wave formation in the interaction of two counter...
2022 has been a performance consolidation year for the Low Energy Ion Ring (LEIR) at CERN that demonstrated its capability of delivering the target beam parameters required for high luminosity production in the LHC in a reproducible and reliable way. The main steps that have led to the high performance reach of this beam, together with the machine stability improvements deployed, are detailed...
The cryocooled DC electron gun at Arizona State University (ASU) is the first electron gun built to implement single-crystal, ordered surface and epitaxially grown photocathodes to produce cold and dense electron beams at the source. These high brightness electron sources are extremely desirable for ultrafast electron applications such as Xray Free Electron Lasers (XFELs), Ultrafast Electron...
The {2, 2} Danilov distribution is self-consistent — it is a Vlasov equilibrium distribution that produces linear space charge forces. Additionally, the distribution has zero (four-dimensional) transverse emittance. Thus the Danilov distribution may be of use for overcoming space charge limitations at high intensities, increasing collider luminosity, or pushing the limits of transverse bunch...
INFN LASA photocathode lab develops and produces films that are used in high brightness photoinjectors. Besides the long-time and still on-going experience on Cs2Te, recently we have restarted an activity on alkali-antimonide films, sensitive to visible light, exploring the possibility of their stable operation in CW machine. We report in this paper the recent results obtained both on the...
The ARES linac at DESY (Deutsches Elektronen-Synchrotron) is a dedicated accelerator research and development facility for advanced accelerator technologies and applications, including high gradient accelerating schemes, high-resolution diagnostics and medical applications. It provides ultra-short, high quality electron beams with charges between a few femtocoulombs and a few hundred...
The photoinjectors of FLASH at DESY (Hamburg, Germany) and the European XFEL are operated by laser driven RF-guns. In both facilities cesium telluride (Cs$_2$Te) photocathodes are successfully used since several years. We present recent data on the lifetime and quantum efficiency (QE) of the current photocathode at FLASH #105.2, operated before and after a long shutdown. In addition, data for...
As accelerators and electron microscopes become more advancement, high-performance photocathodes are required. In particular, CsK2Sb photocathode is of interest because of its low emittance, excitability in visible light, and high quantum efficiency (QE). On the other hand, it has drawbacks such as weak structure, limited operating vacuum pressure, and short lifetime with time or charge. To...
Integrating the advances made in photonics with efficient electron emitters can result in the development of next generation photocathodes for various accelerator applications.
In such photonics-integrated photocathodes, light can be directed using waveguides and other photonic components on the substrate underneath a thin (<100 nm) photoemissive film to generate electron emission from...
The proposed Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) aims at generating FEL pulses between 1nm and 30nm. At phase-I, two undulator beamlines work at EEHG principle. The shortest wavelength is about 2.3nm at a harmonic of 104. However, the various three-dimensional effects of beam can smear out the fine structure in the longitudinal phase space for the EEHG, especially...
The proposed Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) aims at generating FEL pulses whose wavelengths ranges from 1 to 30 nm. As part of the first phase of S3FEL, two undulator beamlines working under SASE operation mode is planned. The two beamlines generate FEL pulses with wavelengths ranging from 1 to 3 nm and 2.3 to 15 nm, respectively. The physical designs and the...
Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) is a newly proposed high repetition-rate X-ray FEL facility. It will be located at Guangming Science City in Shenzhen with a total length of 1.7 km. The electron beam is generated from a VHF photocathode gun and accelerated to 2.5 GeV through a superconducting RF linac. At initial phase, it is planned to build four undulator lines...
A 35MeV/2 mA S-band electron linear accelerator used to interact with solid targets to generate neutrons, gamma rays, and X-rays has been proposed to provide a scientific research platform for nuclear energy development, material development, biomedicine, deep space exploration besides other industrial applications. The accelerator has a three-stage accelerating structure, after the...
The CERN-wide coordination of the programmed stops requires a tool to centralize and collect all the activities at a macroscopic scale. It includes the activities foreseen during Long Shutdowns (LS) and Year End Technical Stops (YETS).
The CERN tool named PLAN centralises all the activities foreseen by the Groups, to have a global strategic view, assessing priorities across CERN. Thanks to...
In 2021, the Italian Institute for Nuclear Physics (INFN) was awarded the project for installing, testing and commissioning the energy upgrade of the Southern European Thomson back-scattering source for Applied Research (STAR) which is currently installed at the University of Calabria (UniCal). The STAR high-energy Linac, STAR-HEL, consists in a layout comprising RF accelerating structures...
Betatron radiation produced in the plasma acceleration process could be used as seed for Free Electron Laser (FEL). A broad band radiation in the X-ray spectral region is produced by the strong transverse electron oscillation in the plasma channel driven by particle or laser wake field acceleration. Selecting the betatron radiation wavelength matched with FEL resonance, with proper...
To generate high-current B+ ion beams for ion implantation, a hybrid ion source that combines electron cyclotron resonance and thermal surface ionization, which is called a high-temperature surface microwave source (HSMS), is under development. A high-temperature hot surface (2000℃) and microwave heating are the essential components of an HSMS to produce high-energy electrons for the B+...
Particle beams with highly asymmetric emittance ratios are employed at accelerator facilities and are expected at the interaction point of high energy colliders. These asymmetric beams can be used to drive high gradient wakefields in plasmas. In plasma, the high aspect ratio of the drive beam can create a transversely elliptical blowout cavity and the asymmetry in the ion column creates...
Plasma-based accelerators enable compact acceleration of beams to high energy and are being explored as a potential technology for future linear colliders. Conventional linear colliders require damping rings to generate the required beam emittance for particle physics applications. We present and discuss a plasma-based linear radiation damping system that allows cooling of ultrashort bunches...
Cavity based X-ray free-electron lasers (CBXFEL) are next generation X-ray sources promising radiation with full three-dimensional coherence, nearly constant pulse to pulse stability and more than an order of magnitude higher spectral flux compared to SASE FELs. However, especially for the low gain X-ray free-electron laser oscillator (XFELO), the outcoupling of the radiation stored inside the...
The RAON ultra-low energy experiment team decided that the first experiment was to accelerate the proton 70 MeV using a cyclotron and collide with the SiC target to generate a radioactive isotope beam. Before this experiment, a preliminary experiment was conducted to confirm the exact location and shape of the proton beam before directly colliding with the target to generate a lot of radiation...
We are building a new infrared Free Electron Laser (FEL) facility in China that will produce infrared laser covering the spectral range from 2.5 um to 200 um. It is made up of two oscillators generating middle infrared and far infrared laser respectively, which are driven by a single RF linear accelerator (linac) with a tunable beam energy from 12 MeV to 60 MeV. According to the requirement of...
Two-beam acceleration (TBA) in Terahertz (THz) regime is the natural extension of Gigahertz TBA pursued in Structure Wakefield Acceleration Community. Recently proposed CSR-free shaping technique using deflecting cavities showed the feasibility of generating a high-charge (~1 nC per bunch) bunch train compatible with THz frequency. Wakefield from THz structure with such a h high-charge bunch...
There are two accelerator based infrared light sources in Kyoto University Free-Electron Laser (FEL) facility. One is a mid-infrared FEL covering the wavelength range from 3.4 to 26 micro-m driven by 40-MeV multi-bunch electron beams supplied from an S-band RF gun and an S-band linac. The other is a coherent undulator radiation* covering the wavelength range from 0.1 to 0.6 THz driven by...
We study ultrafast laser surface nanopatterning as an alternative to improve the photo-emissive properties of metallic photocathodes. By tailoring the physical dimensions of these surface nanostructures, one can localize the optical field intensity and exploit plasmonic effects occurring in such nanostructures. As a result, this surface nanopatterning technique can become a great tool for...
The new C-Band RF gun, developed in the context of the European I.FAST project has been realized. It is a 2.5 cell standing wave cavity with a four port mode launcher, designed to operate with short rf pulses (300 ns) and cathode peak field larger than 160 MV/m. In the paper we present the realization procedure and the results of the vacuum and low power RF test. The gun is now ready for the...
At its restart after a major shutdown in 2029, the LHC will see its interaction regions upgraded by the installation of the HL-LHC equipment, with new Nb3Sn triplets and cold powering system, crab-cavities for crossing angle compensation and luminosity levelling, an upgraded collimation system, and fully remote alignment for the final focusing region. In the following operational runs, the LHC...
Velocity bunching, sometimes called rectilinear rf bunch compression, is a common technique to generate femtosecond MeV electron bunches from a photoinjector system. Such ultrashort beam can be used to generate coherent THz radiations, in particular, coherent undulator radiation (CUR). However, beam properties such as beamsize, transverse emittance, bunch length and energy spread after bunch...
n recent years the interest in high intensity, short-pulse coherent THz radi-
ation for non-linear experimental research and applications grew with upcoming
high intensity lasers. In contrast to lasers, accelerators provide free electrons
for which emission properties can be tailored to the demand at typically much
higher repetition rates than high-intensity lasers can provide. Efforts are...
A high-power proton linac at KOMAC uses a drift tube linac structure to accelerate protons up to 100 MeV. Currently, a total of 148 drift tubes with electromagnetic quadrupoles are used in DTL sections for accelerating protons from 3 MeV to 20 MeV. A drift tube based on a permanent magnet quadrupole has been designed and prototyped to replace the EMQ-based drift tube to enhance the DTL...
The Electron-Ion Collider (EIC) incorporates beam crabbing to recover geometric luminosity loss from the nonzero crossing angle at the interaction point (IP). It is well-known that crab cavity imperfections can cause growth of colliding beam emittances, thus degrading collider performance. Here we report a particle tracking study to quantify parts of these effects.
cERL in KEK is a test accelerator for development works of technologies related to Energy Recovery Linac (ERL) and CW-Superconducting accelerators. It can produce a low emittance and short bunch beam at a high repetition rate. This feature is suitable for producing a high average power terahertz (THz) coherent radiation. We have been developing a THz source based on Coherent Diffraction...
In accordance with the program of NSC KIPT Subcritical Neutron Source physical start up that was approved by State Nuclear Regulator the basic measurement method of reactivity and keff is an area ratio measuring method. In the method, the neutron response of the SCA on the electron beam pulse is measuring. For on-line monitoring of the system reactivity the neutron flux to beam current ratio...
A shared ambition in the R&D of future light sources is designing and constructing an ideal free-electron laser (FEL). Such a machine will produce tunable, multicolor, near transform-limited pulses, with a controlled delay, and fully coherent beams with precisely adjustable phase profiles enabling state-of-the-art measurements and studies of femtosecond dynamic processes with high elemental...
Plasma accelerators are emerging as formidable and innovative technology for the creation of table-top devices thanks to the possibility to sustain several GV/m accelerating gradients at normal conducting temperature. Among others, the particle-driven configuration has been successfully tested at the SPARC_LAB test facility also demonstrating the emission of plasma-based FEL radiation in SASE...
Coherent, wide-tunable frequency and high intensity terahertz (THz) source is under preparation at the Shanghai Soft X-ray free-electron laser facility (SXFEL). The strong field THz radiation from 0.1 to 5 THz is generated by coherent transition radiation (CTR) when compressed electron bunches pass through the metal foil. In addition, the electron bunches modulated by frequency beating light...
The 3 GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) provides more than 800 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). We have been continuing a beam study to achieve 1-MW, design power operation. In addition, we have also improved and maintained the accelerator components to establish a stable operation. This...
FLASH, the Free electron LASer in Hamburg is currently undergoing a substantial refurbishment and upgrade project (FLASH2020+). A major stage was the 9 month shutdown in 2021/22. During this shutdown key components of the injector/linac where inserted, moved, rebuild or upgraded to enable the efficient and reliable preparation of electron...
Future proton superconducting RF (SRF) linacs used as accelerator driven systems (ADS) must achieve high reliability and availability to meet the challenging parameters for applications in medical treatment, nuclear waste reduction, and nuclear power generation. What SRF innovations and advanced concepts are needed? To answer this question, a case study of the past, current, and possible...
Xi 'an 200 MeV Proton Application Facility (XiPAF) will be upgraded to proton and heavy ion synchrotron recent-ly. In order to ensure the enough life of heavy ion beam, the synchrotron requires ultra-high vacuum, and the de-signed static vacuum is better than 5×10-10 Pa. In order to place enough vacuum pumps in the synchrotron, the circumference of the synchrotron was increased from 30.9m to...
The Radio Frequency Quadrupole (RFQ) for the High-Intensity Photon Injector (IPHI) project has been designed and manufactured in the early 2000s. It is now operating at CEA Saclay since 2016 and accelerates a 100-mA continuous beam up to 3 MeV. It is a 6-meter-long, 3 segments vane RFQ, with 352.2 MHz operation frequency and non-constant voltage profile. From this RFQ, a lot of experience has...
We review the theory of optical klystrons with SASE FEL applications in mind. Previous theories miss terms in the power gain factor that cannot be neglected, and we illustrate differences between the previously known analytical expressions, new ones discussed here, and numerical calculations. We then consider the use of optical klystrons for electron energy-spread and radiation coherence-time...
The Linear IFMIF Prototype Accelerator (LIPAc) is designed to accelerate 125mA of deuteron beam to 9MeV in continuous wave (CW). The superconductive RF Linac has not yet been installed and the final accelerating stage now under commissioning is the RFQ. This system has been designed and developed by INFN (Italy) before installation in QST (Japan). The RFQ is the longest in the World with its...
The Cyrcé facility of IPHC in Strasbourg operates a TR24 cyclotron to produce medical isotopes, lead radiobiology programs and test detectors.
A RF kicker has been developed in order to discard one beam bunch over two to get a rate close to 40MHz. An RF voltage at a quarter of the cyclotron frequency applied to a deflector in the injection line allows to reach that goal. The 30keV DC beam...
The recent layout of the Jülich High Brilliance Neutron Source (HBS) driver linac is based on short crossbar H-mode (CH) cavities operated at a fixed synchronous phase. In the last decades the computing power for the development of linacs, available to physicists and engineers, has been increased drastically. This also enabled the accelerator community to finally carry out the required R&D to...
Accelerators having large electric field gradients are the need of the hour for building future electron or proton colliders. Plasma wakefield accelerators using short electron or proton bunches can solve the problem of achieving large amplitude plasma wake. In PWFA, we have witnessed that, large amplitude wakefields generated by such mechanisms have both transverse and longitudinal components...
Flat beams are preferred at high energies due to their ability to achieve high intensity and luminosity, as one of the transverse emittances is smaller. However, at low energies, collective effect such as space charge becomes dominant in the smaller dimension. Intra-beam scattering(IBS) effect is dominant when local beam density is high, from medium to high energies. Circular mode beams, which...
IAEC/SNRC (Israel) is constructing an accelerator facility, SARAF, for neutron production. It is based on a linac accelerating 5 mA CW deuteron and proton beam up to 40 MeV. As a first phase, IAEC constructed and operated a linac (SARAF Phase I), from which remains an ECR ion source, a Low-Energy Beam Transport (LEBT) line and a 4-rod RFQ. Since 2015, IAEC and CEA (France) are collaborating in...
As Compton X-ray and gamma-ray sources become more prevalent, to understand their performance in a precise way it becomes important to be able to compute the distribution of scattered photons precisely. An ideal model would: (1) include the full Compton effect frequency relations between incident and scattered photons, (2) allow the field strength to be large enough that nonlinear effects are...
The Scheduling Tool Project (ST Project) is in charge of ensuring the scheduling and coordination of CERN accelerator programmed stops and facilities installation managed within the Accelerator Coordination and Engineering (ACE) Group, inside the Engineering Department (EN) at CERN, since 2019. The scheduling tools should consider all the activities, that take place in large facilities,...
FLASH, the Free-Electron Laser in Hamburg, houses an experimental beam line for the study of seeding called Xseed. For the upcoming realization of a seeded FEL in the scope of the FLASH2020+ project, these components offer a unique possibility to study hardware, procedures and software for a future seeded operation. In this contribution we give an overview of the FLASH accelerator, the...
ECR ion sources produce ion beams with an intensity proportional to the heating frequency. SEISM (Sixty gigahErtz Ion Source using Megawatt magnets) is a unique source operating at the record frequency of $60~GHz$ thanks to a gyrotron producing high intensity HF pulse (up to $300~kW$). The prototype is based on a simple magnetic geometry, the cusp, using polyhelix coils (developed with the...
A relativistic, charged particle bunch propagating in plasma is subject to various instabilities. When the bunch is much longer than the cold plasma skin depth, it is subject to the self-modulation instability (SMI). This instability is routinely observed in the AWAKE experiment with narrow (200microns), long (7cm) proton bunches**. Bunches wider than the skin depth are subject to the...
Externally seeded free electron lasers (FELs) offer fully coherent and stable FEL radiation in the soft x-ray regime. While electron bunches of superconducting-based FELs are available at MHz repetition rates, seeded radiation is limited by the repetition rate of the seed laser used in the process. Combining standard seeding schemes with an optical klystron is a simple and promising trick to...
With the FERMI2.0 upgrade plan FERMI is planning a major upgrade of the two FEL lines and the linac in order to extend the tuning range toward 2 nm in the fundamental and with full polarization control. The shortest wavelength range will be reach with a two stage FEL relying on a first Echo Enabled Harmonic Generation operating at harmonic close to 30 to convert the UV seed laser wavelength to...
Extraction by third order resonance in low-energy stage will suffer from strong space charge effect, high beam emittance, high power ripple and so on. Low-energy slow extraction at 10 MeV has been explored theoretically and experimentally at synchrotron of Xi'an Proton Application Facility (XiPAF), which is a compact synchrotron with injection energy of 7 MeV and extraction energy up to 230...
Different from the high Q value of ferrite cavity, the Q value of magnetic alloy cavity in CSNS RCS is only about 1.25, the frequency band of impedance is wide, and the beam loading effects is strong. Based on the impedance measurement results, the influence of the beam load effects on the longitudinal distribution of the magnetic alloy cavity in CSNS RCS is studied by simulation, and the...
We propose a simulation model of the field enhancement and quantum efficiency (QE) increase of metallic surfaces as a result of a surface nanostructuring. In the framework of photoinjector facilities for electron accelerators at CERN, achieving optimal nanostructuring parameters may become a significant asset. The presence of a well-designed periodic surface topography can give rise to...
One of the key aspects to provide on chip acceleration in Dielectric Laser Accelerators (DLA) from tens of keV up to MeV energies is the phase velocity tapering.
This paper presents the simulated performance of sub-relativistic structures, based on tapered slot waveguides. We engineered channel/defect modification in order to obtain a variable phase velocity matched to the increasing velocity...
At Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), the scheme for generating attosecond XFEL pulse at soft X-ray undulator line is developing. Enhanced Self-Amplified Spontaneous Emission (E-SASE) method with external laser pulse is adopted to induce the current spike in the electron beam and generate attosecond XFEL pulse. E-SASE section consists of the wiggler and the...
Externally seeded high-gain free electron lasers (FELs) are capable of providing fully coherent radiation with high shot-to-shot stability at wavelengths down to the soft X-ray range.
However, present seed laser sources are not suitable for the generation of short wavelength FEL radiation at high repetition rates. As a result, such setups have been unable to make use of the full repetition...
In many advanced accelerator facilities such as e+e--linear colliders and high gain free electron lasers, magnetic bunch compressors are often used for enhancement of beam brightness. However, the energy chirp (correlated energy spread) introduced into the beam by the chirper linac remained after bunch compression is undesirable in some applications. In this report, we present our study of a...
Plasma wakefield acceleration (PWFA) is a method for accelerating charged particles using large electric fields sustained by plasma waves (up to hundreds of GV m−1) for the accelerating longitudinal fields. In this project, we will evaluate the impact of perturbations on basic particle motion. These perturbations are affected by any number of terms of the equations of motion. The most...
In this study we investigate simulation results for a virtual diagnostics concept that is planned for the SASE1 beamline at the European XFEL. These virtual diagnostics will be used to predict photon beam properties like pointing and divergence. We first use the GENESIS simulation framework to compute different lasing conditions in the undulator beamline, and then use Artificial Neural...
The Laser Ion Source (LIS) can easily produce high charge state and high intensity ion beams, especially the refractory metallic ion beams, so it is a promising candidate as an ion source for heavy ion cancer therapy facilities and a future accelerator complex, where a pulsed ultra-intense and high-charged heavy ion beam is required. Due to the capability of LIS to produce high-brightness ion...
J-PARC Main Ring (MR) delivers slow extracted 30 GeV proton beam to the Hadron Experimenal Facility using third-order resonance.
Various particle and nuclear physics experiments are being conducted there, and one of the important properties required for the proton beam is the flatness of the time structure of the extracted beam (spill structure).
At J-PARC MR, the large current ripples in...
SOLARIS injector LINAC is designed to efficiently fill the electron storage ring. The injection currently takes place at 540 MeV, two times per day. After the accumulation of electron current, the energy is ramped up inside the ring to 1.5 GeV via two active RF cavities.
Top-up injection would be of extreme benefits for user operation, therefore here we present a simulation study for the...
A program is under way at the Argonne Wakefield Accelerator (AWA) facility, in collaboration with Euclid Techlabs and Northern Illinois University (NIU) to develop a GV/m-scale photocathode gun, with the goal of producing bright electron bunches. The novel X-band (11.7 GHz) photo-gun (Xgun) is powered by high-power, short rf pulses (9 ns), which are generated by the AWA drive beam in a...
The matter-antimatter asymmetry may be explained through CP-violation by observing a permanent electric dipole moment (EDM) of subatomic particles. An advanced approach to measure the EDM of charged particles is to apply a unique method of "Frozen spin" on a polarized beam in a storage ring. To increase the experimental precision step by step and to study systematic effects, the EDM experiment...
Developments of new research areas and breakthroughs in science are often linked to the progress in new instrumentation. Here we briefly summarize the scientific opportunities and the proposed layout of an X-ray Compton source based on superconducting accelerator technology. The X-ray source is envisioned to provide scientists at Uppsala University and collaborating research groups with 100...
SIS18 will be used as booster for FAIR’s main synchrotron SIS100. In addition, it provides a wide variety of ions from Protons to Uranium for users directly at GSI and FAIR.
An upgrade program to enhance the overall performance for the booster operation has been carried out.
Part of the upgrade program for booster operation was a complete overhaul of the control system including data...
Optimising the slice energy spread in X-ray free electron lasers (XFELs) is key to their effective operation, and must be considered from the photoinjector at the very beginning of the machine. The standard approach, in which the measured beam size is entirely attributed to the product of the dispersion and the energy spread, has only a resolution on the order of several keV, meaning that a...
At Eindhoven University of Technology a lab-based tabletop Inverse Compton Scattering (ICS) source is being commissioned. This compact and affordable X-ray source will bridge the gap between conventional lab X-ray sources and synchrotrons.
A 100 kV DC photo electron gun is used in combination with a bunching cavity to produce electron bunches that are injected in a X-band accelerator. The...
Inverse Compton Scattering (ICS) sources are becoming more popular as the future of lab-based x-ray sources. Smart*Light is one such facility, under commissioning at Eindhoven University of Technology (TU/e). This compact X-ray source aims at bridging the gap between conventional lab X-ray sources and synchrotrons.
Electron bunches are produced by a 100 kV DC photo electron gun in...
Seeding of free-electron lasers (FELs) is based on a periodic modulation of the electron energy by an external radiation pulse converted to a density modulation in a dispersive section. In complex configurations such as cascaded high-gain harmonic generation (HGHG) or echo-enabled harmonic generation (EEHG), the density-modulated electron beam may need to be propagated through drift spaces or...
The SPS proton fixed target beams are spilled via a third integer resonant extraction, for which high momentum spread is beneficial. To increase the momentum spread prior to the slow extraction, the bunches are stretched at the unstable phase by inverting the sign of the RF voltage. The RF phase is then flipped back, and the voltage is turned off when the bunch distribution is rotated to the...
Shanghai HIgh repetitioN rate XFEL and Extreme light facility (SHINE) is an x-ray FEL facility based on an 8 GeV CW superconducting linac and 3 FEL undulator lines, with the capability that delivering wide spectral range coherent radiation to multi end stations.
In this paper, we present the detailed dynamics design strategy based on global optimization with start-to-end simulations from...
Southern Advanced Photon Source (SAPS) is a 3.5 GeV diffraction limited storage ring, being planned to be built near the site of the China Spallation Neutron Source (CSNS). Full energy Linac injector reserves the possibility of using the Linac for free electron laser application in a future upgrade. In this paper, the start-to-end simulation of the full energy Linac working on the ring...
FACET-II is a National User Facility at SLAC National Accelerator Laboratory with the goal to develop advanced acceleration and coherent radiation techniques using a 10 GeV electron beam of unprecedented beam intensity with >100 kA peak current and <10 µm spot size, a 10 TW experimental laser system, and a variety of solid, gas and plasma targets. A diverse experimental program will...
The 70MeV cyclotron at Laboratori Nazionali di Legnaro was installed and commissioned in 2017 and the accelerator was operational until March 2021. The shut down was foreseen in order to permit the completion of the SPES facility, while the resume of activities is expected on 2023. The status of the cyclotron and related high intensity beamlines will be presented as well as the last...
To advance in the characterization of photocathodes for high brightness sources, the measurement of the thermal emittance plays a key role. The TRAnsverse Momentun Measurement device developed at INFN LASA will allow equipping our photocathode laboratory with an advance device able gving in quasi on-line feedback during the photocathode growth process.
This paper reports on the status of the...
The synchrotron SIS100 at FAIR, currently under construction in Darmstadt, Germany, will deliver slow extracted proton and ion beams up to 100 Tm employing resonant extraction. Its compact super-ferric dipole and quadrupole magnets allow fast ramping of magnetic field up to 4 T/s and 57 (T/m)/s, respectively. Recently, field errors has been measured for the dipole magnets and the first batch...
A beam cooler device has been constructed by the Laboratories de physique corpusculaire (LPC) of Caen (France) in collaboration with Laboratori Nazionali di Legnaro (INFN) for the SPES project. The design phase started in 2018 and the construction was carried out in 2021. In 2022 the functionality test have been done at LPC and the beam commissioning started. The Beam Cooler is capable to...
A prototype electron lens for space charge compensation in the synchrotron SIS18 that could pave the way for pushing the space charge limit of hadron synchrotrons is currently under development at GSI. Accompanied by beam transport simulations, a 3D construction model is being worked out as well as the integration into the existing accelerator facility. The electron gun and collector...
The European Spallation Source (ESS) aims to build and commission a 2 MW proton linac ready for neutron production in 2025. Commissioning of the normal conducting section of the linac is underway and previous papers have reported the performance of the microwave-discharge ion source, Radio Frequency Quadrupole (RFQ) and first Drift Tube Linac (DTL) tank.
This paper describes the recent...
FLUTE (Ferninfrarot Linac- Und Test-Experiment) at KIT has a compact versatile linear accelerator. One of FLUTE's main goals is to serve as a platform for a variety of accelerator studies as well as for the generation of high intensity, ultra-short THz pulses for photon science experiments. The linear accelerator is envisioned as an injector for a Very Large Acceptance compact Storage Ring...
The free-electron laser user facility at DESY – FLASH – is operating two undulator beamlines simultaneously and delivers XUV and soft X-ray radiation for photon experiments. It is driven by a superconducting linear accelerator. In a shutdown from November 2021 to August 2022 FLASH underwent a comprehensive refurbishment and a substantial upgrade (FLASH2020+). In this paper we summarize the...
The H– linac pre-injector used at the ISIS spallation neutron and muon source is being upgraded to include a medium energy beam transport (MEBT) line after the radio frequency quadrupole (RFQ). The improved beam transport allows the use of a more modern and reliable RF-driven H– ion source. To test the new ion source and MEBT for long-term end-to-end reliability, an...
The laser manipulations of H- ion beam by single or double neutralization is a very promising technique and highly essential to utilized in accelerator processes such as stripping, pulse chopping, collimation, extraction, and beam diagnostics for the present and future high-intensity proton accelerators. At J-PARC, we are preparing for a POP (Proof-of-Principle) demonstration 400 MeV H-...
In the framework of the FLASH2020+ project, the FLASH1 beamline will be upgraded to deliver seeded FEL pulses for users. This upgrade will be achieved by combining high gain harmonic generation and echo-enabled harmonic generation with a wide-range wavelength-tunable seed laser, to efficiently cover the 60-4 nm wavelength range. The undulator chain will also be refurbished entirely using new...
The heavy ion synchrotron SIS100 is the flagship accelerator of the Facility for Antiproton and Ion Research (FAIR) currently under construction at GSI, Darmstadt. It will provide high intensity beams of particles ranging from protons to uranium ions at beam rigidities up to 100 Tm. Part of the machine protection system is an emergency beam dump that is partly inside the vacuum system and...
Heavy ions have been accelerated for the first time by SPIRAL2 in 2022. A fast method to tune the linac cavities has been used (< 1 hour by now, < 10’ in the future) to obtain a 7 MeV/A 18O6+ beam (50 microA CW). Then an automatic Q/M beam change procedure has been successfully used to directly produce a 18O7+ beam. The goal was to demonstrate the possibility to tune a beam even if its...
The SPIRAL2 installation at GANIL, Caen France is al-ready in operation since 2019 and produce a large num-ber of new radioactive ion beams at high intensities. In 2027, the DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation) and from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions). The construction of...
European XFEL is a x-ray free-electron laser (FEL) user facility covering a nominal photon energy range from 250eV to 25keV. At the soft x-ray undulator beamline SASE3 and the two hard x-ray undulator beamlines SASE1 and SASE2, identical permanent magnet phase shifters are installed. In standard operation of the hard x-ray undulator beamlines these phase shifters introduce only small delays...
The search for the Electric Dipole Moments (EDM) of charged particles in storage rings necessitates polarized beams with long Spin Coherence Time (SCT) of the circulating beam. The SCT is the time during which the RMS spread of the orientation of spins of all particles in the bunch reaches one radian. A long SCT is needed to observe the coherent effect of a polarization build-up induced by the...
The electron accelerator S-DALINAC at TU Darmstadt was successfully operated in single and double-turn energy-recovery mode. The latter was realized using a shared beam-transport where two beams are superimposed in the first recirculation beamline. Due to its current design, the S-DALINAC can be upgraded with reasonable effort to be operated in triple-turn energy-recovery mode with shared...
A crystal-based hybrid e+ source could be a good alternative to conventional sources based on the e- conversion into e+ in a thick target and is currently under consideration for the FCC-ee [1]. In a hybrid source an e- beam crosses a thin oriented crystal with emission of channeling radiation, featuring enhanced photon flux w.r.t. Bremsstrahlung [2]. It results in an increase in the number of...
CSNSII is an upgrade project of China Spallation Neutron Source (CSNS), which needs to increase the beam power from 100kW to 500kW. In order to find a suitable working point area in advance and evaluate the influence of space charge effect on CSNSII, the measurements of beam loss with different tunes on CSNS was carried out and beam loss simulation in transverse tune space on CSNSII has been...
An energy-recovery-linac (ERL)-based X-ray free-electron laser (FEL) is proposed considering its three main advantages: i) shortening the linac by recirculating the electron beam by high-gradient SRF cavities, ii) saving the klystron power and reducing the beam dump power through the energy recovery in the SRFs, iii) producing a high average photon brightness with high average beam current....
Fermilab pre accelerator (Preacc) and Linac send H- beam at 15Hz to the Booster which is a resonant circuit synchrotron. The beam is accelerated from 35 keV to 750 keV with RFQ in the Preacc, and then accelerated to 400 MeV in the Linac. There are 17 cavities in the Preacc and Linac, however a few of the cavity phases are adjusted for a daily tuning. The phase and amplitude have not been...
Cryo-cooled C-band (5.7 GHz) copper distributed-coupling cavities are a new approach to the structure-based accelerators for the future multi-TeV energy range linear collider. It provides numerous degrees of freedom to optimize the cavity geometry to achieve high gradient and high-power in the linear collider. In this study, we analyze the dipole modes of C-band 20-cells cavity and calculate...
Nanostructured electron sources exhibiting simultaneous spatio-temporal confinement to nanometer and femtosecond level along with a low emittance can be used for developing future ordered electron sources to generate unprecedented electron beam brightness and can revolutionize stroboscopic ultrafast electron scattering and steady-state electron microscopy applications. In addition, high...
Terahertz radiation plays an important role in cutting-edge scientific research. Terahertz radiation source based on relativistic electron beam can provide excellent terahertz radiation source. The performance of such radiation is closely related to the distribution of the electron beam. Therein, the laser modulation technology based on the undulator is widely used to manipulate the...
The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in the field of next-generation compact and cost affordable particle accelerators. Recent results obtained at SPARC_LAB show evidence of the FEL laser by a compact (3 cm) particle beam plasma accelerator. This work is carried out in the framework of the SPARC_LAB activities...
Slowly extracted beams from a synchrotron have temporal fluctuations, the so-called spill micro structure. The reason is related to power supply ripples that act on the quadrupole magnets, leading to unintended tune fluctuations during extraction. Related simulations regarding the dependency of spill quality on the power supply ripples are executed with varying excitation levels of the...
The Los Alamos Neutron Science Center (LANSCE) is a highly versatile H-/H+ 800-MeV linear accelerator that serves five distinct user facilities. Currently, H+ is accelerated through the drift tube linac down a stub line for the Isotope Production Facility at 100 MeV. The other four user facilities at LANSCE use the H- beam accelerated to 800 MeV. The H+ beam had historically been accelerated...
Plasma wakefield acceleration (PWFA) is a burgeoning field, attracting much attention as an option to extend acceleration gradients from the present 100 MeV/m level to the TeV/m level. The effort will be expended to resolve the question of the long-term behaviour of the disturbances left behind in the plasma and the time it takes to reach equilibrium after the wakefield interaction occurs. The...
Online models are becoming increasingly more important for the tuning of particle accelerators. Photo-injectors are especially notorious due to there sometimes finicky nature and the difficulties involved in developing models that are suitable for online use. Surrogate models using artificial neural networks are increasingly popular for this application due to their ability to model nonlinear...
A key aspect of the LHC Injectors Upgrade project is the connection of the PSB to the newly built Linac4 and the related installation of a new 160\,MeV charge-exchange injection system. The new injection system was commissioned in winter 2020/21 and is now used operationally to tailor the transverse characteristics for the various beam types at CERN, such as high-intensity fixed target beams,...
High-Brightness SASE (HB-SASE) is a proposed method for greatly improving the temporal coherence of SASE FEL pulses using magnetic delay chicanes along the undulator beamline. Isochronous chicanes, which include high-strength quadrupoles, promise to deliver the greatest improvement in temporal coherence but it is more convenient if the delay chicanes are composed only of dipoles. In this paper...
A new tool is under development aimed at complementing the hadronic physics of GEANT4.
The tool interfaces most of the standalone nuclear interaction models and the pre-equilibrium and evaporation models to Geant4.
The tool can generate primary hadronic interactions between particles, ions, and matter.
The tool has been designed to optimize the design of targets for the next generation of...
The Advanced Wakefield Experiment (AWAKE) at CERN relies on the seeded Self-Modulation (SM) of a long relativistic proton bunch in plasma, to accelerate an externally injected MeV witness electron bunch to GeV energies.
During AWAKE Run 1 (2016-2018) and Run 2a (2021-2022), two seeding methods were investigated experimentally: relativistic ionization front seeding and electron bunch seeding....
X-ray free electron lasers (XFEL) and other x-ray producing light sources are large, costly to maintain, and inaccessible due to minimal supply and high demand. In addition, concepts for future electron colliders benefit from cost reduction size is reduced through normal conducting RF cavities are operated at very high gradients. It is advantageous then to consider miniaturizing electron...
Corrugated structure modules are being proposed for installation after the end of the linac and before the undulator regions of SHINE facility, where it has been used for energy chirp control and as a fast kicker for two color operation of the FEL.When ultra-relativistic bunch of electrons passing through corrugated structure will generate strong wakefield, we find most of the wake power lost...
Mega electron volt (MeV) accelerators used for ultrafast electron diffraction (UED) have provided a unique insight into visualizing elusive ultrafast processes from photochemical reactions and lattice motion, to phase transitions occurring in quantum materials. In this work, we demonstrate recent measurements of strong THz streaking of ultrafast electron bunches generated from an rf...
The terawatt-scale free electron lasers (FELs) are of great interest for the possibility to allow X-ray single molecular imaging experiments and nonlinear x-ray science. At Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL), for the second hard undulator plan (HX2) the enhanced Self-Amplified Spontaneous Emission (E-SASE) scheme with an external laser pulse will be installed to...
We present the latest developments of the test facility for LANSCE Front-End Upgrade. The upgrade will significantly improve the operations and reliability of LANSCE, with upgrade options for future capability. This effort includes a highly diagnosed ion injector, low-energy beam characterizations, and RFQ analysis. Comparisons between beamline measurements and simulations are presented.
Worldwide there is a push for producing medical isotopes using particle accelerators rather than fission reactions. Here we report on the operation of a DC-photogun designed for producing Mo-99 in the Lighthouse facility and commissioned by the Institute for Radio Elements (IRE, Belgium).
The gun is based on the successful CBETA design by Cornell University. It is installed at the RI site in...
Electron acceleration in solid-state plasmas is of interest within the Laser Wakefield Acceleration (LWFA) research. Layered nanostructures such as graphene nanoribbons can be used as targets for intense UV lasers to generate and accelerate electron bunches. We present numerical Particle in Cell (PIC) simulations of a novel sub-femtosecond self-injection scheme which relies on edge-plasma...
In this work, we develop a concept of an accelerator arranged as follows: electrons are accelerated by an electromagnetic field in a waveguide immersed in a longitudinal uniform axial magnetic field and a transverse spatially periodical undulator magnetic field. There are several types of resonances in such a system. Namely, cyclotron, undulator, and combined resonances. Herewith, these...
The C70XP is a cyclotron operated for production of radionuclides in nuclear medicine, for research in physics, radio-chemistry and biology. It aims at providing high intensity beams to the various experiment for long or very short time runs. The beam transverse distribution, e,g. homogeneity and emittance, has a great impact on the experiments. The ion source and subsequently the injection...
The “standard” way of a high energy positron beam in proton accelerator-driven systems includes two stages. Firstly, the proton beam is directed on a target material. The protons produce neutral pions that after a short decay they decay to 2 gamma rays. At the second stage, these gammas are producing electron-positron pairs on a high-Z (typically Pb) converter. Magnets between the target and...
Accelerator facilities are among the most complex projects, integrating advanced engineering systems and components. At the ESS, the need to visualise the intricate integration activities has led to the development of Aggregation Diagrams (ADs). The diagrams follow the facility breakdown structure with sections and system diagrams showing their integration of the devices with enabling and...
Particle accelerators demand high particle transmission and reduced longitudinal emittance; hence, effective bunching systems are requested. The concept based on an efficient, compact design called “Double Drift Harmonic Buncher - DDHB” fulfills these two requirements for a c.w. or pulsed beam injection into an RFQ, a DTL, or a cyclotron. The proposal is associated with two buncher cavities...
The Extreme Photonics application Centre (EPAC) is a planned UK national facility. The current intention is for EPAC to use a 1 PW 10Hz laser system to drive laser plasma acceleration with output energies ranging from 100 MeV up to, at least, 5 GeV. The initial design for the electron beam transport of the EPAC facility is presented in this paper. This includes some initial considerations on...
The EIC requires an electron gun to provide a high current high brightness electron beam for EIC cooler. A 550 kV DC gun using alkali antimonide photocathode was designed to generate a 110 mA electron beam , 1 nC with normalized emittance < 1 mm-mrad. Here, we present the design parameters of this high voltage DC gun. The details of the gun design with electron beam simulation will be described.
As part of the goal of increasing the beam power of the Main Ring for Fast eXtraction (FX) in J-PARC to 750 kW, the two low-field septa and three high-field septa for FX were installed into MR in 2022. The most significant goals regarding the magnets are achieving an extremely low leakage field in the circulating line. To reduce the leakage field in
the circulating line, the new pure iron...
A new proton beam-delivery line for the TOP-IMPLART linac is under assembly and testing at the ENEA Frascati Research Center. TOP-IMPLART is an RF pulsed linear accelerator developed for medical applications, consisting of a 425 MHz, 7 MeV injector, followed by eight accelerating SCDTL modules operating at 3 GHz, driven by two 10 MW peak power klystrons. Proton beam can be accelerated at 63...
Subcritical Assembly Neutron Source facility of the National Science Center “Kharkiv Institute of Physics & Technology” (NSC KIPT), Kharkov, Ukraine is Accelerator Driven System with tungsten or uranium neutron generating target and 100MeV/100kW electron linear accelerator as a driver.
The facility physical start up was started in the middle of 2020 fnd completed in August 2022. The program...
SNRC and CEA collaborate to the upgrade of the SARAF accelerator to 5 mA CW 40 MeV deuteron and proton beams (Phase 2). CEA is in charge of the design, construction and commissioning of the linac downstream the existing RFQ (SARAF-LINAC Project).
The MEBT is now installed at SNRC and has been commissionined with beam. Transverse and longitudinal emittances have been measured and beam...
The minimum achievable particle beam emittance in an electron accelerator depends strongly on the intrinsic emittance of the photocathode electron source. Reducing the electron beam emittance in an accelerator which drives a FEL delivers a significant reduction in the saturation length for an X-ray FEL, thus reducing the machine’s construction footprint and operating costs whilst increasing...
Electron field emission and the related process of strong laser-field emission are promising mechanisms for the creation of high brightness beams. These processes deviate from the photoelectric effect in that the normal energy – not the total energy – is the predominant factor determining the likelihood for an electron to ionize. In this paper we continue our investigation of the material...
This article presents an IH-DTL prototype, capable of accelerating carbon ion beams from 5 MeV/u to 5.5 MeV/u, for manufacturing and assembling validation in a hadrontherapy linac injector. A multi-physics study is made in CST Studio concerning steady-state thermal, stress and deformation analysis. Convenient water-cooling circuits close to drift tubes are simulated to evaluate field errors...
In this paper, a cooling scheme was designed for the THU VHF gun, and simulations of thermal and structural analyses were conducted. A total of 19 independent cooling channels were designed and distributed on the gun to remove the heat generated. The maximum temperature was 67.8 ℃ with a total flow rate of 3.28 L/s and dissipation power of 92.5 kW. The accelerating gap distance decreased by...
Strong laser-field electron emission enhanced by nanostructures is a growing topic of study, owing to its ability to generate high brightness beams. Experiments have shown that the nanoblade structure, a wedge shape, notably outperforms nanotips in the peak fields achieved. These higher fields result in a brighter emission. In this paper we study the thermodynamics of the electron system...
We study THz radiation generation from a few-periods magnetic device for THz pump – x-ray probe experiments at the European XFEL, or at other facilities like the LCLS-II. We compute THz radiation accounting for the boundary conditions imposed by a vacuum pipe. Calculations were performed for a single-period magnetic device as well as for a nine-period one. We address the problem of modes...
The LHC Injector Upgrade (LIU) programme forms a cornerstone of the High-Luminosity LHC project. Among its targets, a new Beam Position Monitor (BPM) system has been deployed in the Low Energy Ion Ring (LEIR) to facilitate optics measurements. This paper reports on the commissioning and analysis of turn-by-turn data from the new BPM system. Furthermore, the specific challenges and current...
Semiconductor photocathodes, particularly those produced with thin films and heterostructures, are promising candidates of high brightness electron sources. It is also well-known that electron beam brightness increases with the photocathode gun’s operating gradient. Combining both heterostructure semiconductor photocathode and cyro-cooled high-gradient photocathode gun may improve electron...
The ALTO research platform at the Laboratoire de physique des 2 infinis Irène Joliot Curie (IJCLab) is dedicated to wide-ranging research in nuclear physics, nuclear astrophysics and interdisciplinary activities such as health physics. ALTO-LEB is the low energy beam area of ALTO where neutrons rich exotic nuclei are studied.
A new precision experiment is being installed at the ALTOLEB...
A 1 MeV/n Radio-Frequency Quadrupole (RFQ) has been developed and commissioned at Korea Multipurpose Accelerator Complex (KOMAC). The RFQ is designed to accelerate ions with mass to charge ratio up to 2.5. The designed peak current is 10 mA with 10 % duty factor. Currently we are utilizing the RFQ as a test bench for the reliable operation of the 100 MeV proton linac operational at KOMAC since...
Particle accelerators are devices of primary importance in a large range of applications such as fundamental particle physics, nuclear physics, light sources, imaging, neutron sources, and transmutation of nuclear waste. They are also used every day for cargo inspection, medical diagnostics, and radiotherapy worldwide. Electron is the easiest particle to produce and manipulate, resulting in...
In this proceeding, we demonstrate the synthesis of epitaxial Cs$_3$Sb films with a high degree of crystallinity on silicon carbide substrates. Films less than 10 nm thin are grown in vacuum and exhibit percent level quantum efficiencies at 532 nm. We find a positive correlation between quantum efficiency and improved crystallinity of the photocathode film, particularly in the longer...
We are developing an ultrafast and ultracold electron source (UCES), based on near-threshold femtosecond photoionization of a laser-cooled cloud of rubidium gas, stored in a Magneto Optical Trap (MOT). The UCES is characterized by electron temperatures as low as ~ 10 K, enabling a unique combination of ultra-low emittance ~ 1 nm rad and relatively high bunch charges. Recently we have...
High brightness photoinjectors demand low thermal emittance and high electric field to deliver brighter electron beams for modern accelerator-based scientific instruments. High quantum efficiency, low thermal emittance photocathodes, mainly semiconductors, easily degrade in poor vacuum conditions and could not operate with an extended lifetime. Therefore, an ultrahigh vacuum electron gun is...
This talk will report on the status C-band high gradient research program at Los Alamos National Laboratory (LANL). The program is being built around two test facilities: C-band Engineering Research Facility in New Mexico (CERF-NM), and Cathodes And Radio-frequency Interactions in Extremes (CARIE). Modern applications require accelerators with optimized cost of construction and operation,...
LNL heavy ion accelerator complex is based on three main accelerators: Tandem, ALPI and PIAVE. The Tandem XTU is a Van de Graaff accelerator normally operated at terminal voltages of up to about 14 MV. It can be operated in stand–alone mode or as an injector for the linac booster ALPI. The linear accelerator ALPI is built of superconducting resonant cavities and consists of a low–beta branch,...
A 350 MHz, 3 MeV radio frequency quadrupole (RFQ) has been operating since 2005 at Korea Multi-purpose Accelerator Complex (KOMAC) as a low energy part of the 100 MeV proton linac. Recently, it was considered to upgrade the existing RFQ because of its low beam transmission rate and vane erosion. Several options were compared to upgrade the RFQ considering a number of sections, coupling plate...
The Large Hadron electron Collider (LHeC) is proposed as a future particle physics project colliding 60 GeV electrons from a six-pass recirculating energy-recovery linac (ERL) with 7 TeV protons stored in the LHC. The ERL technology allows for much higher beam current and, therefore, higher luminosity than a traditional Linac. The high-current, high-energy electron beam can also be used to...
Tetrode vacuum tubes are used under the positive grid region
to accelerate a high intensity beam in the RCS.
A tube amplifier is operated in push-pull mode and two tubes are installed in the amplifier. Although each control grid should be driven in counterphase for the push-pull operation, the waveform becomes asymmetric by the positive grid biasing. The vacuum tube operation analysis...
For HL-LHC intensities, transient beam loading after injection between the Super Proton Synchrotron (SPS) and the Large Hadron Collider (LHC) is expected to push the RF power in the LHC to the limit of the installed system. A detailed understanding of this process is necessary to minimize beam losses during LHC injection. Realistic models of the local SPS and LHC cavity control systems were...
Experiments at CRYRING using beams accelerated and decelerated in the accelerator chain SIS18 - ESR - CRYRING at GSI are considered as the first real FAIR experiments. For these experiments, CRYRING receives fast extracted beams from the ESR, which are cooled and decelerated down to about 10 MeV/u in the ESR. The beam transport from ESR to CRYRING is difficult, since part of the beamline has...
Wakefield acceleration in structured solids (nanotubes and crystals) has a promise of very high accelerating gradients and simultaneous continuous channeling focusing. All that can manifest a new, long thought solution of many challenges faced by advanced acceleration techniques. We outline the concept and present the progress and status of the E336 Experiment at FACET-II.
The Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) is designed to be one of the most advanced free electron laser user facilities around the word. The repetition is aiming at 1 MHz and the high-repetition-rate electron beams are delivered into three undulator lines through the beam delivery section. The main functional elements are kickers. The vacuum chamber in the...
The energy loss of the electron beam due to synchrotron radiation and wakefields determines an undulator tapering in order to keep the resonance condition along the undulator. The contribution of synchrotron radiation to energy loss can be calculated analytically, whereas the calculation of wakefield energy loss requires knowledge of the beam current profile and the wakefield function at the...
FEL oscillator is the main working mode to produce infrared and THz radiation. However, in the long wavelength range, the waveguide is essential to suppress the diffraction losses. We have developed a method to study this effect by wGenesis that is modified with Genesis in combination with OPC code. However, this method is limited by the optical elements given in OPC. In this paper, we tried...
We have been developing an in-situ work function (WF) measurement system to investigate an unexpectedly short lifetime problem of a CeB6 thermionic cathode at the SACLA electron injector. Photoelectron yield spectroscopy using a nanosecond tunable pulsed laser in the wavelength range from 410 to 709 nm was adopted because this method provides a high S/N ratio in a hot operational condition of...
In our recent work [1], we proposed a plasma-driven light source that can generate coherent tunable XUV pulses with TW peak power and pulse durations of 40 attoseconds (or longer) in a m-length undulator. The pulses synthesized in this approach carry particular merit for tracking chemical dynamics and enabling measurements that extend beyond the range of conventional HHG and XFEL...
Multi-bend achromat (MBA) lattices have initiated a fourth generation for storage-ring light sources with orders of magnitude increase in brightness and transverse coherence. A few MBA rings have been built, and many others are in design or construction worldwide, including upgrades of APS and ALS in the US. The Hybrid MBA (HMBA), developed for the successful ESRF–EBS MBA upgrade has proven to...
Electron beam irradiation is a method that has shown a good potential to reduce several pollutants in wastewater. One of the main challenges towards wider adoption of this method is the need for compact, reliable, cost-effective, high-power accelerators. Jefferson Lab is working on the design and prototyping of accelerator components, based on superconducting radio-frequency (SRF) technology,...
ALBA is working on the upgrade project that shall transform the actual storage ring, in operation since 2012, into a 4th generation light source, in which the soft X-rays part of the spectrum shall be diffraction limited. The project was launched in 2021 with an R&D budget to build prototypes of the more critical components. The storage ring upgrade is based on a 6BA lattice which has to...
The I.FAST CBI is an immersive challenge-based innovation program funded by the H2020 I.FAST project. The 10-day face-to-face challenge brings together students of different disciplines from all over Europe to work together on innovative projects using accelerator technology applied to environmental challenges. We report on the first edition of the I.FAST CBI, the proposed projects and...
In this contribution we report on the commissioning of the ELIMAIA beamline laser-plasma Ion Accelerator carried out with the high repetition-rate, high peak-power L3-HAPLS (>10J in 30 fs) laser available at the ELI Beamlines user facility. The optimization process to achieve a stable energy cutoff exceeding 30MeV with high proton fluxes will be described providing an overview of the available...
SIRIUS is a green-field 4th generation Synchrotron Light Source Facility based on a 3 GeV electron storage ring with 518 m circumference and 250 pm.rad emittance. It was de- signed, built, and is operated by the Brazilian Synchrotron Light Laboratory (LNLS/CNPEM). After completion of Phase-0 commissioning of the accelerators and first beam- lines, SIRIUS is now open for external users, with 6...
To ensure physical start up of NSC KIPT SCA Neutron Source, 100 MeV/ 100 kW electron linear accelerator should provide stable operation mode with 100 MeV electron beam energy, 20 Hz repetition rate, 35-40 mA pulse beam current, ± 3 beam energy spread and about ± 3 mm beam sizes. During preparations to the facility start up the required beam parameters were adjusted and secured during the SCA...
In recent years, even accelerators, which are fundamental tools for advanced researches, should be green regarding energy/resource consumption and operation efficiency. How to improve the performance of accelerators in such an environment will be a major challenge for the field of accelerator science and technology. Against this backdrop, we have developed a long-term plan to promote the...
IFMIF-DONES (International Fusion Materials Irradiation Facility, DEMO-Oriented Neutron Early Source) – a powerful neutron irradiation facility for irradiation of materials to be used in fusion reactors – is planned as part of the European roadmap to fusion electricity. Its main goal will be to characterize and qualify materials under a neutron field similar to the one faced in a fusion...
Measurements of the small beam sizes in current and future low-emittance light sources represent a serious challenge to the accelerator community due to the diffraction effects, and X-ray inteferometric techniques offer an interesting method to overcome this challenge. Here we report on 2D beam size measurements with a novel interferometric technique named Heterodyne Near Field Speckles...
FLASH (Free Electron Laser in Hamburg) is the first FEL in the world to deliver ultrashort radiation pulses in extreme ultraviolet and soft X-ray ranges, currently being upgraded at DESY within the FLASH2020+ plan. The upgrade covers implementing new tunable undulators, improving the beam energy to 1.35 GeV, and a complete redesign of the FLASH RF Reference Generation System. That system...
The European Spallation Source is a spallation neutron source driven by a superconducting proton linac and currently under construction in Lund, Sweden. The proton linac of a 5 MW design power, with a 62.5 mA peak current, 2.86 ms pulse length, and 14 Hz repetition rate, is undergoing staged beam commissioning towards the initial user operation planned in 2026 at a reduced power of 2 MW. In...
The complete knowledge of electron bunch properties is of great interest to understand and optimize the performance of accelerators and their applications. A new tomographic beam diagnostics method to reconstruct the full 5-dimensional phase space (x, x', y, y', t) of bunches has recently been proposed. This method combines a quadrupole-based transverse phase-space tomography with the variable...
To develop the next generation of safe and cleaner nuclear energy, the accelerator-driven subcritical(ADS) system emerges as one of the most attractive technologies. The Chinese ADS proofing project(CAFe) was launched in 2011 under the management of the Chinese Academy of Sciences to demonstrate the key technologies including superconducting proton linac, heavy metal target and subcritical...
The MYRRHA design for an accelerator driven system (ADS) is based on a 4mA, 600 MeV CW superconducting proton linac. The first stage towards its realization is called MINERVA and was approved in 2018 to be constructed by SCK CEN in Belgium. This consist of a 4mA 100MeV superconducting linac as well as two independent target stations, one for radio-isotope research and production of...
Commercial electron microscopes with a few hundred keV energies are fundamental tools for understanding the micro- to nano-scale world. One of the frontiers in electron microscopy development is to push the beam energy to MeV range to achieve improved lateral resolution for thick samples. Here we show the theoretical and preliminary experimental analysis of the electron beam quality required...
The Electron Ion Collider is preparing now the design for the project baseline, to provide the high luminosity, polarization and flexibility for the EIC. This talk outlines the accelerator physics challenges including complex interaction region, flat hadron beams, beam cooling, high beam currents leading possibly to electron clouds and instabilities, and high beam polarization.
Firstly introduced in 2010 at the MIT Francis Bitter Magnet Laboratory, the so-called “no-Insulation (NI)” winding technique has been regarded as a “game changer” in high temperature superconductor (HTS) magnet technology, as it enables an NI HTS magnet to be highly compact and affordable, yet reliable to a level that has never been achieved with conventional systems. Significant progress in...
A lepton-collider Higgs factory, to precisely measure the couplings of the Higgs boson to other particles, followed by a higher energy run to measure the Higgs self-coupling, is widely recognized as a primary focus of modern particle physics. In the talk a description of the new technology based on cool copper that can lead to compact and affordable machine will be described as well as the...
In the past five years, seven short models of the inner triplet quadrupole for the High Luminosity LHC, based on Nb3Sn conductor, have been built and tested, reaching conductor peak fields above 13 T. In this talk we will review the main features of this program, outlining the scope of the program, the different variants manufactured, and the test results. Special emphasis will be given to...
In laser-plasma accelerators (LPA), due to extremely high accelerating gradients, electron bunches are accelerated to high energies in only a few millimeters to centimeters of acceleration length. To efficiently capture and transport the LPA-generated bunches in a compact transport line, beam line designs employing high-strength combined-function magnets based on high-temperature...
Based on current efforts in the U.S. on the novel concept of parallel-feed RF accelerator structures, and in the U.S. and abroad in producing Nb3Sn films on either Cu or bronze, we rec-ommend that the Particle Physics community foster R&D in Superconducting Nb3Sn coated Cu RF Cavities instead of costly bulk Nb. The paper includes methods to process the coated cavi-ties at temperatures...
In a linear collider, the colliding beam has to be flat in the transverse plane to suppress energy spread by Beamstrahlung and to maximize the luminosity, simultaneously. In the current design of ILC, the flat beam is realized by the asymmetric emittance generated by the radiation-damping effect. We propose to generate the equivalent beam directly in the injector linac employing the emittance...
Novel iron lamination with additional interlaminar insulation has been successfully developed for magnet cores of fast kicker magnets in particle accelerators. By minimizing the eddy current induced between core laminas, a pulse profile of the excited magnetic field has been significantly improved up to a few MHz range. The magnet core is formed by alternately stacking thin steel and...
Coupled-bunch instability arising from impedances of higher-order modes (HOMs) in RF cavities is a problem to be suppressed in high-current, low-emittance electron storage rings. As a countermeasure against the problem, we have developed a compactly HOM-damped cavity resonating in the TM020-mode at a frequency of 509 MHz. The damping structure compromises circumferential and shallow slots in...
The development of ERLs has been recognized as one of the five main pillars of accelerators R&D in support of the European Strategy for Particle Physics (ESPP). The international panel in charge of the ERL Roadmap definition recognized PERLE project as “a central part of the roadmap for the development of energy-recovery linacs”, with milestones to be achieved by the next ESPP in 2026....
The fourth-generation synchrotron light sources aim to achieve ultralow emittances and have very small dynamic aperture, which are expected to adopt on-axis injection schemes. Lower frequency rf systems are required for a large separation between RF buckets due to the limitations of kicker. We designed a 166.6 MHz normal conducting cavity with HOM damped used for the main cavity of storage...
This paper presents the design concept of the dipole magnet with 50 mm aperture, 20 T nominal field and 13% margin based on a six-layer cos-theta (CT) hybrid coil design. Due to the high stresses and strains in the coil at high field, Stress Management (SM) elements are implemented in the CT coil geometry. The results of magnet magnetic analysis are presented and discussed. The key parameters...
Seen in the light of finding ways to reduce the CO2 footprint in the Big Science world and at the same time make big saving in operating cost due to 90% lower LHe consumption I will in the presentation share the following insights:
1) initial idea and economic business case for 10-20 kA current leads
2) the 13 kA Hybrid Current Lead design by using LN2
3) the application in a test...
The control of beam emittance growth in high-current Radio Frequency Quadrupole (RFQ) accelerator is fairly challenging because of the strong space charge effect. The transverse beam emittance growth in the RFQ is well controlled in many international high power accelerator projects, while the longitudinal beam emittance growth is really significant which affects the beam transmission in the...
Additive manufacturing is a promising approach to reduce production costs for high-frequency cavities while increasing design freedom. This potential will be evaluated through studies on several cavity prototypes and their performance. Especially for the evaluation of the field distribution in cm-sized S-band cavities and thus the shunt impedance, the development of a measurement setup for...
An important problem in present accelerators is the determination of the electromagnetic (EM) wakefields and their effect in the machine performance. These wakefields are generated inside the accelerator vacuum chamber due to the interaction of the particle beam with the surrounding structure. Among the properties that characterize their impact on the machine are the beam coupling Impedance in...
Due to a recent interest in scanning thinner containers such as cars or aviation unit load devices (ULDs), lower energy linac solutions are required in order to obtain sufficient image contrast. In this work, we present the complete design of a C-band, bi-periodic, 2 MeV electron linac to fulfil this need. Multi-objective optimisation techniques are employed to optimise the RF cavities for...
Fringe fields at the entrance and exit of multipole magnets can adversely affect the dynamics of particles in the beam, but there is also the possibility that fringe fields of the right form could be used to enhance the accelerator performance. Accelerator design work could benefit from efficient and realistic models of multipole fringe fields at an early stage in the design process. We...
Thanks to recent evolutions of electromagnetic computer-aided engineering tools, nowadays the simulation of complex particle accelerator components is feasible by commercial software packages. A practical limitation of these tools is strictly related to the solver ability to discretize real devices’ material and geometry into a numerical model, which, in some particular situations, could lead...
Due to the beam in the storage ring has a very low vertical emittance. The angular dispersion induced microbunching (ADM) scheme is used to generate high brightness coherent synchrotron radiation. To apply a similar scheme in a linear accelerator, it is necessary to reduce the vertical emittance of the beam in the linear accelerator. Generally, angular-momentum-dominated round beams can be...
Grid-controlled electron gun usually uses specially designed power supplies to supply power, the performance of the power supplies can directly affect the beam performance of the accelerator. In this paper, a nanosecond power supply for a grid-controlled electron gun is designed. It uses avalanche transistors and superimposes Marx generators to improve the power. Finally, its rise edge is less...
For the Elettra 2.0 upgrade project, a new class of DC power converters have been internally designed and eventually installed in a number of around 1000 pieces to power multipole and corrector magnets in the synchrotron storage ring. In order to fulfill evolving scenarios over the expected lifecycle of the accelerator, the power converters will be supervised by one of the most advanced...
The tracking code PLACET is widely used in the linear collider community to simulate the beam dynamics. It is a powerful tool for analyzing the static and dynamic imperfections in the lattice and has many built-in correction techniques. The original PLACET code was written in C with a TCL interface. Detailed data analysis including plotting is often performed with other programming languages,...
Space charge forces represent main induced effects in an RF-injector that degrade the beam quality. In this scenario the laser distribution sent on the photocathode acquires an
important role in the emittance compensation process, as the slice analysis shows. A novel model of space charge forces is proposed for bunch with arbitrary charge distribution to derive expressions of self-induced...
Acceleration for a muon collider will have to be extremely fast to ensure efficient transmission of the decaying beams, with acceleration times of the order of 1ms. One of the proposals for such a machine is centered around a rapid cycling synchrotron (RCS), a hybrid lattice of cells with alternating superconducting and resistive dipole magnets. Resistive magnets will swing from negative to...
The Dynamic Aperture (DA) is an important concept for the study of non-linear beam dynamics in a circular accelerator. The DA is defined as the extent of the phase-space region in which the particle's motion remains bounded over a finite number of turns. Such a region is shaped by the imperfections in the magnetic fields, beam-beam effects, electron lens, electron clouds, and other nonlinear...
Klystrons and IOTs are widely used in accelerators as high-power RF sources. Development and optimization of klystron and IOT designs is aided by the use of different simulation tools, including highly efficient large-signal codes. We present an overview of the advances in the code development and modeling using Naval Research Laboratory (NRL) set of TESLA-family of large-signal codes,...
Vertical Fixed-Field Alternating Gradient (vFFA) accelerators exhibit particle orbits which move vertically during acceleration. This recently rediscovered circular accelerator type has several advantages over conventional ring accelerators, such as zero momentum compaction factor. At the same time, inherently non-planar orbits and a unique transverse coupling make controlling the beam...
Thus ends 63 years without a theory of longitudinal capture able to predict the final beam distribution and optimize the voltage law. We show the relationship between average values of the initial and final Hamiltonian is a universal function independent of voltage law, provided the adiabaticity parameter is small. The deviations from average are also given. This means the bunch profile and...
Design of circular lattices involves optimizing figures of merit (FoMs) characterizing the beam properties subject to the constraint that the beam distribution function be approximately periodic in trips around the lattice. We have developed an algorithm that accomplishes this with minimal computational effort. The algorithm takes advantage of recent developments in adjoint techniques * that...
It is often required to estimate the effect of small perturbations of design parameters on various performance metrics of RF sources as a part of optimization and sensitivity analysis. The direct approach, assuming an accurate simulation code is available, is to change slightly the value of an input variable of interest; a simple example is a calculation of how a small change in klystron...
High brightness electron beams enable a wide spectrum of applications ranging from short wavelength radiation sources to high gradient wakefield acceleration. The rich dynamics that are intrinsic in charged particles accelerated in complex systems require a careful description in the analysis and design of a given machine, particularly regarding its stability. Numerous computer codes are in...
The microbunching instability is one of the most significant effects,
which can lead to a severe degradation of the beam quality in the linac
section of free-electron lasers.
Direct analytical treatment of the microbunching instability is however
challenging.
In particular when multiple bunch compression stages are considered,
an exact closed-form expression for the charge density of...
The cost of a klystron for the SNS is estimated to be in the $200K range. A magnetron with the same power level is about one-fourth the cost. With ancillary equip-ment to functionally duplicate the performance of the klystron and allowing for the reduced lifetime of the magnetron compared to the klystron, about half the cost. Additional operational cost savings are related to the 805 MHz...
The ALBA synchotron operates in a Touschek dominated lifetime regime, which depends mainly on the momentum acceptance and the transverse beam size along the machine. Although in the current ALBA machine the RF dominates the momentum acceptance, this will not be the case for the foreseen upgrade of the machine ALBA-II. For this reason, we have developed an algorithm to optimize the beam...
While the design of the ALBA-II is in progress, it is required to assess the consequences of realistic imperfections such as alignment tolerances and magnetic errors. Compensation of insertion device induced optics variation has been studied, as well as the small impact on the emittance due the introduction of 3 T superbends. We demonstrate that non-linear optics is rather robust in the...
Hefei Advanced Light Facility (HALF), a planned key mega-science facility approved by the Chinese government in 14th five-year plan, will be constructed in Hefei, China, and National Synchrotron Radiation Laboratory (NSRL) is responsible for the construction. HALF is a 4th generation diffraction limited synchrotron radiation light source which includes a 240 m injector, a 180 m transport line,...
KIT operates the storage ring KARA (Karlsruhe Research Accelerator) as an accelerator test facility, which serves as a testbed for different electron beam-based experiments. Thus, it motivates to study the beam conditions extensively.
To extend the existing characterisation of non-linear parameters, the amplitude dependent tune shift (ADTS) was measured. ADTS is typically controlled by...
Many high intensity proton or ion accelerators employ sources with solenoidal magnetic fields that produce beams carrying a large amount of angular momentum. To simulate such beams, one has to generate a 4D transverse phase space distribution with the right amount of angular momentum as initial conditions. In this paper, we first show that such distributions can be obtained through different...
A new method is introduced to process the closed orbit modulation by two corrector magnets modulated with sinusoidal waveforms. The new method can extract linear optics information from tens of thousands of orbits and represent such information with only a few parameters per beam position monitor. The concise form makes it easy to fit for linear lattice errors. The method has been demonstrated...
Beam splitting can be performed by adiabatic crossing of a given one-dimensional non-linear resonance. This process is routinely used at the CERN PS to deliver the proton beam to the SPS fixed-target physics. To improve the efficiency of the intensity sharing between the various beamlets, a dipole kicker can be used to excite the beam during the resonance crossing process. This entails a...
We explore the physics of high-current electron beam propagation through the accelerating cells of linear induction accelerators (LIAs), using a field-adapted coordinate transformation that extends the usual rotating Larmor frame analysis to account for simultaneous acceleration. This is useful for LIAs, since the focusing solenoids must be integrated into the accelerating cells to transport...
Single-bunch instabilities are among the major effects limiting beam intensity in synchrotrons. In the case of a light source with ultra-low emittances, this might be a critical issue causing poor performance of the synchrotron. This study elaborates on the case of the Diamond-II storage ring showing the results of particle simulations for different configurations of the updated lattice and...
This study primarily discusses a unique topology for constructing a double full bridge circuit. The study establishes a push-pull inverter model and analyzes the balance circuit in its architecture. This allows the power supply to initiate the balance circuit and ensures the TPS booster magnet power supply operates smoothly in a safe and balanced voltage region when magnet energy is...
As part of the Diamond-II upgrade project, the booster synchrotron is due to be replaced with a low-emittance solution that enables efficient injection into the Diamond-II storage ring. The new booster lattice uses cells of combined-function gradient bends that integrate dipole, quadrupole and sextupole components into single magnets, alternating between focussing and defocussing bends....
For an integral part of electron-ion collider (EIC) de-sign, the crab crossing scheme provides a head-on collision for beams with a nonzero crossing angle. Recently we provided a framework for accurate numerical simulations of beam-beam effects with crabbing crossing dynamics. The framework was implemented in a simulation code package named “CASA BeamBeam”. We offer com-prehensive formulas for...
Formulae to compute the footprint (amplitude-dependent detunings) and Resonance driving terms RDT, generated by long-range beam-beam collisions and wire correctors have been implemented in a Python code. The paper briefly outlines the method and code and provides several examples of its usage. The maximum extent of the footprint (in geometric sense) can be efficiently computed.
We adopt the standard field matching technique to solve the general electromagnetic problem consisting of two parallel layers with arbitrary complex relative permittivity and permeability. Analytical formulae for the longitudinal impedance are discussed in the general case, and in the specific case of a two-layer system consisting of a metal-coated ceramic chamber. The solution of the...
The potential in the Radio Frequency Quadrupole (RFQ) can be expressed as a sum of a transverse multipolar expansion: $\sum_{m=1}^\infty{A_{0m}}\left(\frac{r}{r_0}\right)^{2m}\cos(2m\theta)$, and a longitudinal term expressed as sum of Bessel functions: $\sum_{m=0}^\infty\sum_{n=1}^\infty A_{nm}I_{2m}(nkr)\cos(2m\theta)\cos(nkz)$. Since the paper of Kapchinskii and Teplyakov...
Minimizing resonance driving terms (RDTs) is a traditional approach to enlarge the dynamic aperture (DA) of a storage ring. However, small RDTs can not guarantee a large DA. In this paper, the fluctuation of RDTs along the ring is taken into consideration. A large number of nonlinear lattice solutions based on one double-bend achromat lattice are analyzed. The results show that minimizing the...
The CERN Linear Electron Accelerator for Research (CLEAR) has been operating since 2017 as a user facility providing beams for a large variety of experiments. Its RF photocathode-based linear accelerator can accelerate electrons up to 220 MeV with a bunch charge of 0.1-1.5nC with single or up to 150 bunches per train. The flexibility of providing various beam parameters following user demands...
Transverse wigglers and wakefield structures are promising candidates for imparting arbitrary correlation on transverse and longitudinal phase spaces respectively. They provide sinusoidal electromagnetic fields that become building blocks for Fourier synthesis. We present the progress of arbitrary correlation generation using transverse wiggler and wakefield structures.
The CERN’s Electrical Power Converters group is responsible for around 4000 power converters controlled, monitored, and diagnosed using Function Generator/Controller (FGC) devices. These devices run either on in-house designed embedded hardware (FGC2, FGC3) or in Front-End Computers. The latter flavour of devices is encoded in the FGCDv1 framework, which also implements the logic interfacing...
CERN's North Area comprises several target and experimental systems and is a zone of interest for future development. Provision of beam to this area relies upon several beam-intercepting devices located in various branched transfer lines from the Super Proton Synchrotron. In several lines, these include a primary production target system of beryllium plates followed by a combined collimation,...
In ultralow-emittance synchrotron light sources, harmonic RF cavities are very useful to lengthen the beam bunches by which the adverse effects due to intrabeam scattering can be mitigated. We are developing a 1.5-GHz TM020-type normal-conducting harmonic cavity which is to be used for the KEK future light source project. The harmonic cavity using the TM020 resonant mode has distinct...
Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particles species in an accelerator to predict and understand beam losses, secondary radiation,...
High luminosity electron-positron linear colliders constitute a fundamental instrument in the field of elementary particle physics. The ``Cool copper collider", or C3, is a proposal for a 250 COM GeV Higgs factory, with possible extension to the TeV-scale, and it represents a promising candidate for the near future high energy physics. The C3 infrastructure is conceived as a modular facility...
The accurate analysis of any possible source of beam instability is mandatory for the design of a new particle accelerator, especially for high current and ultra low emittance synchrotrons. In the specific case of instabilities driven by the coupling between the charged particle beam and the electromagnetic field excited by the beam itself, the corresponding effect is estimated through the...
The NEWGAIN (NEW GAnil INjector) project aims at supplying higher mass-to-charge ratio ions (from A/Q=3 to 7) with an energy of 590 keV/A to the present SC-Linac of SPIRAL2. It comprises a new SC source, a dogleg LEBT, an 88 MHz RFQ, and a MEBT, optimized for a current of up to 350 uA of uranium. Additionally, an extension of the present LEBT is considered to merge into the new one. This paper...
At EuPRAXIA@SPARC_LAB an X-ray FEL user facility is driven by a plasma accelerator in the particle-driven configuration where an ultra-relativistic beam, the driver, through a plasma generates a wake of charge density useful for accelerate a witness beam. The electron bunches are generated through the so-called comb technique in an RF injector that consist of a 1.6 cell S-band gun followed by...
The upgrade of the European XFEL to support a future high duty cycle (HDC) operation mode requires new design concepts for the photoinjector. In particular, the electron gun is crucial for achieving high quality beams at high peak currents. Among other variants, a 1.6-cell TESLA-type RF-gun is the preferable solution for the HDC EuXFEL. The SRF gun design, however, requires the application of...
At KEK a design of the compact 10 MeV, 50 mA accelerator for irradiation purpose was proposed. Current design includes a 100 kV thermionic DC electron gun with an RF grid, 1-cell normal-conducting buncher cavity, and Nb3Sn superconducting cavities to accelerate the beam to the final energy of 10 MeV. The goal of the present beam dynamics study is the beam loss suppression (to the ppm level),...
Accelerating technology is evolving towards compactness and high intensity. In such a scenario, beam loading effects result in significant energy losses for long trains of bunches. To address these effects, we generalised the Beam Loading module of the tracking code RF-Track to allow the study of beam loading independently of the particle type and velocity or the accelerating cavity design....
The Extremely Brilliant Source (EBS) at the European Synchrotron Radiation Facility (ESRF) is a 4th generation light source operating with a horizontal emittance of 135 pm. This low horizontal emittance reduces the lifetime in filling modes with high current per bunch. This will be alleviated in the future with an active 4th harmonic cavity. In order to simulate the effect of the 4th harmonic...
The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab employs recirculating linac SRF technology to generate a high polarization 12 GeV electron beam
for nuclear physics users. New opportunities to study multipass energy recovery have also emerged with the proposal of a 5-pass energy recovery demonstration, ER@CEBAF. New beam optics with minimized beta functions have been...
Beam-beam effects are known to undermine the performance of the LHC during proton-proton collisions. In order to enhance the luminosity production and increase the tolerance of the working point of the machine after the High Luminosity upgrade of the LHC, it is relevant to study the possibility of using current-carrying wires to compensate long-range beam-beam effects. Following proof of...
In 2017, a proton-impact test HL-LHC collimator materials was carried out in the HiRadMat facility at CERN. The experiment, called “MultiMat”, enabled the testing of bulk and coated materials developed at CERN for different beam collimation functionalities. Manufacturing of these materials was then passed to the industry, leading to a series production for use in the collimators installed in...
Beam-induced heating of equipment can have several undesirable effects, including rendering the equipment temporarily inoperative, equipment degradation and/or damage. Hence, to avoid these problems, it can be necessary to limit beam intensity. Beam-coupling impedance mitigation of existing devices and/or design optimization of new accelerator elements are essentials to overcome these...
Beam-ion instabilities belong to a broader class of two-beam instabilities caused by the interaction of a primary beam (electron or hadron bunches) with a secondary beam (ion or electron cloud). The transverse oscillations of these beams can couple with each other. Their amplitude will grow, leading to beam losses. These instabilities can limit the operation of fourth-generation light sources...
Laser-plasma electron beams are known for their large divergence and energy spread while having ultra-short bunches, which differentiate them from standard RF accelerated beams.
To study the laser-plasma beam dynamics and to design a transport line, simulations with CODAL [1], a code developed by SOLEIL in collaboration with IJCLab, have been used. CODAL is a 6D 'kick' tracking code based...
The Upgrade from the third to the fourth-generation light source of the SOLEIL synchrotron requires significant work on the reorganization of the equipment in the storage ring. Higher performance such as low emittance, small transverse size and high brightness are expected but requires redesigning the lattice. New constraints appear, requiring innovative designs of insertion device (ID) in...
The advanced storage ring light source needs to realize ultra-low emissivity beam operation, and improving the Touschek lifetime puts forward higher requirements for the performance of RF cavity. In this paper, a novel bimodal normal conducting RF cavity is proposed. In one cavity, two power sources will be connected at the same time to realize the simultaneous operation of the two...
Linear coupling in storage rings mixes horizontal and vertical beam motion. This is similar to the mixing of states in an atomic two-level system by a resonant laser interaction or the mixing of the two states of any spin-½ particle in static and dynamic external magnetic fields like, for example, in nuclear magnetic resonance, NMR, measurements. These coupled two-level systems are usually...
The Rapid Cycling Synchrotron is the key part of the China Spallation Neutron Source with the repetion rate of 25Hz. The lattice of the RCS is based on triplet cells with the superperiod of four. Due to ultilizing the trim quadrupoles in June 2021, the BPM OffSets were carefully measured, and the beam operation is more steady. In this paper, we will review the preparation of BPM OffSets...
A common feature in the design of low-emittance lattices is the small momentum compaction, which implies a short nominal equilibrium bunch length. A short bunch length can lead to beam-induced heating of the storage ring vacuum components, and, combined with the small transverse emittances, can degrade the beam quality and pose severe limitations on the beam lifetime. To mitigate the...
The description of coupling phenomena in electron storage rings is extended beyond the very common formula based on the coupled Hamiltonian [1] into the region where the small coupling is in competition with damping and diffusion from synchrotron radiation. In the derivation, the moment mapping approach is used in combination with the simplified simulation of radiation effects introduced by...
The upcoming Jefferson Lab K-Long experiment at Hall D will require unique beam conditions with a much lower bunch repetition rate and atypically high bunch charge. To optimize the Continuous Electron Beam Accelerator Facility (CEBAF) injector for this experiment, we performed Multi-Objective Genetic Optimization (MGO) using General Particle Tracer (GPT) to determine the magnetic elements and...
CERN-MEDICIS is an isotope mass separation facility for biomedical R&D located in a class A laboratory, receiving up to 50% of the 1.4GeV PSB protons. It was commissioned with radioactive ion beams in 2017. MEDICIS has operated for the past 5 years in batch mode, with targets irradiated in a dedicated beam dump station at HRS, and with external sources provided by cyclotrons and nuclear...
Over recent years four dedicated facilities have been built at Daresbury Laboratory by a team working on thin film SRF cavities. Firstly, a conventional DC resistance facility allows measurements of critical temperature and residual resistance ratio. In addition, three other facilities were designed in house to address superconducting thin film (STF) characterisation specific to cavities. In a...
Measurement of hadron beam emittances with very high dynamic range, one part-per-million and above, become available recently. This level of dynamic range is required for studying the origin and evolution of the halo in high intensity hadron linacs. There are no established or commonly known metrics to describe such distributions. Using data from the emittance measurements of 2.5Mev H- beam at...
The insertion device for FAXTOR, the new hard XR tomography beamline at ALBA, is a 54mm-period in-vacuum wiggler. The device is of hybrid PM-type, consists of 11 poles for a total magnetic length of 362mm, and it will operate at a minimum mechanical gap of 5mm. The device has been manufactured by AVS Company. During the manufacturing process, the field quality of each individual magnetic...
In this paper, the dynamic response measurement of fast corrector at the High Energy Photon Source (HEPS) is reported. The measurement system for the fast corrector of the HEPS is based on a flat coil with high cut-off frequency. Both amplitude-frequency response and step response are measured. The measurement results indicate that the open-loop bandwidth of the fast corrector is higher than 5 kHz.
In the framework of the High Luminosity Upgrade of the LHC (HL-LHC) the beam intensity from the injectors must be doubled while keeping longitudinal beam parameters unchanged. As such, high-quality beams with high intensities are required also from the Proton Synchrotron (PS). The beam coupling impedance plays a crucial role and mitigation measures must be taken to remain within a stringent...
Following the successful implementation of the LHC Injectors Upgrade (LIU) project, the CERN injectors were re-commissioned in 2021 and have been delivering beam to the LHC since 2022. The operationally delivered beam is well within the specifications regarding its brightness. However, heavy population of non-Gaussian tails of the transverse beam profiles were observed.
These tails lead to...
Neural network (NN) has been tentatively combined into multi-objective genetic algorithms (MOGAs) to solve the optimization problems in physics. However, the computationally complex physical evaluations and limited computing resources always cause the unsatisfied size of training set, which further result in the combined algorithms handling strict constraints ineffectively. Here, the...
A 1.2-m-long superconducting wiggler with the peak field of 4.3 T and period length of 70 mm has been recently installed for the High energy Engineering X-ray (HEX) Diffraction beamline at Cell 27 of NSLS-II Storage Ring. The commissioning result for the orbit feedforward system will be presented, including the uncorrectable dispersive pattern in horizontal orbit and non-negligible hysteresis...
HZB has completed the commissioning of SupraLab, a complete cavity processing and testing facility. It has been used to recover several superconducting cavities for different accelerators. This article describes all the tested and validated steps from cavity processing to cold rf test and module assembly. They include approved filed-emission free cleanroom work, on-site chemical processing,...
The RF Accelerator Research Division at SLAC is developing fully integrated linear accelerator systems for low energy applications, with a smaller footprint and higher efficiency than facility-scale accelerators. These systems are packaged as single units that include the high voltage power supply, RF sources, controls, and the linac structure itself. A considerable part of the effort is in...
The Iranian Light Source Facility (ILSF) is in the detailed design phase. It will operate at 3 GeV and 400 mA with an ultra-low horizontal emittance of 0.27 nm. rad. The main storage ring combined dipole magnet has a 0.56 T magnetic field and a -7 T/m gradient. It can serve as a soft X-ray source, and there are several ways to achieve hard X-rays; one is to use a high-field dipole. It is...
The standard injection scheme of ILSF is composed of 2 septum and 4 kicker magnets installed in a 7-meter-long straight section. Further tuning of the 4 kicker devices to reduce perturbations has proven to be almost impossible since it requires having 4 identical magnets, electronics, and Ti-coated ceramic chambers. Different from pulsed dipole kicker magnets used in a conventional local-bump...
The Spallation Neutron Source (SNS) Radiofrequency (RF) Systems have operated at over 98.5 percent availability for the last several operational periods. The implementation of a more stringent goal for the SNS RF – to exceed 99 percent availability – coupled with the more general desire to increase reliability for accelerator-driven systems has required a more subtle approach to reducing...
It took a decade to develop the 500-MHz module for the Solid State Power Amplifier (SSPA) in NSRRC. Performance of a single module was gradually improved to reach a steady output power of 960W by using the RF chip IC-BLF578XR. Heat dissipation unit and high-efficiency power supply are key issues in improving integral performance (49.5% RF power) of the single module. A 110-module SSPA tower...
The PETRA IV upgrade project is aiming at building a 6 GeV diffraction-limited light source. The storage ring’s off-axis accumulation injection scheme will allow generating a wide range of filling patterns for the needs of photon science users. To preserve high beam quality and low transverse emittances it is imperative to ensure beam stability against collective effects. In this paper we...
We present a theory of coupled-bunch longitudinal instabilities for storage rings that employ a harmonic cavity to lengthen the bunch. We find growth rates associated with the m=0 and m=1 modes for both "optimally" and "overstretched" bunches; the former is a Robinson-like instability, while the latter corresponds to the "periodic transient beam loading" effect described in Ref *. By...
A promising approach for compact linear accelerators in the THz frequency range is based on dielectric-loaded waveguides (DLWs). Higher breakdown fields expected at THz frequencies should enable higher acceleration gradients. However, the accelerating mode of a cylindrical DLW (TM01) is not the fundamental and only mode inside the waveguide at operating frequency. Therefore, a...
For the upgrade of the 6 GeV synchrotron light source PETRA III into a diffraction-limited storage ring PETRA IV it is planned to replace the 23 m long double-bend achromats by hybrid six-bend achromats (H6BA). The high packing density of elements in the H6BA cells requires that the distance between magnets are small with only a few centimeters between the yokes for some of the magnets....
NHa and IBA are collaborating to develop a new cyclotron dedicated to hadron therapy.
This cyclotron is based on two symmetric NbTi superconducting coils, cooled at 4,3 K in helium bath. The cold mass is 15 tons, the diameter of the cryostat is about 5 meters. 470 liters of liquid helium are cooled by cryocoolers, and the coils are maintained at superconducting temperature by using a...
Significant developments in the future of linear accelerators including the operation of high gradient cavities, novel cathodes, and improved magnet designed are enabled by cryogenic operation of various subsystems and components. In order to address the growing needs of traditional infrastructure operating in a new low temperature regime, we have commissioning infrastructure for the testing...
Minimizing projected emittance of high brightness electron beam is important for efficient overlap between electron beam and radiation pulse in an FEL facility. Coherent synchrotron radiation (CSR) emission in a single bending section in the beam transport system usually introduces different slice energy modulation hence different slice transverse kicks in the designed dispersion-free lattice,...
As various experimental reactors in Europe are already
or will be decommissioned over the next years, new neutron
sources will be necessary to meet the demand for neutrons
in research and development. The High Brilliance Neutron
Source is an accelerator driven neutron source planned at the
Forschungszentrum Jülich. The accelerator will accelerate
a proton beam up to an end energy of 70...
Korea-4GSR is a greenfield electron storage ring with circumference of 800 m and natural emittance of 60 pm. Preliminary conceptual lattice design of Korea-4GSR is fully periodic 28-cell H7BA. By keeping the conceptual design as much as possible, we have been exploring modification on the design for higher brightness and better nonlinear properties such as dynamic aperture and Touschek...
The damage mechanisms and limits of superconducting accelerator magnets caused by the impact of high-intensity particle beams have been the subject of extensive studies at CERN in the recent years. Recently, an experiment with dedicated racetrack coils made of Nb-Ti and Nb3Sn strands was performed in CERN’s HiRadMat facility. In this paper, the design and construction of the sample coils as...
Particle accelerators and light sources are some of the largest, most data intensive, and most complex scientific systems. The connections and relations between machine subsystems are complicated and often nonlinear with system dynamics involving large parameter spaces that evolve over multiple relevant time scales and accelerator systems.
Data Intensive Science offers exciting prospects...
We have designed and fabricated a new DC septum magnet for modern accelerators. Septum magnets feature a dipole magnetic field deflecting designated beams at one side of the septum while providing no deflecting field on the other side. Conventional direct-drive type DC septa is embedded with coils inside the magnet gap, which usually results in rather high current density in the thinner septum...
Recently, a double-double bend achromat (DDBA) lattice is designed for Hefei Light Source (HLS), a second-generation synchrotron radiation light source, which reduced the natural emittance a lot. In this paper, to further reduce the emittance and improve the brightness, a DDBA-hybrid 6BA lattice is proposed and applied to the design for the potential HLS upgrade. With more bending magnets, the...
In Particle accelerators, commissioning of a complex beam line requires extensive use of computer models. When the as-built beam line cannot be exactly modeled by the simulation (due for example to mechanical errors or to the extensive usage of the non-linear focusing forces), the solution found in the simulations needs to be adjusted. Thus, it is often required to modify the settings by...
We describe an experiment to demonstrate Derbenev’s flat-to-round (FTR) and round-to-flat (RTF) optical transformations*, designed to match electron beams from a high-energy storage ring into and out of a solenoidal cooling channel. We are using a linear transport system with a design optimized by a computationally-efficient adjoint moment equation technique developed by our group for general...
Expressions to quantify betatron mismatch and chromatic effects are frequently used in accelerator physics, but their derivations are not given in standard text books, making their interpretation difficult. First parameters describing betatron mismatch are introduced using normalization with respect to reference Twiss parameters describing a lattice. In a second step, the derivatives of these...
Synchrotron light sources of the 4th generation typically use varying radius dipoles (also called longitudinal gradient bends). The longitudinal variation of these magnets needs to be properly modeled as the preconditions of the common local 2D approximation are only fulfilled at certain places.
We describe our concept of modelling such magnets using basis functions (approximately)...
Cornell is designing a standalone superconducting radio-frequency (SRF) accelerating cryomodule which utilizes a conduction cooling scheme in place of liquid helium. A key component of this system is a new single-cell 1.3 GHz Nb$_3$Sn-coated SRF cavity. This cavity was designed based on Cornell’s ERL injector cavities in order to replicate their RF properties, such as being able to operate at...
In 2018, an Advanced Electron Test Facility, named Dalian Advanced Light Source (Pre-research) was proposed and approved, which consists of an electron source, two cryomodules based on superconducting technology, a Transverse Deflecting Structure (TDS) system, and beam dumps. As an eminently practical instrument, TDSs are used for longitudinal and transverse phase-space analysis in Free...
Multi-objective evolutionary algorithms (MOEAs) are usually used to optimize two or three objectives in the accelerator field and perform well. However, the optimization objectives are often equal to or greater than four for an accelerator, which causes severe deterioration of the performance of these algorithms. Recently, many-objective evolutionary algorithms (MaOEAs) that can solve the...
In this paper we present the design and validation of a compact LEBT for the LINAC 7 project. Specifically, the LINAC 7 project focuses on building a new generation, low-energy, low-current compact accelerator. The core idea is to achieve an energy of 7 MeV in less than 12 m while maintaining enough current to generate isotopes for medical uses.
Through this work we explain the procedure we...
Transverse deflecting cavity (TDC) providing time-dependent kick with fixed polarization is an important tool for beam diagnostics and manipulation. Recently, several types of novel TDC with variable polarization have been developed to fulfill the requirements of multi-dimensional phase space measurement of high-quality electron beam as well as fast scanning in proton therapy. Based on the...
The Hefei Advanced Light Facility (HALF) is a future soft X-ray diffraction-limited storage ring at National Synchrotron Radiation Laboratory (NSRL), which aims to decrease the horizontal emittance to improve the brilliance and coherence of the soft X-ray beams. The lattice of the ring depends on the use of many short and high field multipole magnets, dipole-quadrupole magnets with high...
The PETRA IV storage ring is a project planned to upgrade the synchrotron light source PETRA III at DESY. The main aim is to decrease the horizontal emittance as low as 20 pmrad. This nominal emittance will be achieved by a hybrid six bend achromat lattice (H6BA) and a series of damping wigglers. The magnets used in this lattice will be a combination of resistive quadrupole and higher...
The Lanzhou Light Ion Cancer Therapy Facility (LLICTF) is a compact medical accelerator currently under construction. It is designed to treat cancer using a 230MeV, 30mA H+ beam and a 85MeV/u, 1mA 3He2+ beam. The facility comprises two ion sources, a low-energy beam-transport (LEBT), a Radio Frequency Quadrupole (RFQ), a medium-energy beam-transport (MEBT), and the main ring accelerating...
This paper describes the design progress of the electron gun, and solenoid of 50 MW class klystron at C-band frequency (5720 MHz) for CEPC LINAC. The beam optics is designed in DGUN code for a space charge beam current of 318 A at an acceleration potential of 350 kV with average cathode loading of less than 6.0 A/cm^2. The maximum surface electric field at the beam optics and high voltage...
For an experimental setup at the laser plasma accelerator (LPA) at the JETi Laser at Jena, Germany, an energy upgrade of a linear beam transport line has been studied. The transport line, originally designed to match the LPA beam to a transverse gradient undulator (TGU) at 120 MeV and successfully experimentally tested in 2014, will be upgraded to up to 300 MeV by employing stronger focusing...
The investigation of the processes, materials, technology and welding procedures used to manufacture accelerating components for maximum accelerating gradient (>100 MV/m) and minimum RF breakdown probability has led us to the proposal of hard-copper structures in Ka-Band made of multiple parts.
In this paper, we illustrate the TIG welding tests, including visual inspection and temperature...
In order to provide hard X-rays with a 1.5 GeV electron ring, a new superbend-magnet will be used in the middle of each standard cell at Wuhan Advanced Light Source (WALS). The design, assembly, and detailed magnetic measurement of the superbend-magnet prototype has been finished. It is a three-stage combined magnet, with a high-field permanent magnet in the middle and two low-field...
We image the five-dimensional phase space distribution of a hadron beam in unprecedented detail. The resolution and dynamic range of the measurement are sufficient to resolve sharp, high-dimensional features in low-density regions of phase space. We develop several visualization techniques, including non-planar slicing, to facilitate the identification and analysis of such features. We use...
The Future Circular Collider (FCC) study develops the technologies for next generation high performance particle colliders and accelerating structures. It places high requirements on the performance of Superconducting Radio Frequency (SRF) cavities used to accelerate the particle beam. While niobium-coated copper cavities are being considered for FCC-ee, alternative superconducting materials...
The radio frequency system of High Energy Photon Source adopts a double-frequency design with a main frequency of 166.6 MHz and a third harmonic frequency of 499.8 MHz. There are six normal-conducting cavities on the booster, and each cavity will be driven by a 500-MHz 100-kW solid-state amplifier (SSA) with high modularity, high efficiency and sufficient redundancy. Five 166.6-MHz and two...
Since its operation in 2013, Taiwan Photon Source (TPS) has been constantly maintaining and developing new technologies to improve its power electronics systems. The availability of GaN FETs power devices with integrated drivers and protection functions has allowed designers to achieve new levels of power density and efficiency in these systems. This paper explains how to use GaN FETs for...
The extraction system of the superconducting AGOR cyclotron consists of an electrostatic deflector and three electromagnetic channels. As the electrostatic deflector has only a moderate field strength (<100 kV/cm), the first electromagnetic channel has to generate a rather strong dipole component resulting in current densities up to 169 A/mm^2 in water-cooled copper coils.
In the original...
The invention relates to a special power supply for injection of a compact electronic storage ring and an injection method, belonging to the technical field of special power supply for particle accelerators. The power supply includes a DC power module, a switching power module, a high-frequency resonant capacitor and a control circuit. The invention adopts the series resonance scheme, drives...
Lens based proton radiography is a powerful diagnostics technique capable of resolving ultra-fast processes on the ns-scale in dense matter with unprecedented micrometer spatial resolution. This unique performance is currently realized by the use of a chromatic imaging system consisting of four quadrupole magnets that are configured to suppress the most significant 2nd order position dependent...
An air-core pulsed magnet named Ceramics chamber with integrated Pulsed Magnet (CCiPM) was developed as a fast dipole kicker at first. A prototype of a dipole CCiPM was designed and tested successfully at KEK Photon Factory (KEK-PF). Because of the feature of an air-core magnet, a CCiPM can also generate an octupole magnetic field for pulsed multipole magnet injection. Compared with the pulsed...
The injector of Hefei Advanced Light source Facility (HALF) will choose the full energy injection method with beam energy up to 2.2 GeV by a LINAC, which will contain 40 S-band normal conducting traveling wave tubes. Quasi-symmetric single-feed racetrack couplers were used in design of TW tube utilized for reduction the field asymmetry inside the coupler cavity. The design and test result of...
After 20 years of use, the Hall-probe system at the Na-tional Synchrotron Radiation Research Center (NSRRC) has poor measurement reproducibility. The granite bench is 6m long and is robust but the Hall-probe stage with air bearings has deteriorated. To create a reasonable operat-ing space for field correction for an insertion device (ID), the distance between the ID and the measurement system...
SLAC has been developing the parallel finite element electromagnetics simulation suite ACE3P (Advanced Computational Electromagnetics 3D Parallel) for accelerator modeling using high performance computing (HPC) platforms. ACE3P employs the parallel high-order finite-element method with conformal (tetrahedral) mesh for high-fidelity representation of geometry, and further accuracy can be...
An RF Fundamental Power Coupler(FPC) designed to operate under 7 kW CW for 325 MHz superconducting(SC) single spoke resonator(SSR) in the high energy SC Linac of the RAON. A prototype FPC has a coaxial shape with an impedance of 98 ohm and an outer radius of 36 mm. It is checked that the MP exists within the SSR operating range. Reduction or elimination of the MP is estimated applying DC...
Permanent Magnet (PM) based bending magnets are state-of-the-art concepts to gain stable beam operation and to reduce the power consumption of the magnetic system in an accelerator. This is even more true in injector and beam transport beamlines with fixed beam parameters and low repetition rates. An example is the B2PT magnet in the BESSYII transfer beamline between booster and storage ring....
The Advanced Light Source Upgrade (ALS-U) project at Lawrence Berkeley National Laboratory (LBNL) is major upgrade of the ALS that involves the design and installation of a new Accumulator Ring and an upgraded Storage Ring. The RF High Power Amplifier (HPA) with 60 kW CW output power at 500 MHz is a complex and very costly piece of equipment that will provide high power RF to the accelerating...
Coherent Synchrotron Radiation (CSR) is regarded as one of the most important reasons that limits beam brightness in modern accelerators. Current numerical packages containing CSR wake fields generally use 1D models, which can become invalid in extreme compression regime. On the other hand, the existing 2D or 3D codes are often slow. Here we report a novel particle tracking codes --- DFCSR ---...
Dielectric Assist Accelerating (DAA) structures based on ultralow-loss ceramic are being studied as an alternative to conventional disk-loaded copper cavities. This accelerating structure consists of dielectric disks with irises arranged periodically in metallic structures working under the TM02-π mode.
Here, the numerical design of an S-band DAA structure for low beta particles, such as...
Particle accelerators require extensive optics measurement and correction. Due to the complexity of analytic treatments, numerical optimizations are often employed. A disadvantage of this approach is the lack of gradients, limiting optimization methods to derivative-free ones such as simplex or genetic algorithms. We explore a reformulation of beam optics that preserves gradient information by...
As multipurpose synchrotron radiation facilities, the Korea-4GSR is being promoted in Korea from July 2021 to the end of 2027. The construction project includes linac, 4 GeV booster, and storage ring. The circumference of the storage ring is about 800 meters, the beam emittance is 58 pm.rad, and there are more than 40 beamlines with 28 superperiods. A large number of electromagnets are used in...
An algorithm for determining the eigenvalues of the eigenfunctions of a
multilayer cylindrical waveguide is constructed. A relationship is found
between dispersion relations and impedances. A method for determining
the resonant frequencies of the wake field in the linear and helical
motion of a particle is described. The damping coefficients of
eigenmodes at resonant frequencies are determined.
The calculation of the volume of the phase-space stability region of hadron storage rings is currently performed through computer simulations of particles tracking in 6D coordinates, which are resource -and time- intensive processes. We have investigated in a previous paper the ability of an ensemble reservoir computing approach based on Echo State Networks to predict the long-term evolution...
Dynamic Aperture (DA) studies based on single-particle tracking simulations have proven to be a powerful tool for optimizing the performance of the Large Hadron Collider (LHC), as well as its future High-Luminosity upgrade (HL-LHC). The present paper presents the studies performed for the first year of HL-LHC operation at the beginning of the fourth operational run of the LHC. The main focus...
The design and tuning of accelerators are both complicated processes involving many physical effects. Of these, the modeling of coherent synchrotron radiation has long been one of the most complicated and time consuming. This is especially true when modeling two and three-dimensional CSR, which is often neglected in state-of-the-art accelerator modeling due to its time consuming nature. We...
Solid-state RF amplifiers (SSAs) are being developed to compose SIRIUS storage ring’s RF plant for operation with superconducting cavities. Each amplifier must deliver up to 65 kW of RF power at 500 MHz and a high AC-to-RF efficiency is desired to minimize operation costs. To this end, amplifier modules able to deliver 900 W with approximately 70 % DC-to-RF efficiency were designed. To combine...
The EIC Crab Cavity Low-Level Radio Frequency system will have to regulate the crabbing and uncrabbing voltages, while also keeping their sum close to zero. The system will have to reduce the crab cavity impedance to prevent transverse instabilities. It will also have to maintain extremely low RF noise levels injected to the beam. This work presents an estimate of the required performance for...
The electrodeposition of copper onto niobium using commercial acidic and alkaline electrolytes was tested. The continuous dense polycrystalline copper films were successfully obtained in aqueous alkaline-type bath containing copper sulphate, sodium hydroxide and sodium gluconate. The effect of benzotriazole and sodi-um lauryl sulphate additives on the morphology and crystal structure of the...
X-ray flash radiography is a powerful diagnostic used worldwide for investigating the structural response of matter under impulsive loading during hydrodynamic experiments. These experiments require a specific X-Ray source generated by a Linear Induction Accelerator (LIA). LIAs produce an intense electron pulsed beam, with a high-energy and providing a high dose at 1 m. Therefore,...
Fermilab Booster synchrotron requires an intensity upgrade from 4.5×1012 to 6.5×1012 protons per pulse as a part of Fermilab’s Proton Improvement Plan-II (PIP-II). One of the factors which may limit the high-intensity performance is the fast transverse instabilities caused by electron cloud effects. According to the experience in the Recycler, the electron cloud gradually builds up over...
When operated with the nominal bunch spacing of 25 ns, the Large Hadron Collider (LHC) suffers from significant electron cloud effects. During the second operational run (Run 2) of the LHC, beam-induced conditioning allowed a satisfactory exploitation of 25 ns beams for luminosity production but could not fully suppress electron cloud formation. It has since been understood that this...
Optical Stochastic Cooling (OSC) is a feedback beam cooling technique that uses radiation produced by a beam to correct particles' own momentum deviation. This system is made up of two undulator magnets, the pickup and kicker, separated by a bypass chicane that introduces a momentum-dependent path length. The beam produces radiation in the pickup and arrives in the kicker with a delay...
Elettra 2.0 is the Project finalized to upgrade the Storage Ring (SR) and part of the beamlines (BLs) of Elettra. The machine optics requires a significant number of magnets and additional coils to energize individually. More than 1200 DC power converters (PCs) are foreseen. A synergic design of the magnets and the associated PCs led to a great standardization: four current ranges (300 A, 100...
A simple acceleration of a high charge, needle-shaped electron bunch from a cathode is affected by strong correlated emittance growth due to current-dependent transverse space-charge forces. It was shown that such emittance growth could be reversed by focusing the bunch soon after it emerges from the cathode, and that one can expect to retrieve the emittance the beam was born with – the...
The exchange of transverse and longitudinal emittances is a unique feature of emittance exchange (EEX) beamline, but it is also a limitation of it at the same time. Most of the modern high-brightness injectors provide much smaller emittance in the transverse plane than the longitudinal plane. Thus, a beam passing through a single EEX beamline ends up with a large transverse emittance, which...
A crucial common parameter for the new 4th generation machines is the reduced dynamic aperture at injection point.
Will be presented the analyzed strategies and what have already been done in order to reduce the emittance of the injected beam and garantee a good injection efficiency.
Limited dynamic aperture which is in the consequence of strong nonlinearities in a low emittance storage ring, is a challenging issue from beam dynamics point of view. In the present study, we have applied three families of focusing and defocusing octupoles to the storage ring lattice with the aim of increasing dynamic aperture and beam lifetime . We have discussed different methods to...
An experiment to study damage caused by the impact of 440 GeV/c protons on sample superconducting racetrack coils made from NbTi and Nb3Sn strands was recently carried out at CERN's HiRadMat facility. This paper reports on the detailed Monte Carlo simulations performed with FLUKA and Geant4 to evaluate the energy deposition of the 440 GeV/c proton beam on the sample coils positioned in the...
Hefei Advanced Light Facility (HALF) is a fourth-generation storage ring with an emittance lower than 100 pm∙rad. To assess the real performance, in this paper, static error effects are studied and corrected for HALF. Simulation corrections of closed orbit, linear optics and transverse coupling are presented and the results show that the HALF lattice has reasonable robustness. The emittance...
We describe here field emission measurements set-up, diagnostics tools used, analysis and results developed for ESS medium and high beta cryomodules tests . For high gradient, in particular, field emission can be the mechanism which limits cavities performances. A particualar focus will be given to analysis tools developed to tack potential materials activation, due to high energy photons...
The European Spallation Source (ESS) will accelerate a beam of protons with a beam pulse width 2.86ms long and pulse repetition frequency 14Hz. The acceleration will be provided by 155 cavities, out of which 97% of the cavities are superconducting.
The first section of the ESS superconducting linac is the Spoke linac. The spoke linac increases the beam energy from 90MeV to 216MeV using the...
A source for polarized positron beams at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is being designed. The Polarized Electrons for Polarized Positrons (PEPPo) concept is used to produce polarized e$^+$e$^-$-pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. The scheme under...
The beam screen for the Future Circular hadron-hadron Collider (FCC-hh) has a baseline design based on a copper (Cu) coating. Calculations have indicated that the resistive wall impedance will be the major contributor to the beam impedance for the FCC-hh at both injection and collision and that Cu might be on the limit to ensure beam stability. To increase the safety margin, it is desirable to...
We present the results of the first experiments on 4-dimensional phase-space tracking of a single electron in a storage ring, using a linear multi-anode photomultiplier tube for simultaneously measuring transverse coordinates and arrival times of synchrotron-radiation pulses. During the next few months, full 6D tracking will be implemented. This technology makes it possible to characterize the...
Merging beams from multiple beamlines is critical to energy-recovering linear accelerators and beam-driven wakefield accelerators. Recently, a "straight-merger" beam line was proposed as a compact beamline to merge beams. The concept is based on a deflecting cavity with a superimposed dipole field. It provides a large deflecting kick at the injection phase where the RF and magnetic kicks add...
Experimental beamlines often are regularly reconfigured to meet changing requirements of the experiments and to minimize beam losses. The configuration is usually done with the help of beam optics tools like MADX. These tools offer matching capabilities which allow to find solutions in terms of quadrupole strengths. However, such solutions are found by satisfying the given constraints only and...
The beam dynamics of a bunch both longitudinally and transversely play a major role in the design process of an RF cavity, from the feasibility of cavity lengths, to the focusing schemes required to maximise capture. Often, computer simulations track particles using computationally intensive numerical techniques, which can be extremely time-consuming to run. In this paper, we present a...
Many accelerators employ axisymmetric structures, such as RF cavities, induction cells, and solenoids, to accelerate and transport charged particle beams. To analyze the motion of the beam in solenoids, it is common to make a transformation to the rotating Larmor frame. In the presence of an electric field, this transformation can be modified to obtain further simplifications in the equation...
The new fourth-generation synchrotron radiation source PETRA IV at DESY (Hamburg) will use a fast orbit feedback system to meet stringent orbit stability requirements. To this end, hundreds of fast orbit corrector magnets will be installed to minimize orbit distortions from external sources. These magnets are operated at high frequencies, creating strong eddy currents that result in Joule...
Upcoming projects requiring ~650 MHz medium-to-high-beta elliptical cavities such as Michigan State University’s Facility for Rare Isotope Beams’ energy upgrade and Fermilab’s Proton Improvement Project-II drive a need to understand magnetic RF loss mechanisms in greater detail. It remains to be seen whether flux trapping mitigation techniques used in 1.3 GHz cavities are as effective at ~650...
A higher-order-mode-damped 166.6 MHz beta=1 quarter-wave superconducting cavity is being developed for the High Energy Photon Source. The frequency variation of the cavity in all the processes comprising of manufacturing, post-processing and cooldown to 4.2 K, should be strictly controlled due to the relatively small coarse tuning range. The step-by-step evolution of the cavity frequency was...
In the lattice design of the BESSY II successor, the diffraction-limited, Multi-Bend-Achromat (MBA) storage ring BESSY III, HZB follows the approach of deterministic lattice design. MBA lattices are composed of rather simple sub-structures: the repetitive unit cell, two dispersion suppression cells at the end of the achromatic section, and the focusing doublet or triplet with the straight...
This paper is the follow-up of a previous one where we reported symmetry breaking as the main factor that establishes transverse resonance island buckets (TRIBs) close to a third-order random resonance in one of BESSY III design lattices by using a single knob. Here we present a more complete picture of the analytical framework and we show that there are two types of resonances close to which...
Field emission (FE) is one of the main reasons for the degradation of superconducting cavity quality factor. Its presence can limit the ultimate performances of superconducting RF (SRF) cavities and hence the cryomodule in which they are assembled.
For these reasons, it is essential to better understand how this phenomenon is generated and evolves from the SRF cavity preparation, in the...
Corrugated structures have been used widely in X-ray free-electron laser facilities for chirp control, fresh-slice applications, and diagnostics. In this paper, we present a general method for calculating the short-bunch wakefield of corrugated structures with arbitrary shapes. At zeroth order, we give analytical solutions via the method of conformal mapping. At first order, we give...
The Generalized Gradient (GG) formalism of Venturini and Dragt for describing static magnetic or electric fields has been implemented in the Bmad toolkit for accelerator simulations. In conjunction with this, a new method for calculating GG derivatives from a field table has been developed which avoids some of the problems of the Venturini and Dragt method. Generalized gradients are also...
Accurate and efficient particle tracking through Siberian Snakes is crucial to building comprehensive accelerator simulation model. At the Alternating Gradient Synchrotron (AGS) and Relativistic Heavy Ion Collider (RHIC), Siberian Snakes are traditionally modeled in MAD-X by Taylor map matrices generated at specific current and energy configurations. This method falls short during ramping due...
In the radio-frequency system of synchrotron light sources, it is necessary to lengthen the bunches by creating harmonic cavities to improve the beam lifetime. In this paper, we propose three harmonic cavity designs: TM010 mode cavity, TM020 mode cavity, and dual mode cavity, with the Wuhan Advanced Light Source (WALS) as the background. By comparing the beam quality, beam lifetime, and...
The growth rate of the Head-Tail mode 0 instability is related to the real part of the transverse beam coupling impedance. The SPS transverse impedance model, which includes the major impedance contributions in the machine, can be benchmarked through measurements of growth rates as a function of chromaticity. This paper summarizes the methodology established to explore a wider range of...
A solution is presented for the radiation field of a particle moving along
a helical trajectory in a cylindrical waveguide with multilayer walls. The
number of layers and their filling is arbitrary. The solution was obtained
by the partial domain method and is a generalization of the solution for a
resistive waveguide obtained earlier.
The industrial, medical and homeland security markets for low-to-moderate energy electron linacs are growing rapidly, often requiring beam currents that strongly load the accelerating fields. The two-beam accelerator (TBA) is one concept for the structure wakefield acceleration approach to an electron-positron collider. Transient beam loading effects are a significant challenge for the drive...
J-PARC MR is a high intensity synchrotron that accelerates protons from 3 GeV to 30 GeV. In MR, beam study for 1.3 MW upgrade plan is now in progress. The upgrade is done by shortening the repetition period and increasing the number of protons, and it is crucial to understand their effects on beam motion. Especially, the betatron function is one of the most important parameters that determines...
Pulsed electron beams probe the dynamics of matter out of equilibrium with high spatial and temporal resolution. Ultrafast electron diffraction in particular is sensitive to sub-angstrom, sub-picosecond scale atomic motion. To collect all the structural information available in an electron diffraction pattern, the experimentalist must control the angular magnification onto the detector plane....
This paper presents the magnetic design, mechanical design and assembly tooling design for four 500T/m Hybrid Halbach Quadrupoles with an aperture radius of 4mm. The quadrupoles will be used for capture of a 1-5 GeV electron beam produced in a plasma acceleration stage at the Extreme Photonics Application Centre which is currently under construction at Rutherford Appleton Laboratory in the...
We developed high-precision digital control magnet power supplies (MPSs) aiming at next-generation light sources such as SPring-8-II. The system consists of a high-precision ADC circuit and an FPGA that processes a proportional-integral control and pulse-width-modulation. Using the system, the current ripple and long-term stability (8 hours) of the MPS are controlled within 20 ppm. The MPS can...
A new 1.3 GHz solid-state high-power RF amplifier (SSA) has been built for the Lighthouse project in close cooperation between Cryoelectra and RI Research Instruments. The amplifier was developed by Cryoelectra as a scalable compact system with an RF-power density of 40 kW/m². Its industrial design is very reliable and easy to maintain. The SSA delivers a continuous RF output power of more...
MedAustron is a synchrotron-based ion therapy center in Wiener Neustadt, Austria, constantly working towards the performance improvement of cancer treatment. A major improvement opportunity comes from the scanning magnets system – a crucial element of dose delivery system at MedAustron - that is influenced by the bandwidth and power density of the magnet power supplies. Therefore, a novel...
A superconducting (SC) 1.5 GHz (3rd harmonic) cavity is being developed for lengthening bunch and improving beam lifetime in the Hefei Advanced Light Facility (HALF) storage ring.This SC cavity is excited by an electron beam with 350 mA current, 1 nC charge, and ~6.7 ps length and requires strong damping of higher-order-modes (HOMs) in order to meet beam instability requirements. Two fluted...
Current and historic tracking studies of the RHIC accelerator lattice find difficulty in explaining the transmission efficiency of spin polarization from the AGS extraction to
RHIC storage energies. In this paper, we discuss mechanisms that result in resonant depolarizing behavior, beyond the usual intrinsic and imperfection resonance structures. In particular, the focus of this paper will be...
Cryoelectra’s 3rd generation of solid-state RF amplifiers (SSA) for synchrotron applications is presented in the frame of a poster. The SSA delivers up to 160 kW cw RF output power at 500 MHz. The amplifier is of industrial design regarding space and maintenance requirements. Together with its redundant architecture this allows for a 24/7 operation over several months without any need of...
The MAX IV 100 MHz RF cavities are the main contributors for the 3 GeV storage ring longitudinal coupled bunch instabilities. With the knowledge of strong higher order modes (HOMs) since the design stage of the cavities, extra ports are present for the future HOM dampers. This contribution presents the electromagnetic and mechanical designs and the thermal simulation for the HOM damper...
Two types of crab cavities, one at 197 MHz and the other at 394 MHz, are designed to compensate the loss of luminosity due to a 25 mrad crossing angle at the interaction point (IR) in the Electron Ion Collider (EIC). The Higher Order Mode (HOM) damper designs of the EIC differs from the LHC designs since in the EIC the impedance budget is tighter, especially longitudinally, and in the EIC the...
The heavy-ion accelerator of the Rare Isotope Science Project (RISP) in Korea has been developed. There are three types of SRF cavity, which are 81.25MHz quarter-wave resonator (QWR), 162.5MHz half-wave resonator (HWR), 325MHz single-spoke resonator (SSR). There are 22 QWRs and 102 HWRs in the superconducting linac#3 (SCL3), and 69 SSR1s and 144 SSR2s in the superconducting linac#2 (SCL2). The...
The modeling of current and next-generation particle accelerators is a complex endeavour, ranging from the simulation-guided exploration of advanced lattice elements, over design, to commissioning and operations.
This paper explores hybrid beamline modeling, towards coupling s-based particle-in-cell beam dynamics with machine-learning (ML) surrogate models.
As a first example, we train a...
Crab Cavities (CCs) are a key component for the HL-LHC luminosity upgrade. To significantly reduce the Long-Range Beam-Beam (LRBB) effects a large crossing angle scheme is needed . The installation of 4 CCs per beam in each of the two main interaction points aims to restore the luminosity loss caused by the crossing angle. Noise injected through the Low-Level RF (LLRF) system in these cavities...
The LHC particle-physics program requires that the delivered luminosity be measured to an absolute accuracy in the 1% range. To this effect, the absolute luminosity scale at each interaction point (IP) is calibrated by scanning the beams across each other according to the van der Meer method. During such scans, the orbit and the shape of the colliding bunches are significantly distorted by...
Solid-state power amplifier systems as RF sources for particle accelerator are paving their way into industrial products due to several advantages compared with established tube technology. Within this change a demand for optimized performance as trade off from power gain and efficiency rises to reach the high-power levels and for ensuring an electrical efficient operation. When combining...
This proceeding addresses the effect of the neutral molecules trapped by the beam. It is in particular discussed the effect of a non-uniform neutral molecule distribution on the beam profile and the resulting beam lifetime. According to the trapping temperature it is discussed in a general framework how the beam profile is modified. and the consequent beam loss.
In the presence of a tune spread induced by chromaticity or amplitude detuning, decoherence will lead to the damping of the beam centroid motion after a single transverse excitation. This in turn has implications for the analysis of turn-by-turn based optics measurements, as it affects the precision of the spectral analysis. In the past, it has been shown how the effect of decoherence on...
In order to maintain the continuity of the vacuum system wall and comply with beam stability limits, radio frequency contact bridges are utilised as transitional elements in beam vacuum line interconnections. These radio frequency contact bridges must absorb and correct longitudinal, angular, and transverse misalignments brought on by mechanical motions during assembly, alignment, operating...
Sirius is a 4th generation synchrotron light source at the Brazilian Center for Research in Energy and Materials in Campinas, Brazil. The storage ring is currently operating with a normal conducting seven-cell cavity and an upgrade of the whole RF plant is foreseen to take place in the beginning of 2024. Two CESR-B superconducting cavities will be installed in the storage ring and comb-type...
Impedance modeling is an important subject in diffraction limited storage rings based light sources, due to the adopted small beam pipe as well as the tight requirements from beam collective effects. Therefore, a batch of impedance bench measurements are performed or planned for the dominant impedance contributors in HEPS, including resistive wall impedance of the NEG coated vacuum chambers,...
Recently, the Korean government decided to construct a fourth-generation storage ring (4GSR). Compared to a third-generation storage ring (3GSR), emittance is significantly smaller so that we can achieve higher photon beam brightness. This small emittance enables because of a multi-bend achromat (MBA) which necessitates high magnetic field gradients. Accordingly, the vacuum chamber aperture is...
Impedance-induced tune shifts and instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Calculation of these beam observables are obtained using both Vlasov solvers and macroparticle tracking simulations, and are compared with those observed during dedicated measurement campaigns. Thanks to improvements in the...
Nonlinear integrable optics (NIO) are a promising novel approach at improving the stability of high intensity beams. Implementations of NIO based on specialized magnetic elements are being tested at the Integrable Optics Test Accelerator (IOTA) at Fermilab. One method of verifying proper implementation of these solutions is by measuring the analytic invariants predicted by theory. The initial...
Barrier-Bucket (BB) systems provide a method to apply a short gap to a coasting beam. This is utilized for different applications, like ion cleaning, or to compensate the medium energy loss caused by internal experiments. BB-cavities are broadband cavities, and the applied signal is commonly a short sine burst, followed by a flat section at zero voltage. Since the transfer function of the...
The commissioning of the APS Upgrade storage ring will need to be completed fast in order to minimize the dark time for APS users. To help speed up commissioning, lattice commissioning simulations were developed that allow to test commissioning algorithms and automate the entire process. In this paper, we describe recent improvements and additions to the commissioning simulations. We cover...
RF pulse compressors are used for higher acceleration gradient in the KEK electron positron injector linac. S-band spherical-cavity type pulse compressors (SCPC) with a high quality factor Q of 100,000 have been newly developed, and one of them was installed in the linac. The performance of the compressor is characterized by its cavity parameters such as resonant frequency and Q-value....
As the series production of PIP-II 650 MHz low beta cavities approaches, INFN-LASA R&D activities on cavity prototypes are ongoing. Different surface treatments have been exploited in a joint effort between INFN and FNAL, to establish the series cavity recipe. Meanwhile, the vertical test facility has been upgraded for the test of high-Q cavities, by increasing its capability to reduce the...
It is crucial to have a particle beam with high intensity and small emittance in a timely manner. The main challenges restraining the availability of the beam to the user and limiting the beam intensity in storage rings are a lengthy optimization process, and the injection losses. The setup of the Injection Beam Line (IBL) depends on a large number of configurations in a complex, non-linear,...
Passive superconducting harmonic cavities may cause two types of instabilities when operated in bunch lengthening mode. One is the mode-zero Robinson instability and the other is the periodic transient beam loading instability. In this paper, these two instabilities will be briefly introduced using the parameters of the Hefei Advanced Light Facility storage ring.
Octupole magnets are a central mitigation method against the transverse collective instabilities expected for the high-intensity operation of the SIS18 and SIS100 synchrotrons in the FAIR project. For these beam parameters, the self-field space-charge effect dominates the betatron footprint, and strongly modifies the instability drive and the Landau damping properties. The space-charge tune...
The European Spallation Source (ESS) linear accelerator is designed to accelerate a 62.5 mA, 2.86 ms, 14 Hz proton beam up to 2 GeV for delivery to a rotating tungsten (W) target. The beam transfer sections between linac cryomodules and approaching the target contain over 200 quadrupole, dipole and corrector magnets for beam envelope and trajectory control. In addition, a raster magnet system...
The Radia code is used widely to model magnets for various particle accelerator applications, especially for insertion devices at synchrotron radiation sources. Although Radia provides many useful capabilities, including generally nonlinear relationships between applied fields and material magnetization, it previously lacked a full description of the hysteresis dynamics present in...
The 3rd harmonic cavity is a key component for the 4th generation storage ring. A bunch lengthening by the harmonic cavity increases the Touschek lifetime, which can reduce the emittance in the storage ring. The resonant frequency is selected as 1500 MHz due to the resonant frequency of the main RF cavities being 500 MHz. The prototype cavity is an elliptical double-cell geometry to reduce...
One of the key issues in the technology of superconductors is the protection against quenches. When designing a superconductor as a magnet, a coil or even current leads, the design should be made such that the superconductor withstands all operational conditions as fast discharges, pulsed loads or even rapid transient background fields.
Computational modeling of pulsed-current...
Residual gas atoms, ionized by the electron beam, may create two effects in an electron accelerator. One is the trapping of ions in the beam channel by the Coulomb forces of the beam and the other is the fast beam ion instability, a dynamic mutual transverse oscillation between ions and electrons.
While the strongly reduced beam emittance of the accelerator upgrade SLS 2.0 is helpful in...
Magnetic alloy cavities have been used in many accelerators. We have irradiated small magnetic alloy rings in J-PARC to evaluate radiation effects on magnetic properties. Complex permeabilities and hysteresis curves were measured before and after the irradiation. No significant variation was observed by the total ionization dose of 18 kGy and neutron flux of 2.3$\times10^{14}$ n/cm$^2$. The...
An Injector upgrade at Jefferson Lab presented new requirements for the Wien filter magnets power supplies. In addition to raising the output amperage requirements from 10Amps to 20Amps, the new power supplies are required to drive loads with very low inductance, capacitive effects and stringent ripple limitations. Existing power supply solutions required loads with a minimum of 25mH to...
Korea fourth generation storage ring (Korea-4GSR) is the low emittance storage with an emittance of 61 pm and a circumference of 800 m. The design has been updated to add an injection straight section, where the beta function intentionally made to have high value to relieve the requirement of the off-axis injection. With the injection straight section, the improvement of the injection...
A pulsed electron lens produces a betatron tune shift
along a hadron bunch as a function of the longitudinal coordinates, which is a longitudinal detuning. An example of transverse detuning is the tune shifts due to octupole magnets. This paper considers a pulsed electron lens as a measure to mitigate the head-tail instabilities. A detailed analytical description within a Vlasov formalism...
The design concept of the Electron Ion Collider (EIC), which is under construction at BNL, considers adding a 2nd Interaction Region (IR) and detector to the machine after completion of the present EIC project. Recent progress with development and fabrication of large-aperture high-field magnets based on the Nb3Sn technology for the HL-LHC makes it interesting for using this technology in the...
The synchrotron of XiPAF (Xi'an 200MeV proton application Facility) is a compact proton synchrotron, which can accumulate and accelerate 1e11 particles for 3-order resonance slow extraction, with H^- stripping injection and phase space painting scheme. Now XiPAF is under the challenge of more particle species for single event effect study, like He+, C4+ and so on. This paper report the lattice...
The LHC low-beta quadrupole magnets, also known as “Inner Triplets”, are the final focusing magnets located on each side of the LHC interaction points. The design of the currently operated LHC Inner Triplets is based on NbTi superconducting technology. The magnets are operated in superfluid helium and use a longitudinal heat exchanger to extract the power deposited by the secondary particles...
Proposals to measure a possible Electric Dipole Moment (EDM) of protons in an electro-static machine are studied by a world-wide community. The machine is operated at the so-called magic energy to satisfy the "frozen spin" condition such that, without imperfections and the well-known magnetic moment of the particle, the spin is always oriented parallel or antiparallel to the direction of...
A new accelerator simulation code named Advanced Virtual Accelerator Software (AVAS) was developed by the Institute of Modern Physics, Chinese Academy of Science. Although the code is proposed to simulate the particle transport in the linac of the China Initiative Accelerator Driven System (CiADS), it can be also used for common linacs. The code is based on particle-in-cell (PIC) algorithm and...
At the NSLS-II ring, a 1.2 m long superconducting wig- gler with the maximum 4.34T magnetic field has been in- stalled at a low-β straight section (cell 27) to drive the high energy engineering X-ray scattering (HEX) beamline. To mitigate the potential performance degradation due to the linear optics distortion, a local compensation scheme was adopted and confirmed with the online beam...
Logistics is not "rocket science" nevertheless a poor coordination and planning of procurement, transportation, and storage can cause congestion in the supply and movimentation of components and systems, increasing the risk of delays, damages and - worst of all - injuries to the personnel.
Upgrading an existing machine doubles the difficulties, handling the old parts and the new ones, almost...
The compact STorage ring for Accelerator Research and Technology (cSTART) project aims to store electron bunches of LPA-like beams in a very large momentum acceptance storage ring. The project will be realized at the Karlsruhe Institute of Technology (KIT, Germany). Initially, the Ferninfrarot Linac- Und Test-Experiment (FLUTE), a source of ultra-short bunches, will serve as an injector for...
The proposed upgrade of ALBA to a 4th generation light source, ALBA-II, will involve several changes in the beam dynamics. The most significant change in the longitudinal plane is the addition of a harmonic RF system, which is expected increase the bunch length by at least a factor of three and raise the Touschek lifetime by a similar amount. However, RF systems with harmonic cavities can be...
The Hefei Advanced Light Facility (HALF) is a vacuum ultraviolet (VUV) and X-ray diffraction-limited storage ring light source. It has a relatively large dynamic aperture, and an injection scheme with a nonlinear kicker (NLK) was considered for the HALF. This kind of magnet was designed with a small gap shield in the central area to gain a flat magnetic field. A complete prototype has also...
Landau damping plays a crucial role in preserving single-bunch stability. In view of delivering the beam to the High-luminosity LHC (HL-LHC), the Super Proton Synchrotron (SPS) must double the intensity per bunch. In this intensity range, the loss of Landau damping (LLD) in the longitudinal plane can pose an important performance limitation. Observation of the beam response to a rigid-bunch...
Longitudinal microwave instabilities are driven by beam coupling impedance sources which have a very short wavelength compared to the bunch length. These instabilities can be a significant limitation to performance on an accelerator. In the CERN Proton Synchrotron (PS), microwave instability is mostly observed at transition crossing for ion and proton beams, when bunches are shortest. Vacuum...
The worldwide first in-vacuum elliptical undulator, IVUE32, is being
developed at Helmholtz-Zentrum Berlin. The 2.5 m long device with a
period length of 3.2 cm and a minimum gap of about 7 mm is to be
installed in the BESSY II storage ring. The device follows the Apple-II
design and features four magnet rows. Both the two bottom and two top
rows can be shifted longitudinally. This...
In the next-generation light sources, the bunch lengthening using the combination of the fundamental and harmonic cavities is a key technology to generate ultra-low emittance beam. Since the performance of the above bunch lengthening is limited by the transient beam loading (TBL) effect on the cavities, we proposed a TBL compensation technique using a wide-band longitudinal kicker cavity [1]....
The electron injection chain of the DELTA accelerator facility starts with a 90 keV electron gun, followed by a linear accelerator (70 MeV), a first transfer line (T1) between linac and booster, a booster synchrotron (70 MeV to 1.5 GeV) and a second the transfer line (T2) connecting the booster and the storage ring (1.5 GeV). Since DELTA does not use a fast topping-up injection mode, each...
Traditionally PIC solver compute electric field created by the beam as a mean field. The effect of particle collisions is normally neglected by the algorithm. In this proceeding we address how to include the collisions between the macro particles, and discuss the computational challenges and strategies to include the collisionallity in PIC solvers as particle-particle interaction. We present...
An injection-locked amplitude modulated magnetron is being developed as a reliable, effi-cient RF source that could replace klystrons used in particle accelerators that have superconducting cavities. This paper will describe the magnet system which is designed to provide a reasonably uniform field over the magnetron interaction region (IR). Most of the field in the IR is provided by a large...
In this report, we present our recent progress in the de-sign and high-power testing of the 2nd harmonic cavity for the China Spallation Neutron Source upgrade project. To achieve optimal performance, high-performance mag-netic alloy (MA) cores with dimensions of Ф850mm × Ф316mm × 25mm were meticulously developed and fabricated to serve as the load material for the radio-frequency (RF) cavity....
The transverse gradient undulator (TGU) concept is a way to enable short-gain length free electron lasers with laser-plasma accelerated electron bunches, although their energy spread is typically in the percent range. In this contribution, we report on the magnetic field measurements on a 40-period superconducting TGU designed, manufactured and commissioned at the Karlsruhe Institute of...
Magnetic Field Tools is an open source library being developed by the Insertion Devices and Magnets group at the ESRF. It is dedicated to the analysis of static magnetic field values obtained from simulations and measurements. Magnetic field models such as 2D and 3D multipoles in various geometries, as well as boundary element models, can be built from sets of field samples. The library was...
The Elettra 2.0 project involves the installation of more than 600 new magnets for the upgrade of the existing light source. All the magnets will be measured in house in a new magnetic measurement laboratory to be built and equipped by 2024. The measurements will be carried out over a period of two years and will consists of acceptance tests, magnetic characterization and, to meet the...
he Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBL) is going through an upgrade (ALS-U) where the ALS triple-bend achromat will be replaced by a nine-bend achromat storage ring (SR) with an on-axis injection using beam swapping from a triple-bend achromat accumulator ring (AR). About 700 magnets will be used for the ALS-U accelerator systems. The paper gives an...
High-order corrector magnets will be required for the magnetic system of the HL-LHC inner triplets. These magnets are based on a superferric design thus the saturation of the iron poles affects the field generated in the aperture, i.e., the magnetic transfer function shows a nonlinearity. One of the challenges for the operations of these magnets is to find a suitable fit of the magnetic...
The APS Upgrade storage ring will keep the same rf system that is currently used at APS. This rf system has amplitude and phase noise dominated by the lines at 60, 180, and 360 Hz. APS presently operates with a synchrotron frequency close to 2 kHz, which is far away from the rf noise frequencies, but APS-U will operate with a bunch-lengthening cavity, which could lower the synchrotron...
Work at the SNS beam test facility has focused on high dimensional and high dynamic range measurements of the medium energy (2.5 Mev) beam distribution. This is motivated by the need to understand and predict beam losses down to one-part-per-million. The initial demonstration of full-and-direct 6D phase space measurement was done at a current of 40 mA transported through the RFQ. Since that...
Landau damping represents the most efficient stabilization mechanism in hadron synchrotron accelerators to mitigate coherent beam instabilities. Recent studies allowed expanding the novel analytical criteria of loss of Landau damping (LLD) to the double harmonic RF system case above transition energy, providing an analytical estimate of the longitudinal stability. The threshold has a strong...
Nb3Sn superconducting radiofrequency (SRF) cavities have been an ongoing research topic for many years motivated by the potential for higher accelerating gradients and quality factors compared to niobium SRF cavities. The highest performing Nb3Sn cavities are manufactured using tin vapor-diffusion coating, which creates a Nb3Sn film with a surface roughness of around 100-200 nm. This is...
The planned Electron Ion Collider (EIC) has an Energy Recovery Linac (ERL) which provides Strong Hadron Cooling (SHC) in order to control the beam quality of the hadrons. This requires that the electron beam delivered to the cooling section be minimally perturbed by the preceding bunch stretcher necessary in the 100 GeV configuration. This paper evaluates different stretcher designs for the...
A system is being developed for the maintenance of a space-charge neutralising plasma from the residual gas within the LEBT of the Front End Test Stand (FETS) at UKRI-STFC Rutherford Appleton Laboratory. Space-charge neutralisation will occur when an ion beam is allowed to collide with and ionise a background gas with pressure greater than 10-4 Torr in the presence of a solenoid fringe field,...
The ESRF presently operates with the HMBA lattice that features beta-functions of 6.9 m and 2.7 m in the horizontal and vertical planes at the center of the the straight sections. These are not optimal for a length of in-vacuum undulator of approximately 2 m that is used at ESRF. New optics with reduced beta functions at the center of the straight section were designed to better match the...
In CLS, Deep Learning was applied to make a dynamic model for the Orbit Correction System (OCS). The OCS consists of 48 sets of BPMs BERGOZ (96 data sheets with 900 Hz recording) that measure the beam position and use the SVD matrix to calculate the strength of the orbit correctors (48 sets of Orbit Correctors 'OC'). The Neural Network was built, trained, and tested using 96 BPM signals. Five...
Sealab (SRF Electron Accelerator LABoratory) is composed of an SRF photo gun and an SRF booster, followed by a diagnostic line and a recirculation path for ERL applications. It is the follow-up project of bERLinPro, which ran from 2010-2020 at HZB. In an SRF injector, a single solenoid is sufficient to optimally focus the beam for small emittance. The alignment of the solenoid is crucial, as...
As a follow on to the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility, the front end of the DC photo-gun-based injector has gone through a phased upgrade. The first phase focused on the beamline between the gun and the RF chopper system, and the second phase addresses the beamline after the RF chopper system including replacing the capture section and quarter cryomodule...
Optical Stochastic Cooling (OSC), a beam cooling technique based on Stochastic Cooling, is in the early stages of experimental development. It uses radiation produced by the beam in an undulator magnet (the pickup) to correct the momentum deviation of particles downstream in another undulator (the kicker). The OSC mechanism was recently demonstrated at Fermilab’s IOTA ring using a passive...
Current-carrying wires have long been proposed as measures to mitigate beam-beam effects. Dedicated hardware has been installed at CERN Large Hadron Collider (LHC) and experimental sessions have been organised to study the beam dynamics in the presence of the wire compensators. In this paper, a diffusive model is presented to model the collected experimental data and its performance is...
Exploring the fundamental properties of materials, including niobium or Nb3Sn, in high-precision surface resistance measurements is relevant to superconducting radio-frequency (RF) technology. For the precise determination of the RF properties of such materials, the calorimetric measurement is carried out with a quadrupole resonator (QPR). Mathematically, a QPR model is governed by a set of...
An ongoing study at the Spallation Neutron Source (SNS) seeks to better understand and address potential multipacting issues associated with the Drift Tube Linac (DTL) RF vacuum windows. An analysis of several failed operational windows showed indications of excessive RF heating on the TiN-coated alumina ceramics. Coupled with vacuum bursts and arcing during conditioning and/or operational...
The Future Circular Collider (FCC) is a project of high performance particle collider. Several accelerating cavity technologies may equip it and are currently under study. One of them is the Slotted Waveguide ELLiptical (SWELL) superconducting (SC) cavity. It is a good candidate for nearly all the range of electron-positron interaction energies. It is made up of four independent quadrants...
SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb3Sn and conduction cooling. SRF gun can provide a CW operation capability while consuming only 2W of RF...
Nb3Sn on Nb thin films cavities by Tin Vapor Diffusion already show performance at 4.2 K comparable to Nb bulk cavities at 2 K, but a real breakthrough would be the use of copper (instead of Nb) as substrate, to enhance the thermal conductivity, opening up the possibility to cool down the cavity using cryocoolers instead of the more expensive helium bath.
Magnetron sputtering is the most...
In recent years, the use of machine learning methods has proved to be capable of considerably speeding up both fundamental and applied research. Accelerator physics applications have also profited from the power of these tools. This includes a wide spectrum of applications from beam measurements to machine performance optimisation.
PETRA III is one of the world's brightest...
Electromagnetic processes of charged particles interaction with oriented crystals provide a wide variety of innovative applications such as beam steering, crystal-based extraction/collimation of leptons and hadrons in an accelerator, a fixed-target experiment on magnetic and electric dipole moment measurement, a positron source for lepton and muon colliders, X-ray and gamma radiation source...
A new kicker power supply using SiC-MOSFETs is under development at J-PARC. SiC-MOSFETs enables the fabrication of compact high-speed pulse power supplies to replace thyratrons switch power supply. The base circuit uses an induction voltage superposition circuit of the LTD method, and the semiconductor module circuit consists of a radial symmetry type that achieves low noise. The three main...
Fixed Field Alternating Gradient Accelerators (FFAs) that follow the conventional scaling law have – by definition – high order multipole components in their magnetic fields. It is the presence of these nonlinearities that in many cases determines several important properties of the machine, including amplitude-dependent tune shift and dynamic aperture. Consequently, understanding of the...
We expanded the capability of the nonlinear optics from off-energy closed orbits technique proposed by Olsson et al. to include harmonic sextupole correction in storage rings. The existing technique was successfully used to correct the errors of chromatic sextupoles on the MAX-IV machine. However, it was not applicable to harmonic sextupoles, which are widely used in $3^{rd}$-generation light...
Crab cavities are fundamental components of the LHC upgrade in the framework of the HL-LHC project. These Radio Frequency cavities, operated at the appropriate frequency, ‘tilt’ the proton bunches to increase the luminosity at the collision points IP1 (ATLAS) and IP5 (CMS). During operation, the walls of the cavities are deformed due to the loading conditions. This deformation changes the...
In recent years the generation of high power millimeter wave and Terahertz radiation has progressed substantially, enabling electron beam manipulation and acceleration in structures with a footprint of several centimeters. However, in many experiments the external driving pulse is coupled collinearly into the waveguide structure which increases the coupling footprint relative to the wavelength...
An accelerating charged particle emits electromagnetic radiation. The motion of the particle is further damped via self-interaction with its own radiation. For relativistic particles, the subsequent motion is described via a correction to the Lorentz force, known as the Lorentz-Abraham-Dirac force.
The aim of this research is to use the Lorentz-Abraham-Dirac force to computationally...
A new set of nonlinear beam manipulations have been recently proposed, with the goal of extending the transverse beam splitting that is routinely used at the CERN PS to deliver beam to the SPS for fixed-target physics. Using a simple Hamiltonian model, it has been shown how the transverse emittances can be shared by crossing a two-dimensional nonlinear resonance. Moreover, it has been shown...
SIRIUS is the 4th generation storage ring-based synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). Beam accumulation at SIRIUS storage ring occurs in an off-axis scheme, using a nonlinear kicker (NLK), for which the efficiency depends on a sufficiently large dynamic aperture (DA). This work reports on the application of online optimization using...
OPAL (Object Oriented Parallel Accelerator Library) is a C++ based massively parallel open-source program for tracking charged particles
in large scale accelerator structures and beam lines, including 3D space charge, collisions, particle-matter-gas interaction, and 3D undulator radiation.
The meticulous parallel architecture allows large and difficult problems, including one-to-one...
The CEBAF energy upgrade will require magnets with high fields to bend electron beams of up to 22GeV in the 80.6m radius tunnel. A peak field in excess of 1.5T, together with a large gradient of 40T/m or more, are used in its fixed-field arc lattice to bend multiple recirculation energies in a single pipe. Additionally, the magnet must have an open midplane to allow synchrotron radiation to...
Cryogenic permanent-magnet undulators (CPMUs) have emerged as a focal point in the development of short-period undulators. At the Taiwan Photon Source (TPS), two 2-meter CPMUs have been developed using different magnet materials and cooling techniques. Spe-cifically, a PrFeB-based CPMU, equipped with cryocooler cooling, and a NdFeB-based CPMU, utilizing liquid nitrogen (LN2) tank cooling, have...
The energy of a collider is proportional to the field of the dipoles and to the length of the arcs available to dipoles. A way to increase energy without increasing the field or making a longer tunnel is to have a larger filling factor (fraction of the arcs covered by dipoles), ie to reduce the space dedicated to quadrupoles, correctors, interconnections ... In this paper we discuss three...
The new generation of storage rings aims to push the limits of the luminosity and the size of the electrons beam that can be achieved. One of such planned machines is the e+/e- Future Circular Collider (FCC-ee) with 100km circumference. The FCC-ee lattice components can be subject to random misalignments and field errors. These errors can adversely affect the beam's closed orbit and beam...
In shanghai, a hard X-ray free electron laser facility named SHINE is under construction which is composed of three undulator lines. As part of the facility, it is preferable to incorporate a beam distribution system just before the undulators to provide suitably tailored beams for diverse experiments. In order to drive a FEL, a good overlap between the electron beam...
Electropolishing (EP) and buffered chemical polishing (BCP) are conventional surface preparation techniques for superconducting radiofrequency (SRF) cavities that remove damaged material from the cavity surface. One main issue with EP and BCP treated SRF cavities is high field Q-slope (HFQS), a drop in quality factor at high gradients that limits quench field. High gradient performance in EP...
In view of the High-Luminosity (HL-LHC) upgrade of the LHC collimation system, different materials were investigated to determine how the jaws of the new collimators could be manufactured to meet the demanding requirements of HL-LHC, such as thermomechanical robustness and stability, RF impedance, UHV, etc. During the Long-Shutdown 2 (LS2), five primary and 10 secondary low-impedance...
During Long Shutdown 2 (2019-20), the injector chain of the Large Hadron Collider (LHC) has been upgraded to reach the High Luminosity LHC goals in terms of beam intensity and brightness. In the CERN Proton Synchrotron (PS), this upgrade consisted in hardware modifications to double the intensity at extraction, while preserving the transverse emittance available from the CERN PS Booster. The...
At TTX, we try to use machine learning to give the virtual detection of the beam spot. The prediction of beam spot is difficult when the dimension becomes larger. We try to use PCA to make it smaller and use Neural networks to predict it. However, the weight of different dimension varies widely. We predict them parallel and get good results with easy neural networks.
Permanent Magnets (PM) and Electro Magnets (EM) with conventional resistive conductors are widely used in particle accelerator. The different applications include all types of multipoles, bending magnets, chicanes, kicker and undulators.
Both types of Magnets have specific advantages and disadvantages, state of the art PM comprise expensive raw materials like Nd, Dy, Tb and Co and reach only...
Transverse resonance island buckets (TRIBs) have been successfully observed at the Cornell Electron Storage Ring (CESR) after optimizing the distribution of seventy-six sextupoles to achieve the desired amplitude-dependent tune shift and the resonant driving term near a third-order resonant line (3vx=2). A novel knob is created to adjust the resonant driving term h22000 while minimizing the...
We present a physics-constrained neural network (PCNN) approach to calculating the electromagnetic fields of intense relativistic charged particle beams via 3D convolutional neural networks. Unlike the popular physics-informed neural networks (PINNs) approach, in which soft physics constraints are added as part of the network training cost function, our PCNNs respect hard physics constraints,...
We present the latest updates to the PLACET3 tracking package which focus on the impact of both transverse and longitudinal wakefields on a beam travelling through accelerating and decelerating structures. The main focus of this update was the first implementation of 6D tracking through Power Extraction and Transfer Structures (PETS) for the Compact Linear Collider (CLIC) which is described...
Plasma processing can be used to mitigate hydrocarbon-related field emission in SRF cavities in situ in cryomodules. At Fermilab we developed plasma cleaning for LCLS-II 1.3GHz N-doped cavities and we successfully applied to the LCLS-II High Energy verification cryomodule (vCM). This test demonstrated that plasma processing can be a valuable tool to mitigate both field emission and...
As a part of the effort to expand the capabilities of CE-BAF 12 GeV (Continuous Electron Beam Accelerator Facility) at Jefferson Lab, the addition of a polarized positron source is considered. This capability would provide acceleration of high duty-cycle polarized posi-trons, with spin >60% polarization, through the same main CEBAF accelerator machine with appropriate mag-net field reversals...
A beam collimation in the distribution system is designed to protect the undulator and beam pipe in the SHINE FEL.A tracking with a big initial distribution provide a result of the collimation efficiency. Detailed simulation studies about the evaluation of the available collimation design limits for the acceptance of the undulator is described.
The compensation of the long-range beam-beam interactions by DC wires is currently being investigated as an option for enhancing machine performance in the framework of the High-Luminosity LHC Project. In this paper, we report and comment on the potential of wire compensation during the first HL-LHC run. The results are based on numerical simulations and optimisations of the machine dynamic...
A permanent dipole magnet assembled by Sm2Co17 was fabricated and measured at NSRRC. The main magnets were consisted of several small magnet blocks. A simple coil was wound to measure the total flux of permanent magnet. The flux coil was compared and calibrated by the Helmholtz coil using small magnet block. A flux sorting process was implement to obtain more homogeneity magnetic field. A NiFe...
Superconducting magnet technology is one of the foundations of large particle accelerator facilities. A challenge with operating these systems is the possibility for the magnets to quench. The ability to predict quenches and take precautionary action in advance would reduce the likelihood of a catastrophic failure and increase the lifetime operability of particle accelerators. We are...
Research Instruments (RI) and Thales have been producing the first two prototype 1.5 GHz fundamental power couplers for the VSR (Variable pulse length Storage Ring) DEMO since early 2021 and delivered these prototypes in late March 2023. These couplers are designed to provide up to 16 kW power to two 1.5 GHz superconducting cavities of the VSR DEMO module and provide variable coupling with a...
In order to ensure strict phase synchronization between power supplies, CSNSRCS resonant power supply receives 25Hz and 100KHz timing signals provided by the timing system. The 25Hz rising edge is used as the trigger signal of RCS cycle, and the 100KHz signal is the AD sampling clock of the power digital controller. These two signals are distributed by the timing system according to the clock...
The Insertion device development and measurement laboratory of Devi Ahilya University, Indore, India has ongoing activities on undulator design, development and measurements. A new type of undulator known as Asymmetric magnet pole with upper and lower structure having different period lengths will be designed and fabricated. Asymmetric magnet pole undulator has a special demanding field...
The EIC to be built at BNL is a unique high-energy, high-luminosity, polarized electron-proton/ion collider. The EIC accelerator complex consists about 10 new RF and SRF systems operating with frequencies spanning 24 MHz to 1,773 MHz, requiring at least 60 new high power fundamental power couplers (FPCs). These couplers will operate in either pulsed mode or CW modes with peak traveling wave...
Recent efforts at SLAC aim at developing high-power accelerators powered by compact, high-efficiency rf sources such as klystrons and Inductive output tubes (IOT). In particular, a high-efficiency IOT is an electron-beam-driven RF source employed in the UHF band that offers high efficiency at variable output power levels. Due to the improved linearity, high efficiency, and reduced size, it is...
FCC-ee is a proposed lepton collider with a circumference close to 100 km to produce an unprecedented amount of luminosity. The FCC-ee optics tuning working group is addressing one of the most critical aspects of the FCC-ee, that is the recovery of the optics design performance in presence of realistic imperfections.
Various teams from laboratories all around the world have got together to...
The ALBA-II upgrade lattice to a diffraction limited soft X-rays storage ring calls for an emittance smaller than 200 pm*rad in a 269 m circumference at an energy of 3 GeV. In this paper we report on progress of the 6BA lattice with distributed chromatic correction. This lattice relies on transverse gradient dipoles and reverse bends to suppress the emittance. Several modifications to the...
The SOLEIL II storage ring project will require an injected beam with small transverse and longitudinal sizes. To meet this requirement, a new multi-bend 14BA Higher-Order Achromat lattice has been de-signed to reduce the booster emittance from the pre-sent 140 nm.rad to 5 nm.rad @ 2.75 GeV. In this paper we report the progress in the booster beam dynamics studies, considering the linac energy...
Tracy, the code base used for designing synchrotron light sources with predictable performance, has been significantly refactored. Furthermore it now uses mad-ng gtpsa library.
We describe the achieved progress, discuss its python interface. We show how to use it for achieving a robust design for a modern synchrhotron light source.
The CERN ISOLDE facility is currently equipped with two uncooled iron blocks acting as beam dumps. In order to guarantee the reliability and safety of the installation for the years to come, a study has been launched to evaluate the possibility to exchange the ISOLDE beam dumps during LS3. The consolidation would also allow compatibility with the 2 GeV and intensity upgrade being discussed....
PyTao is a Python interface to the Bmad based Tao program for accelerator design and simulation. This enables advanced design and optimization beyond the normal capabilities of Tao as well as simplifying the use of Tao as an online model for an operating accelerator. Here we will describe this interface and some of its applications, including online models for the the LCLS and LCLS-II at SLAC...
Vacuum chambers of flat aspect ratio are source of a quadrupolar component of long-range resistive wall wake fields whose amplitude only depends on the trailing test particle.
In multi-bunch filling this leads to an accumulation of the long-range quadrupolar resistive wall wake field which expresses in multi-bunch tune shifts on both planes. The tune shifts were measured at the ALBA storage...
ER@CEBAF is an effort to demonstrate multi-GeV multi-pass energy recovery with a low beam current in CEBAF. The race-track-shaped CEBAF geometry allows its linacs to accommodate multiple energy beams simultaneously. However, five energy recovery passes complicate the beamline optics design process. Individual recirculating arcs each transport one beam energy, and are shared between...
This report discusses the design of a current feedback component for a TPS correction magnet power supply. The component utilizes a low-cost and small-sized TI INA253 resistor combined with a temperature compensation control circuit to improve the output current thermal equilibrium time. With these measures, the system achieves thermal equilibrium quickly, resulting in improved performance....
Superconducting materials such as niobium have been extremely useful for rf accelerator technology but require low temperatures for operation ~2-4 K. The development of high temperature superconductors (HTS) is promising due to their transition temperature in excess of 80 K. In this work we are exploring the high-power RF performance of such materials at X-band (11.424 GHz). We are testing two...
Controlling beam losses is of paramount importance in superconducting particle accelerators, mainly for ensuring optimal machine performance and an efficient operation. Models based on global diffusion processes, in which the form of the diffusion coefficient is the stability-time estimate of the Nekhoroshev theorem, have been studied and proposed to investigate the beam-halo dynamics. Recent...
As a scientific system with many subsystems, particle accelerator system is getting more complex， due to rising demands on accelerator performance. Meanwhile, it is increasingly difficult to study such complex systems using traditional research methods based on physical models. At present, machine learning (ML) is mature enough to be applied in accelerator science such as beam diagnostics and...
A algorithm is demonstrated which performs first-principles tracking of relativsitic charged-particles for determining the power they deposit into their surroundings (in particular, blackbody cavities and pillbox accelerating cavities). A computationally costly, but highly accurate covariant approach is used, which employs retarded vector potentials for trajectory integration instead of...
In CSNS, there are more than 350 devices in the accelerator power supply system, which respectively provide precise excitation current for the magnet load. Therefore, the stable operation of the power supply is an important prerequisite to ensure the beam quality, and also one of the necessary conditions for the normal operation of the CSNS.
In accelerator power system, digital controller is...
The compact 166 MHz HOM-damped quarter-wave superconducting cavities for HEPS have complex geometries, resulting in streak defects on the inner surface of the cavity after BCP etching. Surface areas with low flow velocity from fluid dynamics simulations coincide with defects observed on the cavity inner surface. Based on the 166 MHz cavity structure, an improved BCP setup with holes and discs...
As the precise sensor system for monitoring the rela-tive altitude changes among multiple points, the capacity hydrostatic leveling system (HLS) is widely used in particle accelerators. To expand its application in provid-ing the elevation constraint for the control network ad-justment, the research on the issue of the HLS for alti-tude difference measurement between multiple points is carried...
One of the interesting topics among accelerator physicists in the last decades has been the resistive wall impedance of vacuum chambers with general cross sections. The resistive wall impedance of a round pipe was calculated more than half a century ago, followed by parallel plates, rectangular pipes, and, in more recent years, oval shapes. Analytical solutions usually require some...
The ultra-low emittance specification of the SOLEIL II storage ring requires a challenging lattice design of the booster that will inject the beam into it. The dimension of the vacuum chamber in the new booster must be reduced compared to that in the present machine. The resistive-wall (RW) instability is then expected to become more important than in the current booster. However, the...
The cryomodule qualification test stand (TS2) at Lund has been commissioned fully in 2021 and is delivering the components for the installation in the linac, which started in Q1 2023 after the end of the cryogenic distribution system commissioning.
All the available medium beta cryomodules have been tested and the facility is now delivering the high beta cryomodules for the full scope of the...
The accelerators constituting the LHC injectors chain have been gradually built and commissioned since the CERN foundation in the fifties. The operation of the Proton Synchrotron, the Proton Synchrotron Booster and the Super Proton Synchrotron started in 1959, 1972 and 1976 respectively. During the Long Shutdown 2 (LS2) of the CERN accelerator complex in 2019 and 2020, a large upgrade of these...
Recent efforts have shown that the SRF technology developed for accelerators can be successfully applied to new applications, including quantum computing, dark matter searches and beyond the standard model physics. The ultra-high quality factor of SRF cavities can allow to achieve unprecedented sensitivity in fields outside of the usual accelerator applications, for examples in dark photon and...
Future high duty cycle (HDC) operating modes are under development for the
European XFEL. A L-band superconducting RF (SRF) gun is foreseen as the
injector operating continuous wave (CW). To preserve the small beam
emittance distracting effects like RF kicks from the power coupler,
trapped higher order modes (HOMs) in the cavity end group and RF field
asymmetries need to be considered and...
We present here the RF test program of the ESS TS2. Several tools have been prepared at TS2 for the later stages of the technical commissioning in the linac. Automated tools for tuning the cavities to resonance using spectral analysis or cavity gradient calibration have been deployed and tested to assist the later stages of facility commissioning.
In this paper, the design of a compact C-band SLED RF Pulse Compressor for a Very High Electron Energy (VHEE) FLASH machine is presented. A spherical cavity RF pulse compressor - selected because of its compactness and relative ease of fabrication - is adopted to compress the 50 MW 3 µs RF pulse, down to 1 µs obtaining a peak power gain greater than 3. The main parameters – operating resonant...
A pulse compression system based on double-height waveguides was designed for the Klystron-based CLIC main linac. The optimized power gain of the system is 3.81 with the particular pulse shape required for the CLIC-K accelerating structure. This pulse compression system consists of a main Barrel Open Cavity (BOC)-type pulse compressor and 4 novel correction cavities. The BOC pulse compressor...
A new RF Module was designed for the Klystron-based CLIC main linac. The new module deploys two X-band klystrons to feed eight CLIC-K accelerating structures giving a beam energy increase of 156 MeV. This module will use a double-height waveguide distribution network which can reduce the RF power loss in the network by about 37%. All the RF components were redesigned to match the double-height...
The brightness can be increased by minimizing the emittance in the light source, but the reduced emittance also increases the number of collisions of electrons in the beam bunch. Therefore, the bunch lengthening by using the 3rd harmonic cavity reduces the collisions of electrons and increases the Touschek lifetime. Since the resonant frequency of the main RF cavity is 500 MHz, the resonant...
QWR cavities are prepared for beam commissioning. RF conditioning is performed for each QWR cavity. The total heat load including static and dynamic heat loads are measured for each cavity. The helium pressure fluctuation is reduced by changing the flow rate, supply pressure, return pressure, liquid helium level in reservoir, cryogenic valve control, etc. The cavity pressure is monitored...
What happens when the temperature reaches absolute zero? Physical phenomena at the zero-temperature limit are studied in accelerator physics. The background temperature of the universe goes down as long as expansion goes on. The BCS resistance of a superconducting cavity is shown as a function of temperature at different frequencies. The surface resistance of the Nb superconducting cavity is...
Tuning becomes essential at the end of manufacturing an RFQ to acquire the operating frequency and achieve the required RF field profile along the length of the structure. During commissioning, unexpected detuning events may also necessitate tuning to obtain the original design field profile. Proper separation of quadrupole and dipole modes is needed to maintain the desired field distribution...
Abstract
A geometric control theory method is outlined & pre- sented to improve the on & off-momentum dynamic aper- ture for synchrotrons. And applied to the two lattice op- tions/solutions for BESSY III. A guideline is also provided for how to estimate the resulting performance for the “real lattice. The so-called tune confinement approach [32].
In this paper, we present a study of the transformation of a magnetized electron beam from round to flat and back to round using a skew quadrupole triplet. Electron cooling of hadron beams requires a magnetized electron beam, which can be generated from an RF photoinjector. However, such a beam is coupled in four-dimensional phase space, making it difficult to transport through beamlines. To...
RUEDI, the Relativistic Ultrafast Electron Diffraction and Imaging facility for the UK, is a planned facility that will deliver single-shot, time resolved, MeV electrons for imaging and ultrafast (~10 fs) diffraction. The facility naturally separates into two lines, both fed by the same RF gun. The first line is for microscopy and imaging whereas the second is dedicated to diffraction....
With the development of Mega-electron-Volt ultrafast electron diffraction technology, electron microscopy based on photocathode radio-frequency (RF) electron guns has become a promising tool for high spatiotemporal resolution and shows obvious advantages of suppressing the space charge effect. An ultrafast electron microscopy is being developed at HUST. Russian quadruplet (RQ) based electron...
A beam transport section using the scaling fixed-field alternating gradient-type (FFAG) magnets is designed to transport laser plasma accelerator (LPA) electron beams to a specific application. This beam transport section has a large momentum acceptance, which is able to collect and transport the LPA beams with a momentum acceptance of up to 10%. Also, using the periodical FFAG magnet cells,...
In the injector section of electron linacs, both internal space charge forces and wakefield effects influence the beam dynamics. To account for both effects, full electromagnetic PIC simulations are usually required. Unfortunately, PIC solvers require large computational resources. On the other hand, particle-tracking codes in the bunch reference frame describe the beam dynamics under...
This work investigates the behavior of a free-electron laser (FEL) system composed of a slowly modulated wiggler field, constant laser field amplitude, and self-consistent fields due to the charged particles. The dynamics of each particle of the beam is studied through a Hamiltonian formalism, from which a ponderomotive approach represents its mean motion. The purpose of the present analysis...
The electron ion collider, the next generation nuclear physics collider is being actively studied. In order to achieve the designed luminosity 10^34/cm^2/s with a reasonable lifetime, an efficient coherent electron cooling scheme was proposed to reduce the hadron beam emittance and counter intrabeam scattering. Such a cooling scheme requires a good electron beam quality with a small energy...
Modern SRF applications require precise control of a wide range of material properties, from microscopic material parameters to macroscopic surface structures. Historically, Nb has been the primary superconducting material in SRF cavities. The past decade has seen increasing amounts of research into the development of cavities using next generation materials, such as Nb3Sn. These materials...
The Figure-8 storage ring (F8SR) concept for fusion reaction research in context of astrophysics is under development at Frankfurt University. In contrast to traditional storage rings, a guiding longitudinal magnetic field is used for confinement of very low energy charged particle beams continuously with high transverse momentum acceptance. Due to the strong magnetic field level (B=6 T), low...
In the KIT storage ring KARA (Karlsruhe Research Accelerator), two parallel plates with periodic rectangular corrugations are planned to be installed. These plates will be used for impedance manipulation to study and eventually control the electron beam dynamics and the emitted coherent synchrotron radiation (CSR). In this contribution, we present simulation results showing the influence of...
The effect of radiation reaction is often negligible in inverse Compton scattering. However, in the nonlinear Compton regime, at high laser fields and high electron beam energies where electron recoil must be properly accounted for, there is experimental data which demonstrates the onset of radiation reaction * . We model the radiation reaction as a series of emissions from individual...
Third-order resonance lines will have a detrimental effect on the high-intensity operation of the Recycler Ring (RR), under the current Proton Improvement Plan (PIP-II) for the Fermilab Accelerator Complex. Increasing intensity will increase space charge effects, leading to the excitation of normal and skew sextupole lines. Dedicated normal and skew sextupoles have been installed in order to...
The half-integer resonance is considered to be one of the strongest effects limiting the intensity of the FAIR SIS100 heavy-ion synchrotron which is currently under construction at GSI. Results of simulations under realistic synchrotron-operation conditions show that for bunched beams, a relatively small gradient error can result in a large half-integer stop-band width significantly reducing...
Many current accelerators use cavities that are manufactured as two half cells that are electron beam welded together, across the peak surface current of the cavity. This weld can limit the performance of Thin Film (TF) coated cavities by causing an increase in the surface resistance. Many problems with the coating process for TF Superconducting Radio Frequency (SRF) cavities are also due to...
Bunch lengthening with a double radio-frequency (rf) system combining fundamental and harmonic cavities (HCs) is essential in achieving extremely low emittance along with suitable lifetime as required for ring-based fourth-generation synchrotron light sources in the low-to-medium energy range.
Recent studies have pointed out that, in many cases, an unstable beam motion, as so-called...
The question we try to answer in this paper is: what is the standard error of using particle tracking result to represent the real beam parameters? Or how much confidence do we have when we say that the tracking gives the correct theoretical prediction? Particle tracking or numerical simulation in general is used by accelerator physicists every day and we believe this question needs a definite answer.
This report presents new investigations on beam dynamics for the separation beamline which allows to transport and compress electron bunches from the second electron source MIST to the first acceleration section of MESA. Several beamline configurations are compared concerning the capability for transport of elevated bunch charges.
The Accelerator Toolbox (AT) is a multipurpose tracking and lattice design code relying on a C tracking engine. Its MATLAB interface is widely used in the light source community for beam dynamics simulation and can be integrated in control systems through the MATLAB Middle Layer. In recent years major effort was made to develop a python interface to AT: pyAT. In this framework, several...
The RF system for storage ring in TPS is adopted two sets of 500 MHz KEKB-type SRF modules, with total operating voltage of 3.2 MV. Its power is provided by two sets of klystron-type transmitters with an output power of up to 300 kW, and the RF feedback loop is controlled by analog LLRF system. Since the RF system started to operate, it has been continuously improved and introduced new...
MAD-X is a popular beam optics code used to design, model and operate a large number of synchrotons and linacs. In this paper, we present the features added in the most recent versions and improvements we intend to make in future releases. Physics models have been added and improved to support the needs of the Future Circular Collider (FCC) and the Electron Ion Collider (EIC), regarding...
A 4th generation storage ring based light source is being developed in Korea since 2021. It features < 100 pm rad emittance, about 800 m circumference, 4 GeV e-beam energy, full energy booster injection, and more than 40 beamlines which includes more than 24 insertion device (ID) beamlines. This machine requires about ~1300 magnets including dipole, longitudinal gradient dipole, transverse...
Wuhan Advanced Light Source (WALS) is a proposed 4th generation light source, which accelerators include a 1.5 GeV Linac, 1.5 GeV storage ring and one beam transport line. The ring lattice consists of 8 identical units of 7BA. In each unit, there are 7 longitudinal gradient dipoles with transversal gradients, 10 quadrupoles, 6 sextupoles, 4 anti-bending gradient dipoles. Moreover, a combined...
The MQXFB magnets are superconducting quadrupoles with nominal peak field on the conductor of 11.3 T. With their magnetic length of 7.2 m, they stand as the longest Nb3Sn accelerator magnets designed and manufactured up to now. Together with the companion MQXFA 4.2 m long units, built by the US Accelerator Research Program, they are at the heart of HL-LHC, as they shall replace the inner...
Super Fragment Separator (Super-FRS) is the highest priority accelerator facility in construction of the FAIR at GSI, Darmstadt Germany. Super-FRS will provide desired exotic isotope beams to various experiment sites for fundamental researches. The high energy branch of Super-FRS will be the earliest to be built and will enable to execute the first experiment of FAIR.
Key elements of the...
The proposed PETRA IV electron storage ring, that will replace DESY’s flagship synchrotron light source PETRA III, will feature a horizontal emittance as low as 20 pm∙rad. It is based on a hybrid six-bend achromat lattice. In addition to the storage ring PETRA IV, DESY IV booster synchrotron and the corresponding transfer lines will be renewed. About 4000 magnets will be manufac-tured. Some of...
SOLEIL, the French third-generation synchrotron radiation facility, is in the TDR phase of its upgrade to a new fourth-generation synchrotron light source, called SOLEIL II. Its storage ring lattice design has evolved over the last year to better adjust its parameters taking into account the results of the mechanical integration, more realistic magnet design~[1], and the geometrical...
Superconducting dipoles with a strong curvature (radius smaller than 2 meters, for an aperture of about 100 mm and a length of 1-3 meters) are required for applications where compactness is key, such as the synchrotron and gantry for Carbon-ion therapy developed within the European program HITRIplus.
Such magnets challenge several assumptions in the field description and put to the test the...
The High Energy Photon Source (HEPS), which is a 6 GeV diffraction-limited storage ring (DLSR)-based synchrotron light source, is under construction in Beijing, China. HEPS consists of a Linac, a booster synchrotron, and a storage ring. The HEPS booster is proposed to operate in multi-bunch mode. And the 5-cell PETRA-type cavity, which is rich in high-order modes (HOMs), is chosen to be used...
The ongoing FCC-ee collider design aims at optimizing beam parameters and developing the different accelerators systems. For this reason, the coupling impedance modeling is in evolution following the design of the collider vacuum chamber and hardware components. Respectively, studies of collective effects and instabilities are continuously updated and refined. In this paper we describe the...
Beam-beam interaction in FCC-ee can be seriously affected by the vacuum chamber coupling impedance resulting in a safe tune areas reduction, tune shifts and spread, bunch length and energy spread variation. The interplay of the two effects have a drastic impact on the stability of colliding bunches and respectively on the achievable luminosity. In this paper beam-beam collisions in FCC-ee with...
Longitudinal beam manipulation have been widely employed for various scientific and industrial applications in many hadron (heavy ion or proton) synchrotrons. One of the most important manipulations is the longitudinal bunch merging based on the dual rf system. For high-intensity hadron beams, longitudinal space-charge matching and cavity beam loading matching and compensation are of practical...
Modelling electron cloud driven instabilities using a Vlasov approach enables studying the beam stability on time scales not accessible to conventional Particle In Cell simulation methods. A linear description of electron cloud forces, including the betatron tune modulation along the bunch, is used in the Vlasov approach. This method is benchmarked against macroparticle simulations based on...
Intra-beam scattering (IBS) is one of the prominent effects for low-emittance rings resulting in a significant growth of the emittance, energy spread, and bunch length. This effect is partially mitigated by the bunch lengthening caused by the longitudinal impedance. However, a significant bunch lengthening provided by higher-harmonic cavities is needed to keep the emittance low enough for...
We present a study of the systematic uncertainties in beam size determination using sextupole strength variations. Variations in strength of a sextupole magnet in a storage ring result in changes to the closed orbit, phase functions and tunes which depend on the position of the beam relative to the center of the sextupole and on the beam size. We take advantage of the beam-based measurements...
Xi'an 200MeV proton application Facility, as known as XiPAF, is upgraded to a heavy ion synchrotron, which replace H^- stripping injection with multiturn injection scheme. New synchrotron circumference is much bigger than original one for injection equipment installation space, which means that this heavy-ion lattice is much different from original proton lattice. Simulation is performed with...
Al2O3 is one of the potential insulator materials in the superconductor-insulator-superconductor (SIS) multilayer coatings of superconducting radio-frequency (SRF) cavities for pushing their performance limits.
We report on the successful coating of two 1.3 GHz Tesla- shaped SRF cavities with 18 nm and 36 nm layers of Al2O3 deposited by thermal atomic layer deposition (ALD). The coating...
The Elettra 2.0 upgrade project is a new storage ring that will replace the existing Elettra. Among the project's flagships are those of three beamlines with a photon flux generated by dedicated bending magnets of up to 10^13 ph/ses at 50 keV. Since a magnetic field of around 6 tesla is needed to do this, the magnet designed for those beam lines will employ superconducting technologies, for...
At the Facility for Antiproton and Ion Research in Darmstadt, Germany, fast-cycled superferric magnets will be utilised for ion optics in the main accelerator SIS100. After an intense testing campaign, the full series of dipole magnets has been equipped with cryogenic beam vacuum chambers and is ready for tunnel installation. Currently ongoing is the procurement of the quadrupole and...
The microbunching instability (MBI) driven by beam collective effects can cause significant electron beam quality degradation in advanced x-ray free electron lasers. Typically, multiple stage magnetic bunch compressors used to generate high peak current electron beam will dramatically amplify the microbunching instability. In this paper, by redesigning the solenoid elaborately and adopting a...
Annealing of niobium (Nb) cavities in UHV is crucial for the performance in the later cryogenic tests and operation. Recently, a so-called “mid-T bake” treatment has exhibited very high-quality factors for Nb cavities. In this way, the first set of mid-T treated samples were produced with cavities at Zanon Research & Innovation Srl. The cavity performances have been improved with lower BCS and...
The performance of superconducting cavities depends extremely on the material and surface properties. In the last decades processes have been developed for the successful series production of accelerating cavities needed for large scale facilities like the European XFEL. A main feature of these cavities are relatively large beam ports on both sides which can be used for the surface treatment...
The self-consistent nonlinear dynamics of a relativistic charged particle beam interacting with its complete self-fields is a fundamental problem underpinning many of the accelerator design issues in high brightness beam applications, as well as the development of advanced accelerators. A novel self-consistent code is developed based on a Lagrangian method for the calculation of the particles’...
Elliptically polarized undulator (EPU) plays an essential role in providing circularly polarized light from the third generation to upcoming synchrotron light sources. To meet the demand of energy tuning, the operation is also discussed to change from the adjusted gap method to the adjusted phase method in many of the designs. However, the adjusted phase operation causes a transverse field...
Radio-frequency (RF) modulations can influence the microbunching instability dynamics and serve to eventually control them with reinforcement learning (RL) methods. Implementing such a feedback system at the Karlsruhe Research Accelerator (KARA) will require that the action decided by the RL agent, in this case an RF modulation, is applied effectively to the electron beam. Such a modulation...
A new high intensity fixed target facility could be accommodated at CERN by fully exploiting the Super Proton Synchrotron. Multiple physics experiment proposals such as BDF/SHiP, NA62-BD, HIKE and SHADOWS are being considered. Amongst the different possibilities to locate such experiments and their respective target complex at CERN, the ECN3 hall in the North Area has been selected for further...
A major part of the 520 MeV Cyclotron's RF system is the high-power RF amplifier. The amplifier is based on eight 4CW250,000B tetrodes. A new high-power tetrode or a high-power tetrode that underwent refurbishing could trip the RF system through inner sparks. The likelihood of those sparks should be reduced prior to applying nominal power to the new and refurbished tetrodes. This could be...
Electromagnets have traditionally been used in accelerators due to their wide range of tuneability with high accuracy, but are a major factor in power consumption due to resistive losses in the coils and inefficiencies in power and cooling systems. Use of permanent magnets can greatly reduce power consumption, but it has proved difficult to produce the same range of tuning with comparable...
In this paper, the nonlinear coupling resonance $2 Q_x -2 Q_y = 0$ is studied by means of a Hamiltonian model. The detailed analysis of its phase-space topology unveils the possible phenomena that can occur when crossing adiabatically such a resonance. These considerations are probed by means of numerical simulations carried out using a symplectic map and the results are presented and...
Classical canonical Lagrange for the electromagnetic potentials has been formulated for beam-wave interaction enclosed by periodic structure or slow wave structure (SWS). The analysis procedure is based on expanding the potentials in the Lagrange of the given SWS in terms of the solenoidal and irrotational eigenmodes of a canonical cavity with cross-section enclosing that of the original...
In preparation for the High Luminosity phase of the LHC at CERN, to start in 2029, a refurbishment of the electronics of the CMS electromagnetic calorimeter (ECAL) is planned. The ECAL barrel section is organized in 36 elements called Supermodules (SMs), 18 in each side. All SMs, weighing about 3 tons each, must be ex-tracted, upgraded and inserted again during the Long Shutdown 3 (LS3) using...
The superconducting radio-frequency (SRF) community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity profile of niobium with a low residual resistance ratio (RRR) and correlate...
The National Synchrotron Radiation Research Cen-ter (NSRRC) has developed a 320 kW solid-state am-plifier based on an 80 kW solid-state amplifier. In the design of the 80 kW amplifier, the DC power supply and solid-state amplifier racks were separated, with the DC power supply providing power to the solid-state amplifier power terminals through cables. This separa-tion allows the DC power...
The effect of both existing and the planned insertion devices on linear optics, dynamic and momentum aperture was modeled using the kick map approach. Cross check for some IDs have been done with different tracking codes. Mitigation strategy for avoiding the crossing of a 4th order resonance line, excited by some of the IDs, is proposed.
The High Luminosity Large Hadron Collider (HL-LHC) project is an upgrade of the LHC aiming to increase by a factor 10 the harvested integrated luminosity foreseen early 40s. During Long Shutdown 3, scheduled to begin at the end of 2025, nearly 1.2 km of accelerator components, including a range of services spread across surface and underground facilities, will be replaced with new equipment...
The Rapid Cycling Synchrotron (RCS) of the Electron Ion Collider (EIC) is the injector of the Electron Storage Ring (ESR). The dynamic range of the RCS is from 0.4 GeV to 18 GeV. The RCS will use normal conducting dipoles, quadrupoles, and sextupoles. With errors to the main dipole field and misalignment to the elements included in the model, an orbit correction scheme has been developed....
The resistive contribution of the vacuum chamber is a significant part of the impedance budget. Due to the NEG-coated re-designed ILSF vacuum chamber, the resistive-wall effects must be carefully studied. The resistive impedance of the insertion devices and general cross-section of the storage ring was calculated by CST and WI2D code. In addition, the fast-correctors containing a resistive...
Recent studies have shown that accelerating $+19^{\circ}$ off-crest in all RF cavities in the MAX-IV linac reduces voltage-induced timing jitter from the klystrons. The current bunch compressors in the linac have fixed first-order longitudinal dispersion, and the RF phase is varied to control the amount of compression. Variable bunch compressor designs have been considered at MAX-IV in recent...
A uniform distribution of nucleation tin sites is essential to the growth of high quality Nb3Sn thin film by vapor diffusion method. The less-nuclear zones were commonly observed in previous nucleation experiments. However, a fully understanding of the occurrence of less-nuclear zones has not yet been achieved. Here, the adsorption energy of nuclear agent SnCl2 on different crystal planes of...
Optical Stochastic Cooling (OSC) was recently demonstrated at Fermilab’s Integrable Optics Test Accelerator (IOTA) storage ring. This demonstration marked the first realization of the stochastic cooling (SC) principle in the optical regime and achieved a system bandwidth of approximately 20 THz, more than three orders of magnitude greater than state-of-the-art SC systems. The initial...
Nb3Sn thin films are mainly used on superconducting radio frequency (SRF) cavities, single-photon detectors and RF logic circuits. Copper-based Nb3Sn thin-film SRF (TFSRF) cavities are promising for particle accelerators because they may combine the advantages of high thermal conductivity and high gradient. In this paper, a bronze method, including multi-layer deposition and heat treatment,...
The RAON accelerator facility which is under construction in South Korea consists of many subsystems. These subsystems have many control devices such as Programmable Logic Controller, Power Supply, Motor, and FPGA. In order to integrate these devices into the main control system, the RAON integrated control system consists of three parts which are the main control room, server & storage...
The RF group constructed a second radio frequency (RF) system for the Taiwan Photon Source (TPS) RF system. This RF system employs a high-power RF transmitter to deliver RF energy to the cavity. The RF transmitter is composed of multiple power supply modules (PSMs) that are installed in series. PSMs are critical and fragile components of the RF transmitter.
This article presents the...
The Hefei Advanced Light Facility (HALF) storage ring will be an ultralow emittance storage ring with 2.2 GeV beam energy, less than 100 pm·rad emittance, 480 m circumference and 350 mA nominal current, which is designed with 20-long and 20-middle straights, so more insertion devices can be installed for users. To facilitate its high performance, the beam-coupling impedance effect must be...
Superconducting (SC) undulators composed of high-temperature superconducting (HTS) tapes, which can be applied to compact light sources such as a table-top free-electron laser, are a part of research and development projects at Karlsruhe Institute of Technology (KIT). In order to minimize the beam heat loads in a cryostat including the compact SC planar undulator, a vacuum chamber (liner)...
The Mainz Energy-Recovering Superconducting Accelerator (MESA), an energy-recovering (ER) LINAC, is currently under construction at the Institute for Nuclear physics at the Johannes Gutenberg-Universität Mainz, Germany. In the ER mode continues wave (CW) beam is accelerated from 5 MeV up to 105 MeV. The energy gain of the beam is provided through 2 enhanced ELBE-type cryomodules containing two...
The study and understanding of collective effects plays a vital role for fourth-generation light sources. These effects mostly need to be mitigated and controlled to achieve the design operational parameters. However, they can also be utilized to gain insights into the properties of the machine.
While the 3 GeV storage ring at the MAX IV light source is running in multi-bunch mode during user...
The existing code for particle scattering and tracking in collimation systems integrated in SixTrack, called K2, was migrated from the current software in FORTRAN, to a new Python/C interface integrated in the Xsuite tracking code that is being developed at CERN. This is an essential step towards a full integration of collimation studies using Xtrack, and will allow profiting from GPU...
Optimization and design of particle accelerators is challenging due to the large number of free parameters and the corresponding lack of gradient information available to the optimizer. Thus, full optimization of large beamlines becomes infeasible due to the exponential growth of free parameter space the optimization algorithm must navigate. Providing exact or approximate gradient information...
The transfer line that carries the electron beam from the plasma to the undulators is certainly a critical line in EuPRAXIA@SPARC_LAB as in all plasma driven Free Electron Lasers.
This machine section must serve multiple purposes: capturing the highly divergent bunches at the plasma exit, separating the driver bunch from the witness and finally matching the witness to the FEL undulators....
An upgrade project is ongoing at Elettra Sincrotrone Trieste for a 4th-generation storage ring light source called Elettra 2.0. The new machine poses new challenges in terms of performance of the accelerator and sub-systems. One concern, currently under investigation, is about the effects of the passive superconducting third harmonic cavity on the stored beam due to the presence of a dark gap...
The quest of laser plasma accelerators is of great interest for various applications such as light sources or high energy physics colliders. This research has led to numerous performance improvements, particularly in terms of beam energy versus compactness [1] and ultra-short bunch length [2]. However, these performances are often reached without the achievement of sufficient beam quality,...
After the LHC Injectors Upgrade (LIU) project, the CERN Proton Synchrotron Booster (PSB) operates with a new injection kinetic energy of 160 MeV and an extraction energy of 2 GeV. In light of this, several measurements have been performed to characterize the behaviour of the accelerator in terms of beam stability and beam coupling impedance in the new energy range. In particular, the...
The growth time of transverse coupled-bunch instability (TCBI) in the vertical direction was
measured at SuperKEKB rings. Resistive wall (RW) impedance is the primary source of driving
TCBI. As a collider, special vacuum chambers are remarkable sources of RW impedance in
addition to RW impedance from regular chambers. Such chambers include collimators where the
chamber gap is very small...
The International Muon Collider Collaboration is currently investigating the possibility to build a muon collider with a center of mass energy of 3 TeV in a first phase, with an option to build a 10 TeV collider in a second phase. The muon beam decay is the global challenge of such a collider and fast acceleration is required to reach high luminosities. A series of three or four Rapid Cycling...
In the framework of the International Muon Collider Collaboration, a 10 TeV muon collider ring is being studied, with the option of an intermediate 3 TeV collider stage. The decay of high-energy muons represents a great challenge in terms of heat load management and radiation shielding for the superconducting magnets of the collider ring. Materials such as tungsten are being considered to...
Several studies have been performed in the 2021 and 2022 runs to build a better understanding of the behaviour of the accelerator with high intensity beams. Transverse beam instabilities at injection energy are known from previous measurements and simulations to be a potential limitation to reach the LHC Injectors Upgrade (LIU) target beam intensity. This paper summarizes the limitations...
The Karlsruhe Research Accelerator (KARA), the storage ring at KIT, allows short electron bunch operation with positive as well as negative momentum compaction factor. For both cases, the beam dynamics are studied. Using a line array camera KALYPSO (KArlsruhe Linear arraY detector for MHz rePetition rate SpectrOscopy), based on TI-LGAD, the horizontal intensity distribution of the emitted...
Coherent Synchrotron Radiation (CSR) occurs when electron beams traverse a curved trajectory. In novel accelerators, CSR poses a potential limit for electron beams to reach high brightness. While the longitudinal CSR wake has been well studied in one-dimensional theory and implemented in several simulation codes, transverse wakefields have received less attention. Following the recently...
The tracking code RF-Track has been updated to include a large set of single-particle and collective effects: beam loading in standing and travelling wave structures, coherent and incoherent synchrotron radiation, intra-beam scattering, multiple Coulomb scattering in materials, and particle lifetime. This new set of effects was focused on the simulation of high-intensity machines such as...
The lattice design process for BESSY III is based on a systematic & deterministic approach where sub-structures of the MBA lattice are analyzed and optimized before the lattice is composed. During this process, 5 standardized Higher-Order-Multi-Bend-Achromat (HO-6MBA) lattices were developed utilizing different combinations of homogeneous and gradient bends in the unit and the dispersion...
A high-density temperature and X-ray mapping system has been developed.
The X-ray mapping system, which uses strips with 32 channels of X-ray sensors, is now ready for use. The current sensor chip was selected about 10 years ago for Nb cavities operating at 2K, but recent advances in SRF cavities have required detection at higher temperatures, such as 20K for Nb3Sn materials. The current...
The Rapid Cycling Synchrotron (RCS) in China Spallation Neutron Source (CSNS) is a high intensity proton accelerator, the impedance can drive collective instabilities and limit the machine performance. Due to new component installation, the impedance model should be updated. A thorough estimation of the coupling impedance is presented and the impedance model in the RCS is obtained.
New S-band disk-loaded TM01-2pi/3-travelling-wave structures and pulse compressors have been developed for upgrades of the injector linac for SuperKEKB and Photon-factory storage rings in KEK. The structures 2-m long have ingenious disk irises with oval fillets reducing discharge in high-power operation and modulations in radius suppressing beam break-up instabilities arising from HEM11...
The main ring (MR) of the Japan proton accelerator research complex (J-PARC) delivers the high-intensity proton beams to the T2K long-baseline neutrino experiment. To observe charge-conjugation and parity-transformation violation in the lepton sector with high accuracy, the upgrade of the MR toward the beam power of 1.3 MW is mandatory. One promising method for increasing the beam power is to...
Volume and precision are tightly related to magnetic components that are typically necessary in a power converter for filtering (inductor) or voltage adaptation (transformer) purposes.
This paper presents a methodology for creating an efficient design tool for magnetic components to be used in power electronics applications. Specifically, an air cored inductor is taken as an example. The...
The relatively high transition temperature of A15 superconducting materials makes them a potential alternative to Nb for radio-frequency applications. We present PVD deposition of one A15 material, V$_3$Si, on Cu and sapphire substrates. The surface structure and composition of the films were characterised via SEM and EDX. The superconducting properties were investigated using a field...
The storage ring of the High Energy Photon Source will be driven by five higher-order-mode-damped 166.6 MHz beta=1 quarter-wave superconducting cavities operating at 4 K. Three prototype cavities were manufactured in Beijing and the surface preparations were conducted in Ningxia and Beijing. The cavities were subsequently vertical tested at PAPS in Huairou (Beijing). The cavity Q0...
Developing HTS dipole inserts producing fields larger than 5 T within 15 T Nb3Sn outserts is necessary to generate 20 T or higher fields for future high energy colliders. Dipole inserts based on the cos-theta coil geometry with various stress management concepts and Bi2212 super-conducting strand and cable are being developed at Fermilab both within and beyond the U.S. national effort. On...
Superconducting radio-frequency cavities made out of niobium form the fundamental block of modern particle accelerators. A model proposed by Gurevich [1] suggests the use of a superconductor-insulator-superconductor (SIS) structure to achieve higher accelerating fields and a reduced surface resistance beyond the thermodynamic limits of Nb. As a first step to pursue this approach, a single-cell...
We need something more than "adding" more women in our work context, we need to change the culture and our work organization. In these years we learned many things, mainly that if we want to change something we have to really include the gender dimension in our labs, in our researches, in our management tables. and when I speak of gender, I speak not only of women and for women, but for all.
Looking back while looking forward, a gender target would have seemed revolutionary in 1983. More recently, after ten years of gender and other diversity-related policies and actions, the Diversity and Inclusion Programme at CERN proposed a gender target strategy, “25 by ‘25”. Unanimously endorsed by the Senior Management in 2021, implementation is well underway and interim results are in....
Light sabers, hyper speed and space fights – how do they all connect with the latest accelerator research?
Since 2017 Professor Welsch has hosted a number of Physics of Star Wars events in the UK. He used the iconic films to explain applications of accelerator R&D to science, society and commerce. Each event reached hundreds of people on the day, and Millions around the world through media...
The analog LLRF system of the Taiwan Photon Source (TPS) booster ring was replaced by the DLLRF system at the beginning of 2018. The difference between setting points and measured values during the ramping process was controlled within 0.3% and 0.2° for the accelerating field amplitude and phase, respectively. Moreover, the sidebands of 60-Hz noise and their high-order harmonics were...
Developing Free Electron Lasers using Laser Plasma Acceleration open great hopes for compact laboratory scale light sources. The COXINEL line developed at Synchrotron SOLEIL (France) has been moved at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Germany) for using high-quality electron beam generated by the 150 TW DRACO laser. After proper electron beam transport, seed and undulator radiation...
An easy to install method for controlling electron injection in relativistic plasma waves relies on a sharp density downramp that is achieved by introducing a hydrodynamic shock into the gas flow before it gets ionized. Although the leading-order, desired effect of the shock is the generation of a 1D longitudinal drop in the density profile responsible for well localized electrons injection,...
The Compact Linear Collider (CLIC) beam-based acceleration baseline uses high-gradient travelling wave accelerating structures at a frequency of 12 GHz. In order to prove the performance of these structures at high peak power and short pulse width RF, two klystron-based test facilities will been put in operation this year. The first Southern Hemisphere X-band Laboratory for Accelerators and...
Beam-driven plasma-wakefield acceleration is a promising avenue for future accelerators, where a high electric field gradient could reduce the size and cost of a high-energy physics or a photon-science facility. Successful experimental results in recent decades have demonstrated the feasibility of high-gradient acceleration in plasma. However, to meet the demands of current conventional...
Intelligent robotic systems are becoming essential for inspection, maintenance, and repair tasks, both for the validation of systems before installation as well as during operation. Aiming to increase personnel safety and machine availability, robots can perform repetitive or dangerous tasks that humans either prefer to avoid or are unable to complete due to hazards, size or access...
Plasma based accelerators have achieved beams with multi-GeV energy, percent-level energy spread, micron emittance and stability over a full day however it remains a challenge to generate beams with all these properties simultaneously. External injection of a beam from a RF linac into a plasma-based accelerator holds the prospect of improving the beams from plasma accelerators by combining...
Sparks in TRIUMF's main cyclotron have to dissipate a lot of energy due to the large volume of the RF cavity, causing a trip of the system, resulting in down time of the machine and provide a risk of damaging the system if not reacted to immediately. A spark detection system evaluating the rate of change of the reversed power signal within the cyclotron when a spark occurs is employed but can...
The international accelerator facility FAIR, one of the largest science projects worldwide, is being built in Darmstadt, Germany. At FAIR, matter that usually only exists in the depth of space will be produced in a lab for research. With the planned experiments scientists will be able to gain new insights into the structure of matter and the evolution of the universe from the Big Bang to the...
The Electron-Ion Collider requires several crabbing systems to facilitate head-on collisions between electron and proton beams in increasing the luminosity at the interaction point. One of the critical RF systems is the 197 MHz crabbing system that will be used in crabbing the proton beam. Many factors such as the low operating frequency, large transverse voltage requirement, tight...
The SPARC\textunderscore LAB test facility at the LNF (Laboratori Nazionali di Frascati, Rome) holds a high brightness photo-injector used to investigate advanced beam manipulation techniques. High brightness electron bunch trains (so-called comb beams) can be generated striking on the photo-cathode of a Radio Frequency (RF) photo-injector with a ultra-short UV laser pulse train in tandem with...
A 1.6 m long 16 mm period superconducting undulator (SCU16) has been installed and commissioned at the Australian Synchrotron. The SCU16, developed by Bilfinger Noell GmbH, is based on the SCU20 currently operating at at KIT. The SCU16 is conduction cooled with a maximum on axis field of 1.084 T and a fixed effective vacuum gap of 5.5 mm. The design and performance of the longest...
Current analytical beam tomography methods require an accurate representation of the beam transport matrix between the reconstruction and measurement locations. In addition, these methods need the transport matrix to be linear as the technique depends on a simple mapping of the projections between the two areas, a rotation, and a scaling. This work will explore expanding beam tomography for...
The proton linac, for the European Spallation Source (ESS) currently in construction, will be powered by 155 high power RF systems. The RF systems will ultimately deliver in excess of 130 MW peak power, 5 MW of average power to a mixture of normal and superconducting accelerating structures at 352.21 and 704.42 MHz. ESS is a long pulse machine and will operate at 14 Hz with beam pulses of 2.86...
Gradient-free algorithms are commonly used because of the lack of knowledge about the derivative of the beam properties with respect to the accelerator parameters while running accelerator optimization simulations. However, similar to the automatic differentiation algorithms widely used in the AI/ML community, recent efforts have been made in the accelerator community to develop differentiable...
Climate change and its consequences require strong changes in our consumption modes and approaches. Large research infrastructures consume a large amount of various energy sources, from helium to electricity. Therefore, their societal impact in the current energy crisis is tremendous, as well as their environmental impact. The Energy for Sustainable Science at Research Institutes workshop,...
Nb3Sn will be a workhorse superconductor for building high-field accelerator magnets (dipoles, quadrupoles) for future energy-frontier circular colliders, but the performance of the state-of-the-art Nb3Sn conductors is still insufficient for this application. In the past few years a new type of Nb3Sn conductor with artificial pinning centers (APC) based on the internal oxidation method has...
Development of an accelerator-based tunable THz source prototype for pump-probe experiments at the European XFEL is ongoing at the Photo Injector Test facility at DESY in Zeuthen (PITZ). The proof-of-principle experiments on the THz SASE FEL are performed utilizing the LCLS-I undulator installed in the PITZ beamline. The first lasing at a center wavelength of 100 µm was observed in the summer...
In 1981 when I entered KEK, I did not know anything about accelerators and beam dynamics at all. Since then I have been helped by so many accelerator researchers in Japan and many countries. Here let me pick up a number of such people who could help me though my accelerator research. This prize is only made possible by those people.
The structural analysis of historical musical instruments is essential for the definition of restoration and conservation protocols, but also for the study of ancient manufacturing techniques and for the acoustic analysis of these precious objects. The use of synchrotron light microtomography has proved to be the ideal tool for a non-destructive approach in the analysis of instruments of...
The Photo Injector Test facility at DESY in Zeuthen (PITZ) utilizes slit scan technique as a standard tool for reconstruction of horizontal and vertical phase spaces of its space charge dominated electron beams. A novel method for 4-dimensional transverse phase space characterization, known as Virtual Pepper Pot, is proposed at PITZ, that can give
insight to transverse beam phase space...
The 288m long SLS 2.0 Storage Ring consists of several vacuum chambers with unique geometries. Complicated features, with many changes in the cross sections, are essential to provide the best impedance matching and to allow synchrotron light extraction under the tight geometrical constraints. In order to speed up the commissioning time, it was decided to NEG coat most of the vacuum chambers. A...
The APAM (Accelerators of Particles for Medical Application) Laboratory in the ENEA-Frascati Research Center developed a prototype of a self-shielded device dedicated to the treatment of breast cancer with the patient in prone position. It consists of a rotating X-ray source, based on a compact 3 MeV electron accelerator, placed under the patient bed which is provided with a circular opening...
Dielectric gratings are used in Dielectric Laser Acceleration due to their high damage thresholds in high acceleration gradients. When an electron bunch passes close to these gratings, it emits radiation, and the features of this radiation will be dependent on the beam position relative to the grating, the bunch charge, and the bunch length. A compact high-resolution diagnostic device will be...
The production of high-current and intense spin polarized electron beams is of great importance in electron-based facilities. Tests are planned to produce such beams in 2023 using GaAs-based photocathodes installed in the Brookhaven National Lab RHIC Coherent electron Cooling superconducting radiofrequency (SRF) photogun [1]. A fast and efficient electron polarimeter operating in the MeV...
High-brightness photoinjector has been an indispensable electron source driving X-ray free electron lasers (FEL). To improve the performance of the next-generation FEL, a high-quality electron beam with a small emittance, e.g, 0.1 micrometers for 100 pC bunch charge, will be of vital importance. A consecutive double-slit emittance meter has been proposed to measure such a small-emittance beam...
Reinforcement learning (RL) algorithms are investigated at KIT as an option to control the beam dynamics at storage rings.
These methods require specialized hardware to satisfy throughput and latency constraints dictated by the timescale of the relevant phenomena.
The KINGFISHER platform, based on the novel Xilinx Versal Adaptive Compute and Acceleration Platform, is an ideal candidate to...
The growing interest in upgrading European XFEL to high duty cycle operation requires an adaptation of the current low-level RF system to the new machine specifications. In the current upgrade scenario, the principal change in the RF parameters will be the loaded quality factor (QL) of the superconducting cavities, which will increase from the current value of 4.6e6 to more than 5.3e7 to...
Progress in cancer therapy with ions heavier than protons, i.e., helium, carbon, oxygen and neon, requires research and development capability. Ion research activity, however, is limited from the absence of U.S. accelerator facilities offering ion beams for therapy – placing the U.S. significantly behind Europe and Asia. With dramatic advances in beam delivery and compact accelerators, the...
Particle accelerator projects are complex, and CERN’s current engineering tools already manage millions of documents that follow various lifecycles and workflows. Future projects will push size and complexity to yet higher levels, in addition to increased collaboration with external partners. As reliable data is critical for success of complex system design, CERN is now implementing a new PLM...
Beam monitoring for Ultra High Dose Rate (UHDR) radiation therapy using pulsed beams, i.e. Very High Energy Electrons (VHEE), is a major challenge. The lower pulse repetition of VHEE beams means a larger dose-per-pulse is necessary to achieve the mean dose rates required for UHDR therapy (so-called FLASH). The currently used transmission ion chambers suffer drastic recombination effects under...
A design study is currently underway at the University of Melbourne for a large energy acceptance beamline to enable future hadron therapy modalities. As part of the TURBO project, a beam delivery system demonstrator is being developed for a DC Pelletron accelerator, which will provide 3 MeV H+ beams. Fixed Field Accelerator optics will be used to maximise momentum acceptance, with dispersion...
The Beam Interlock System (BIS) is the backbone of the machine protection system in CERN’s accelerator chain, ensuring that the beams are safely transported through the injector chain and circulated in the Large Hadron Collider. A new version of the BIS is currently under development and planned to be deployed in the SPS, LHC and the North Area experimental zone during the Long Shutdown 3...
Contaminated photon beams which comes from upstream and downstream dipole magnet in between an Insertion Device (ID), the main light source, often cause a critical measurement error on blade-type Photon Beam Position Monitors (PBPMs). The reason of such misreading is that the center position of the beam is calculated by only with the weak photoelectric current generated from both ends of the...
Ultrafast Electron Diffraction (UED) probes the dynamics of material structures which are triggered by a fs pump laser pulse. Some materials of interest for UED study, such as wide-bandgap insulators, require the use of UV pump lasers. Furthermore, UED with a probe size on the single micron scale requires high stability in the position, power, and size of the pump laser, which demands...
Thin targets, in the form of wires, stripes, or foils, are often used in accelerators to measure the properties of particle beams. Motivation for a small thickness, typically between several and to hundred micrometers, is diverse and depends on a particular case. For instance, small diameters of wires allow for precision measurement because it is probing a small fraction of the beam transverse...
Developments in current and future experiments in the SPS North Area (NA) and PS East Area (EA) fixed target beam lines at CERN, including the “Physics Beyond Colliders” (PBC) program, require accurate determination of the number of protons on target (POT). The re-calibration of Beam Secondary Emission Intensity monitors (BSI), recently completed in one of the NA branches, reduced the...
Capacitive Pick-Ups (PUs) are typically used for monitoring the beam position and measuring the relative intensity of bunched beams. We explore the potential usage of capacitive PUs for measuring the absolute charge in a bunch over the full range of beam energies, transverse beam offsets and bunch lengths found at ion accelerators. The results suggest that absolute charge measurements can be...
To harness the full potential of the ultrafast electron diffraction (UED) and microscopy (UEM), we need to know accurately the electron beam properties, such as emittance, energy spread, spatial-pointing jitter, and shot-to-shot energy fluctuation. Owing to the inherent fluctuations in UED/UEM instruments, obtaining such detailed knowledge requires real-time characterization of the beam...
LIEBE (Liquid Eutectic Lead Bismuth Loop Target for EURISOL) is envisaged to enhance production of short-lived isotopes at higher beam powers. Radioisotopes produced at MEDICIS facility are extracted via mass separation, implanted in a small foil and delivered to other research facilities and targets like LIEBE. The high intense neutron and gama radiation produced in the liquid PbBi target...
Traditionally produced SRF cavities are characterized by many limiting drawbacks, such as welding lines and poor reproducibility of their properties. Additive Manufacturing, and in particular Laser Powder Bed Fusion (LPBF), may overcome these issues: with this technology, it is possible to create seamless components with reproducible characteristics. But 6 GHz cavities cannot see internal...
The Laser Powder Bed Fusion (LPBF) is an AM technology suitable to produce almost free-form metallic components. At Legnaro National Laboratories of the Italian National Institute for Nuclear Physics, the LPBF process was recently used to produce parts of the Forced Electron Beam Induced Arc Discharge (FEBIAD) ion source for the SPES Isotope Separation On-Line (ISOL) facility.
Such device is...
During the 2022 maintenance outage, installation was completed for the new generation of spallation target-moderator-reflector-shield, known as Mark-IV at the LANSCE. The upper-tier of Mark-IV target requires precision Flight Path (FP) alignment, because of the line-of-sight view of the spallation disk within. This paper demonstrates the importance of using advanced Laser Tracker Survey (LTS)...
The Heidelberg Ion-Beam Therapy Centre (HIT) provides proton, helium, and carbon-ion beams with different energies and intensities for cancer treatment and oxygen-ion beams for experiments. For several experiments and possible future applications, such as helium ion beam radiography, a low-intensity ion beam monitor integrated into the dose delivery feedback system for the accelerator control...
Physics models, particularly for online operations, such as for our MAD-X or Bmad models, depend on a good understanding of the magnet characteristics. While we often measure the magnets or some subset of the magnets, those measurements are only meant to verify that the magnets meet specifications before being installed. We often have magnets that are not precisely understood. As a result, we...
At a heavy-ion linac facility, such as ATLAS at Argonne National Laboratory, a new ion beam is tuned once or twice a week. The use of artificial intelligence can be leveraged to streamline the tuning process, reducing the time needed to tune a given beam and allowing more beam time for the experiment. After establishing the required automatic data collection procedures, we have developed and...
Taiwan Photon Source (TPS) is a 3-GeV synchrotron radiation light facility that was constructed in 2014. The magnets of the storage ring are installed on the girder system, and the girder system of TPS is an adjustable mechanism that is drove by motors of the cam mechanism. The control network of TPS is surveyed twice in ever year to observe the change of position of girders. The maximum...
A unique muon linear accelerator (linac) for the muon g-2/EDM experiment at J-PARC is under development. Digital feedback (DFB) design employed in a low-level radio frequency (LLRF) control system is crucial to fulfilling the required RF amplitude and phase specifications in the RF cavities for a stable and continuous acceleration of the whole bunched particles. To this end, a micro...
The aim of this work is to demonstrate the principal possibility to enhance the electron beam dose deposition in the depth of the sample for radiation therapy purposes. Trains of electron bunches of 22 MeV generated at PITZ are focused inside the sample using a dedicated fast deflector and a solenoid magnet. To explore the capabilities of the proposed setup, dose distributions are calculated...
The CNAO orbit measurement system consists of 20 electrostatic pickups. They are based on a nineties’ design and reliably working from over fifteen years, despite a not very effective calibration system.
At beginning 2020, a new control software was installed, with two significant improvements: firstly, pickups signal is acquired continuously and beam orbit is saved every cycle; secondly, it...
The ANSI* steel penetration test is an important measure of the image performance capability of a cargo inspection system. Currently, the method for determining the arrow's visibility is completely subjective, as what one may deem 'visible', another may claim as not. An objective method is to calculate the contrast-to-noise ratio (CNR) between the steel plate and the arrow. A series of...
The design, execution, and analysis of light source experiments requires the use of sophisticated simulation, controls and data management tools. Existing workflows require significant specialization to accommodate specific beamline operations and data pre-processing steps necessary for more intensive analysis. Recent efforts to address these needs at the National Synchrotron Light Source II...
Anodic bonding technology is a method which mainly by the aid of the electric field and temperature for connecting two materials such as glass-glass or glass-silicon wafer substrate by forming covalent bonding. The bent monochromator used in the synchrotron radiation which was made by high quality silicon wafer bonded onto concave cylindrical shape Pyrex glass base. In the past, it is made by...
After the upcoming upgrade, the storage ring in the Advanced Photon Source (APS-U) will have over two thousand magnet power supplies. They will be constantly monitored in order to prevent impeding failures, when possible. The new data acquisition system (DAQ) will deliver 22600 samples of each power supply’s current per second. The data can be saved at this rate for a short period of time...
On AREAL RF photogun linac at CANDLE, time-separated ultrashort electron bunch pairs are generated by means of temporal shaping of the laser pulses driving the photocathode. The free-space interferometric delay line method used for the laser pulse shaping provides the means for tailoring the beam characteristics such as the charge contrast and relative delay of the bunch pairs in the train. In...
The energy consumption in accelerator structures during beam downtimes is a significant fraction of the overall energy budget. Accurate prediction of downtime duration could inform actions to reduce this energy consumption. The LCAPE project started in 2020 and develops artificial intelligence to improve operations in the FNAL control room by reducing the time to identify the cause of a beam...
The Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Lab uses an electronic shift log to record machine performance, save beam tune data, relay information between shifts, and track the facility's operational status for budget reporting. In early 2021, the legacy shift log was retired and upgraded to a modern platform to increase reliability and expand functionality. This...
Since its commissioning, operators at the Argonne Tandem Linear Accelerator System (ATLAS) have used an analog current meter to manually record beam current measurements from Faraday cups along the beamline. Recently an automated process using a digital picoammeter was developed for beam current measurements. This automation has streamlined daily operations, increased the precision of...
The CERN SPS Beam Dump System (SBDS) is responsible for disposing the beam in the SPS in case of any machine malfunctioning or end of cycled operation.
This is achieved by the actuation of kicker magnets with predefined pulses, which aim to: i) deviate the beam towards the absorber block (TIDVG); ii) dilute the particle density. Evidently, a malfunction of this system may have negative...
Beam arrival time is one of the key fundamental parameters for free-electron laser (FEL) facilities to ensure an accurate synchronization between an electron bunch and a seeded laser. Thus a high-performance beam arrival time/flight time measurement (BAM) system is indispensable for an FEL. A cavity-based BAM system has already been established at the Shanghai Soft-X-ray FEL test facility...
The unique electronic band structure properties of two-dimensional (2D) materials allow for a multitude of cutting-edge applications involving electrical and optoelectronic devices. Atomically thin 2D materials such as MoS2 face major obstacles during synthesis and processing into precise electronic band gap properties adjustments. Few-layer MoS2 films are synthesized using alkali halide...
The ionization profile monitors (IPMs) are used to measure the transverse profiles of the beams accelerated at the Brookhaven National Laboratory (BNL) AGS. These devices use multi-channel plates (MCP) to collect electrons generated by ionization of the residual gas to get an image of the beam projection onto the two transverse planes. The gains of each of the 64 channels in the MCP can vary...
Parameter tuning is a regular task and takes considerable time for daily operations at FEL facilities. In this contribution, we demonstrate SASE pulse energy optimization at the European XFEL with Bayesian optimization (BO) as an alternative approach to the widely used simplex method. Preliminary experimental results show that BO could reach a comparable performance as the simplex method, even...
The X-band lineariser linac planned to be installed on CLARA will be aligned using beam induced higher order modes (HOMs). Higher order modes in the cavity were studied using a bead-pull measurement technique. A software application was developed in LabVIEW to control the 3D motorised bead position scanning setup and VNA for S-parameter measurements. Propagation of HOM frequencies in the linac...
Boron Neutron Capture Therapy(BNCT) is useful for cancer therapy. To generate safe and efficient neutron beams, we accelerate 2.5 MeV protons and irradiate a lithium target. This is an endothermic reaction that avoids activation of the accelerator and produces neutrons of relatively low energy. We are designing a beamline to deliver such protons to a lithium target. Tokyo Institute of...
The Mainz Energy recovering Superconducting Accelerator (MESA) is currently being installed in the final area of the Institute for Nuclear Physics at Johannes Gutenberg-University in Mainz. To optimize and operate the accelerator reliably luminescence screens, wire scanners and RF cavity monitors are used. In this paper we will present the ongoing development of the beam diagnostics foreseen at MESA.
Real-time dosimetry for ultra-high dose-rates (UHDR) and Very High Energy Electrons (VHEE) is a challenge which is currently being studied using the electron beam at CERN Linear Accelerator for Research (CLEAR). These studies are motivated by the demand for reliable dosimetry for FLASH radiotherapy. This mode of irradiation relies on UHDR, a dose rate regime where conventional dosimetry...
Many beam instrumentation systems at Brookhaven National Laboratory’s Collider-Accelerator complex are over 20 years old and in need of upgrading due to obsolete components, old technology and the desire to provide improved performance and enhanced capabilities. In addition, many new beam instrumentation systems will be developed for the future Electron Ion Collider (EIC) that will be housed...
The Beam Loss Monitoring (BLM) system of the Large Hadron Collider (LHC) at CERN is essential for the protection of machine elements against energy deposition from beam losses. Employing around 4000 detectors placed around the 27-km LHC ring, the BLM system measures secondary particles continuously and can trigger beam extraction in less than 3 turns, in case the signals exceed certain...
The High-Luminosity LHC (HL-LHC) project requires a doubling of the proton intensity transferred from its injector (SPS). Beam loading compensation in the SPS 200 MHz cavities is essential to limit losses when the beam is transferred into the LHC 400 MHz RF system. The SPS Low Level RF (LLRF) has been completely redesigned during the LHC Long Shutdown 2 (LS2, 2019 – mid 2021). The new system...
The Fermilab Linac is a roughly 145 meter linear accelerator that accelerates H- beam from 750 keV to 400 MeV and provides beam for the Booster and the rest of the accelerator chain. The first section of the Linac is a Drift-Tube Linac (DTL), which in its current state, suffers from a lack of instrumentation along its length. As a result, operational staff do not have access to the diagnostic...
Beam Loss Monitors will be installed along the primary SPES beam line to detect proton beam losses in the cyclotron area. They will be connected to the cyclotron Machine Protection System (MPS), as it is significant for the proper management of the accelerator during the operation. This report shows the work of characterization of such devices.
Preliminarily, the characteristics of models...
The Proton Testbeam At KAHVE-Lab project aims to accelerate protons to 2 MeV energy using a locally designed and built linear proton accelerator. An optimized Low Energy Beam Transport (LEBT) line is installed to transfer the protons from the ion source towards the Radio Frequency Quadrupole cavity operating at 800 MHz. The LEBT line includes a compact measurement station to determine the...
The mitigation of heat loading is one of the important issues for beam instrumentation to measure the high-power proton beam. Recently, the highly-oriented pyrolytic graphite (HOPG) material was used for the target probe of the bunch-shape monitor at the front-end in the Japan Proton Accelerator Research Complex (J-PARC). Since the thermal conductivity of the HOPG is high, it is suitable to...
The Heidelberg ion beam therapy facility HIT has more than ten years experience in patient treatment. More than 7800 patients have been treated with protons and heavy ions, about 700 are treated every year.
Outside the beam time dedicated to therapy, quality assurance (QA) and machine tuning, we provide beams for a large spectrum of experiments in physics, biology and medicine which make...
Advancements in low-emittance x-ray sources have required the exploration of various diagnostic techniques to push the resolution limit. Here we will present the two techniques to measure the size of the electron beam using X-rays: zone plate transmission microscope and a multi-crystal diffraction-based beam property analyzer. Both techniques have been tested at the Swiss Synchrotron Light...
In recent work, it has been shown that reinforcement learning (RL) is capable of outperforming existing methods on accelerator tuning tasks. However, RL algorithms are difficult and time-consuming to train and currently need to be retrained for every single task. This makes fast deployment in operation difficult and hinders collaborative efforts in this research area. At the same time, modern...
In order to steer beams through the center of focusing elements, the field center
with respect to adjacent Beam Position Monitors needs to be known precisely.
Often individual qudrupoles are varied to find the center, where the orbit does
not change, but this requires costly field control for each quadrupole. Here we
analyze beam-based Alignment(BBA) techniques that utilizes sextupoles...
Beam-Beam Long-Range Compensators employing current-carrying wires are considered as valuable options in hadron colliders to increase dynamic aperture at small crossing angles. This paper presents a simple design proposal for application at CERN LHC. The preliminary design allows for a certain scalability of the number of modules, current flowing in the wire, and dimensions. It complies with...
Hefei Advanced Light Source is the fourth generation of synchrotron radiation light source based on diffraction limit storage ring, and its emission and brightness index design goal is the world's first, and will be the world's most advanced diffraction limit storage ring light source after completion. This paper is based on the Hefei Advanced Light Source Beam Measurement Project. CST...
Bunch-by-bunch systems are developed at the Taiwan Light source and the Taiwan Photon source to monitor the transverse position and filling pattern. This system consists four channels with 500 MHz sampling rate which synchronizes with the radio frequency of the accelerator. This system is used to diagnose the injection transition due to the kick mismatch and beam oscillation coming from the...
In order to fulfill the target performance of Elettra 2.0 light source, a brand new button type beam position monitor detector has been developed. From a theoretical point of view, the transfer function which relates beam position information to electromagnetic signal intensity induced on pick up electrodes is well known. In practice, due to a number of constraints, a real device...
Sub-millimeter precision is a crucial criterion for beam delivery in proton therapy. Nowadays, most of the therapy systems use the Pencil Beam Scanning (PBS) technique where single beams with regulated amount of protons are delivered sequentially to different locations within the target. Beam energy defines the depth of the beam propagation and scanner magnets deflect the beam to the desired...
The European Spallation Source ERIC (ESS) is poised to be a high intensity and high energy neutron source for scientific applications. The source behind this high intensity neutron beam is a long pulse linear proton accelerator. In order to meet the stringent requirements on the proton beam, the protons need to be accelerated in stable accelerating gradients in the accelerating cavities. In...
A set of twelve Polycrystalline Chemical Vapour Deposition (pCVD) diamond detectors are installed in the beam injection, extraction and betatron collimation areas of the Large Hadron Collider (LHC) as fast beam loss monitoring detectors. Their high-radiation tolerance and time resolution in the order of a few ns makes them an ideal candidate to monitor bunch-by-bunch losses in the LHC beams,...
An ISO 14644-1 cleanroom is a contained environment where particle counts must be kept low in order for the cleanroom to function properly and meet critical certification criteria. These particles are typically dust, airborne microbes, aerosol particles, and chemical vapours. The Additive Manufacturing Department at Daresbury Laboratory was used to appraise the Cleanroom mechanical assembly...
Capacitive beam position monitors (BPM) are widely used as diagnostics tools in particle accelerators. Typically due to a large number of BPM in an accelerator, their contribution to the beam coupling impedance cannot be neglected. In addition to the broadband part at low frequencies, the impedance exhibits resonant peaks at higher frequencies due to electromagnetic fields trapped around the...
The Future Circular Collider (FCC) R&D study was started in 2021 as a comprehensive feasibility analysis of CERN’s future accelerator project encompassing technical, administrative and financial aspects. As part of the study, Beam Instrumentation (BI) is a key technical infrastructure that will have to face unprecedented challenges. In the case of electron-positron FCC-ee, these are...
In the field of Particle Accelerators engineering, the design of the cooling channels of its components has been extensively based on experimental correlations for the calculation of convective heat transfer coefficients. In this scenario, this work is focused on studying whether the experimental correlations are conservative when the flow is turbulent in fully developed and non-fully...
Vacuum chambers prepared from aluminium alloys bring unique fabrication challenges, and with recent experience preparing and testing a series of insertion-device vacuum chambers, new processes were developed and limits to mechanical design better understood. These challenges and new understandings are presented. Processes include: precision machining of almost 6 metre long aluminium...
The normal conducting part of the European Spallation Source (ESS) linear accelerator (Linac) entered the phase of staged beam commissioning in 2021. To allow carrying out commissioning activities and operating the normal conducting Linac (NCL), safe conditions for personnel must be assured, for which the Personnel Safety Systems (PSS) at ESS play a substantial role. The Personnel Safety...
Supersonic gas jets are useful tools in particle accelerators used in both scientific and medical applications. They can provide real-time, longitudinal and transverse beam profile measurements for charged particle beams in accelerators and are also being used as a plasma source in wakefield accelerators. For gas jets to be used effectively as beam profile monitors, the density profile of the...
In the extraction of booster to storage (BTS) for High Energy Photon Source (HEPS), four pulse bump magnets are applied to create a local bump to ease extraction. In this paper, a lot of characteristics of the pulse bump mag-net such as magnetic field, eddy current, induced voltage, vibration are introduced and thoroughly discussed. Ac-cording to measurements, four pulse bump magnets are...
Very High Energy Electron (VHEE) beams represent a promising alternative for treating deep-seated tumors. However, VHEE beams generate quasi-uniform dose distribution along the beam path, leading to healthy tissue overexposed. Focused VHEE beams are a revolutionary radiotherapy technology that enables concentrating doses into a small and well-defined spot with an extremely high dose rate. This...
At the Ferninfrarot Linac- und Test-Experiment (FLUTE) at the Karlsruhe Institute of Technology (KIT) a new and compact method for longitudinal diagnostics of ultrashort electron bunches is being developed. For this technique, which is based on THz streaking, strong electromagnetic pulses with frequencies around 240 GHz are required. Therefore, a setup for laser-generated THz radiation using...
Niobium thin films are used in macroscopic SRF cavities for particle accelerators which are under study for microscopic superconducting qubits for quantum computing. The superconducting properties of niobium in microwave fields vary significantly with lattice defects and impurity content, where sub-at.% impurity level can reduce or increase microwave surface resistance by an order of...
Sirius is one of the first 4th generation synchrotron light source globally, currently in operation by the Brazilian Synchrotron Light Laboratory (LNLS). One of the components that will be part of the light source are the vacuum chambers defining the environment in which the electron beam travels under the influence of electromagnetic fields. This environment should be substantially free of...
The generation of Cherenkov diffraction radiation when a charged particle beam passes in close proximity to a dielectric target is being studied and developed for various non-invasive beam instrumentation applications. One such instrument is a beam position monitor (BPM) composed of four cylindrical dielectric inserts. A challenge of using the conventional stretched wire technique to...
Monte Carlo simulations are used to model neutron transport through matter for estimating backgrounds or to design adequate shielding for radiation safety. Detailed neutronics calculations require thorough descriptions of the geometry, so that the influence of all physical features and materials are captured. It is most convenient to import existing CAD models into Monte Carlo software to...
To support commissioning and early operation of the ESS normal-conducting linac, a variety of beam instrumentation systems have been deployed. These include beam chopping systems, Faraday cups, beam current monitors, and beam position and phase monitors as well as specialised systems such at wire scanners, emittance measurement units and neutron beam loss monitors. Commissioning has proceeded...
The oscillator-type mid-infrared free-electron laser at Kyoto University named Kyoto University FEL (KU-FEL) has achieved the extraction efficiency of 9.4% and the micro-pulse duration of 4.2 cycle* with the electron bunch charge of about 200 pC by the photocathode operation of 4.5-cell thermionic RF gun. Then the micro-pulse energy obtained was 100 micro-J. A new and dedicated 1.6-cell RF...
We built a test stand for evaluating the performance of the thermionic electron sources for the electron lens project at the Integrable Optics Test Accelerator (IOTA) in Fermilab. The lens will be used to study nonlinear dynamics and electron cooling of 2.5 MeV protons with strong space charge. The test stand will validate the characteristics of the thermionic sources and the main parameters...
ThomX is a 50-MeV electron accelerator made of a linac and a storage ring. Severe constraints on the RF-gun frequency have led to the choice of an heterodyne low-level radiofrequency distribution system. We report on the performances of this system during the first two years of commissioning of the machine.
While ion therapy provides an immense opportunity for advancement in the treatment of various cancers, present-day mechanical systems that deliver beam from the accelerator to the patient are large and complex. A new patent pending compact beam delivery system concept has been explored and is presented here. The concept is to provide a continuously rotating magnet system wherein the...
In this paper we present a systematic benchmark between the simulated and the measured data of radiation monitors useful for Radiation to Electronics (R2E) studies at the Large Hadron Collider (LHC) at CERN. The radiation levels in the main LHC tunnel on the right side of the Interaction Point 1 (ATLAS detector) and 5 (CMS detector) are simulated using the FLUKA Monte Carlo code and compared...
The high-brightness electron beam at the Photo Injector Test facility at DESY in Zeuthen (PITZ) is now also used for FLASHlab@PITZ: an R&D platform for studying radiation biology and the FLASH effect in radiation therapy. The available parameter space of the electron beam with a momentum of 22 MeV/c allows bunch charges from 10 pC up to 5nC, bunch durations of 0.1–60ps, and bunch train lengths...
Many vacuum applications, such as accelerators, optical chambers, superconducting cavities, SEM/TEMs, are particularly sensitive to dust and require an ultra-clean working environment. Non evaporable getter pumps with porous sintered elements are already extensively used in UHV and XHV particle-sensitive systems as well as in industrial applications, laboratories and large R&D facilities. In...
On the one hand fault occurs with high cost in accelerator operation, on the other hand operation data is treasure for modelling the accelerator from the other side.
Due to limited capacity of data processing, massive data is discarded in accelerator operation. However, regular data recorded can not meet the need for measuring the damage of fault. Therefore, a balanced design to capture as...
Thanks to their superior dose conformality and higher radiobiological effectiveness with respect to protons, helium ions are considered as the new tool of choice in the fight against cancer using particle beams. A facility to produce helium beams at therapeutical energy can also accelerate protons, at energies permitting both standardised treatment and full body radiography, and heavier ions...
In recent years, there has been an increasing demand for high-intensity beams related to electron beam irradiation, such as mass production of nuclear-medicine examination by using 99Mo and high-efficiency production by material modification through material irradiation. While the acceleration of high-current beams can be realized by using a superconducting cavity, a compact accelerator is...
Hadron therapy is established as a method of choice for a number of cancerous diseases, and its advantages are well-established for specific malignancies. Modern medical particle accelerators still struggle to fulfil critical features required by advanced treatment modalities, such as variable energy beams, high repetition rate, and pulse-by-pulse intensity modulation. Fixed Field Accelerators...
Experiments requiring the use of plasma sources often have trouble getting time on large plasma sources to perform their experiments despite needing only a few centimeters of high density plasma. It is significantly more convenient to have a short, high density plasma source that is available on demand for immediate experimentation. A capillary discharge plasma source was built at UCLA for...
Dedicated wakefield-generating structures are capable of measuring the electron beam current profile, and of removing residual energy chirps (dechirping). Furthermore, at Free-Electron Laser (FEL) facilities they can be used to measure* or shape the photon pulse power profile. We motivate and present the mechanical design of the rectangular, double-sided corrugated structures used at SwissFEL,...
The Cryogenic Current Comparator (CCC) is able to provide a calibrated non-destructive measurement of beam current with a resolution of 10 nA or better. The non-interceptive, absolute intensity measurement of weak exotic ion beams (< 1 µA) is essential in heavy-ion storage rings and in transfer lines, as the ones in FAIR. With traditional diagnostics this measurement is challenging for bunched...
The National Synchrotron Radiation Research Center (NSRRC) uses cryogenic fluids to create a low-temperature cooling environment for equipment and to conduct various experiments. However, exposure to these cryogenic fluids can cause frostbite, hypoxic suffocation, behavioral incapacitation, insanity, and even death in severe cases. To evaluate oxygen deficiency hazard (ODH) in the NSRRC, we...
The existing heavy ion synchrotron SIS18 at GSI will be used as a booster synchrotron for SIS100 at FAIR operation. In order to reach the intensity goals, low charge state heavy ions will be used. Unfortunately, such ions have very high ionization cross sections in collisions with residual gas molecules, yielding in beam loss and pressure rise via ion impact stimulated gas desorption. To...
High Energy Photon Source is a 6 GeV fourth-generation synchrotron light source currently under construction in Huairou, Beijing. It consists of 13 Radio Frequency (RF) stations. Each RF station consists of a solid-state amplifier, an RF cavity, an LLRF controller, an interlock controller .etc. To monitor the status of all 13 RF stations, approximately 60,000 process variables need to be...
The Quench Protection System (QPS) of the LHC is crucial for integrity of the superconducting circuit elements. It also plays an important role in the acquisition of data from the circuit elements during the magnet qualification, equipment commissioning and accelerator operation. The new superconducting circuits for the HL-LHC era, which will be assembled and operated for a first time in the...
Protection of the superconducting circuits of the High Luminosity Upgrade of the LHC project (HL-LHC) will be ensured by a new generation of quench detection systems and various quench protection systems for the superconducting circuits and magnets.
The HL-LHC quench detection systems serve as well as high-performance data acquisition systems, that also provide essential input for the...
Measuring transverse beam profiles using thin wires is a very successful and widely used method. The signal is generated either by measuring scattered particles outside of the vacuum chamber or by measuring the current of the secondary electrons emitted from the wire. In high-brightness accelerators, the heating of the wire induced by the direct beam interaction or by coupling to RF fields can...
Particle therapy has advantages over conventional radiotherapy, but is not so widespread because of significant facility costs. In this work, we developed a compact, low-cost, expandable and high-performance beamline for a multi-room particle therapy facility. The accelerator is located at a lower level (underground) and the beamline guides the particles to treatment rooms located on the upper...
Electro-optic diagnostics are able to non-destructively resolve the longitudinal charge profile of highly relativistic bunches without complicated calibrations and ambiguous phase recovery techniques. The most implemented technique is EO spectral decoding as it is simple and reliable, and has an easy to interpret output. However, its resolution is limited to the geometric mean of the...
Ultrashort electron beams with high brightness are of vital significance in probing nanoscopic dynamics on the pico-to-femtosecond temporal scales. Electron sources are the most critical element in such apparatuses, whose advancements are expected to further improve the resolving capabilities. In this contribution, we report on the development of a DC photocathode electron gun aiming at...
The electrons, which passed the undulators in a linac-driven Free Electron Lasers, could be utilized for additional radiation generation in an Inverse Compton Scattering process (ICS). The PolFEL, facility, currently in preparatory phase in NCBJ, is planned to be equipped with ICS system, to generate continuous (10kHz repetition rate) pulses train of hard X-ray radiation, in addition to THz-,...
The Hefei Advanced Light Facility (HALF) is a diffrac-tion-limited storage ring (DLSR) light source based on the compact multi-bend achromat (MBA) lattice. There-fore, the gaps between those focusing magnets are small. The commonly used ConFlat® flange, with a large axis dimension, is not suitable for the compact lattice in HALF. In this work, a stainless steel tapered flange fas-tened by a...
The High Energy Storage Ring (HESR) has been designed for acceleration and storage of antiprotons and ions by Forschungszentrum Jülich (FZ-Jülich) for FAIR in Darmstadt.
The HESR kicker magnets have been designed for the injection of charged particles with magnetic rigidity of 13 Tm. Kicker magnets shall generate a total integral field of 57.8 mT during 500 ns with rise- and fall-times of...
The Flash Therapy is a revolution in the cancer cure, since it spares healthy tissue from the damage of the ionization radiations without decreasing its effectiveness in the tumor control. To allow the implementation of the FLASH therapy concept into actual clinical use and treat deep tumors, Very High Electron Energy (VHEE) should be achieved in range of 50-150 MeV. In the framework of VHEE...
The VSR DEMO SRF 1.5 GHz cavities require a large tuning range of 1 MHz to allow for the desired operation, including a cavity parking mode. The tuning system composed of blade tuner, stepper motor, release mecha-nism, and pre-loaded piezos installed into frames features mostly components already validated and used for other applications. However, the operational demands for the VSR...
Wuhan Advanced Light Source (WALS) is a fourth-generation synchrotron radiation facility with 1.5 GeV designed energy and 500 mA beam current. The high-heat-load absorber is designed to protect downstream ultrahigh-vacuum chambers from overheating. It is the only heat mask component to absorb large amount of synchrotron radiation (bending magnet) in the storage ring. This presentation is...
The Beam Interlock System (BIS) is the backbone of the machine protection system throughout the accelerator complex at CERN, including the LHC. The present BIS needs to be upgraded to ensure the required level of dependability and maintainability for the lifetime of the HL-LHC, which is planned to become operational in 2029. The present BIS, designed more than 15 years ago, has proven its...
High power particle producing target components in research facilities often consist of refractory metals. They experience challenging thermo-mechanical conditions and therefore require dedicated cooling systems. Employing water-cooling in direct contact with the target materials, especially tungsten (W), induces erosion and corrosion. Cladding the target blocks with...
The CLARA accelerator facility at Daresbury Laboratory, UK, was originally designed to operate as a free-electron laser test facility. To improve the user exploitation of the facility a dedicated full energy beam exploitation (FEBE) area has been designed and is currently being installed in a separate experimental bunker on the CLARA accelerator. This facility will allow users to conduct...
Medical isotopes are used for diagnostics and cure of tens of millions of patients worldwide every year. For the largest parts they are produced in fission reactors from enriched Uranium-235 leaving behind long-lived nuclear waste. Around the world organizations are therefore working to make medical isotope production more sustainable.
RI Research Instruments was commissioned by the Institute...
The Extreme Photonics application Centre (EPAC) is a new national facility to support UK science, technology, innovation and industry currently under construction at the Rutherford Appleton Laboratory, UK. EPAC is designed to facilitate a wide variety of user experiments with 1PW 10Hz laser systems. It is anticipated that early experiments will include laser-plasma acceleration of electrons to...
The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is composed of 5 independent Tanks, each of which of 8 t in weight and 8 m in length, is made of 4 modules and is positioned and aligned to the Nominal Beam Line with 2 mechanical supports. The supports are designed to perform the iso-statical alignment of the tank, and to allow its longitudinal displacement for the...
A pulsed septum magnet (SMH40) is used for heavy ion extraction from the Low Energy Ion Ring (LEIR). A non-conformity on the coil cooling circuit made it necessary to consolidate the design of the septum blade and related manufacturing process. A stringent failure analysis, including structural analysis and computational fluid dynamics, combined with destructive and non-destructive testing,...
The Electron Ion Collider (EIC) is being built at Brookhaven National Laboratory (BNL). Early preliminary design phase efforts are underway. In addition to upgrading the existing RHIC instrumentation for the EIC hadron storage ring, new electron accelerator subsystems that include a 400 MeV Linac, rapid-cycling synchrotron, electron storage ring, and a strong hadron cooling facility will have...
In the J-PARC linac, the low-level RF (LLRF) with the digital feedback (DFB) and the digital feedforwaed (DFF) of the cPCI system had been adopted to satisfy the requirement of amplitude and phase stabilities. It has been operated without a serious problem so far. However, more than 15 years have passed since the construction of the J-PARC linac and the life of the apparatuses used since the...
The Electron-Ion Collider (EIC) facility at Brookhaven National Laboratory is in the preliminary design phase and advancing towards establishing the project baseline. One challenging task is to design cryogenic BPM pick-ups for the Hadron Storage Ring (HSR) that will ensure reliable beam position measurements over a large dynamic range. The BPM pick-up design must take into consideration...
KoBRA (Korea Broad acceptance Recoil spectrometer and Apparatus) of RAON (Rare Isotope Accelerator complex for ON-line experiments) in Korea is preparing for producing rare isotopes with stable ion beams from SCL3(Superconducting Linac 3) at an energy range of 5 - 25 MeV/u in early-phase experiments. Due to quite a lengthy transport beamline from the end of SCL3 to the target of KoBRA...
ZAP-X is an innovative radiosurgery platform that is self-shielded, using gyroscopic motion to allow precision neurosurgical treatment. It requires a compact linac with lower than typical energy for medical applications. A 3 MeV S-band linac is designed and fabricated for this purpose. Thorough, clinical style testing was performed to verify the performance. The characteristics of photon...
Characterizing the phase space distribution of particle beams in accelerators is a central part of accelerator understanding and performance optimization. However, conventional reconstruction-based techniques either use simplifying assumptions or require specialized diagnostics to infer high-dimensional (> 2D) beam properties. In this work, we introduce a general-purpose algorithm that...
Comprehensive simulations for the FETS laserwire have been made with the developed Geant4 laser package. Feasibility of the longitudinal mode laser to provide full 6D beam characterisation has been made. Simulation results have been used to outline minimum detector requirements. The detector necessary for measuring the 6D phase space requires a drift distance of at least 2.5m between...
In modern accelerator facilities, femtosecond synchronisation between an optical master oscillator (OMO) that provides facility-wide timing pulses and an external experiment laser is needed to achieve the few-fs resolution required for experiments such as pump-probe spectroscopy. This can be achieved with a balanced optical cross-correlator (BOXC), which determines the timing delay between two...
A new dedicated materials irradiation beamline and target station was developed and recently commissioned at the ATLAS facility at Argonne National Laboratory. The new ATLAS Materials Irradiation Station (AMIS) is located just downstream of the first linac section (PII) and designed to receive heavy-ion beams with energies of 0.5 - 1.5 MeV/u. The main activity at AMIS is the irradiation of...
A quantum gas jet-based beam scanner is under development at the Cockcroft Institute (CI) in the UK. This device is based on detecting the ionisation induced in a gas jet by a beam of charged particles. It aims at generating a dense gas jet with a diameter of less than 100 μm by exploiting the quantum wave nature of neutral gas atoms to generate an interference pattern with a single maximum....
Based on an initial proof-of-concept, a full-size single-piece pure-copper Radio Frequency Quadrupole (RFQ) prototype module was for the first time designed and additively manufactured (AM), as a result of a multi-disciplinary collaborative effort and of the deployment of state-of-art AM technology. The 39-cm long prototype with modulated electrodes replicates, with several improvements...
Precision measurements of the permanent electric dipole moment (EDM) of fundamental particles require the development of new methods and techniques. The precursor experiments to measure the proton and deuteron EDM at the Cooler Synchrotron COSY in Jülich led to the of a ring concept with combined magnetic and electric field elements. The building of high-stability electric and magnetic field...
An X-ray detector is being developed for diagnostic measurement and monitoring of the Drift Tube LINAC (DTL) at the Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Lab. The detector will consist of a row of x-ray spectrometers along the DTL which will measure the spectrum of X-rays resulting from bremsstrahlung of field emission electrons (FEE) and spilled beam. Each...
The electron gun control system, which serves as the TLS LINAC's power source, has been in operation for more than two decades. Since some components of a previously designed circuit have aged and been discontinued, the control system will become unreliable and irreparable. A new control interface of electron gun pulser has been developed to improve the operational stability and future...
A new digital low-level RF (LLRF) system has been developed for the High Energy Photon Source (HEPS), a 6 GeV diffraction-limited synchrotron light source under construction in Beijing. The system is composed of a digital signal processing board (DSP), two ADC/DAC daughter boards and a RF front-end board. The FPGA of the DSP board has been changed from the original ALTERA Stratix III to Xilinx...
The high-energy beam transfer lines at GSI serve numerous experimental stations such as HADES, HTC and HTD as well as the fragment separator FRS and the storage rings ESR and CRYRING with a wide range of different heavy ion beams from the SIS18 synchrotron. The large amount of experiments carried out during beam times under different beam conditions require frequent changes of beam optics and...
We are developing a fast pulsed power supply using Silicon Carbide (SiC) MOSFETs for a camshaft bunch kicker in KEK-PF. In the kicker system, the pulsed power supply needs to generate a high-precision short pulse with high power. A high repetition rate is also required due to the short circumference of the KEK-PF storage ring of 187 m. Therefore, the target specifications are 500 A pulsed...
Reliability in high power hadron accelerators is a major issue, particularly for Accelerator Driven Systems (ADS). For example, the Japan Atomic Energy Agency (JAEA) ADS maximum frequency of beam trips longer than 5 min was set to 42 per year. A significant number of breakdowns are caused by the failure of accelerating cavities or by their associated systems. Hence, we studied how these can be...
The emittance of fourth-generation storage ring(4GSR) will be built in Cheongju-Ochang, Korea, is expected to be 100 times smaller than the existing third-generation storage ring. As the emittance decreases, more precise beam stabilization is required. To satisfy this, the resolution of the Beam Position Monitor (BPM) should also be further improved.
We have performed an optimization study...
Beam commissioning is underway at STF of KEK. Since beam diagnostics are important to realize stable operation, as one of the beam diagnostics, we have developed a time-resolved beam loss distribution monitor. This monitor can observe a pulsed beam of about 800 µs, separated by every 100 µs, using up to 16 PIN photo diodes as X-ray sensors. Thus, 128 data can be acquired per bunch. The data is...
A Low Energy Branch is being built at Micro Analytical Centre * that will allow us to produce a variety of high current (up to 50 µA) ion beams, ranging from light (i.e. H, He, C, B, 15N), mid-mass (i.e. Si) to heavy (Ag, W, Pb, Bi) ion beams in the energy range of 100 eV up to 30 keV. Ions will be produced with the use of ion sources that are currently available at the facility.
The...
The Rare isotope Accelerator complex for ON-line experiments (RAON) is under construction in Daejeon, Republic of Korea. RAON is a device that accelerates various ions generated from ion generators such as Electron Cyclotron Resonance(ECR) and Isotope Separation On-Line(ISOL) system with a superconducting linear accelerator. The low energy superconducting linac(SCL3) is composed of 22...
The J-PARC main ring is being upgraded to a beam intensity of 1.3 MW. The capacity of the beam dump used for beam tuning is planned to be increased from 7.5 kW to 30 kW. The current beam dump has a vacuum that extends from the accelerator tunnel to 4.5 m inside the wall, keeping the radiation back scattered from the dump at a sufficiently low level. The new beam dump design requires to have a...
The J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) accelerates the beam pulses with different conditions to two facilities. Therefore, it is indispensable to be able to correctly monitor the beam conditions. Then, we developed the synchronized data system for RCS beam monitor. This system is enabled to provide real-time synchronized data and to also archive all synchronized data with no data...
The electron beam at CERN Linear Accelerator for Research (CLEAR) has been intensively used to study the potential use of Very High Energy Electrons (VHEE) for radiotherapy, including the so-called FLASH regime. An important part of these studies revolves around the development of reliable dosimetry methods, given that generally accepted standards are partly lacking for electron beams in the...
Abstract
As part of the modernization of the Los Alamos Neu-tron Science Center (LANSCE), a digital low level RF (LLRF) control system for the LANSCE proton storage ring (PSR) is designed. The LLRF control system is im-plemented on a Field Programmable Gate Array (FPGA). The high resolution tunable 2.8MHz reference RF is gen-erated by a direct digital synthesizer (DDS) at the LANSCE front end...
Standard methods of measuring the transverse beam profile are not adaptable for sufficiently high-intensity beams. Therefore, the development of non-invasive techniques for extracting beam parameters is necessary. Here we present experimental progress on developing a transverse profile diagnostic that reconstructs beam parameters based on images of an ion distribution generated by beam-induced...
A suite of diagnostic was designed to fully characterize a high current electron beam in a short section of a beamline. The entire suit of diagnostics is housed in ~1.2 m in length and contains 7 diagnostic assemblies that have 78 fast channels and two cameras. The suite contains a slit-harp emittance diagnostic, energy analyzer, two beam position monitors, a Faraday cup/beam stop with 14...
The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is currently undergoing an upgrade known as ALS-U. As part of this upgrade, the existing Triple-Bend Achromat (TBA) storage ring lattice is being replaced with a Multi-Bend Achromat (MBA) lattice, which allows for the tight focusing of electron beams to approximately 10 um, reaching the diffraction limit in the soft x-ray...
High Demand for stability, accuracy, reproducibility and monitoring capability were placed on accelerators LLRF systems, because of fundamental and applied experimental requirements. Meanwhile, availability of FPGA boards became better during last two decades. Nowadays, it is possible to implement FPGA based LLRF feedback using boards with S-band (or L-band) ADC&DAC (direct sampling technique)...
Digital beam signal processor is critical for the beam diagnostic resolution and on-line application performance. High speed & high precision ADC, high performance FPGA are the key devices for the evolution of the processor. At present, ADC technology has entered the era of RF direct sampling, which bandwidth is up to 9GHz, sampling rate is higher than 2GSPS, and sampling bits is up to 14...
ALBA is facing the upgrade towards a low emittance synchrotron light source machine. An active harmonic RF system operating at 1.5 GHz is foreseen to increase the longitudinal bunch length and therefore the Touschek lifetime. The main purpose of the DLLRF is to control the cavity voltage and resonating frequency of the cavity by means of the drive towards the amplifier and the plunger inside...
The Taiwan Photon Source (TPS) is equipped with 16 real-time radiation monitoring stations around the accelerator. Each operating scenario entails a different dose rate and accumulated dose. In this study, we assessed the beam current and injection efficiency of the accelerator and the dose rate and accumulated dose at the radiation monitoring stations in five scenarios. The background...
The synchrotron-based ELSA facility delivers up to 3.2 GeV electrons to external experimental stations. In a new setup the irradiation of tumor cells with doses of up to 50 Gy by ultra-high energy electrons (UHEE) in time windows of microseconds up to milliseconds (FLASH) is currently investigated. This technique may enable highly efficient treatment of deep-seated tumors alongside optimal...
The CLEAR facility at CERN allows users to receive an electron beam with energy up to 200 MeV, allowing flexibility in intensity, beam size and bunch structures. Separate from the main CERN accelerator complex, it is capable of hosting numerous experiments with rapid installations at two test stands.
It would be highly desirable for many applications, but particularly those of a medical...
The computation of residual gas density profiles in particle accelerators is an essential task to optimize beam pipes and vacuum system design. In a hadron collider such as the LHC, the beam induces dynamic effects due to ion, electron and photon-stimulated gas desorption. The well-known VASCO* code developed at CERN in 2004 was already used to estimate pressure profiles in steady state...
Polycrystalline SiC wafers were implanted with 300 keV strontium ions at room temperature to a fluence of 2×10^16 cm^−2. Silicon dioxide (SiO2) layers of about 100 nm thick were deposited onto the surface of implanted SiC via magnetron sputtering of a SiO2 target in argon-oxygen atmosphere. The as-deposited (i.e., SiO2/implanted SiC) samples were subjected to sequential isochronal annealing,...
Theoretically copper resistivity to a good approximation may be viewed as the sum of a term phonon-electron scattering term, and a constant term. The first follows the Bloch-Gruneisen formula; goes to zero as T5 at low temperature. The constant term corresponds to scattering off defects and magnetoresistance. The defect part is due to impurities and finite crystal size. Since copper coating...
RadiaBeam has developed a novel design of high-power RF windows to be used in high-power proton accelerators, such as SNS. This design is based on the utilization of coaxial windows between two waveguides to coax transitions, instead of a ceramic window in a uniform cylindrical waveguide, which provides several significant benefits. First, the diameter of the ceramic disk in the coaxial line...
The APAM Laboratory of the ENEA Frascati Research Centre hosts two electron beam S-Band standing wave linacs. The older one, named REX, produces a 5 MeV, 150 mA electron beam with maximum PRF of 20 Hz. The second one, named TECHEA, was recently commissioned within a Research and Development program focused on breast radiotherapy applications: it produces a 3 MeV, 130 mA electron beam with...
A beam position monitor based on Cherenkov diffraction radiation (ChDR BPM) is currently under investigation to disentangle the electromagnetic field of an electron bunch from that of a proton bunch travelling together in time and space in the beam-line of the AWAKE plasma acceleration experiment at CERN. The signals from a horizontal pair of ChDR BPM radiators have been studied under a...
For the x-ray free electron laser operation, the correlated energy spread of electron beam should remain optimized for the best performance. However, it could be varied owing to the drift of RF stations, even though a feedback system with low-level RF is operating. Non-destructive energy spread monitoring could stabilize such a variation and offer a tool to maintain the correlated energy...
In the novel device described in this presentation uses a simple, strip cathode provides a sheet beam probe for tomography instead of a scanning pencil beam that was used in previous electron probe bunch profile monitors. The apparatus with the strip cathode is smaller, has simpler design and less expensive manufacturing, has better magnetic shielding, has higher sensitivity, higher...
Beam position monitors (BPMs) are fundamental diagnostic tools for lightsources: thanks to their data readout, machine orbit can be stabilized and corrected by control systems. New generation machines need better performances on these diagnostic devices due to increased demands, such as smaller photon beam size and long-term stability. This article outlines all the devices that will make up...
At Elettra-Sincrotrone Trieste (Italy), the Elettra 2.0 project aims to develop a new-generation storage ring. Taking into consideration the numerous constraints, we decided to adopt a new design of a vacuum chamber, while utilizing novel pumping solutions to overcome hugely reduced conductance compared to the current machine. Large sputter ion pumps (SIP) will be in majority replaced by...
In everyday the lighting environments is increasingly replacing incandescent and fluorescent bulbs with light-emitting diodes (LEDs), which offer superior electricity-to-light conversion efficiency. In accelerator facilities, too, the time has come to replace conventional lighting with LEDs and other high-efficiency, green lighting. In order to promote the replacement of lighting in an...
Emittance is one of the most important beam parameters in accelerators. Therefore, many emittance measurement methods such as Allison-type scanners, pepper pots, slit-scan methods, quadrupole scan methods, etc. have been widely used. In the case of the RAON heavy ion accelerator, an Allison-type emittance scanner is installed at the low-energy beam transport section. However, there is no other...
The high luminosity specifications for future linear colliders, such as the Compact Linear Collider (CLIC) require extremely small vertical beam emittance at the interaction point. This relies on minimizing the emittance growth in the collider sub-systems. One major source of emittance growth is the Main Linac, mainly caused by misaligned quadrupoles and accelerating structures. The current...
Beam lines magnets for high rigidity particles can have a large power dissipation. In presence of a high duty cycle, this translates in a considerable amount of energy waste. The call for sustainability of large research infrastructures, like particle accelerator centers, and also the recent increase of the cost of energy, requires to take measures to reduce the energy consumption, even if at...
At the KIT storage ring KARA (Karlsruhe Research Accelerator), a far-field electro-optical (EO) experimental setup to measure the temporal profile of the coherent synchrotron radiation (CSR) is implemented. Here, the EOSD (electro-optical spectral decoding) technique will be used to obtain single-shot measurements of the temporal CSR profile in the terahertz frequency domain. To keep the...
To better understand the beam-RF jitter at the Argonne Wakefield Accelerator Facility, a high-resolution bunch arrival monitor (BAM) is being developed. The BAM take advantages of a commercial, electro-optic modulator (EOM) to measure the bunch timing though optical modulation. This non-descructive technique is far superior and the resolution can be as high as several femto-second. A...
After 25 years of successful research in the nuclear and radiation physics domain, the KVI-CART research center in Groningen is upgraded and re-established as the PARticle Therapy REsearch Center (PARTREC). Using the superconducting cyclotron AGOR and being embedded within the University Medical Center Groningen, it operates in close collaboration with the Groningen Proton Therapy Center....
ESS is poised to be a high intensity and high energy neutron source for scientific applications. The source behind this high intensity neutron beam is a long pulse linear proton accelerator. In order to meet the stringent requirements on the proton beam, the protons need to be accelerated in stable accelerating gradients in the accelerating cavities. In order to achieve this, the LLRF system...
In EUV lithography, high volume manufacturing already started using a laser-produced plasma (LPP) source of 250-W power at 13.5 nm. However, development of a high-power EUV light source is still very important to overcome the stochastic effects for a higher throughput and higher numerical aperture (NA) in future. The required EUV power for the 3-nm node and beyond at the maximum throughput of...
Additive Manufacturing (AM) offers different benefits such as efficient material usage, reduced production time and design freedom. Moreover, with continuous technological developments, AM expands in versatility and different material usage capabilities. Recently new energy sources have been developed for AM – green wavelength lasers, which provide better energy absorption for pure copper. ...
Conventional RF vacuum windows are made of metalized ceramics, hermetically brazed to a pillbox cavity. High-power windows, operating in UHF band, require the fabrication of ceramic disks with diameters on the order of 200mm (8’’). Furthermore, a Titanium Nitride (TiN) multipactor suppression coating must be applied to the ceramic surfaces. The large size and complex internal geometry of these...
The Low-Level Radio Frequency (LLRF) control system is one of the most critical superconducting linac infrastructures responsible for the parameters of the beam acceleration. The LLRF system mainly focuses on the electromagnetic field parameters inside the cavity. While it incorporates fast feedback algorithms to optimize energy transfer to the passing particle beam it does not follow other...
The handling of very sensitive bi-alkali antimonide photocathodes as the electron source for the SRF photoinjector of SEAlab is a critical procedure for its operation. After the growth of the photocathode, they have to be transferred in-situ under extreme UHV conditions using a vacuum suitcase and under particulate-free conditions to avoid the contamination of the SRF cavity. Therefore, we...
The MedAustron Ion Therapy Centre is a synchrotron-based particle therapy facility, which delivers proton and carbon beams for clinical treatments. Currently, the facility treats 40 patients per day and is improving its systems and workflows to further increase this number. Although MedAustron is a young and modern center, the life-cycle of certain crucial control electronics is near...
The Superconducting RF photo-injector with the prototype 1.4 lambda/2-cell Niobium cavity of the bERLinPro Energy Recovery Linac (ERL), recently renamed to SEALab, was tested and characterized in a dedicated beam test facility called Gunlab to analyze its performance for the ERL*. After dismantling and refurbishing of the cavity, a small surface defect was found close to the cathode opening...
Older cyclotrons still find a variety of applications in research and education, but in many cases the beam dynamics of these machines is not well understood, which can be a limitation to achieving their ultimate performance.
The cyclotron at the Crocker Nuclear Laboratory at UC Davis is a capable of accelerating protons, deuterons, or alpha particles to variable energies up to a maximum...
Achieving a high signal-to-noise ratio is challenging in electron scattering experiments that require low average probe current or low total electron dose, e.g., time resolved hard-matter or radiation-sensitive soft matter experiments. A promising method for improving the signal-to-noise ratio when electron counts are low is to structure the electron wavefunction with optical fields and then...
New generation low-emittance storage rings bring new challenges for vacuum system design and to industry partners. Vacuum chambers from copper alloys are more frequently required, and processes for forming, machining, welding, cleaning and non-evaporable getter coating have been developed in response to this demand.
The technical challenges, available processes, and examples of recent...
The SIS100 heavy ion synchrotron as core part of the Facility for Antiproton and Ion Research (FAIR) will be equipped with 14 accelerating RF stations in the first stage of realization. Each RF station consists of a tunable ferrite-loaded cavity powered by a tetrode amplifier. Further key components are a solid-state pre-amplifier, a power supply unit, and dedicated Low-Level Radio Frequency...
The accelerator upgrades of SLS and Elettra will use newly designed kickers adapted for their small aperture beam pipes.
The striplines of the transverse kickers conform closely to the aperture of the beam pipe with special grooves to avoid synchrotron light on the blades. The multitude of trapped higher order modes, caused by a high beam pipe cut-off frequency and dangerous in terms of...
Protons are dominant radiation source in the space environment causing radiation effects such as SEE(Single Event Effects), DD(Displacement Damage) to EEE(electrical, electornics and Electromechanical) parts of spacecraft. Until now, radiation effect test for space EEE parts have been carried out by using a 100 MeV proton irradiation facility (BL102) at KOMAC(Korea Multi-purpose Accelerator...
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will reuse most of the existing superconducting magnets from the RHIC storage rings. To comply with the more demanding operational scenarios imposed by the EIC hadron beams, the beam pipes of the reused RHIC magnets will be equipped with low surface impedance and low SEY screens.
The installation of these screens will be done with the...
The Hefei Advanced Light Facility (HALF) is a diffraction limited storage ring (DLSR) being constructed. As the main component of the storage ring vacuum system, the vacuum chamber transports the beam and withstands the thermal effect of synchrotron radiation simultaneously. The thermal and mechanical condition of the vacuum chamber of HALF were quantitatively analysed by means of ANSYS...
The NHa C400 is the first compact superconducting cyclotron used for carbon therapy in the world. Carbon therapy is particularly effective for treating radiation-resistant tumors, as compared to more conventional radiotherapy techniques.
In this work, a 3D finite element model of the Nb-Ti coil has been developed using the open-source solver GetDP. First, an accurate representation of the DC...
Ultrafast electron microscopy (UEM) can be used to probe
ultrasmall (nm scale) and ultrafast (fs scale) world. At the
fundamental level, atomic potentials determine the elastic
electron scattering in UEMs. Here we calculate the first
correction term analytically for elastic scattering of electrons
by atoms in the weak phase object approximation. Its effect
varies with atom types and...
Recently presented RF cavity prototypes printed entirely from pure copper illustrate the potential of additive manufacturing (AM), and particularly laser powder bed fusion (L-PBF), for accelerator technology. Thereby, the design freedom of L-PBF is only limited by overhanging geometries, which have to be printed with supporting structures to ensure sufficient accuracy. However, subsequent...
A new real-time measurement system for accelerator control, named FIRESTORM (Field In Real-time Streaming from Online Reference Magnets), to measure the integrated bending field has been recently deployed and commissioned in six synchrotron rings at CERN. We present the operational experience during the preparation phase and the restart of the accelerator complex for Run 3, focusing on the...
The Karlsruhe Research Accelerator (KARA) is an electron storage ring, which features an electro-optical near-field monitor within the beam pipe in vacuum as a tool for longitudinal bunch profile measurements. The device performs very well in single-shot turn-by-turn measurements during single-bunch operation and over the years. The design has been optimized to be prepared for measurements in...
CEPC can also work as a powerful and excellent synchrotron light source, which can generate high-quality synchrotron radiation. This synchrotron radiation has potential advantages in the medical field, with a broad spectrum, with energies ranging from visible light to X-rays used in conventional radiotherapy, up to several MeV. FLASH radiotherapy is one of the most advanced radiotherapy...
The two dominant radiotherapy methods are either simplified in terms of beam generation and handling, which compromises the energy deposition curve in tissues (photon therapy) or require extensive accelerator facilities and complex beam delivery systems to provide a favourable shape of the energy deposition curve (hadron therapy). The advantages of both of these methods, such as the low cost...
Iterative Learning Control (ILC) is a technique for adaptive feed forward control of electro-mechanical plant that either performs programmed periodic behavior or rejects quasi-periodic disturbances. ILC can suppress particle-beam RF-loading transients in RF cavities for acceleration. This paper, for the first time, explains the structural causes of ``bad learning transients'' for causal and...
SPES (Selective Production of Exotic Species) is an ISOL type facility for production and postacceleration of exotic nuclei for forefront research in nuclear physics, for the operation it must be equipped with a safety system compliant with the Italian regulatory framework.
The object of this work is to report how the Safety Requirement Specifications, generated from the safety analysis, are...
Proton therapy provides significant advantages over classic radiotherapy for specific cancerous diseases, notably by limiting the delivered dose to organs at risk (OARs). Novel treatment modalities such as flash and arc therapy require changing the energy delivered at the isocenter while providing a high dose rate. Fixed-field achromatic transport lattices satisfy both constraints, allowing...
Laser Compton Scattering Gamma-ray beam (F-LCS), which has a flat distribution in the energy spectrum and the special distribution, has been developed to study an isotope selective CT Imaging application in the beamline BL1U in UVSOR. The generation of F-LCS beam has been demonstrated by using the Apple-II undulator installed in BL1U in UVSOR*. The principle of F-LCS generation, EGS5...
At FAIR, GNU Radio* is being used as part of the generic monitoring and first-line diagnostics for acceleratorrelated devices, and to further support equipment experts, operation, and FAIR users in developing basic to advanced top-level measurement and control loops.
GNU Radio is a free and open-source software development toolkit supporting hundreds of low-cost to high-performance...
The building blocks of a scientific facility based on particle beams is made of magnets and electro-magnetic devices such as accelerating cavities. The optical design usually imposes a demanding accuracy with respect to their theoretically exact position and orientation. It is however frequent that the functional features are either not clearly defined – what is the « axis » of a magnet –, or...
The CHIMERA (up to December 2022) and HEARTS (as of January 2023) projects aim to facilitate radiation effects testing of electronics components using heavy ion beams before deployment in harsh radiation environments such as space or high energy accelerators. The required (micro-) electronics reliability assurance testing conditions can be met by using 100 MeV/n - 5 GeV/n Pb ion beams...
A center for ion beam therapy and research is under development in Waco, TX with site preparation and construction underway. The center incorporates state-of-the-art accelerator technologies including the capability to perform ultra-high dose irradiation (FLASH) research with ions. The ion source and beam capture system will be comprised of an Electron-Cyclotron-Resonance (ECR) source...
We present design of a normal conducting, high efficiency linac that would provide a CW beam of 1 MW electrons at 1 MeV energy for various environmental applications. When a flowing sheet of wastewater is exposed to such a beam, various radiation-induced reactants are generated that lead to water purification by decomposing the chemical and biological pollutants therein. Such a linac could...
The strong penetrating ability of relativestic electron beam with energy as high as several tens of MeV prohabits the possibility forming an image based on absorption by material. However, we demonstrate that it can make a shadowgraphy based on scattering. The demand for electron beam is analyzed and simulations are conducted, experiments carried out at the 120 MeV linear accelerator proves...
Tetrode-based amplifiers are well-established, and now have a revitalized supply chain after their demise looked imminent. High power tetrodes have been to show a greater power density and frequency range than solid state amplification, making them a robust choice for future accelerators and fusion devices. Recently, the MIT PSFC spearheaded an effort to source new pyrolytic graphite grids,...
An electro-optic beam position monitor is in development for the HL-LHC to enable high-bandwidth monitoring of crabbed bunch rotation and intra-bunch instabilities. Following in-air beam tests of a prototype at HiRadMat and the Clear facilities at CERN in 2021 and 2022, a new in-vacuum version is being prepared for operation in the SPS during LHC Run 3. We report on progress toward the design...
The Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Lab is a superconducting ion linac capable of delivering beams ranging over all possible elements, from hydrogen to uranium, and at a wide range of beam currents and energies. The ATLAS scientific program is focused primarily on basic nuclear physics. In this contribution, we present the capabilities of ATLAS for...
The technological evolution of analog-to-digital and digital-to-analog converters increases the amount of data that can be processed in the digital domain. Therefore, direct digitization enables many advanced signal processing techniques and is attracting more and more attention in the field of accelerator instrumentation. The future HL-LHC Beam Position Monitor (BPM) data acquisition system...
IC@MS is a modular and containerized web-based alarm management system. Scientific facilities need alarm management tools to increase effective operation. Experience shows that control systems face unexpected issues, that should be tracked and archived. The mature control system may require the involvement of many engineers to access the alarm list and focus on the most important ones. IC@MS...
Magnetic field errors pose a limitation in the performance of circular accelerators, as they excite non-systematic resonances, reduce dynamic aperture and may result in beam loss. Their effect can be compensated assuming knowledge of their location and strength. Procedures based on orbit response matrices or resonance driving terms build a field error model sequentially for different...
The Hollow Electron Lens (HEL) was proposed to actively remove the beam halo of the proton beam for the HL-LHC upgrade. Currently, the concept of generating such an electron beam is being tested in a dedicated Electron Beam Test Stand (EBTS) at CERN. It currently produces a hollow electron beam with 7 keV energy and 0.4 A current 25 us pulsed with 2 Hz which will be confined in a strong...
Beam-based alignment (BBA) for quadrupoles is a routine process for circular accelerators to steer beam orbit through the magnetic centers such that the orbit is unperturbed when the strengths of quadrupoles are varied. The random errors associated with BBA are well known, but a type of systematic error appears to be neglected by the community. A standard measurement procedure involves...
The Forward Physics Facility (FPF) is a proposed experimental facility to be installed several hundred meters downstream from the ATLAS interaction point to intercept long-lived particles and neutrinos produced along the beam collision axis and which are therefore outside of the acceptance of the ATLAS detector. The construction of this facility, and in particular the excavation of the...
Superconducting curved magnets are able to reduce accelerator footprints by producing strong fields (>3T) for applications such as carbon ion therapy, however the effect of strongly curved magnetic multipoles and fringe fields on accelerator beam dynamics is not fully understood. This is especially important in compact synchrotrons, where fringe fields can significantly affect beam quality and...
The TLS (Taiwan Light Source) is a third generation of synchrotron light source which has been operated for more than 25 years, and its control system is a proprietary designed system. Due to component outage issues, the maintenance of the TLS control system is challenging. Some parts of the control system are being rejuvenated with the help of the EPICS framework used in the TPS (Taiwan...
This paper describes the changes in the design of the MTCA-complaint Local Oscillator (LO) Rear Transition Module (RTM) board providing low phase noise clock and heterodyne signals for the 704.42 MHz Low-Level Radio Frequency (LLRF) control system at the European Spallation Source (ESS). Global chip shortage, as well as experience gained during the production and operation of Revision 1.2,...
The longitudinal phase space tomography, which reconstructs the phase space distribution from the one-dimensional bunch profiles, is used in various accelerators to measure longitudinal beam parameters. At the J-PARC, an implementation of the phase space tomography based on the convolution back projection method has been used to measure the momentum spread of the injected beam. The method...
Methodical studies to improve the existing e-beam Longitudinal Phase Space (LPS) tomography were performed at the Photo Injector Test facility at DESY in Zeuthen. Proof-of-principle simulations were done to address some core concerns e.g. booster phase range, space charge effects and noisy artefacts in results. Phase advance analysis was done with the help of an analytical model that...
The LHC interlock BPM system is used as part of the beam abort system to insure that beam trajectories in those regions are conform with a safe extraction of the beams from the main ring to the dump lines.
After more than 10 years of operation, the system has shown some limitations in bandwidth and dynamic range and a study was initiated to look for improvements.
Nowadays, with the...
The Los Alamos Neutron Science Center (LANSCE) employs the use of BPPMs (Beam Position and Phase Monitors) to track the position and phase of beam throughout the site. In the past, BPPMs in the 805MHz CCL (Coupled Cavity Linac) section of the site used a 201.25MHz reference over facility network fiber, using RF media converters. This fiber reference distribution gave rise to give a large...
The IBA ProteusOne (P1) system is suitable to treat ocular tumors and achieves efficient dose conformality using state-of-the-art pencil beam scanning. Nevertheless, with the limited cyclotron current of the P1 system, clinically relevant (> 15 Gy/min) dose rates can barely be achieved in eye tumors treatment cases with the baseline configuration of the system due to the significantly high...
Properly managed asset and maintenance processes is key for minimizing unplanned downtime and to ensure efficient operations of any large-scale technical installation, including particle accelerator complexes. CERN has therefore over the last years significantly increased its use of a commercial EAM (Enterprise Asset Management) platform in order to support such efforts. With its advanced...
SuperKEKB is an asymmetrical lepton collider with a circumference of 3 016 meters, which collides 7 GeV electrons with 4 GeV positrons. To optimize the luminosity, which recently reached a world record of 4.71 10^34 cm-2 s-1, all the undesirable effects on beam parameters must be analyzed in detail, especially close to the interaction point where the Belle II detector is operated. The...
Machine learning techniques have developed rapidly in the last decade and are widely used to solve complex scientific and engineering problems. Many accelerator laboratories internationally have begun to experiment with machine learning and big data techniques for processing accelerations. This paper presented the application of machine learning to the Hefei Light Source. Including the...
In this article, the results obtained with a new designing approach for the active disturbance rejection control (ADRC) algorithm are presented, where loop shaping techniques are used in order to stabilize the controller and make it more resilient to delay. The objective of this work is to describe the experiment performed to test the microphonic reduction capability of the modified ADRC...
Additive Machining (AM) technology is already used in many manufacturing domains and provides many benefits such as design freedom, cooling, and performance improvements as well as significant manufacturing time reduction. AM is also being considered for the manufacture of a Radio Frequency Quadrupole, where an important unknown is the voltage holding capability of AM surfaces. To address this...
The Collider Accelerator Complex at Brookhaven National Lab (BNL) contains millions of control points. Monitoring tolerances for these control points is crucial for the system and is a challenging task. Catching early signs of failures in those systems will be very beneficial as they can save extensive downtime. Anomaly detection in particle accelerators has been highlighted and can...
Modern hadron-therapy accelerators have to provide high intensity beams for innovative dose-delivery modalities such as FLASH, pencil beams for 3D scanning, as well as multiple ions with radio-biological complementarity. They need to be compact, cheap and have a reduced energy footprint. At the same time, they need to be reliable, safe and simple to operate. Cyclotrons and compact synchrotrons...
Superconducting radio-frequency (SRF) photoinjectors offer a broad range of electron beam parameters and are therefore suitable for many applications such as energy recovery linac (ERL) driven lightsources, particle colliders, or for ultrafast electron scattering experiments. We are now nearing completion of the setup a SRF photoinjector with a SRF gun and SRF booster linac at the SEALAb...
This project aims to develop a 100 MeV proton accelerator-based space environment chamber and create a radiation test database of electronic and optical components in the space environment. The chamber for the space radiation environment consists of various beam diagnostic equipment and control points. An integrated control system for remotely monitoring and controlling these signals has been...
Neutron scattering experiments have undergone significant technological development through large area detectors with concurrent enhancements in neutron transport and electronic functionality. Data collected for neutron events include detector pixel location in 3D, time and associated metadata, such as, sample orientation, neutron wavelength, and environmental conditions. RadiaSoft and Oak...
The potential for developing compact, high-brightness particle and radiation sources has given a strong impetus to the development of the underpinning laser technology, including increasing the efficiency and repetition rate of the lasers. A result of this technological development can be seen in the new generation of ultrafast high-power laser systems working at a high repetition rate which...
The Italian Minister for University and Research has recently funded a large program for an Innovative Research infrastructure on applied Superconductivity in Italy. Based on the LASA lab in Milan it is a partnership among: INFN (leader, participating with 4 labs: Frascati, Genoa, Milan, Salerno); CNR (SPIN institute in Genoa, Naples and Salerno); five Universities: Genoa, Milan, Naples,...
Jacobs remote leak sealing service seals holes of up to 10mm effective diameter within inaccessible pipes where access is either dangerous, impractical, or not cost effective. Many complex research facilities such as particle accelerators contain large amounts of remote pipework in inaccessible areas. This inaccessibility can be caused by being:
• Buried post construction in...
KEK LUCX facility is a compact linear accelerator used for advanced accelerator technology and electron beam instrumentation R&Ds.
New LLRF (Low-Level RF) phase and amplitude feedback based on FPGA (Field-Programmable Gate Array) board was developed and tested during the LUCX facility routine operation. The RedPitaya 125-14 (also known as STEMLab 125-14) FPGA board was chosen due to its...
The Los Alamos Neutron Science Center (LANSCE) timing system leverages a commercial event-driven system from Micro Research Finland (MRF) which is in use at various (16+) accelerators facilities around the world. Recent upgrades to the LANSCE accelerator machine protection [Fast Protect] system utilizing MRF event receivers will address some long-standing issues that require non-intuitive work...
The Los Alamos Neutron Science Center (LANSCE) continues to invest into the future of its facility. In 2022 and after a 11-year effort the original and reliable RICE (Remote Instrumentation and Control Equipment) system was decommissioned. It was replaced with a modern customized control system in small stages during each annual 4-month outage. Since 1972 when the first proton beam was...
Copper and copper alloys are widely used in the Nuclear Fusion field for their outstanding characteristics, especially in terms of thermal and electrical conductivities. CuCrZr is peculiarly suitable and well-known in High Energy applications because it combines good conductivity and good mechanical properties. Moreover, the material properties can be tuned with thermal treatments to fit the...
Niobium is particularly appreciated for its superconductive properties. One of the main applications of this metal in Nuclear Physics is the production of superconducting radiofrequency (SRF) cavities for particle accelerators. Additive Manufacturing (AM) gives the chance to fabricate objects with very complex shapes; also, high melting temperature and hard-to-machine materials can be easily...
Modelling the fast orbit feedback (FOFB) system for the upcoming PETRA IV storage ring is in progress. The single-input-single-output (SISO) simulations provide an abstract insight into the FOFB system's performance and stability. Nevertheless, to investigate the orbit correctability in general and at spatial locations of interest, i.e. insertion devices, the simulations are extended to...
LhARA*, the ‘Laser-hybrid Accelerator for Radiobiological Applications’, will be a novel, uniquely flexible, facility dedicated to the study of radiobiology. LhARA will use a high-power pulsed laser to generate a short burst of protons or light ions. These will be captured using strong-focusing electron-plasma (Gabor) lenses. Acceleration using a fixed-field alternating-gradient accelerator...
The synchrotron light source BESSY-II has been in operation for almost 25 years and modernization measures are needed to maintain competitiveness until its successor BESSY-III comes online. One measure is to replace the old analogue LLRF control units with new, state of the art mTCA.4-based digital ones. The so-called “single cavity” firmware developed by DESY is being used together with the...
We present an approach for detection of anomalous behavior of magnet power supplies (PSs) in storage rings, which may serve as an early indication of an impending PS trip. In this new method, we train a Long Short-Term Memory (LSTM) neural network to predict the temperature of several components of a PS (transistors, capacitors) based on the PS current, PS voltage, room temperature, and...
The MAX IV 3 GeV linac delivers electron beams to two synchrotron rings and to a dedicated undulator system for X-ray beam delivery in the Short Pulse Facility (SPF). In addition, there are plans to use the linac as an injector for a future Soft X-ray Laser (SXL). For both SPF and SXL operations, longitudinal beam characterisation with a high temporal resolution is essential. For this purpose,...
Longitudinal phase space (LPS), referring as the current profile and the energy spread, is among the most important parameters to be known in many accelerators that require high quality electron beams, such as an Ultrafast Electron Diffraction (UED) or a Free Electron Laser (FEL). For a UED or a long wavelength FEL, the beam energy is usually on the level of several MeV or a few tens MeV. In...
The Los Alamos Neutron Science Center’s proton storage ring (PSR) extraction kicker systems consist of two thyratron switched blumlein modulators. The operating parameters of the PSR have changed over the years and the flattop voltage of the modulator outputs has become a limiting factor in the length of the beam pulse able to be extracted from the ring. The extraction voltage pulse travels...
The Alternating Gradient Synchrotron (AGS) is a particle accelerator at Brookhaven National Laboratory (BNL) that accelerates protons and heavy ions using the strong focusing principle. In this work, we perform simulation studies on the AGS ring of a machine error detection method by comparing simulated and measured orbit response matrices (ORMs). We also present preliminary results of...
Longitudinal beam diagnostics are a useful aid during tuning of particle accelerators, but acquiring them usually requires destructive and time intensive measurements. In order to provide such diagnostics non-destructively, computational methods allow for the development of virtual diagnostics. Existing Fourier-based reconstruction methods for longitudinal current reconstruction, tend to be...
The temporal profile of the electron bunch is of critical importance in accelerator areas such as free-electron lasers and novel acceleration. In FELs, it strongly influences factors including efficiency and the profile of the photon pulse generated for user experiments, while in novel acceleration techniques it contributes to enhanced interaction of the witness beam with the driving electric...
Various initiatives in Europe have bene launched to study superconducting magnets for a rotatable gantry suitable for delivery up to 440 MeV/A carbon ions for hadron therapy. One initiative is led by INFN inside an agreement with CERN, CNAO and MedAustron aiming at designing and manufacturing a strongly curved costheta dipole (Rbending = 1.6 m) rated for 4 T central field and a ramp rate of...
In 2021 there were 36 particle therapy facilities under construction world wide of which 5 are planned to be able to deliver Carbon. One in Caen France and four in Asia. In May 2022 Mayo Clinic Florida (MCF) broke ground to build a Proton and Carbon Ion treatment center in Jacksonville Florida. The MCF facility is comprised of a hybrid synchrotron 56.8 m in circumference with twelve dipoles...
CERN is currently developing a 40 kV proof of concept Inductive Adder (IA) for replacing the Proton Synchrotron (PS) complex pulse generators, which currently use 80 kV SF6 gas filled pulse forming lines. The experience gained during the design, commissioning and operation of this prototype device will be crucial for upcoming decisions on the type of future kicker pulse generators. The...
Linac is the first machine in the accelerator chain at Fermilab where H$^{-}$ ions are accelerated from 35 keV to 401.5\,MeV and then injected into a synchronton known as Booster where they are stripped of their electrons to become protons. One of the tools used during tuning of the Linac extraction energy is two beam pickups known as Griffin Detectors. Our goal is to control the output energy...
This paper reports the results of the first measurements of the differential cross section of the 80Se(γ,n)79Se reaction with a linearly polarized gamma-ray (γ-ray) beam. The cross section was measured at three incident γ-ray beam energies: 15.6, 15.8, and 16.0 MeV, with a beam energy spread of 3.0% full width at half-maximum (FWHM). The differential cross section for the excitation spectrum...
NEG-coated chambers have been adopted as the beam ducts for large particle accelerators and synchrotron light sources for the sake of the lower yields of the photon stimulated desorption (PSD) and the photoelectrons (PE) from the NEG films in addition to their pumping performance. Measurement of the photoelectron yield (PEY) was performed at the BL19B (PSD) beamline of the 1.5 GeV Taiwan Light...
Measurements of the extracted beam current (BC) for a Clinical Hitachi carbon therapy synchrotron and a Hitachi compact proton therapy synchrotron are reported for a nominal extracted beam current (BC0) of $\approx$ 10 $\frac{MU}{sec}$ and a sample rate of 5 usec (Carbon) and 8 usec (proton). A noise power spectrum analysis identifies the source of variation to be beam or power supply...
The Beam Position Monitor (BPM) is one of the crucial components for Sirius, and they were manufactured in the Materials Group – CNPEM, through the vacuum brazing process. The mechanical strength characterization of the brazed interface is extremely important to protect the storage ring from unwanted leaks in case of breakage of these sensors. The objective of this work is to report the tests...
Commercial Nuclear Reactors have been licensed for construction and operation by the US Nuclear Regulatory Commission based on ensuring that criticality accidents and accidental releases of radioactive isotopes are acceptably unlikely. The process to get these licenses is long and expensive, involving extensive calculations and demonstrations, with explicit requirements...
The fast cyclic synchrotron (IS) using the principle of induced acceleration was demonstrated at KEK in 2013 and is now being studied for application to a compact hadron therapy driver (ESCORT) capable of energy swept beam extraction**. The ESCORT has the feature of avoiding instability caused by synchro-beta coupling by accelerating ions using a true variable amplitude pulse voltage that...
Lambda-squared scaling of the ponderomotive potential makes long wavelengths preferable for certain regimes of laser-based particle acceleration, including the laser-wakefield acceleration of electrons at low plasma densities and the acceleration of ions from gaseous targets. Currently, multi-terawatt levels of peak power at long-wave infrared (LWIR) wavelengths around 10 μm can only be...
IFMIF-DONES* is a key device in the EUROfusion roadmap for studying and licensing materials for future fusion reactors. It will be a unique neutron fusion-like irradiation facility equipped with a linear particle accelerator impinging an intense deuteron beam (125 mA, 40 MeV) onto a liquid lithium target. In terms of safety analysis of the facility, relevant accidental scenarios are related to...
Non-Evaporable Getter (NEG) development at DESY has been ongoing to accommodate PETRA IV machine requirements. While most of the PETRA IV beam vacuum chambers will be manufactured from oxygen-free silver-bearing (OFS) copper and coated with NEG, getter film performance on these substrates has not been tested as extensively as on the stainless-steel. In order to investigate pumping and...
Controls of the White circuits for the booster synchrotron of Taiwan Light Source was developed in late 1990s. That design based on various analog circuitry to detect 10 Hz magnet amplitude and phase. The existed implementation consists of analog regulation for amplitude control and digital regulation for relative phase between magnet family. Modernized of the White circuits controls was...
The Linac system at Taiwan Light Source (TLS) has been in operation for almost a quarter of a century and requires upgrades to improve its reliability. To achieve this, some components of the control system have been replaced with new digital low-level RF control units that use emerging technologies. A new unit is based on the open-source hardware platform which is named “Red Pitaya STEMlab”...
The Taiwan Light Source (TLS) is a third generation of synchrotron light source, and it has been operated since 1993. Legacy timing system of the Taiwan Light Source was delivered in early 1990s. To deal with obsolete com-ponents and improve functionality, upgrade to event-based timing system for TLS is under way. The system need coordinate the operation the linac, White Circuit based booster...
Taiwan Light Source (TLS) delivery user service since 1993. Some legacy system have been updated recently to avoid obsolesce and to provide better performance to improve operation efficiency. Proprietary designed timing modules were replaced by event based timing system recently. The magnets of the booster synchrotron configured as three White circuits and drive by resonance excitation....
The CERN PS booster features four extraction kicker systems, one for each of the four superposed rings and three transfer kicker systems for recombination of the beams when being transferred towards the PS. Each of these systems consist of SF6 gas filled Pulse Forming Lines (PFL) which are resonantly charged and then fast discharged by thyratron switches into SF6 gas filled transmission...
The work goal is to present the concept and the model for the reconstruction of the beam emittance from the spectrum of the scattered photons. The Compton process is a back-scattering of a laser pulse on the relativistic electron beam and is at the base of X-ray sources, as for instance, the project STAR. In the scattering process, the scattered photons get energy boost. The energy boosted...
The European Spallation Source - ESS, has achieved its major construction in Lund, Sweden and is currently continuing in parallel the commissioning of its first systems. ESS aims to install and commission the most powerful proton LINear ACcelerator (LINAC) designed for neutron production and a 5MW Target system for the production of pulsed neutrons from spallation. In support of this ambitious...
The bunch length in linacs is an important parameter to characterize the beam as well as to tune and optimize the final accelerator performances. In linear machines this observable is typically determined from the bunch imaged on a screen located downstream of a Transverse Deflecting Structure (TDS) used to impinge a time dependent kick along the longitudinal coordinate of the beam. This kind...
The widely used transverse parameters characterizing particle beams are the Twiss parameters. These parameters can be measured experimentally but they do not fully characterize the beam since they do not account for possible correlations in particle distribution between two transverse coordinates. These correlations may occur due to uncompensated magnetic field at the cathode or misalignment...
To realize more stable operation of a high-intensity ion beam accelerator with a minimum beam loss, we have developed a non-destructive beam profile monitor detecting photons produced by interaction between the beam and a gas sheet injected into the beam line. The gas-injection-type profile monitor should induce scattering of the beam particles, and the beam emittance is considered to become...
At the Karlsruhe Research Accelerator (KARA), an analytical online model of the orbit response matrix (ORM) has been developed and tested. The model, called the bilinear-exponential model with dispersion (BE+d model), is derived from the Mais-Ripken formalism describing coupled betatron motion. Compared to the standard approach of measuring the ORM, this method continuously adapts to changing...
Spatio-temporal couplings (STCs) [1] can have a detrimental effect on the intensity at focus of ultrashort femtosecond lasers. The laser spatio-temporal intensity profile control is a key issue for stable operation of laser wakefield acceleration (LWFA) [2]. Thus, it is necessary to measure and correct STCs. Techniques such as INSIGHT [3] or TERMITES [4] allow reconstructing the full spatial...
OpenDigitizer* is an open-source modernisation of FAIR's modular digitizer infrastructure and graphical user interface based on OpenCMW, WebAssembly, and the GNU Radio 4.0 frameworks.
Already used to provide generic monitoring and first-line diagnostics for accelerator-related devices, it further supports equipment experts, operation, and FAIR users in developing basic to advanced top-level...
CERN’s digital Low-Level RF (LLRF) family for injectors is deployed on CERN’s PS Booster (PSB), Low Energy Ion Ring (LEIR), Extra Low ENergy Antiproton (ELENA) ring and Antiproton Decelerator (AD). It implements multiple capabilities, including beam and cavity feedback loops, bunch shaping, longitudinal blowup, bunch splitting and longitudinal diagnostics.
New capabilities are now available...
The current injector system, composed by a linac and a synchrotron booster, will be used to inject into the new storage ring.
After 15 years of operation, some upgrade of the instrumentation devices are required to well characterize the beam parameters extracted from the booster, before and after the implementations in action to reduce the beam emittance.
Brookhaven National Laboratory Accelerator Test Facility is working on development software tools to achieve automated instrument for tuning and alignment of electron source and beam transport line. The end goal is a robust, efficient, and autonomous method of alignment that can operate on a generalized notion of beam fitness, that can optimize any quantifiable metric about the beam (size,...
The CERN SPS injection kicker magnets (MKP) were developed in the 1970's, before beam power deposition was considered an issue. There are two types of these magnets in the SPS: MKP-S (small aperture) and MKP-L (large aperture) versions. The MKP-L magnets are very lossy from a beam impedance perspective: this would be an issue during SPS operation with the higher intensity beams needed in the...
Emittance measurements are a universal requirement when operating particle accelerators. Many techniques exist to achieve these measurements, each suiting the specific requirements of a machine. Most are multi-shot or invasive, and struggle to function with low energy beams or where space-charge effects are dominant. Generally, these limitations can be restricting, but especially so in...
Optical Transition Radiation (OTR) is commonly used in imaging systems of highly relativistic charged particle beams as the light yield and collection efficiency increase with beam energy. For low beam energies, scintillating screens are typically preferred but they saturate or even get damaged when using a high beam current. For such a beam, OTR screens can, therefore, still be an attractive...
A beam profile monitor using gas jet technology is being designed and manufactured at the Cockcroft Institute for high intensity electron beams. It generates a thin, supersonic gas sheet that traverses the beam at a 45-degree orientation and measures the beam-induced fluorescence interactions to produce a 2D beam profile image. The gas sheet acts similar to a scintillating screen, but remains...
Beam-based alignment and feedback systems are essential for the operation of the Free Electron Lasers (FELs). Cavity BPMs having the advantage of high position resolution are widely used in the field of accelerators. Systematically analyze the impact of the key parameters of each subsystem on the performance of the whole system, so that the key technical indicators of each subsystem can...
Following works aiming at optimizing photonic focal spot size measurement conditions on AIRIX, we decided to improve our electron beam picture processing software with a goal of studying a potential relationship between AIRIX electronic and photonic focal spot size dimensions. AIRIX electronic focal spot size is obtained from an OTR measurement chain established by adapted optics and an...
During the Long Shutdown 2 (LS2) at CERN, the new Linac4 (L4) accelerator has been
successfully connected to the PS Booster (PSB) to inject 160 MeV H− beam into the 4
superposed PSB rings. The horizontal displacement of the circulating beam during injection
relies on 4 pulsed dipole magnets. During the initial run of the new magnet system, non-
conformities have been observed. These...
One of the Grand Challenges in beam physics relates to the use of virtual particle accelerators for beam prediction and optimization. Useful virtual accelerators rely on efficient and effective methodologies grounded in theory, simulation, and experiment. This work extends the application of the Sparse Identification of Nonlinear Dynamical systems (SINDy) algorithm, which we have previously...
An R&D platform for electron FLASH radiation therapy and radiation biology is being prepared at the Photo Injector Test facility at DESY in Zeuthen (FLASHlab@PITZ). This platform is based on the unique beam parameters available at PITZ: ps scale electron bunches of up to 22 MeV with up to 5 nC bunch charge at MHz bunch repetition rate in bunch trains of up to 1 ms in length repeating at 1 to...
The PSB, PS, and SPS accelerators at CERN provide high-energy proton and ion beams to a wide range of experiments, from fixed targets to the world’s biggest particle accelerator: the Large Hadron Collider (LHC). In 2021 and 2022, their beams have reached unprecedented intensities thanks to the LHC Injectors Upgrade (LIU) undertaken during the Long Shutdown 2 (LS2) in preparation of the...
During the Large Hadron Collider (LHC) operation small fractions of the beam are lost continuously, leading to mixed-field radiation. Whereas the 2022 radiation environment in the majority of the locations follows expectations established both through measurements and simulations, some discrepancies with respect to the Run 2 operation (2015-2018) were detected. This work presents an overview...
With LCLS-II commissioning started and transfer-to-operations being scheduled, users will have more choices to use different scales of X-Ray FEL. LCLS-I instrument hutches and the beam diagnostic systems at SLAC have the requirements to use the same facilities to detect the X-Rays or electron beams from both LCLS-I and LCLS-II accelerators. Synchronization of the phase reference systems...
In an Ultrafast Electron Diffraction (UED), high-brightness ultrafast electron beams are indispensable to capture critical ultrafast events on an atomic/molecular scale. For space-charge effects (SCE) dominated electron beams, the beam emittance increases significantly during propagation. Understanding the beam emittance evolution during its passage is critical for further improving the UED...
The 3 GeV storage ring light source at the MAX IV Laboratory in Sweden is currently operating with 10 insertion device beamlines. Each of them is equipped with a pair of photon beam position monitors (XBPMs) in the beamline front end. During the past years these XBPMs have been developed to be a reliable monitoring tool for measuring photon beam stability during beamline operation. As a...
To achieve the vacuum quality required for the operation of particle accelerators, the surface of the vacuum vessels must be clean and free of hydrocarbons. This is usually done by wet chemistry processes, e.g. degreasing chemical baths that, in case of radioactive vessels, must be disposed accordingly. An alternative way to perform the removal of hydrocarbons exploits the oxygen plasma...
Laser-driven proton beams are characterized by very high intensities per pulse with a very short duration, extremely high dose rates, and broad energy spectra. These specific features do not allow the use of the conventional dosimeters typically suggested by the international dosimetry protocols for conventional proton beams. Precise dosimetry for laser-accelerated protons is an ambitious task...
Compared to classic proton therapy, proton minibeam radiation therapy (pMBT) further spares normal tissue. To fully study this potential with small animal experiments focused minibeams with a sigma of 50 micrometers, a beam current of 1 nA and approx. 4 cm Proton-range (water) is needed. We present a preclinical pMBT beamline concept based on the 68 MeV cyclotron of the Helmholtz-Zentrum...
Recently, Metal Additive Manufacturing technology enables the possibility to realize cooling systems in accelerator components during the manufacturing process phase, obtaining extremely high density, high thermal, and mechanical properties in metals. In the Neutral Beam Injection for the Divertor Tokamak Test facility, the beam acceleration components are submitted to extremely high-power...
Linear accelerators for medical applications present the possibility to reduce costs compared to cyclotrons or synchrotrons while offering higher beam stability and flexibility. In the framework of NIMMS, the Next Ion Medical Machine Study, the design of a linear accelerator for carbon ion therapy has been completed at CERN. The pre-injector is composed of a fully stripped...
Hadron therapy with light ion beams is gaining momentum due to the possibility to treat tumors that are resistant to chemotherapy and radiotherapy. In addition, hadron therapy is the preferred choice of treatment for tumors that are inoperable due to their vicinity to vital organs.
The main advantages of charge particle therapy compared to conventional X-ray radiotherapy are related to the...
Department of Accelerator Science at Korea University, Sejong was established in 2014 to promote accelerator science research and train accelerator scientists and engineers for the growth of domestic accelerator projects in Korea. In addition, Accelerator Research Center and Small Accelerator Application Core Facility Research Center under the department hood were also organized to foster...
Superconducting radio frequency (SRF) cavities performances strongly depend on the surface preparation. Conventional protocol of SRF surface preparation includes electropolishing (EP) as the main treatment achieving low roughness, clean surface, both for Nb and Cu substrates. Harsh and corrosive solutions are typically used: concentrated HF and H2SO4 acids for Nb, and H3PO4 with Butanol...
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications, is a proposed novel facility capable of delivering high intensity beams of protons and ions that will enable radiobiological research to be carried out in completely new regimes. A two-stage facility, the first stage utilizes laser-target acceleration to produce proton bunches of energies up to 15 MeV. A series of Gabor...
TURBO – Technology for Ultra Rapid Beam Operation – is a novel beam delivery system (BDS) in development at the University of Melbourne. The BDS determines several aspects of treatment delivery, where a bottleneck is the deadtime associated with beam energy variation. Beamlines at treatment facilities have a ±1% momentum acceptance range, requiring all the magnetic fields to adjust to deliver...
The Superconducting RF system of Hefei Advanced Light Facility (HALF) can provide an accelerating electric field for the beam, and its stability is required to be of RMS ≤ 0.1% in amplitude and RMS ≤ 0.1° in phase. To achieve this, a LLRF controller is being prepared for the control of the HALF Superconducting RF system. This LLRF controller mainly consists of three modules of RF front-end,...
The HZB cyclotron continues to provide protons for eye tumor treatment in collaboration with the Charité – Universitätsmedizin Berlin after 24 years and more than 4400 patients so far. With the perspective of broadening its research capabilities in the field of radiation therapy, intensive effort has been dedicated towards proton FLASH irradiation, which requires ultra-high dose rates or beam...
A 4th generation storage ring based light source is being developed in Korea since 2021. The storage ring based on the multi-bend achromat lattice concept may be able to surpass the brightness and coherence. It features about 800 m circumference with 28 cells, 4 GeV e-beam energy. The storage ring girders consist of 140 girders and each cell of girder is composed of five pieces. We have...
Electron beam injection and extraction from the various stages of the SOLEIL II accelerator complex will be performed in three different locations, as it is done today. Injection of the LINAC beam into the upgraded booster and then its extraction use traditional on-axis & on-momentum schemes with single turn kickers and septum magnets. The main Top-Up injection scheme in the storage ring*...
Additive manufacturing ("AM") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for direct additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel, as well as pure copper using AM. The Prototype...
Bunch length is an important metric for user experiments at the Compact Linear Accelerator for Research and Applications (CLARA). A prototype Bunch Compression Monitor (BCM) based on Coherent Transition Ration (CTR) was recently installed and commissioned to support recent user experiments. The intensity of CTR is measured using a pyroelectric detector. A noise cancellation scheme based on a...
The availability of modern accelerators has become a key performance indicator. This is especially the case for accelerator-driven-systems (ADS), such as MYRRHA, which need to deliver beam with very few interruptions longer than a few seconds over a period of several months.
Quantification of such beam interruptions at other accelerators such as LINAC4 at CERN and SNS at ORNL show that their...
Recent studies showed significant improvement in quantum efficiency (QE) by negative electron affinity (NEA) GaAs nanopillar array (NPA) photocathodes over their flat surface peers, particularly at 500 ─ 800 nm waveband. However, the underlying physics is yet to be well understood for further improvement in its performance. In this report, NEA GaAs NPA photocathodes with different dimensions...
As one of on-line single-shot and non-destructive absolute measure methods with high resolution, Electro-Optical (EO) techniques have been wildly utilized in Free Electron Laser to measure the longitudinal bunch profile. A bunch length monitor with 100 fs resolution is required for Shanghai Soft X-ray FEL (SXFEL) facility. The solution based on Electro-Optical Temporal Decoding (EOTD) method...
The Large Hadron Collider at CERN is equipped with instruments that exploit collisions between beam particles and gas targets, one of them being the Beam Gas Vertex monitor. By design, its operation generates secondary particle showers used to measure beam properties, that also result in radiation levels in the tunnel proportional to the beam intensity and gas pressure. In this work, the...
We will propose a novel high resolution method for surface scanning. Optical glow discharge spectroscopy (OGDS) devices are simpler and less expensive than secondary-ion mass spectrometry (SIMS),and can provide excellent spatial resolution. A small change in the design of the discharge device makes it possible to localize sputtering on a small portion of the target and to obtain the...
Miniature single-board cameras have been used for several years to monitor beam-induced residual gas fluorescence. This work gives an overview of the use of so-called Raspberry Pi cameras in accelerator experiments. These devices are installed in vacuum at hard-to-reach locations. They have been tested in strong magnetic fields with low energy proton beams from 2 keV to 60 keV. They have also...
The use of artificial intelligence (AI) has the potential to significantly reduce the time required to tune particle accelerators, such as the Argonne Tandem Linear Accelera-tor System (ATLAS). Bayesian optimization with Gauss-ian processes is a suitable AI technique for this purpose, it allows the system to learn from past observations to make predictions without explicitly learning...
Particle accelerators are complex and energy-intensive facilities that require extensive and intertwined connections with the public electrical grid. Furthermore, accelerator facilities are well known for their low power demand flexibility, which depends only on experimental operations, and it must be accommodated independently from the grid. So, it is necessary to develop and test new energy...
Polish Electronics Group (PEG) is one of the in-kind partners to the European Spallation Source (ESS) project. One of its tasks is testing the LLRF control systems before installation in the machine. To perform this task, the Cavity Simulator was developed. It simulates the behavior of an amplifier driving a superconducting cavity, both used in medium and high beta sections of ESS' linac. This...
The beam emittances at the MAX IV 3 GeV fourth generation storage ring are evaluated using synchrotron radiation in the UV to visible energy range. The methods used are combined measurements with various diffraction obstacles and controlled light polarizations. The resolution capability is well covering the needs for the design emittances of the ring. However, accelerator studies often go...
The brightness of the beam in any linear accelerator can be no greater than at its source. Thus characterization of source initial conditions, including spatial and momentum distributions, is then critical to understand brightness evolution in a linac. Often measurement of the initial momentum distribution is hampered by imperfect knowledge of either the spatial source distribution or the...
The transverse size of the electron beam in a storage ring can be measured using the synchrotron radiation of a bending magnet. Due to the diffraction limit, many facilities exploit beam size monitors in the X-ray regime. On the other hand, the visible part of the emitted radiation delivers spatial information via an interference pattern after passing through a double slit. Assuming a Gaussian...
As part of the High Luminosity upgrade for the Large Hadron Collider, several new directive-coupler (stripline) BPMs will be installed near the ATLAS and CMS detectors where the two counter-rotating beams exist within a single beampipe. In the worst case scenario, the bunches of the second beam arrive at the BPM location just 4 ns after those of the first and the BPM signals from the two beams...
The present BPMs of the J-PARC Main Ring have adopted mechanical relays in its processing circuits. Frequency range is limited less than 10 MHz by LPFs. Mechanical relay is chosen due to its good isolation. But the drawback is contact failures due to insulating materials after long suspension period of months. Methods of recovery and checking are reported. Recovery of contacts are performed...
Optimal control is inherent issue in particle accelerators, mainly due to nonlinear and time-varying effects caused by unknown errors such as external environment changes, misalignment, and fabrication defects. In this regard, machine learning techniques are promising to go beyond heuristic methods or traditional optimization algorithms. Reinforcement learning is suited to solve the beam orbit...
The Safe Machine Parameter system (SMP) is a critical part of the machine protection system in CERN’s Large Hadron Collider (LHC) and the Super Proton Synchrotron (SPS). It broadcasts safety-critical parameters like beam energy, beam intensity, the beta functions and flags indicating safety levels of the beam to other machine protection elements. The current SMP will be replaced by a...
Beam currents of particle accelerators used for cancer treatment are often on the nanoampere level. These currents are too low for standard beam current diagnostics used in other fields of particle accelerator science, e.g. current transformers. This led to the general adoption of ionization chambers for beam current and dose rate determination in medical accelerators. However, the development...
Researchers at the National Synchrotron Radiation Re-search Center should use respiratory protective equip-ment to prevent respiratory damage caused by gases, steam, solvents, chemicals, materials containing toxic substances, and oxygen-deficient environments. Those working with organic matter and certain chemical sub-stances and those exposed to occupation dust should use respiratory...
The aims of this work are to measure the energy consumption performance of compressed air systems, determine the weak points, implement the economic assessments and execute energy saving improvements in NSRRC. The compressed air discharge pressure is regulated in 6.0±0.5 kg/cm2. The specific energy requirement (SER) of those compressors is 7.74 ~ 20.05 kW/m3/min. Based on the performance...
Measuring beam parameters in the vicinity of fixed target experiments or interceptive devices like beam dumps is essential to ensure efficient fixed target physics and safe beam operation. At the same time the beam diagnostic reach is very often challenging in terms of robustness and performance. This paper reviews the CERN instruments exploited to measure protons at different CERN fixed...
In accelerator beam chambers and RF waveguides, electron cloud and multipacting can be mitigated effectively by reducing the secondary electron yield (SEY). In recent years, it has been established that laser surface structuring is a very efficient method to create a copper surface with SEY close to or even below unity. Different laser pulse durations, from nanoseconds to picoseconds, can be...
For SRF cavity systems operated in continous wave (CW) at low effective beam loading as in Energy Recovery Linacs or Free Electron Lasers with rather low beam current, control of the tuning and counteracting any detuning caused by microphonics or Lorentz force driven coupled ponderomotive instability is mandatory to deliver and preserve a stable beam in longitudinal phase space regime.
To...
Particle accelerators require continuous adjustment to maintain beam quality. Several machine learning (ML) approaches are being explored for this task. At the Advanced Photon Source (APS), we have recently proposed the adaptive Bayesian optimization (ABO) algorithm and have shown it to be effective experimentally in the APS injector complex. Further testing has suggested several improvements,...
The FAIR complex at the GSI Helmholtzzentrum will generate heavy ion beams of ultimate intensities. To achieve this goal, low charge states have to be used. However, the probability for charge exchange in collisions with residual gas particles of such ions is much higher than for higher charge states. In order to lower the residual gas density to extreme high vacuum conditions, 65% of the...
The upgrade program for AREAL accelerator includes beam energy increase from 5 MeV up to 50 MeV. For this purpose, two 43 cells, and 1.6 m long, S-band accelerating structures are foreseen. The design and fabrication of cells are already carried out in CANDLE. For effective acceleration the tuning of phase advance and frequency of the structure is necessary. The precise geometrical dimension...
In recent years, SAES has deepened its knowledge in the NEG coating field, aiming at uniformly coating vacuum chambers with challenging geometries and fine-tuning the film characteristics, according to the needs and requirements of the final users.
To achieve these goals, several complex vacuum chambers have been coated and studied, both at SAES and in collaboration with various research...
According to the schedule, the commissioning of HEPS injector would start in 2023. The high-energy transfer line ‘BR’ is used to deliver 6 GeV electron beams from the booster to storage ring. Systematic simulation of beam commissioning was carried out for the HEPS high-energy transfer line. The simulation results suggest that it is feasible to deliver not only on-momentum but also slightly...
In the CSNS RCS RF system, a combination of feed-back control and adaptive feedforward control was proposed in in the Low-Level Radio Frequency (LLRF) system to ensure stable beam acceleration. Although the effectiveness of the feedforward control has been confirmed in operation, a detailed study on it is still necessary. This paper presents a detailed study on the feedforward control based on...
A compact TDS (transverse-deflecting system) has been proposed for diagnostics of extremely short electron bunches (up to single-digit femtosecond range). The main idea is to use terahertz radiation, produced from optical rectification of the facility’s electron gun laser pulse. This provides an intrinsic synchronization between the electron bunch and the laser pulse. The proposed system is to...
The installation of the new Swiss Light Source - SLS2.0 will start in October 2023. All beamlines will profit from the increased photon beam brightness. Given the geometrical constraints of the new storage ring, high synchrotron radiation power densities must be dissipated on the crotch absorbers. For the bending magnets, as well as the insertion devices, absorbers have been adapted to...
The installation of the SLS2.0 storage ring will start in October 2023. Most of the vacuum chambers composing the 288 m long storage ring will be made out of copper to dissipate the synchrotron radiation heat and to decrease resistive wall impedance. The nominal inner diameter is 18 mm with a wall thickness minimum of one millimeter and distance to pole going down to 0.2 mm at some locations....
FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a compact linac-based test facility for accelerator and diagnostics R&D located at the Karlsruher Institute of Technology (KIT). A new accelerator diagnostics tool, called the split-ring resonator (SRR), was tested at FLUTE, which aims at measuring the longitudinal bunch profile of fs-scale electron bunches. Laser-generated THz radiation is...
Achieving femtosecond synchronization between charged particle beams and experimental laser systems poses a significant challenge for modern particle accelerators. In particular, tight synchronization of multiple remote accelerator systems is required to achieve femtosecond stability of the electron beam. This paper presents the development of the CLARA fibre-stabilized timing distribution...
With the high beam current in storage ring, it is necessary to consider the instability problem caused by the heavy beam loading effect. It has been demonstrated that direct RF feedback (DRFB), autolevel control loop (ALC) and phase-lock loop (PLL) in the main cavity can lessen the impact of the beam effect. This paper regarded the beam, main cavity, harmonic cavity and feedback loops as...
BDSIM is a Monte Carlo simulation program for start-to-end particle tracking through 3D models of particles accelerators. Based on the Geant4 toolkit, BDSIM provides a holistic approach to accelerator modelling by using Geant4’s particle-matter interaction physics with dedicated accelerator tracking routines for beam vacuum transport. Subsequently, the ability to model the hits, losses, &...
At the visible light diagnostic (VLD) port at the Karlsruhe Research Accelerator (KARA), it is possible to measure the energy spread of electron bunches by measuring the horizontal bunch profile of the incoherent synchrotron radiation. KALYPSO, a MHz-rate line-array detector has been used to measure the bunch profile. Recently, the KALYPSO system has been upgraded to a version incorporating a...
Digital twins have emerged as a powerful tool for monitoring and optimizing complex systems, including Synchrotron Light Sources. This paper describes the development of a digital twin for BessyII and MLS, two Synchrotron Light Sources, which allows for real-time monitoring of the machine status and easy integration of online analysis while measurements are taken. The digital twin is designed...
NHa and IBA are collaborating to develop a new cyclotron dedicated to hadron therapy. The manufacturing of the magnet is in an advanced stage. In parallel, extensive studies are carried out to develop an accurate field mapping system. It is required to perform the high precision magnetic field measurement (75 ppm) that will provide the final isochronous field after the well-known shimming...
The "Facility for Antiproton and Ion Research" (FAIR) is a new international accelerator complex, which is currently built in Darmstadt, Germany. Part of this complex is the SIS100 heavy ion synchrotron with a circumference of ~1086 m. To inject ions into the SIS100, an injection kicker system will be required. For fast extraction of the particle beam from the SIS100, an extraction kicker is...
One of the crucial control systems of any particle accelerator is the Low Level Radio Frequency (LLRF). The purpose of a LLRF is to control the amplitude and phase of the field inside the accelerating cavity.
The LLRF is a subsystem of the CEA control domain for the SARAF-LINAC instrumentation and Seven Solutions has designed, developed, manufactured and tested the system based on CEA...
The 1.5-GeV electron storage ring of the synchrotron radiation source DELTA at TU Dortmund University is surrounded by a 1 m thick concrete radiation shielding wall with a height varying between 3.0 and 4.3 m without the top being covered. The installation of a new 7-T superconducting wiggler and tentative plans for a new building in the vicinity motivated recent studies of background...
Bunch length measurement is an essential diagnostic for FEL facilities and now the interest of ultrashort bunch is continuously rising. The nondestructive methods with high resolution are now the favorite design for short bunches less than 1 ps. The technique of cavity bunch length measurement based on the monopole mode is discussed is this article. The influence of many factors on the...
Coherent X-ray beam focus can be characterized using ptychography, a lensless imaging technique used at synchrotron X-ray light sources and free-electron lasers. Ptychography relies on collecting X-ray diffraction from a thin sample at overlapping regions and reconstructing an image from the data. Since the phase is not measured by the detector, ptychography can solve for the phase of the...
In designing the synchrotron light sources like NSLS-II, non-linear perturbation from the sextupoles are thoroughly studied to secure dynamic apertures large enough for the high-performance operation. Also, it can be well understood that the offsets in sextupoles affect the overall machine performance, closed orbit, linear optics, coupling and dispersion. In this paper, we introduce various...
The purpose of a Low Level Radio Frequency (LLRF) system is to control the amplitude and phase of the accelerating field in the cavity. To improve the RF field stability and to decrease the noisy sideband such as few kHz sideband from RF transmitter, a study for the application of active disturbance rejection control (ADRC) is ongoing. ADRC algorithm is based on an extended state observer,...
One of the projects for upgrading at the Taiwan Photon Source (TPS) is the design and fabrication of an improved multipole injection kicker (MIK). The aim is to improve the injection efficiency using four kickers, to deliver transparent injections during the top-up operation. A uniform titanium coating on the inner surface of the ce-ramic substrate is required to reduce the impedance of the...
The beam orbit stability is the crucial indicator to evaluate the performance of the synchrotron radiation source. In order to obtain higher beam quality, higher stability requirements are placed on the beam orbit. The stability can be improved through accurate meas-urement of beam orbit by beam position monitors (BPMs) and appropriate feedback system. However, due to radiation of the...
In order to improve the sensitivity and long-term sta-bility of Hefei Light Source – II (HLS-II) for beam posi-tion measurement, it is necessary to improve the meas-urement method. The beam position monitor (BPM) electronics is used to measure the beam position and is an important part of the beam position measurement system. In this paper, we propose a beam position meas-urement system based...
Surface annealing using intense nanosecond laser pulses is an emerging technique for SRF cavities. This technique can effectively reduce the cavities’ surface defects and improve their RF performance. However, previous studies in this field limited themselves on solid state lasers or gas lasers, which have very low average power and are not practical for processing actual SRF cavities with ~m2...
The performance of operating particle accelerators has been seriously affected by the electron cloud (e-cloud) effect. The secondary electron emission (SEE) and the e-cloud can be effectively suppressed through laser-etching the inner surface of the vacuum chamber. Oxygen-free copper (OFC) has become the first choice for the vacuum chambers of modern accelerators due to its high electric and...
Cherenkov Diffraction Radiation (ChDR), which is emitted when relativistic charged particles pass around dielectric materials, has recently been presented as non-invasive beam diagnostics in various studies. We intend to measure transverse beam size using ChDR in e-LABs, a 100 MeV electron experimental accelerator at the Pohang Accelerator Laboratory (PAL). The electron energy of e-LABs is...
The 3rd ICFA Beam Dynamics Mini-Workshop on Machine Learning (ML) Applications for Particle Accelerators was held in Chicago, Il, USA, on November 1-4, 2022. This was an in-person workshop focused on ML techniques as applied to accelerator operations, design, and simulations. There were 76 attendees representing 26 institutions from around the world. A total of 59 abstracts were submitted...
The Super Separator Spectrometer (S3) is an experimental device dedicated to fundamental research in nuclear physics at GANIL laboratory in Caen, France. S3 spectrometer was designed in the framework of SPIRAL2 in order to take full advantage of the very high intensity stable ion beam delivered by the superconducting linear accelerator, LINAC*.
In November 2022, the first beam of Argon beam...
The KEKB personal protection system (PPS) takes care of not only KEKB accelerator, but also PF-AR, Positron Damping Ring and their beam transport lines. The PPS is updated step by step. The new beam transport line to the PF-AR was constructed, and it makes possible that the injector supplies the beam to the 5 storage ring (KEKB LER,HER,PF-AR,PF and Positron damping ring) simultaneously. The...
Accelerator physics simulators accurately predict the propagation of a beam in a particle accelerator, taking into account the particle interactions (a.k.a. space charge) inside the beam. A precise estimation of the space charge is required to understand the potential errors causing the difference between simulations and reality. Unfortunately, the space charge is computationally expensive,...
The Slotted Waveguide Elliptical (SWELL) cavity is an elliptical accelerating cavity with an innovative design, proposed by CERN and developed in the scope of the FCC-ee study. The SWELL design is composed of four quadrants, separated by radial slots in order to improve higher order modes (HOM) transverse damping, while minimizing impact on the longitudinal accelerating mode. The quadrants for...
Radiation resistance of materials is an important area of research, relevant to nuclear reactor technology. Various challenges are associated with this research; one of which is the selection of radiation resistant material for the plasma facing wall of the reactor due to its harsh operating environment.* Recent studies reveal that WC has the potential to be developed as radiation resistant...
The Mu2e Experiment has stringent beam structure requirements; namely, it requires short (~200 ns) proton bunches separated by 1.5-2.0 $\mu$s. This beam structure will be produced using the Fermilab 8 GeV Booster, the 8 GeV Recycler Ring, and the Delivery Ring, which was formerly part of the antiproton accumulator system.
Out of time beam is limited to a fraction of level of no more than...
High resolution bunch length monitors are an important diagnostic for the optimisation of any accelerator, from typical linacs or storage rings to novel acceleration systems. Given the availability of synchrotron radiation (SR) in these systems, studies have been carried out into how the spatial profile of the radiation changes with bunch length. Understanding these profile variations offers a...
The CERN SPS Low Level RF (LLRF) has undergone a major upgrade, including the complete redesign of the 200 MHz Cavity-Controllers [1,2] and the Beam-Control [3]
during the Long Shutdown two (LS2) in 2018-21. Two major goals motivated the upgrade, first the required doubling of the proton beam intensity injected from the Super Proton Synchrotron (SPS) for the High Luminosity Large...
The CERN SPS Low Level RF (LLRF) has undergone a major upgrade, including the complete redesign of the 200MHz Cavity-Controller and the Beam-Control during the Long Shutdown (2018-21). This upgrade was motivated by the required doubling of the beam intensity in the SPS for the High Luminosity LHC project (HL-LHC). This paper covers the embedded acquisition core used in both the 200MHz...
The interlock systems of the CERN Experimental North Area will be consolidated in CERN’s Long Shutdowns 3 and 4, planned to start in 2026. The new interlock systems will guarantee the safe and efficient operation of the machine protection systems for the coming 25 years. The consolidation work includes not only the primary beam areas but also the secondary beam lines and possible new beam...
The planned multi-pulse linear induction accelerator, Scorpius, will be used in radiographic experiments at the NNSS U1A facility. One of the many diagnostics, the emittance diagnostics, will provide information on the quality of the beam emanating from the injector and therefore the quality of the beam in the accelerator. A Slit-Harp design was chosen for the emittance diagnostic. COMSOL...
Non-evaporable getter (NEG) coated vacuum cham-bers are widely used as a vacuum solution in modern particle accelerators.
In the development and testing of new NEG coatings to produce better vacuum, the pumping properties are evaluated.
In this paper, Test Particle Monte-Carlo Simulations are created to investigate whether small bends in sample tubes may affect the results of pumping speed...
The Frascati linear accelerator was built in 1996 to be the electron and positron source and the front end of the DAFNE injector, is now also being used to support the DAFNE accelerator complex and the Beam Test Facility (BTF).
The Frascati linear accelerator system consists of four S-band high-power klystron and modulator systems, fifteen accelerating structures, and four SLAC-type energy...
Ion profile monitors (IPM) are used to measure the beam size in synchrotrons. Both the Fermilab Recycler and Main Injector (MI) machines have IPMs. However, they were not well understood enough to provide confidence in their measurements. Accurately measuring beam size through the IPMs was crucial to recognize the loss mechanisms for accelerators and to keep the beam loss to a minimum. Thus,...
Once completed, the Facility for Antiproton and Ion Research in Europe GmbH, FAIR, is to be one of the leading nuclear physics laboratories in Europe and one of the largest and most versatile accelerator complexes worldwide. FAIR can serve a number of experiments simultaneously, using fast-cycling synchrotrons. In this context, safety of personnel has the highest priority. The essential...
The CiADS linac is a superconducting linear accelerator which has hundreds of RF cavities. The stable phase reference line is essential for effective control of accelerating fields in RF cavities, it provides phase reference signals for low level radio frequency systems, beam position monitor systems and timing system with low phase drifts. The phase reference line of CiADS SC linac is a...
The Structured Laser Beam (SLB) is a type of optical beam characterized by an intense, sharply defined, low divergence core at its center, similar in its transverse intensity distribution to a Bessel beam. The SLB can propagate over a theoretically infinite distance, and has recently been tested up to a distance of 900 m. This test confirmed the low divergence of the SLB core, of about 0.01...
We report on the behaviour and tuning of the diagnostics of the ThomX
Compact source during the accelerator commissioning. These diagnostics
consist of Beam Position Monitors, screens used to measure the beam
profile (YAG and OTR), charge monitors, bunch length monitors, beam loss monitors and
synchrotron radiation monitors. For each diagnostics we report on the
performances measured...
The pulsed magnet control system at KEK electron positron injector LINAC changes the magnetic field every 20 ms to realize the simultaneous injection for four target rings, 2.5 GeV PF, 6.5 GeV PF-AR, 4 GeV SuperKEKB LER and 7 GeV SuperKEKB HER. It receives the trigger signal from the event timing system which varies for different beam modes. Then the output of a PXIe DAC board responds to the...
For X-ray spectroscopy applications it has been verified that Germanium detectors are enable to detect efficiently photons of considerable higher energy with respect to Silicon detectors. On the other hand, another advantage for cases like fluorescence detectors for absorption spectroscopy (XAFS), Germanium detectors do not show artifacts due to features like the escape peak interfering with...
For vacuum scientists and the accelerator community, it is of paramount importance to find solutions for high energy machines to mitigate : (i) pressure increases induced by the desorption of electrons, photons and ions; (ii) clouds of ions or electrons inducing beam instabilities, heat deposits on the vacuum chamber walls or stimulated molecular desorption; (iii) multipactor effect in...
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications*, is a proposed facility for the study of proton and ion radiation biology. The accelerator is designed to deliver a variety of ion species over a wide range of spatial and temporal profiles at ultra-high dose rates. The facility requires that the deposited dose distribution be measured in real-time. For this purpose, an...
Using a calibrated permanent magnet spectrometer and a streak camera, a time resolved measurement is made for a multi-pulse beam. These measurements are cross calibrated with cell voltage monitors to have a reliable online energy measurement. The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Axis-II produces a 16 MeV, 1.65 kA electron beam. Timing on the cell voltages is changed...
Orbit feedback system (OFB) of the Taiwan Light Source (TLS) had been deployed two decade ago and upgraded to improve performance several times. The loop bandwidth was limited by existed hardware. The system cannot remove perturbation form fast source. Therefore, to improve orbit feedback performance, the system have been upgraded in 2008 [1]. It included the BPM electronics upgraded from...
For arrival-time monitors of the electro-optical synchronization system at the European XFEL, FELBE and other free-electron laser facilities, a novel concept based on rod-shaped pickups mounted on a printed circuit board is proposed. New simulation results show the huge potential for low charge applications foreseen at the European XFEL and FELBE for future operation modes. A theoretical...
Diffraction Limited Storage Rings, the 4th generation machines, provide transversely coherent beams with uniform phase, maintaining high photons flux and stability. Diagnostic systems play an essential role for both commissioning and operating tasks of Elettra 2.0. The small beam dimensions make measurements of both position and size challenging. Elettra 2.0 diagnostics will rely mainly on...
Before injection into the Karlsruhe Research Accelerator (KARA), the electron storage ring of the KIT Light Source, the beam energy is ramped up from 53 MeV to 500 MeV by a booster synchrotron. The whole booster is located in a concrete enclosure inside the storage ring and thus not accessible during operation. For the study of longitudinal beam dynamics, a cost-effective solution to leverage...
In ion beam therapy most cancer patients are treated using the raster-scanning dose delivery method of heavy ion pencil beams, with the penetration depth determined by the ion beam energy. The beams are provided by synchrotrons, which currently have to start a new cycle to change the beam energy. The number of particles available in one cycle typically exceeds the required amount for a single...
Orbit feedback system of the Taiwan Photon Source (TPS) had been delivered since 2014. As long as more and more insertion devices installed, there are various wide-band disturbance produced. To further improve orbit stability, the fast orbit feedback (FOFB) system upgrade plan had been proposed in 2019. The upgrade plan includes both power supply controller revise and feedback computation rate...
Phase space tomography is a powerful technique for characterising beams in particle accelerators and has found widespread use at many facilities. However, conventional tomography techniques require significant computational resources, particularly when reconstructing the charge distribution for two or more degrees of freedom. Here, we describe a novel technique that employs machine learning...
The low level RF system of TPS booster ring was replaced by the DLLRF in 2018. After that, the phase drift compensation loop for energy saving operation and the tuner loop were also implemented into the DLLRF system sequentially. We used altera-DE3 to build the core of DLLRF and to handle the high speed ADC/DAC procedure for RF signal sampling. As facing to the tuner control requirement, we...
The transverse beam size is a key parameter of electron bunches in the storage ring for beam quality evaluation. High-precision beam size measurement will offer better performance for accelerator monitoring and will be beneficial to study beam instabilities and optimizing machine operation. The interferometer system is a commonly used diagnostic tool for beam size measurement. High accuracy...
Reinforcement learning (RL) is a promising direction in machine learning for the control and optimisation of particle accelerators since it learns directly from experience without needing a model a-priori. However, RL generally suffers from low sample efficiency and thus training from scracth on the machine is often not an option. RL agents are usually trained or pre-tuned on simulators and...
Thyristors triggered in impact ionization mode find their dI/dt capability boosted by up to three orders of magnitude. This innovative triggering requires applying an important overvoltage on the anode-cathode of the thyristor with a slew rate > 1kV/ns. Compact pulse generators based on COTS components would allow the spread of this technology into numerous applications, including fast kicker...
One of the crucial monitoring systems of any particle accelerator is the Beam Position Monitor (BPM). The purpose of a BPM is to provide information on the position, phase and current of the beam at different points along the accelerator line.
The BPM is a subsystem of the CEA control domain for the SARAF-LINAC instrumentation and Orolia-Spain has designed, developed, manufactured and tested...
The ALPI accelerator radio frequency (RF) control system at LNL (Legnaro National Laboratories) is currently undergoing a series of upgrades which will extends its lifetime and provide enhanced performance. This is a multi-year project where the upgrades are delivered incrementally while avoiding disruptions to the accelerator schedule. The first phase includes the development of new Low...
The medium energy beam transport (MEBT) of the SPIRAL2 superconducting linac contains a single bunch selection system equipped with a 7.5 kW beam dump (SBS dump). This device, originally designed with a long plane slope to decrease the power density so that the maximum operating temperature was 170 °C, was impacted by Coulomb scattering generating two side effects: heating of the downstream...
The HZB cyclotron provides protons for eye-tumor treatment in collaboration with the Charité – Universitätsmedizin Berlin. So far, more than 4300 patients have been treated. Parallel to therapy, there is an on-going R & D program for beam dosimetry and beam delivery. Furthermore, beam time is used for external users, e.g. the irradiation of geological samples or radiation hardness tests.
For...
The LNL accelerator complex is equipped with two stable ion beams injectors, employing respectively negative and positive ion sources. In particular, a sputtering-type negative ion source and an Electron Cyclotron Resonance Ion Source (ECRIS) are installed on high voltage platforms, to provide the optimum injection energy in the downstream accelerators. Recently, the two injectors have been...
The Shanghai soft X-ray free electron laser facility has made significant progress in recent years with the rapid, upgraded iterations of the High Level software, including but not limited to energy matching, orbit's feedback and load, beam optimization, etc. These tools are key components in operation and experiment of free electron laser facility. Some key applications are presented in this paper.
Several machine learning (ML) projects on anomaly detection and optimization were recently started at the Advanced Photon Source (APS). To improve training data quality, and accommodate the upcoming APS Upgrade changes, a large increase in the number and size of log files is expected. Recent studies found performance bottlenecks in the current log analysis architecture, especially for large ML...
In the context of Time Sensitive Networking (TSN), the Ethernet standards are being extended with new capabilities for deterministic communication, allowing standard Ethernet to be used in new fields of application. In addition, more and more companies now offer TSN compatible devices and software tools. In accelerator control systems (ACS), which need synchronization in the range of some...
The large-acceptance Superconducting Fragment Separator (Super-FRS) at the Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt poses peculiar challenges for its vacuum systems. Although the vacuum levels ranging from 1E-5 to 1E-7 mbar for the single-pass beamline are rather undemanding in absolute values, a combination of high level of prompt and residual radiation in the target...
Given the current availability of high-gradient accelerator technology for cost effective and compact electron LINACs in the 100-200 MeV energy range, using Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment recently gained a lot of interest. The Ultra High Dose Rate (UHDR) or FLASH dose regime, in which cancerous cells are damaged while healthy tissues are largely spared...
For any linear accelerator, a thorough understanding of the Longitudinal Phase Space (LPS) of the beam is a great advantage. At the synchrotron light source MAX IV the two storage rings are injected with electrons using a 3 GeV linear accelerator, which also serves to provide beam for a short pulse facility (SPF). A newly commissioned Transverse Deflecting Cavity (TDC) is used to reconstruct...
The use of fast computational tools is important in the operation of X-ray free electron lasers, in order to predict the output of diagnostics when they are either destructive or unavailable. Physics-based simulations can be computationally intensive to provide estimates on a real-time basis. This proposed work explores the use of machine learning to provide operators with estimates of key...
Many complex systems require the use of different detector devices. The detectors usually acquire 1D or 2D data, but as the manufacturers differ, they all have diverse controlling interfaces. When the API and interface differ, it can become complex to control multiple different devices. The Lima library was created to overcome those obstacles. It unifies the usage of 1D and 2D detectors by...
The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. However, in practice these algorithms remain inaccessible to the general accelerator community, due to the expertise and infrastructure required to apply them towards solving optimization problems. In this work, we...
A systematic comparison of experimental data with 2-dimensional semi-analytical modelling of beam collective effects at the FERMI free-electron laser has led to the first evidence of intrabeam scattering in a single pass electron accelerator, and of its contribution to beam quality for the production of longitudinally coherent seeded FELs. A quantistic evaluation of FEL coherence is proposed...
Superconducting Energy Recovery Linacs (ERLs) promise a step change in the capabilities, and sustainability, of accelerator based facilities. This was highlighted in the 2022 ECFA/CERN European Strategy for Particle Physics Accelerator R&D Roadmap. Potential beneficiary fields include high energy particle physics, free-electron laser light sources for physical and life sciences and industry,...
From the initial success of LCLS, the world has seen a lot of progress in the X_FEL facilities in Europe and Asia. With the successful implementation of cw operation such as LCLS-II, X-FEL is now able to significantly step up its average brilliance as well as user capabilities. This presentation is expected to share with the accelerator community the decadal operation experiences of existing...
Medipix and Timepix are pixel-based technology detectors that can be employed to measure charged particles, photons (visible through gammas), and neutrons. Their readout chips are used at synchrotron light sources, and as mixed field radiation monitors on the International Space Station. Furthermore, clinical trials have started in the domain of medical spectroscopic X-ray radiology. The...
The SPIRAL2 linac is now successfully commissioned; H+, 4He2+, D+ have been accelerated up to nominal parameters and 18O6+,7+ and 40Ar14+ beams have been also accelerated up to 7 MeV/A.The main steps with 5 mA H+, D+ beams and with 0.8 mA 18O6+ are described. The general results of the commissioning of the RF, cryogenic and diagnostics systems, as well as the preliminary results of the first...
The successful development of a quantum computers, quantum sensing and communication is dependent, amongst other aspects, on the capability of extending the coherence time of qubits - the limit on how long a qubit can retain its quantum state before that state is destroyed by noise. Ultra-high Q radio frequency superconducting cavities, initially developed for particle accelerators, have...
The European Spallation Source (ESS) linear accelerator, one the largest scientific equipment under realisation in Europe, is now in the beam commissioning stage. The project is implemented thanks to the collaboration of several European countries, mostly following the scheme of the in-kind contribution, with the involvement of scientists from many European laboratories and Universities in all...
One of the greatest challenges for nuclear energy is how to properly manage the highly radioactive waste generated during irradiation in nuclear reactors. Accelerator Driven Systems (ADSs) is one methods of addressing the transmutation of such high level nuclear waste. ADS or accelerator driven transmutation of waste (ATW) consists of a high power proton accelerator, a heavy metal spallation...
Particle physics has been a major innovation driver and user of accelerators over the last century. Some past highlights are quickly presented and the future directions in particle physics are discussed. Future options for accelerators are reviewed, also discussing major constraints in beam energy, luminosity and practical details, like power consumption.
