Particle accelerators have long been instrumental in advancing scientific research, medical treatments, and industrial processes. However, traditional radio-frequency accelerators are encumbered by their size, expense, and reliance on external microwave sources.
In this paper, we propose a novel linear accelerator concept that integrates a high-power microwave source directly into the...
A compact TM020-mode radiofrequency (RF) cavity has been proposed and studied by KEK and RIKEN for storage ring of Nanoterasu facility. However, the leakage power of the accelerating mode into the coaxial slots is an issue to limit its performance. This paper presents an improved TM020-mode cavity in order to solve this issue. To protect the operating mode and reduce its leak-age, a choke...
The SEALab facility in Berlin is home to an R\&D superconducting radio-frequency (SRF)photoinjector setup and beamline. Designed to support multiple varied applications - ranging from Energy Recovery Linac (ERL) to Ultrafast Electron Diffraction (UED) and Electron-Beam Water Treatment (EBWT) - SEALab requires flexible, high-precision tuning to support these diverse beam modes. These...
The CLEAR (CERN Linear Electron Accelerator for Research) facility delivers to a wide user community a 200 MeV electron beam with highly flexible parameters.
Running conditions range from single-bunch to multi-bunch operation, with bunch charges from 10 pC to 1 nC, bunch durations from 100 fs to tens of ps, and
includes tunable momentum (30 MeV/c to 220 MeV/c).
Such a variety of beam...
The properties of the photoemitting electron sources are the determining factors contributing to the performance of the most advanced electron accelerator applications such as particle colliders, X-ray free electron lasers, ultra-fast electron diffraction and microscopy experiments. Therefore, low mean transverse energy (MTE), high quantum efficiency (QE) along with long operational lifetime...
Heavy ion therapy (HIT) is a transformative approach to cancer treatment offering precision to target tumors minimizing damage to surrounding normal tissue cells. This study explores the feasibility of applying the particle-in-cell (PIC) method to evaluate and optimize the clinical therapy of HIT. The PIC models ion beams & dynamics by tracking their motion with electromagnetic interaction and...
The International Linear Collider (ILC) is a next-generation electron-positron collider based on the superconducting linear accelerator. Many positrons are required for the ILC because beams are not reused in linear colliders. Therefore, the ILC electron-driven (E-driven) positron source system should be designed to optimize efficient positron generation. In this study, we optimize the...
Ion accelerators use electron cooling to improve luminosity and beam lifetime. However, extremely low momentum spread in a cold beam weakens Landau damping, enabling the development of instabilities and potentially decreasing lifetime. To combat this, the NICA Booster electron cooling system allows to generate electron beams with oscillating energy to increase the momentum spread in ion beams....
Ångström and attosecond represent fundamental spatiotemporal scales for studying electron dynamics in various materials. Recently, high-power attosecond hard X-ray pulses have been successfully demonstrated at the European XFEL using the self-chirping operation mode. However, the current process heavily depends on manual tuning by experienced operators, which is time-intensive and less...
FCC-ee luminosity optimization relies on measuring realistic signals from Bhabha scattering, beamstrahlung, and radiative Bhabha photons. Initial assessments of beamstrahlung signals examine the change in luminosity, beamstrahlung power and vertex detector hits in response to waist shifts, vertical dispersion and skew coupling at the collision point. These ongoing studies aim to extract...
Developing medical accelerators for clinical use presents significant challenges, particularly for FLASH radiotherapy, where specific beam parameters are essential to activate the FLASH effect. At Sapienza University, a new electron FLASH LINAC is being developed, designed to deliver FLASH electrons and adaptable for very high-energy electron (VHEE) applications. This work focuses on...
Muon colliders promise an efficient path to a multi-TeV energy collider facility. In the greenfield study, the final stage of the acceleration chain is planned as a series of four rapid-cycling synchrotrons (RCS). In each RCS, the RF systems are divided into several sections and shared by the two counter-rotating muon bunches. The accelerator requirements are driven by the need to preserve a...
Intra-beam scattering (IBS) has recently gained significant interest in the community of free electron lasers (FELs), as it is believed to produce an increment in the sliced energy spread (SES), which is detrimental to FEL performance. To control and contain this phenomenon, it is important to include IBS in the design phase of an FEL through appropriate numerical simulation. Most existing...
Cavity beam position monitors (CBPMs) are very high-precision devices that, in recent years, have progressed from experimental equipment to standard linac diagnostics in many prominent facilities, most notably free electron lasers. However, the high sensitivity of these devices comes at the cost of a limited measurement range, even with high dynamic range electronics. Furthermore, CBPMs need...
The CERN Proton Synchrotron Booster (PSB) delivers a wide variety of high-intensity and high-brightness proton beams to several destinations, including operations at the Large Hadron Collider (LHC) and various fixed-target experiments. Following the Long Shutdown 2 (LS2) upgrades, discrepancies between beam measurements and macro-particle simulations were observed, highlighting the need for a...
Beam stacking is a key advantage of Fixed Field alternating gradient Accelerators (FFAs) for high-intensity applications. During stacking, one beam is stored as a coasting beam at the extraction energy while another, incoming beam is accelerated. However, the beam loss mechanism termed RF knockout can occur during stacking and undermine gains in extracted beam current. The accelerating RF...
High current linear accelerators require the precise alignment of accelerating cavities to maintain a high beam quality. The PERLE (Powerful Energy Recovery Linac for Experiments) injector cryomodule is composed of four single-cell cavities, each of which can be independently tuned to allow greater control of the beam at this crucial point. Misalignments can lead to perturbations in the beam...
We conducted time-of-flight (TOF) measurements to characterize the spectrum of a quasi-monoenergetic neutron beam driven by a 30-MeV proton cyclotron at the National Atomic Research Institute in Taiwan*. Neutrons were produced by irradiating 30-MeV protons onto a 1-mm-thick beryllium target. The developed TOF spectrometer comprised two 2-inch EJ-309 organic scintillators positioned 200 mm from...
We study the coherent synchrotron radiation instability in a novel synchrotron light source concept, steady-state microbunching storage ring.
Xsuite is a collection of packages developed to simulate beam dynamics in particle accelerators. It includes Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be seamlessly integrated with one another and with both accelerator-specific and general-purpose Python tools, enabling the study of complex simulation scenarios. The Xcoll module, developed for collimation...
The negative impacts of global warming and continuously rising energy costs emphasize a need for sustainable and cost-effective operation also for accelerator facilities. This necessitates optimization of accelerator operation, which then requires a comprehensive profiling of accelerator facilities for power consumption patterns to break down the consumption trends of the whole facility. At...
In recent years, proton and heavy-ion therapy has become increasingly widespread in clinical applications, and has emerged as one of the important means for cancer treatment. The commonly used particle types for this therapy are protons and carbon ions. However, further research into the biological effect has found that helium ions have both high biological effectiveness and small penumbra...
Round beam operation is considered for the planned ultra-low emittance storage ring PETRA IV at DESY, Hamburg. With a natural emittance of 20 pm rad, we evaluate and discuss the advantages and challenges of sharing the emittance between transversal planes. The effect on single and coupled bunch instability thresholds, intra-beam scattering rates and Touschek lifetime of this operation mode are...
Beam-based studies at the LHC injection energy showed that compensation of the strongly driven sextupolar resonance, Qx+2Qy, improved both the dynamic aperture and lifetime of the beam, even when far from the working point and on the far side of the 3Qy resonance. Thus, a reduction of other strong normal sextupolar resonance sources was of interest. In 2024, the first measurements of resonance...
The construction of fourth-generation accelerators, represented by free-electron lasers and diffraction-limited storage rings, is increasingly popular, which sets higher standards for the installation precision of insertion devices. Large-scale insertion devices are installed using two laser trackers, but a rigorous system has not been established. To enhance installation accuracy, we propose...
Magnetic hysteresis and eddy current decay continue to challenge beam quality and operational consistency in multi-cycling machines like the Super Proton Synchrotron (SPS) at CERN. Building on our previous work, this paper presents improvements in the data-driven approach for magnetic field modelling to enhance the reproducibility of SPS dipole and quadrupole fields and thus maintain stable...
The next generation Australian Synchrotron project (AS2), is a proposed 4th generation light source, aims to deliver ultra-low emittance $\sim$100 pm-radians and highly coherent, bright light. Constraints on emittance place tight demands on beam optics correction techniques like linear optics of closed orbit (LOCO) and consequently constraints on accurate estimation of the beam centroid along...
In recent years, several new beam manipulation techniques have been proposed that exploit the crossing of nonlinear resonances and the use of stable islands of the transverse phase space. One such manipulation is a novel approach to slow extraction, which combines particle trapping in stable islands with the use of bent crystals to reduce losses on the extraction septum. As a first step...
This paper presents the design of 750 MHz IH-DTL (Interdigital H-mode Drift Tube Linac) tank, specifically developed to be part of a carbon ion injector for medical treatment applications. These sections provide a highly efficient solution for ion acceleration in the 5 to 10 MeV per nucleon energy range, offering a high shunt impedance. The study includes simulations of electromagnetic fields...
Linear accelerators offer key advantages over circular machines in hadron therapy, such as rapid energy modulation and reduced activation. In this work, we optimized a 3~GHz Side-Coupled Drift Tube Linac (SCDTL) in terms of energy efficiency and the maximum achievable acceleration voltage. Comparative analyses were performed with alternative optimized configurations in TE and TM modes for ions...
In order to fill the gap of X-ray intraoperative radiotherapy technology in China, an X-band standing wave electron linear accelerator with operating frequency of 9.3 GHz was designed for X-ray intraoperative radiotherapy equipment. Using electromagnetic simulation software and beam dynamics simulation software, the outlet energy of the accelerator is 50 keV , and the electron capture...
A novel high-precision beam diagnostic system has been designed for slice emittance and energy spread measurements. The 20-meter diagnostic platform integrates eight quadrupoles, a deflecting cavity, and an energy spectrometer, achieving 100fs temporal resolution in both operational modes through the same beamline layout. The emittance measurement mode provides 50-fold horizontal...
LhARA, which stands for “Laser-hybrid Accelerator for
Radiobiological Applications”, is a novel and flexible facil-
ity dedicated to research in radiobiology. A proton beam
of energy up to 15 MeV can be produced by a laser driven
source, the beam then enters a Fixed Field Alternating (FFA)
gradient accelerator for acceleration to produce a variable ex-
traction energy between 15-127 MeV....
The grid control power supply of the electron gun of the free electron laser (FEL) is a high frequency pulse power supply (HF-PPS), which has a special time structure. The macro pulse repetition frequency of the HF-PPS designed in this paper is 10 Hz, and the micro pulse repetition frequency is 476 MHz.
A collaboration is underway to experimentally demonstrate a novel approach using deflecting cavities to control a particle beam’s longitudinal chirp. While a series of deflecting cavities produces negative chirp, the de-chirping process requires additional modification on the beamline. It has been known that inserting negative drift sections between TDCs enables de-chirping. While the original...
The high current density of HTS material allows electromagnet to induce sufficiently strong magnetic field without relying on any iron core. This permits the design of air-cored cyclotron, where the absence of iron core brings the properties of light-weight and high field reproducibility, making it an ideal medical cyclotron to be installed inside hospitals. However, the cyclotron coil system...
The advancement of broadband terahertz (THz) sources has become increasingly important for various scientific and technological applications, including those in particle accelerators. To enable tunable and flexible THz source development, components capable of selective THz spectrum filtering are essential. In this work, we investigate the use of 3D-printed photonic crystal structures,...
The paper presents a design of an autocorrelator manufactured to measure the duration of infrared picosecond pulses of radiation from the 3rd laser of the Novosibirsk Free Electron Laser facility, as well as the results of testing the autocorrelator when measuring the duration of picosecond pulses in the visible range. The results and future plans for future experiments using developed autocorrelator
In this paper, a multipurpose beam diagnostic system based on a YAG:Ce scintillator is presented. This system was developed in order to measure beam profile, transverse parameters, momentum spectrum, and current of the electrostatic accelerator. The concerning issues in the beam profile monitor design such as image resolution and scintillator temperature distribution have been discussed. In...
A cavity beam position monitor (cBPM) developed by
CEA Saclay was installed at the end of the Accelerator Test
Facility (ATF) linac to evaluate the combined performance
of the monitor and its associated signal processing system.
The setup incorporates a down-conversion architecture inspired
by Royal Holloway, University of London (RHUL),
and employs a digital down-conversion (DDC)...
Effect assessments of high-energy radiations on materials and equipment are expected to become increasingly important in near future space developments. We initiated a project to construct an irradiation environment with high-energy radiations using the electron linear accelerator at Nihon University. The advantages of using this accelerator include the accelerations up to 100 MeV for...
An integrated concept is presented to design a permanent quadrupole magnet (PQM) using tunning modules simultaneously for varying magnetic field gradient. It is anticipated that this design will be utilized for Hefei Advanced Light Facility (HALF) in the future. This design leverages symmetry to achieve both a broad range of magnetic field gradient tunning and a narrow range of precise...
In the scope of the renewal of its injection systems, the ESRF-EBS has decided to implement a new scheme using Non-Linear Kickers (NLK) magnets. These pulsed octupole like magnets are extremely sensitive to any misalignment of the conductors carrying the currents resulting in a degraded magnetic field quality. It is then important to characterize precisely the transverse magnetic fields of...
Slow beam the extraction in synchrotrons is utilized for various nuclear and particle physics experiments and radiology. A beam loss at a septum electrode induces equipment activation and damage. We have been developing a non-destructive electrostatic septum. This septum has multiple electrodes, and those are placed around the outside of the beam. Measuring the 2-D electric field distribution...
Coherent Synchrotron Radiation (CSR) plays a critical role in beam dynamics, significantly influencing beam shape and energy characteristics in particle accelerators. This study investigates the CSR effect through a comprehensive numerical approach, starting from the fundamental Lienard-Wiechert equation and utilizing an explicit, non-approximated methodology to explore beam energy dynamics....
In the SuperKEKB/Belle-II experiment, various new physics searches are conducted by colliding 4 GeV positrons and 7 GeV electrons. Future plans aim to significantly increase luminosity, targeting an integrated luminosity 100 times higher than current levels. However, the realization of this goal is challenged by the phenomenon of "Sudden Beam Loss" (SBL), characterized by the abrupt...
The effectiveness and efficiency of a beam injection scheme is crucial
to achieve high beam intensities while minimizing possible beam losses.
The classical method for injecting from a linac to a synchrotron is
the multi-turn injection. In this scheme the quality of the injected
beam as well as of the injection scheme depends on factors as beam
emittance, type of local bump ramp,...
Coupled bunch instability was observed during beam commissioning of CSNS/RCS. The instability was successfully suppressed by installing sextupoles to control chromaticity. The instability exhibits characteristics influenced by the strength of space charge. We conducted a theoretical study on the effects of chromaticity and space charge on coupled bunch instability and compared results with...
The Advanced Wakefield Experiment (AWAKE) at CERN uses bunches from the CERN SPS to develop proton-driven plasma wakefield acceleration. AWAKE Run 2c (starting in 2029) plans for external on-axis injection of a 150 MeV electron witness bunch. The goal is to demonstrate emittance control of multi-GeV accelerated electron beams. Prior to injection, the electron witness bunch may have to traverse...
Carbon nanotubes (CNTs), known for their versatility as 2D materials, are key to advancing quantum technologies such as qubit fabrication and magnetic data storage. In this study, multi-walled carbon nanotubes (MWCNTs) doped with magnetic impurities (Fe and Co) were exposed to swift heavy ion (SHI) irradiation to explore induced structural modifications. SHI beams transfer energy to the carbon...
Shanghai Synchrotron Radiation Facility/Shanghai Soft X-ray FEL Facility has developed an advanced transverse deflecting structure TTDS (two-mode transverse deflecting structure), using two different rf power sources to deflect beam in any angle. Bandpass filter is a key component in the TTDS, designed to pass low-frequency signals while blocking high-frequency ones. This study uses an...
EuPRAXIA, the "European Plasma Research Accelerator with eXcellence In Applications," represents the next generation of free-electron lasers (FEL). It aims to develop a compact, cost-efficient particle accelerator using innovative wake-field accelerator technology. High-energy physics often demands higher acceleration voltages, and X-band technology offers high gradients in compact structures....
Longitudinal emittance growth is a significant challenge in RF linacs, especially for poorly bunched beams. This stems from particles occupying outer synchrotron oscillation orbits in the LBET, causing unwanted bunch-bunch interactions and degraded beam quality. To address this, we proposed using temporally spaced laser pulses to selectively photo-detach electrons from the longitudinal head...
This study explores the feasibility of using Compton Backscattering (CBS) as a compact source for generating photons in the extreme ultraviolet (EUV) to soft X-ray range, with potential applications in biological imaging and modern lithography. A CBS experiment was conducted at the AWAKE Run 2c test injector (ARTI), where electron bunches, accelerated up to 6 MeV by a high-gradient,...
This theoretical study presents an advanced method for longitudinal phase space tomography in electron storage rings, focusing on reconstructing phase space densities from electro-optical spectral decoding (EOSD) measurements that incorporate crystal geometry effects. The EOSD crystal geometry significantly impacts the measurement signal due to signal integration along its length and...
Symplecticity of the transfer maps is important for reliable evaluation of space-charge dominated beams in accelerators. Unfortunately, most simulation codes that include collective effects, such as space charge, do not use canonical phase-space variables and therefore are not symplectic in the presence of electromagnetic fields. In this paper, we present a numerical method to extract...
The UC Davis Crocker Nuclear Laboratory houses a 72-inch multi-species Isochronous Cyclotron built in the 1960’s. For many years, previously unexplained beam dynamics have been indirectly observed at the cyclotron by both internal and external experimenters. Investigating these effects within the cyclotron, at the bunch level, has proven particularly challenging due to the cyclotron's harsh...
The FCC-ee is a future high-luminosity circular electron-positron collider aiming at achieving unprecedented luminosities with beam energies ranging from 45.6 up to 182.5 GeV. FCC-ee demands precise optics tuning to achieve its ambitious performance goals. This study investigates the tuning and correction of FCC-ee optics under simulated magnet misalignments, with a particular focus on the...
Superconducting radiofrequency cavities made of bulk Nb are reaching their theoretical limits in the maximum accelerating gradient, Eacc, where Eacc is limited by the maximum magnetic field, B, that can be applied on the surface of the accelerating cavity wall. To increase Eacc, the maximum B field, Bmax, which can be applied to the surface, must also be increased. The A15 materials or...
The first experimental observation of a 10 $\mu$m crabbing orbit at 1~$\sigma_z$ induced by head-on collisions with a non-zero crossing angle ($\theta_c$) in a high-energy proton beam at the LHC is presented. This challenging measurement required both the design of a dedicated experiment and a careful calibration and optimization of the beam instrumentation to produce and detect such a subtle...
The microbunching instability (MBI) has long been a persistent issue in high-brightness electron beam transport. The dogleg structure, a dispersive configuration composed of two quadrupole magnets and dipole magnets, has drawn attention in recent studies. It has been pointed out that the Landau damping effect can be enhanced to effectively suppress the microbunching instability by adjusting...
Within the framework of the NIMMS (Next Ion Medical Machine Study) initiative at CERN, a comprehensive design study is being performed for the Helium Light Ion Compact Synchrotron (HeLICS), a compact accelerator for hadron therapy. A key component of this facility is the radiofrequency (RF) cavity. Its proposed design is based on the wideband technology successfully implemented in the CERN PS...
As the High Luminosity LHC (HL-LHC) era approaches, precise control of the accelerator becomes increasingly critical. Machine studies are essential to address the forthcoming challenges and develop correction strategies based on experimental measurements. Although the upgraded inner triplets are not yet available, key features of the HL-LHC optics can still be investigated. This includes...
With the upgrade from PETRA III to PETRA IV the requirements concerning the beam parameters increase. Thus, a special focus is placed on the suppression of higher order modes (HOMs) in the accelerating systems.
An Investigation of the already presented single mode structure showed the emergence of certain higher order modes. These cavity eigenmodes are now examined by evaluating and...
The SRF community has shown that high temperature annealing can improve the flux expulsion of niobium cavities during cooldown. The required temperature will vary between cavities and different batches of material, typically around 800 C and up to 1000 C. However, for niobium with a low residual resistance ratio (RRR), even 1000 C is not enough to improve its poor flux expulsion. The purpose...
Beam stability in the FCC-ee collider is strongly influenced by transverse and longitudinal beam coupling impedance. Developing a flexible and comprehensive impedance model is crucial for accurately evaluating and mitigating instabilities as machine parameters evolve. This study investigates the effect of the FCC-ee collimation system, identifying it as a dominant source of total machine...
Muon colliders offer high-luminosity, multi-TeV collisions without significant synchrotron radiation but require further exploration of muon production, acceleration, cooling, and storage techniques. A proposed 6D cooling demonstrator aims to extend the MICE experiment's validation of transverse ionization cooling to also reduce longitudinal emittance, using bunched muon beams and...
Developing a laser wakefield acceleration (LWFA) scheme by focusing few-TW laser pulses into a thin, dense gas target paves the way for generating high-average-current electron beams driven by a modern high-repetition-rate laser. Our previous study demonstrated that using a sub-mm nitrogen (N₂) gas cell facilitates the routine generation of 10-MeV-scale electron beams from few-TW LWFA with...
National Synchrotron Radiation Research Center (NSRRC) has been advancing its capabilities in producing intense terahertz (THz) radiation from a superradiant free-electron laser (FEL). This system utilizes a photoinjector operating in its velocity bunching mode to achieve ultra-short electron bunches. However, the highest THz frequency from the facility is determined by the shortest achievable...
Betatron radiation is the spontaneous emission of radiation produced by the betatron oscillations of electrons in a plasma during the Laser Wakefield Acceleration (LWFA) process. A high-intensity and ultra-short laser pulse is focused on a supersonic gas jet, simultaneously creating a plasma, injecting, and accelerating electrons, which then emit this radiation. In the framework of the ...
A 2.5 MeV proton injector is being constructed for the IOTA ring at Fermilab to study the interaction of nonlinear integrable optics (NIO) with high space charge beams. Space charge in the transport line from the RFQ to the injection location has a significant current dependent effect on the phase space. Simulation studies to support efficient injection of intense bunches into IOTA are...
The determination of electromagnetic wakefields and their impact on accelerator performance is a longstanding challenge in accelerator physics. These wakefields, induced by the interaction between a charged particle beam and the surrounding vacuum chamber structures, significantly affect beam stability and power dissipation. Accurate characterization of these effects via beam-coupling...
The emission of electrons induced by beam interaction with thin targets is a phenomenon used to measure various properties of particle beams. The main processes of electron emission are: secondary emission, delta electron production and thermionic emission. The last one is not desired, because the intensity of thermionic electrons is not directly related to beam density profile. A common...
Alternative configurations around the ATLAS experiment are investigated aiming to reduce muon rates at forward physics experiments such as FASER and SND@LHC. The Geant4 toolkit BDSIM is used to propagate muons through a model of a section of the LHC and the TI12 tunnel, where the FASER experiment is located. We compare the muon rates in BDSIM with FASER data collected during dedicated tests in...
In plasma-based acceleration, an ultra-relativistic particle
bunch—or an intense laser beam—is used to expel electrons
from its propagation path, forming a wake that is devoid
of electrons. The ions, being significantly more massive,
are often assumed to be stationary. However, both theory
and simulations suggest that any sufficiently dense electron
bunch can trigger ion motion, and its...
Recent results of production of the medical radionuclides 67Cu using a laser wakefield accelerator (LWFA) are presented. This emerging technique utilises powerful, ultrashort laser pulses that are focussed into a gas jet to create a plasma wake that traps and accelerates electrons to very high energies with large accelerating gradients. Accelerated electrons interact with high-Z material to...
The Delhi Light source is a pre-bunched Free Electron Laser facility to generate coherent THz radiation. The electron beam is generated from a normal conducting 2.6 cell RF photocathode (PC) gun operated at 2860 MHz. The RF gun is powered by a high power RF source for a duration of 4 µs at 10 Hz repetition rate. The dark current during the operation of the RF gun has been found to be...
SLAC’s LCLS-II is advancing towards MHz repetition rate attosecond X-ray pulses, creating opportunities to optimize X-ray generation through machine-driven controls and diagnostics via start-to-end simulation. Advanced laser shaping and upconversion techniques at the photoinjector, such as spatial light modulator-based pre-amplifier pulse shaping linked to nonlinear methods such as...
The Novosibirsk Free Electron Laser (NovoFEL) is a facility that consists of three free electron laser (FEL) systems installed on different parts of the Energy Recovery Linac (ERL). These three FELs share the same acceleration system, which enables the generation of high average electron current, typically around 10 mA. Precise measurement of the electron beam parameters is essential for...
A muon linear accelerator is under development at J-PARC for precise measurement of the muon anomalous magnetic moment (g-2) and electric dipole moment (EDM). A disk-and-washer (DAW) structure is employed to accelerate muons from 30% of the speed of light (kinetic energy = 4 MeV) to 70% (40 MeV) at 1296 MHz. The muon DAW consists of tanks accelerating the muons and bridge couplers that couple...
The degree of spin-polarization of electrons photoemitted from unstrained, room-temperature GaAs is usually significantly less than the theoretical maximum of 50%. However, it has been experimentally observed that the degree of electron spin polarization can be increased and even exceed the theoretical maximum when the sample is cooled to low temperatures and in strained-lattice samples. The...
The Muon Collider is a proposed future accelerator for very high energy muon collision. Since muons are heavier than electrons, the synchrotron radiation is negligible at this high energy, allowing to build a compact machine able to deliver Multi-TeV c.o.m. energy collisions, enabling precision measurements of the Standard Model quantities and search for new physics. A challenge of a muon beam...
The accurate assessment of beam quality is the most important aspect in the irradiation facilities operation such as IRRAD at CERN. The Beam Profile Monitor (BPM) sensor system developed for the high-intensity proton beam at IRRAD features minimal particle interaction, improved radiation hardness and higher sensitivity and sampling rate than previous systems. It provides a wealth of...
MedAustron, a synchrotron-based ion therapy centre in Austria, is focused on enhancing cancer treatment performance. A key improvement opportunity lies in the regulation of the main ring bending dipoles, which currently require time-consuming procedures to ensure reproducibility and reliability of the associated magnetic fields (B-Fields). Other therapy centres globally address this through a...
In order to explore an efficient and accurate method for measuring the magnetic field information of accelerator magnets, this paper used the stretched wire system to measure a quadrupole magnet prototype of Hefei Advanced Light Source. In the measurement process, the integral field of the magnet at multiple points was first measured to calculate the magnetic center and multipole components of...
In this study, we investigated the possibility of using a passive dielectric-lined waveguide structure on slice energy spread measurement of femtosecond electron beam. Such diagnostic setup for a 25 MeV electron beam with a duration of a few hundred femtoseconds is simulated using IMPACT-T. The DLW acts as a passive streaker by generating traverse wakefields that deflect the electron bunch....
The radiation damping time is a crucial parameter that depends on the overall magnetic structure of the accelerator. Accurate measurement of this damping time can provide insights into the fidelity of the accelerator model by allowing for a comparison with calculated damping time values. In this study, we present a series of measurements of radiation damping times at the VEPP-4M and VEPP-2000...
The transition from 3rd to 4th generation synchrotron light sources can primarily be characterized by a significant reduction in horizontal emittance. This enables a nearly uniform transverse X-ray beam profile and a brilliance that approaches the diffraction limit. A consequence of the upgrade to Diffraction Limited Storage Rings (DLSRs) is that the traditional emittance measurement...
This work presents techniques for non-invasive transverse profile measurements of high-intensity proton beams using an Electron Beam Profile Scanner (EBPS). The EBPS utilizes low-energy electrons as a probe to analyze the transverse size of proton beams, allowing for potential analysis on a single-bunch basis. Recent upgrades to the Fermilab Main Injector have enhanced beam power on target to...
The injector system of SIRIUS, the brazilian 4th generation synchrotron light source, currently operates with non-ideal injection efficiencies, which may impose limits to future top-up operation modes. Within this context, diagnostic techniques to access beam quality in the injector are essential tools for optimizations. In this work, the MENT algorithm was implemented for the reconstruction...
Charged particle bunches traversing cavity-like discontinuities in the beam pipe at relativistic velocities excite electromagnetic resonant modes that can detrimentally affect the dynamics of trailing bunches. This beam-cavity interaction, characterized in the frequency domain through the concept of beam-coupling impedance, poses significant challenges for beam stability and performance in...
SuperKEKB, located at KEK, is a second generation B-factory, providing beam to the Belle-II experiment. Optics design and simulation of SuperKEKB were previously performed using the optics code SAD, developed at KEK. In this paper, we present a new model of SuperKEKB using the tracking code Xsuite, developed at CERN. An alternative strategy for modelling the interaction region, with...
The ASU cryogenically cooled DC electron gun represents a state-of-the-art platform for testing novel photocathodes at room and cryogenic temperatures. The key electron beam diagnostic tool of this setup is the four-dimensional (4D) phase space reconstruction using the pinhole scan technique. In this work, we use the 4D phase space measurement to extract the Mean Transverse Energy (MTE)...
This study presents a multi-objective optimization scheme for ring cyclotron RF cavities, leveraging a neural network ensemble surrogate model. The cavity geometry is parameterized using Non-Uniform Rational B-Splines (NURBS), with control points and weights as design parameters. To reduce the computational cost of direct eigenmode simulations, an ensemble of neural networks trained using...
Superconducting(SC) radio-frequency(RF) quadrupole (RFQ) integrates the high efficiency of SC technology with the strong focusing and stable acceleration capabilities of RFQ .It is a critical development in next-generation high-performance accelerators.In this study, we present the multi-physics analysis results of a SC RFQ test cavity operating at a frequency of 280 MHz. This test cavity is...
The Landau states of electrons with orbital angular momentum in magnetic fields are important in the quantum theories of synchrotron radiation at storage rings and in many other areas. In realistic scenarios, electrons are often born inside the field or injected from a field-free region, requiring nonstationary quantum states to account for boundary or initial conditions. This study presents...
We recently commissioned the Next GenerAtion Photocathode Laser system (NEPAL) in Hamburg’s XFEL facilities (FLASH and EuXFEL) and at DESY’s Photoinjector Test Facility (PITZ). The system delivers deep UV pulse trains up to 1 ms long at repetition rates as high as 4.5 MHz, with temporal and spatial shaping capabilities and individual amplitude control for bunch charge manipulation. The shaping...
Abstract—A SCILAB Xcos model, developed using SCILAB software version 6.1.1, was implemented to simulate the on-axis radiation intensity of a helical undulator, (undulator parameter= 1, undulator wavelength 5cm, number of periods= 10, device length 0.6 m) with an electron beam (1, 2, & 3 GeV) and beam current as Ib = 3–6 × 10⁻⁶ Ampere. A numerical approach is utilized to perform the undulator...
The Large Hadron Collider (LHC) features a collimation system that protects the machine against beam losses that may induce the loss of superconductivity in some exposed lattice magnets. Thus, optimal cleaning performance must be ensured at all times. The collimation system encompasses more than 100 collimators whose settings are organised in a well-defined transverse multi-stage hierarchy. A...
At CERN’s Low Energy Ion Ring (LEIR), high beam intensities are achieved through phase space painting with up to eight multi-turn injections from the linear accelerator Linac3. After each injection, the beam is cooled and stacked in longitudinal phase space using an electron cooler. During beam operation, key parameters such as RF cavity phases in the linac, the LEIR electron cooler gun...
Additive manufacturing is a now-powerful tool for the rapid prototyping and manufacturing of complex geometries. A proof-of-concept 433 MHz IH-DTL cavity was constructed for direct additive manufacturing of linear accelerator components. The CFD analysis of the initially designed cooling for the drift tube revealed a design with insufficient heat dissipation; this can lead to thermal...
Plasma Wakefield Acceleration (PWFA) is a method of accelerating charged particles using a plasma. It has the potential to produce exceptionally large accelerating gradients on the order of 10’s of GeV/m. The FACET-II test facility accelerates pairs of 10 GeV electron bunches to study the PWFA process—a drive bunch to produce a wake in the plasma in a lithium-ion oven, and a witness bunch to...
The Korea-4GSR is a next-generation diffraction-limited light source designed to provide beam brightness up to 100 times greater than existing facilities. Chromatic aberrations from strong focusing fields in quadrupoles are corrected using sextupoles and octupoles. However, these sextupoles and octupoles introduce nonlinear effects, causing electrons to follow nonlinear trajectories,...
A recent simulation study demonstrated the potential to achieve high 4D-emittance using an emittance exchange (EEX) beamline integrated within a photoinjector. This EEX beamline enabled to achieve the final normalized longitudinal emittance of 0.44 micron, which corresponds to rms bunch length of 7micron and energy spread of 32keV. These results are noteworthy for a 60-MeV photoinjector...
The increased beam intensity during the high lumionsity LHC era is expected to impose tight margins on the operation of the LHC RF system. The larger momentum spread from the injectors together with twice the bunch charge requires a higher RF voltage at injection to avoid beam losses. However, the peak RF power due to the increased beam loading must be kept below the saturation level of the...
Collimators are used to minimize losses and to remove particles that would otherwise get lost downstream and irradiate the machine. Finding the optimal jaw positions is time consuming and with the upstream beam properties changing, the collimation settings would need to be readjusted each time. Therefore, a method to optimize collimator positions and to operate them at full capacity in a short...
Initial experimental investigations of transverse beam splitting, carried out at the CERN Proton Synchrotron, have demonstrated that transverse feedback is highly effective in controlling the characteristics of the transversally split beam. The feedback notably improves the intensity distribution among the beamlets and the emittance of the core, which is the portion of the beam remaining near...
The surface muon beamline at J-PARC provides high-intensity muon beams that are essential for advanced materials science research, particularly in techniques such as muon spin rotation/relaxation (μSR). However, positron contamination in the beam poses a significant challenge by introducing background noise that affects the measurement precision. Therefore, achieving high-purity muon beams is...
China Spallation Neutron Source (CSNS) accelerator complex will employ a new superconducting accelerating section to provide high beam power. To prevent contamination of the superconducting cavity surface caused by sputtering, shedding, or melting of medium materials during interceptive beam measurements, the second phase of the China Spallation Neutron Source (CSNS) superconducting linac...
The National Synchrotron Radiation Laboratory is constructing a 2.2 GeV diffraction-limited storage ring, the Hefei Advanced Light Facility (HALF), using the modified hybrid 6BA lattice, which consists of a total of 20 cells. The synchrotron radiation primarily covers the vacuum ultraviolet (VUV) to soft X-ray bands. To extend the photon energy into the hard X-ray range, two 0.9 T...
A Terahertz (THz) transition radiation monitor, as part of a Bunch compression monitor (BCM), is implemented for longitudinal bunch diagnostics at FELs such as ELBE, FLASH, or EuXFEL. Pulse energy measurements are typically carried out after each bunch compressor stage using coherent diffraction radiation (CDR) in the THz domain and pyroelectric detectors. For higher repetition rates in the...
High-current and low-energy storage ring is an essential part of accelerator for industrial application. However, high intensity poses great challenge to beam stability through collective effects, which can be exacerbated at low energy. In this paper, we present a preliminary study on various collective effects in an application-oriented storage ring. The classical theory is reviewed, and...
Precise measurement of an electron bunch’s longitudinal profile is critical for wakefield accelerators as shaped electron bunches can improve transformer ratios in collinear wakefield acceleration. Electro-Optic sampling of terahertz (THz) radiation from the bunch is one of the most attractive approaches to provide a view into the structure of a relativistic electron bunch due to its...
Gamma-ray induced nuclear physics experiments rely on good signal-to-noise ratio, requiring accurate rejection of detector background. One source of this background is the interaction of cosmic rays with nuclear detectors. The Duke High Intensity Gamma-ray Source (HIGS) is typically operated in quasi-CW mode, requiring background measurements to be conducted independently of data production...
This study presents the development and implementation of a reinforcement learning-based algorithm for real-time luminosity tuning in collider experiments. The algorithm is initially pretrained on historical collider data and subsequently fine-tuned online during experiments. By analyzing accelerator measurements collected over several seconds, the model adjusts the magnetic structure to...
Simultaneous irradiation with mixed helium and carbon ions is being proposed for online range verification in carbon radiotherapy. In 2024, a mixed $^4$He$^{2+}$ and $^{12}$C$^{6+}$ beam, generated by sequential injection of helium and carbon ions into the synchrotron, was extracted successfully for the first time at the MedAustron ion beam therapy and research center. This double injection...
The VEPP-2000 collider is a compact machine, which uses the round-beam concept to achieve high luminosity. Its compact size (24 m in circumference) limits the free space between the magnetic elements. Only 4 BPMs are installed in the ring with large phase advance between them (~2 pi). The key to improve its luminosity is to reduce the power of resonances. The implementing of the RDT...
The Quadrupole Resonator (QPR), originally developed at CERN, is a dedicated radio-frequency characterization equipment for evaluating superconducting material. It employs the calorimetric compensation technique and has a surface resistance resolution of less than 1 nOhm, operaing over a wide range of parameters, such as tem-peratures, resonant frequencies and magnetic fields. As a part of R&D...
The Super Tau-Charm Facility (STCF) is a new generation of electron-positron colliders being planned with a design center of mass energy of 2-7 GeV. In the concept design, the positrons produced by electron targeting are accelerated to an energy of 200MeV by three large-aperture accelerating structures, and then to 3.5GeV by several conventional accelerating structures. The aperture of...
RF breakdown studies are crucial for machines relying on high-gradient, normal-conducting RF accelerating cavities. Searches for breakdown precursors in high-gradient test-stand data have been conducted and highlight the need for a new diagnostic with improved temporal response. Emission of Cherenkov light in optical fibers has been identified as one such diagnostic**, which occurs when...
Previous works on reconstructing the 4D phase space using tomography require optimal selection of projection views to achieve accurate reconstruction. In 2D reconstruction, the process is straightforward, as an object can be evenly sampled by dividing the angles evenly. However, extending this concept from 2D to 4D is not intuitive. This work demonstrates that quaternions can be used to more...
A novel service-based EPICS and new front-end data acquisition method based on a high-availability Kubernetes cluster built on the Proxmox VE platform are proposed in this paper to enhance the performance and stability of the data acquisition system. By deploying EPICS services on the Kubernetes cluster, a new efficient front-end data processing and acquisition method is realized. The data...
TWOCRYST is a machine test designed to demonstrate the feasibility of an in-vacuum fixed-target experiment for the first direct measurement of the magnetic and electric dipole moments of short-lived charm baryons. This setup exploits crystal channeling using two bent crystals. The first one is similar to the existing crystals used in the LHC for beam collimation, deflecting the beam halo...
THz technology being a highly growing and potent field, finds use in a wide range of research applications. Delhi Light Source (DLS) at IUAC, New Delhi is at final stage of commissioning to produce intense and coherent THz radiation based on pre-bunched Free Electron Laser principle. As an addition to the narrowband undulator radiation, broadband Coherent Transition Radiation (CTR) will also...
A circular waveguide lined with a thin dielectric layer enables electron bunches propagating within the structure to radiate light in the (sub-)THz regime. In this work, we perform simulations of low-energy electron beams traversing extended waveguides to analyze the dynamics of beam bunching and lasing within the structure. By exploring the free-electron laser (FEL) process in this context,...
We present an electromagnetic characterization and beam dynamics study of nanostructured plasmonic copper photocathodes for electron gun applications. The study concentrates on photocathodes operated at ultraviolet and infrared wavelengths. Various types of nanopatterns are explored in order to understand how different geometrical parameters affect light reflectance. Optimized nanostructure...
The electron-positron Future Circular Collider (FCC-ee) is a proposed high-energy lepton collider that aims to reach unprecedented luminosity and precision in the measurement of fundamental particles. To fully profit of such performance, it is crucial to keep detector backgrounds under control and operate the machine safely. Due to the high stored beam energy and to a number of complex...
Laser Wakefield Accelerators (LWFA) offer a promising solution for producing high-energy electron beams in compact setups. Beyond obtaining the required energy, the beam quality (emittance, energy spread, intensity) must also be optimized for LWFA to be considered an alternative to conventional accelerators. Achieving precise control of the transverse beam dynamics is one of the key...
Novel acceleration schemes aim to address the need for higher acceleration gradients which enable to minimise the size and costs of particle accelerators. One of these novel accelerator schemes is the dielectric wakefield acceleration (DWA), where an electron bunch is accelerated by the longitudinal wakefields generated within a dielectric lined waveguide by a leading drive bunch with higher...
In ultrafast electron diffraction experiments, the scattering cross-section, q-range, and space-charge effects are critically influenced by the electron beam energy, which is constrained by the high-voltage breakdown. By integrating a 100 kV DC electron gun with a 3 GHz radiofrequency cavity powered with a 400 W amplifier, we demonstrate a net energy gain of up to 31 keV. Here we present...
We have started single electron storage experiments since 2021 at the UVSOR-Ⅲ storage ring with the aim of conducting fundamental research on electromagnetic radiation. At BL1U, which is a beamline dedicated to light source developments, we extracted undulator light in the UV wavelength range into the air and observed its intensity by a photomultiplier tube, as decreasing the electron beam...
The information on phase space in all six dimensions is required for various accelerator experiments. We developed an algorithm based on Convolutional Neural Network (CNN) that can be used instead of the traditional back projection techniques because it is less computationally intensive and has a simple architecture. Our method has shown consistency with the simulation, and we plan to validate...
Transmission Electron Microscopes (TEM) require high voltage DC electron sources, which can quickly grow in size and cost at the higher energies required for standard TEM imaging. We present the progress on a low cost, compact solid-state-driven RF linac to replace high power electron guns in micro-crystal electron diffraction setups. The system accelerates electrons to 50 keV electrons with a...
Highly polarized MeV gamma rays, produced by Laser Compton Scattered (LCS) of a polarized laser with an electron beam, offer a unique probe for basic and applied physics research. As the polarization characteristics of these gamma rays vary with the position of the beam cross section, it is essential to understand the polarization properties when using polarized gamma rays * . However,...
Recently, two SIRIUS beamlines, EMA and PAINEIRA, received their definitive insertion devices (IDs). Both IDs are in-vacuum devices (IVUs), the first of this kind at SIRIUS. Due to the proximity of the IVU cassettes to the electron beam, the spectrum emitted by these devices is highly sensitive to misalignments of the ID magnetic center. Such misalignments can result in photon flux losses,...
Resonant slow extraction is routinely used to provide ion beams to various users. At GSI SIS18, two extraction methods are implemented: quadrupole-driven and Radio Frequency Knock Out (RF-KO) extraction. In either case, delivering a defined beam intensity (spill) without fluctuations or drifts is desired for an efficient beam usage. The Spill Optimization System (SOS) was developed to address...
Non-evaporable Getter (NEG) coating is a breakthrough technology wherein the inner walls of a vacuum chamber are coated with a material that functions as a vacuum pump. This technology is expected to gain widespread adoption across various fields in the future. However, the current coating method, originally developed for long beam ducts, is not adaptable to a wide range of vacuum chamber...
The superconducting cyclotron SC240 is used to accelerate proton beams to 240 MeV for proton therapy. The SC240 is an isochronous 4 sectors compact cyclotron with a central magnetic field of 2.5 T. Particles acceleration is performed under the second harmonic mode of the radio-frequency (RF) system, consisting of two independent cavities located in the cyclotron valleys. Block on the chimney...
The study of beam-cavity interaction is an essential step towards achieving the design objectives of high-intensity storage rings, particularly in the rapidly advancing fourth generation of synchrotron light sources, which rely on the strategy of bunch lengthening with harmonic cavities. Assessing the effectiveness of harmonic cavities typically requires self-consistently solving bunch...
This work examines the dominant coherent head-tail type (< x-z >) instabilities in the vertical plane of the FCC-ee collider, focusing on a mode analysis method with the Circulant Matrix Model (CMM) to assess instability mechanisms under the influence of beam-beam effects and transverse wakefields. While the impact of vertical plane instabilities have been already studied, different...
We propose a phase jump method to improve the electron beam conversion efficiency in FEL oscillator. A fast phase shifter is put between two undulator segments to kick the phase of the electron beam at saturation. The theoretical and simulation results are given based on FELiChEM which is built in Hefei. They indicate that a phase jump value of approximately π at saturation can significantly...
The fast polarization switching of undulator radiation has attracted more and more attention in recent years. Recently, a new method has been proposed for fast polarization switching up to kilohertz of undulator radiation by using magnetic field modulation generated from low-current electromagnetic coils. Through fast switching the power of coils, the radiation spectra of two undulators can be...
The traditional APPLE-KNOT undulator forms composite magnetic fields by superimposing APPLE fields and KNOT fields with the period ratio of 2:3. The APPLE field serves as the main component to approximate the target photon energy, while the KNOT field acts as an additional component to transversely deflect the electron beam away from axis. Variable polarization states can be generated with a...
Cs-Sb compound thin-film photocathodes are an excellent candidate to produce bright electron beams for use in various accelerator applications. Despite the virtues of these photocathodes being known, the mechanics that govern their promising photoemission are not well-understood. Crystalline and other material properties affect the quantum efficiency (QE) as well as mean transverse energy...
The all-optical synchronization system used in many X-ray free-electron laser facilities (XFELs) relies on electro-optical bunch arrival-time monitors (EO-BAM) for measuring the single bunch arrival-time with regards to an optical reference. An upgrade of the established EO-BAM is intended to achieve a sensitivity that enables stable operation with bunches down to charges of 1 pC or...
A 162.5 MHz, optimal beta = 0.19 pure niobium half-wave resonator (HWR) called HWR019 for the superconducting driver linac of the China initiative Accelerator-Driven subcritical System (CiADS) has been designed and analyzed at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). The linac requires 24 HWR019s to accelerate protons from 6.8 MeV to 45 MeV. This paper mainly...
Acceleration by the wakefield in the plasma can provide compact sources of relativistic electron beams of high brightness. Free electron lasers and particle colliders, using plasma wakefield accelerators, require high quality bunches with predictable profile. Previous studies showed that the resonant sequence of electron bunches appears to be unstable due to the destruction of the bunches. In...
Alkali antimonide photocathodes exhibit high efficacy as photoemissive materials in electron sources. This proceeding explores the fabrication of thin, ordered films of sodium potassium antimonide via molecular-beam epitaxy (MBE) at the PHotocathode Epitaxy Beam Experiments (PHOEBE) laboratory at Cornell University. Utilizing a sequential deposition technique, the photocathodes are...
THz sources are typically very limited in power, making high-power sources scarce. One of the most promising THz sources are the Free Electron Lasers (FELs), which can generate high-power THz radiation using an undulator structure. Undulator radiation is an incoherent synchrotron spontaneous emission whose energy is proportional to the number of particles in the beam (𝑁). By longitudinally...
A uniformly moving electron passing through a slab induces electromagnetic
emission known as transition radiation. The generated rays propagate inside
the slab and undergo multiple reflections off the slab boundary. We employ the polarization current method in order to derive the reflectionless
solution for an observed radiation intensity and compare it with that of Pafomov
which accounts...
The synchrotron radiation generated by storage rings offers numerous advantages, including high stability, a broad photon energy range, and the capacity to support multiple users simultaneously. However, one notable limitation is its poor radiation coherence. Achieving coherent harmonic generation (CHG) in storage rings would not only significantly enhance the coherence of the emitted light...
The field of Free-Electron Lasers (FELs) has matured, with advancements prioritizing high repetition rates, full coherence, and an expanded wavelength spectrum. This paper details the establishment of a high-repetition-rate Infrared Terahertz (IR-THz) Free-Electron Laser (FEL) facility at the Hefei Comprehensive National Science Center. This facility is strategically integrated with the...
This study addresses the insufficient focusing force in solenoid focusing devices for low-energy electron accelerators, which leads to beam spot precision issues. A tunable double-ring permanent magnet focusing device based on the Halbach structure is proposed. The use of octagonal magnets replaces traditional sector magnets, avoiding the issue of differing magnetization directions. The...
Multi-bunch instabilities, often driven by narrowband impedance sources such as higher-order modes, present significant intensity limitations in synchrotrons. One approach to mitigate these instabilities is applying a double harmonic radio frequency (RF) system, which can increase the intensity threshold by enlarging the synchrotron frequency spread. In this study, intensity thresholds are...
The collective effects observed in storage rings with high-intensity beams are numerous and diverse. One such effect is that of periodic beam loading of accelerating RF cavities. This effect is contingent upon the impedance of the fundamental mode of the RF cavities and the mode of filling pattern. In a multitude of configurations, the periodic beam loading effect in storage rings leads to a...
The results of Run 24 experiments at Relativistic Heavy Ion Collider (RHIC) for improving luminosity using optics tuning are presented in this study. In the first experiment, MADx matching was used to output magnet strengths corresponding to specific s star movements around Interaction Region 8 (IR8). The corresponding Zero Degree Calorimeter (ZDC) signal was measured in place of luminosity,...
Superconducting radio-frequency (SRF) electron linear accelerators (e-linacs) provide significant advantages over conventional room-temperature accelerators, especially in their capacity to accelerate high-intensity continuous-wave (CW) beams. Recently, the first liquid helium-free (LHe-free) Nb₃Sn SRF cavity was successfully operated at the Institute of Modern Physics of the Chinese Academy...
Ongoing conceptual studies for a 10TeV muon collider identified rapid cycling synchrotrons as major engineering challenge. Due to the muon’s short lifetime of only 2.2µs at rest, normal-conducting bending magnets with field rise rates of well beyond 1kT/s are indispensable to support accordingly fast acceleration cycles. Energies of 100MJ will be interchanged between magnets and capacitor...
Plasma wakefield acceleration in the filament regime can provide wakefields suitable for high-gradient, high-quality positron acceleration while maintaining stability. However, the energy that can be extracted by the positrons is limited. Recent works have proposed accelerating a supplementary electron recovery bunch along with the positron bunch to extract more energy from the wake and...
Determining Yukawa couplings of the Higgs boson is one of the most fundamental and outstanding measurements since its discovery. The FCC-ee, owing to its exceptionally high-integrated luminosity, offers the unique opportunity to measure the electron Yukawa coupling through s-channel Higgs production at 125 GeV centre-of-mass (CM) energy, provided that the CM energy spread can be reduced from...
Single crystal alkali antimonide photocathodes have been shown to produce brighter beams than their polycrystalline counterparts. These single crystal semiconductors require a lattice matched substrate to be grown, but current INFN plugs lack the capability for this growth. To relieve this issue, we modified the INFN plug to hold a disk 1cm in diameter. This allows for studies of a wide range...
Optical frequency comb (OFC) technology provides precise measurement tools for optical frequencies, leading to revolutionary changes in the field of optics.OFCs consist of a series of uniformly spaced spectral lines resembling the teeth of a comb, and they have found widespread applications in timing, precision spectroscopy, and fundamental physics.Extending this technology into the EUV to...
The Taiwan Photon Source (TPS) has been in routine operation at 500 mA since the last season of 2021, utilizing two superconducting cavities, bunch by bunch feedback system, and fast orbit feedback system, along with many technical efforts. The operation of TPS maintains its high reliability and availability. The mean time between failures is more than 190 hours with an availability greater...
Today, new heavy ion accelerator facilities are emerging worldwide, including FRIB in the United States, RAON in Korea, HIAF in China, and FAIR in Germany. While each facility features distinct accelerator configurations, they share a common goal: advancing nuclear science through the acceleration of intense heavy ion beams. Among these, the RIKEN RI Beam Factory (RIBF) in Japan has led the...
Review of nonlinear resonances in accelerators and storage rings; including a discussion of chaos, particle diffusion and dynamic aperture
Liquid metal technology is key to the next-generation high-power hadron facilities. Following early R&D collaboration between Argonne National Laboratory and Michigan State University, FRIB pioneered the technology of liquid lithium thin film and is the first in the world applying such technology in accelerator operations. FRIB uses a liquid lithium film for the charge stripping of high-power...
Achieving high-gradient acceleration is critical to enabling future linear colliders, free-electron lasers, and other compact accelerator applications. The Argonne Wakefield Accelerator (AWA) group has pioneered short-pulse structure wakefield acceleration technology, which has shown remarkable promise for surpassing the long-standing barrier of ~100 MV/m in X-band normal-conducting...
The international linear collider (ILC) is a Higgs Factory, where electron-positrons are accelerated by the linear accelerators using Superconducting RF (SRF) cavities to 125 GeV. In 2013, the GDE, an international organization of researchers, already compiled the TDR. It is currently being studied under the International Development Team (IDT). Especially, from 2023, the ILC Technology...
The utilization of permanent magnets in the design of accelerator magnets has witnessed a surge in prominence, particularly within the realm of advanced light sources. Following pioneering initiatives at SIRIUS and ESRF-EBS, current projects are increasingly embracing permanent magnet technology. Notably, in the case of SLS2.0, over 30% of the magnets in the new storage ring are powered with...
It is about “Development for Various Application at Compact ERL as a high-current CW SRF linac in KEK”. As an introduction, the author will talk about the merit of the superconducting RF (SRF) cavity and also talk about our applied research based on Compact ERL (cERL) in KEK, which uses the Nb superconducting cavity and can make energy recovery operation. The cERL's characteristic using the...
The muon collider concept promises a unique opportunity to push the energy frontier in particle physics. The large muon mass suppresses synchrotron radiation and allows the acceleration and collision of the beams in rings and the use of technology more similar to hadron colliders. Muons are point-like, in contrast to protons, and thus can achieve a similar physics reach with less energy,...
Nb$_{3}$Sn is one of the most promising materials for the next generation of superconducting RF (SRF) cavities. One key advantage is that Nb$_{3}$Sn cavities can achieve high Q-values at 4 K, whereas conventional Nb cavities require cooling to 2 K. This enables the operation of SRF cavities using conduction cooling, thereby eliminating the need for liquid helium, unlike conventional SRF...
Plasma accelerators promise significantly more compact, affordable and greener next-generation facilities, including linear colliders. While high-efficiency and -quality plasma acceleration of electron beams has been achieved, positron beams are much more challenging. The HALHF* (hybrid, asymmetric, linear Higgs factory) collider concept sidesteps the positron problem by accelerating them...
I will discuss potential offered by Energy-Recovery Linacs (ERLs) and particle recycling for boosting luminosity to 1E37 cm-2sec-1 level in TeV-scale electron-positron colliders. ERL-based colliders have promise not only of significantly higher luminosity, but also of higher energy efficiency measured in units of luminosity divided by the consumed AC power. Addition of recycling collided...
CERN has embarked on a new programme of Particle Accelerator Efficiency improvements that is inspired by lessons learned from the last years of operation and by the latest technology advancements. The field of equipment automation is being addressed through a mix of concrete developments and pilot projects. This paper presents the work on preparing a new paradigm of accelerator equipment...
The SuperKEKB accelerator recorded a peak luminosity more than twice that of the KEKB accelerator, but there are various challenges in updating the luminosity beyond that. One of the challenges is to eliminate sudden beam loss (SBL), in which a significant part of the circulating beam is lost in a few short turns. SBLs of the positron ring were investigated and found that the SBLs are...
RF breakdown studies are crucial for machines relying on high-gradient, normal-conducting RF accelerating cavities. Searches for breakdown precursors in high-gradient test-stand data have been conducted and highlight the need for a new diagnostic with improved temporal response. Emission of Cherenkov light in optical fibers has been identified as one such diagnostic**, which occurs when...
The SOLARIS storage ring, Poland’s first synchrotron light source, has marked a decade of successful operation, contributing significantly to scientific research and technological advancement. Commissioned in 2015 and inspired by the innovative design of Sweden’s MAX IV Laboratory, SOLARIS exemplifies the effectiveness of international collaboration in cutting-edge accelerator technologies....
The Electron-Ion Collider, which is currently being designed for construction at Brookhaven National Laboratory, will collide polarized electron beams (5-18 GeV) with polarized hadron beams (41-275 GeV) at luminosities up to 10^34 cm−2 s−1. The electron storage ring will contain about 750 dipoles. These dipoles must fulfill not only complex geometric constraints but also requirements set by...
Compared with conventional radiation therapy, the toxic response of FLASH-RT dose rate is significantly reduced and the irradiation time is significantly shortened, and these advantages make FLASH-RT a hot spot in the current radiotherapy field. This paper investigates the development status of FLASH-RT at home and abroad, summarizes the challenges to achieve its clinicalization, and...
Steady-State Microbunching (SSMB) proposes a novel mechanism for generating high-average-power coherent radiation spanning from THz to EUV, with significant potential for various applications. This paper presents the development of a laser system tailored to serve as the modulation laser for the second phase of the SSMB proof-of-principle (PoP) experiments. To verify the stability of...
The International Muon Collider Collaboration (IMCC) has been formed following the 2020 European Strategy for Particle Physics Update, with the goal of studying the feasibility of a muon collider at a centre of mass energy of around 10 TeV. One of the most challenging sections of a muon collider is the initial cooling before acceleration, due to the necessity to apply intense magnetic and...
It has been attracting attention that the energy chirp, which is formed by the space-charge effect of the electron beam and the beam wake field when the beam passes through the accelerator tube, can be used to generate short-pulse XFELs. Since the energy chirp produced by this phenomenon is such that the energy of electrons in the rear of the bunch is lower than at the front, compression...
SuperKEKB is an asymmetric lepton collider with 7-GeV electron and 4-GeV positron beams. The current vertical beta function (βy) at the collision point is set to 1 mm. Experimental results confirm that reducing βy leads to narrower dynamic apertures in both the horizontal and vertical directions, which in turn decreases the beam injection efficiency. This study presents a numerical...
One of the issues that the AuAu 100 GeV physics program in 2024 in RHIC encountered was background in the sPHENIX MVTX detector, which causes autorecoveries and preventing continuous data taking. Beam studies and track simulations performed to understand the source of the background and potential measures to control it have led to the conclusion that off-momentum particle loss was an issue....
Finding the optimal RF voltage ramp to capture coasting beams in high intensity rings has been the subject of ongoing study for many decades. We are motivated to revisit the topic with a view to capturing coasting, stacked beams in a future high intensity, high power FFA. However, the results have general applicability. We compare various voltage laws including linear, bi-linear and...
The Large Hadron Collider (LHC) at CERN is the world’s most powerful particle accelerator, capable of colliding proton and lead ion beams at energies up to 7 ZTeV. ALICE, one of the LHC’s key experiments, is designed for studying heavy-ion collisions. A proposed fixed-target experiment within ALICE involves directing a portion of the beam halo, extracted using a bent crystal, onto an internal...
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 MBA lattice which has to...
Since synchrotron radiation sources have many advanced characteristics such as high radiation power, high brightness, broad spectral range, transverse coherence, and excellent time structure, they have become powerful tools for exploring microscopic material structures. With the growing demand for industrial researches, several dedicated industrial light sources are under operation or...
A test unit pulser for the proposed NIK (nonlinear in-vacuum kicker) project at TPS (Taiwan Photon Source) was fabricated in order to provide uniform kick strength applying onto the injected bunch train. This newly built flattop pulser gives much improved drive current pulse shape in comparison with previously used half-sine pulser. This flattop pulser will result in high injection efficiency...
The Hefei Advanced Light Facility (HALF) is a diffraction-limited storage ring light source with a beam energy of 2.2 GeV. There are 13 insertion devices (IDs) will be installed in the storage ring, which have severe impacts on the low-energy beam. Especially for the long-period EPU, the non-linear effect can significantly reduce the dynamic aperture of the storage ring. In this paper, the IDs...
Free-electron lasers (FEL) seeded by short radiation pulses can exhibit superradiant behavior. In the superradiant regime, the pulse simultaneously compresses and amplifies as it propagates through the FEL, making superradiance very promising for pushing the performance limits of attosecond x-ray FELs. To date, this regime has been studied in asymptotic limits, but there is no model for how...
In synchrotron light sources, the non-linear magnetic fields and Touschek scattering limit the stability of electron motion, determining the dynamic aperture (DA) and the momentum acceptance (MA). Optimizing both the DA and the MA is crucial to maximize injection efficiency and the beam's lifetime, but it is numerically expensive. We implement recently developed algorithms that speed-up their...
An electron energy measurement based on resonant spin
depolarization has been running permanently at BESSY II
for several years. This high-precision energy measurement
was set up primarily for users of synchrotron radiation for me-
teorological applications from the Physikalisch-Technische
Bundesanstalt (PTB). Recent investigations have led to a
better understanding of the method and the...
The conditioning of room temperature cavities is a long process. Additionally, since the cavity or auxiliary equipment can be damaged, constant supervision or extensive safety precautions are required. To reduce the workload for everyone involved and to increase the efficiency of the conditioning process, it was decided to develop a machine learning algorithm with the goal of fully automated...
At J-Parc, the 500 μs long macro-pulses generated by the LINAC are separated into intermediate-pulses to synchronize it to the frequency of the Rapid-Cycling-Synchrotron (RCS). To secure a stable operation, the knowledge of position and length of those intermediate pulses are crucial, as the pulses need to be adjusted to the RCS frequency. The measurement for this adjustment is done by a beam...
FEL simulation codes are essential tools for simulating various FEL scenarios. Among the algorithms, the orbit-averaged algorithm is the most widely used due to its speed and low computational cost. The averaged algorithm simplifies physics model, so present codes such as GENESIS and SIMPLEX have limitations to model accurate features like FEL polarization and variations in electron beam...
The FCC-ee (Future Circular Collider) is a high-luminosity lepton collider study at CERN. Strong effects from quantum fluctuations, beamstrahlung, and Bhabha scattering limit the expected lifetime to well below one hour. Top-up injection continuously refills the colliding bunches to maximize the integrated luminosity.
The current baseline aims at using conventional on-axis injection and a...
Ångström and attosecond represent fundamental spatiotemporal scales for studying electron dynamics in various materials. Recently, high-power attosecond hard X-ray pulses have been successfully demonstrated at the European XFEL using the self-chirping operation mode. However, the current process heavily depends on manual tuning by experienced operators, which is time-intensive and less...
FCC-ee luminosity optimization relies on measuring realistic signals from Bhabha scattering, beamstrahlung, and radiative Bhabha photons. Initial assessments of beamstrahlung signals examine the change in luminosity, beamstrahlung power and vertex detector hits in response to waist shifts, vertical dispersion and skew coupling at the collision point. These ongoing studies aim to extract...
Currently, a conventional local bump injection system with four pulsed dipole kicker magnets is adopted in the Hefei Light Source II (HLS-II) storage ring to achieve topoff operation. Due to the multipole magnets located between the kickers in the injection section, the local bump injection presents technical challenges in forming a perfect closed
bump, which causes oscillation to the stored...
Beam Dynamic Analysis of An Electron Microtron Using General Particle Tracer.
Since 2015, the National Synchrotron Radiation Center SOLARIS has operated a light source supporting eight experimental beamlines. Following vacuum chamber replacements and beamline upgrades, the total beam lifetime at 400 mA has reached 13 hours in decay mode operation. Regular lifetime measurements are conducted to monitor vacuum quality, residual gas composition, and potential stability...
Muon colliders promise an efficient path to a multi-TeV energy collider facility. In the greenfield study, the final stage of the acceleration chain is planned as a series of four rapid-cycling synchrotrons (RCS). In each RCS, the RF systems are divided into several sections and shared by the two counter-rotating muon bunches. The accelerator requirements are driven by the need to preserve a...
SOLEIL II is an ambitious upgrade project that aims to reduce the horizontal emittance of the SOLEIL facility from 4 nm to 84 pm (to be further reduced to 50 pm by running with round beams). The SOLEIL II lattice will utilise a combination of permanent magnets and electro-magnetic corrector magnets. In the case of beam losses, it is of critical importance to localise the losses to certain...
The Hefei Advanced Light Facility (HALF) which is a green-field diffraction-limited storage ring has a relatively low beam lifetime and very low beam emittance. So it is important to study the beam loss for the HALF storage ring to protect the insertion devices and optimize the radiation shielding. In this paper, a simulation for beam loss from two main mechanisms, beam dump and Touschek...
The Future Circular electron-positron Collider, FCC-ee, is a design study for a luminosity-frontier and highest-energy e+e- collider with a 91 km circumference. In a circular machine, the interactions between the beam particles and the residual gas in the vacuum chamber may degrade the beam quality, potentially affecting the beam lifetime and the collider luminosity, and cause local beam...
In the electron-driven positron source of the International Linear Collider (ILC), positrons are generated through electromagnetic showers by irradiating a target with a 3 GeV electron beam and then accelerated in a positron capture linac in a solenoid magnetic field. Because of the high current multi-bunch beam requirements of ILC, the beam loading effect is one of the important issues. In...
Transverse stabilization of the beam in accelerators is crucial for optimizing any machine’s performance. The most common method for minimizing transverse beam jitter is the Balakin-Novokhatsky-Smirnov (BNS) damping technique. While this method has been successfully implemented worldwide, it has limitations in terms of beam quality preservation and acceleration efficiency, primarily because...
The Future electron-positron Circular Collider (FCC-ee) is a proposed lepton collider for high-energy particle physics succeeding the Large Hadron Collider (LHC). Its ambitious design goals demand excellent orbit and optics control and, therefore, set strict limits on alignment tolerances. One approach to relax the mechanical alignment tolerances is Beam-Based Alignment (BBA), where the offset...
Refining the present longitudinal impedance model is essential for an accurate prediction of beam stability thresholds. Longitudinal loss of Landau damping (LLD) for single bunches were observed in the Large Hadron Collider (LHC). For High Luminosity (HL-) LHC beams, the present stability margin is aimed to be maintained. While coupled-bunched instability has not been detected in the LHC so...
In Korea-4GSR, a beamline utilizing a canted ID is planned to be built. The impact of the electron beam resulting from the canting structure were investigated, and design modifications were implemented to minimize these effects. Simulation results show that the impact on the beam is negligible.
We developed a 6D multi-particle tracking program CETASim in C++ to simulate intensity-dependent effects in electron storage rings. The program can simulate the beam collective effects due to short-range/long-range wakefields for single/coupled-bunch instability studies. It also features the simulation of interactions among charged ions and the trains of electron bunches, including both fast...
Beam stacking is a key advantage of Fixed Field alternating gradient Accelerators (FFAs) for high-intensity applications. During stacking, one beam is stored as a coasting beam at the extraction energy while another, incoming beam is accelerated. However, the beam loss mechanism termed RF knockout can occur during stacking and undermine gains in extracted beam current. The accelerating RF...
High current linear accelerators require the precise alignment of accelerating cavities to maintain a high beam quality. The PERLE (Powerful Energy Recovery Linac for Experiments) injector cryomodule is composed of four single-cell cavities, each of which can be independently tuned to allow greater control of the beam at this crucial point. Misalignments can lead to perturbations in the beam...
The FCC-ee is a collider, proposed after the LHC era, based on a ring of approximately 90 km of circumference. It will have to be able to accommodate beams running at half the z-pole and tt ̅-pole with vertical Interaction point beam size less than 40 nanometer at the z. In the present studies, coherent ground motions are being explored with particle tracking tools such as MAD-X and analytics...
When a microbunched beam is sent to a resonantly tuned undulator it radiates coherent radiation with the intensity propotional to the bunching squared of the beam. According to *, the radiated energy increases with the undulator length. This conclusion, however, is only valid if one ignores the energy spread of the beam (and also the beam angular spread). The finite energy spread smears the...
To understand the risk of damage to the collimator blades and the permanent magnets in Diamond-II, the BDSIM code has been used to model the beam losses. To improve the accuracy, the engineering model and 3D field maps have been used to build the machine model. Energy deposition in the main storage ring components and the fluence of secondary particles (particularly neutrons) have been...
The FLASH facility generates XUV and soft X-ray radiation in two FEL beamlines based on SASE and powered simultaneously by a single superconducting linac. To enable next generation user experiments a series of upgrades is coordinated within the FLASH2020+ project. Upgrades on the linac have been performed in a preparatory 9 month shutdown in 2021/2022 and have demonstrated to deliver an...
A 1.5-m linac is being installed at the hybrid gun’s beamline in UCLA Mithra Laboratory for the advanced accelerator research. A preliminary experiment by using a steering magnet showed the electron beam was accelerated from 4 MeV to greater than 30 MeV. A more precise measurement of the beam energy with a new spectrometer magnet is planned in early 2025 as well as the beam emittance. The...
Over the past year a new beamline dedicated to R&D for electron FLASH cancer radiation therapy and radiation biology was set up at the Photo Injector Test facility at DESY in Zeuthen (PITZ). The beamline runs in parallel to the SASE THz beamline at PITZ and is connected to it with an achromatic dogleg. The dispersion within the dogleg is utilized to install an aperture to scrape off-energy...
Following the successful commissioning of the soft X-ray planar undulator system (SASE3), the European XFEL user community expressed a strong demand to extend the radiation properties and provide the possibility to obtain variable polarization modes. It was therefore decided to build a helical afterburner behind the SASE3 system in collaboration with Paul Scherrer Institute (PSI). The final...
During the Large Hadron Collider (LHC) run in 2024 two beam types were used for physics production with protons. A key difference between the standard 25 ns and the batch compression merging and splitting (BCMS) beams at injection into the LHC, is the smaller transverse emittance achieved with the latter in the injector chain. Despite both beam types appearing indistinguishable in the...
A crucial component for designing particle colliders is the assessment of beam-beam effects at collisions. Particle In Cell (PIC) solvers are popular numerical tools, which solve the Poisson equation for the electromagnetic (EM) potential
$\Phi$ produced by the colliding beam's bunches spread on a discretized grid, and compute the Lorentz force acting on the particles subjected to the...
Xsuite is a collection of packages developed to simulate beam dynamics in particle accelerators. It includes Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be seamlessly integrated with one another and with both accelerator-specific and general-purpose Python tools, enabling the study of complex simulation scenarios. The Xcoll module, developed for collimation...
The insertion devices (IDs) can severely affect the beam dynamics of a storage ring. Recently, a new elliptically polarizing undulator(EPU) is installed in the Hefei Light Source II (HLS-II) storage ring. The effects of this EPU can be modeled using the kick map method. In this paper, we present the kick map of the EPU with vertical mode and how it affects the beam dynamics. Since the HLS-II...
The Dresden Advanced Light Infrastructure (DALI) project at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is a visionary initiative to establish a state-of-the-art light source facility, catering to cutting-edge research in materials science, biology, and other interdisciplinary fields. A cornerstone of this ambitious project is the development of an advanced accelerator lattice tailored to meet...
The SIS100 synchrotron, currently under construction as part of the FAIR project, is set to play a pivotal role in advancing high-intensity ion beam research. Reaching the FAIR design intensities for low charge-state heavy ions, e.g. the reference ion U28+ will, however, be challenging due to limitations of the existing SIS18 synchrotron serving as injector to SIS100. In the long-term, the...
Round beam operation is considered for the planned ultra-low emittance storage ring PETRA IV at DESY, Hamburg. With a natural emittance of 20 pm rad, we evaluate and discuss the advantages and challenges of sharing the emittance between transversal planes. The effect on single and coupled bunch instability thresholds, intra-beam scattering rates and Touschek lifetime of this operation mode are...
Beam-based studies at the LHC injection energy showed that compensation of the strongly driven sextupolar resonance, Qx+2Qy, improved both the dynamic aperture and lifetime of the beam, even when far from the working point and on the far side of the 3Qy resonance. Thus, a reduction of other strong normal sextupolar resonance sources was of interest. In 2024, the first measurements of resonance...
As previously described*, high-intensity beams of ultra-bright light sources present new machine protection concerns by creating high-energy-density (HED) conditions in beam-intercepting components. Simulating these HED conditions required us to develop a method for coupling three codes for particle dynamics (elegant), particle-matter interaction (MARS/FLUKA), and hydrodynamics (FLASH). This...
The electron-positron Future Circular Collider (FCCee) will have a first phase of operation at the Z-pole energy of 45.6 GeV. To reach the target luminosity, a total of 11200 bunches with $2.14 \times 10^{11}$ charges will be used, accounting for a stored energy of 17.5 MJ per beam. Given the small beam emittances, the beam energy density in turn reaches extremely high values. The potential...
In the storage ring of a fourth-generation synchrotron light source such as the Hefei Advanced Light Facility (HALF), a multitude of vacuum elements interact with the beam current, thereby generating beam coupling impedance. This is a crucial factor contributing to beam instabilities and affecting the machine performance. Conducting impedance analysis on a vacuum element-by-element basis,...
Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) is currently investigating the feasibility of upgrading its maximum operating energy using Fixed-Field Alternating-gradient (FFA) recirculating arcs to increase the total number of recirculations of the beam through the pair of LINACs. These FFA arcs will be composed of permanent magnets, with small Panofsky-style multipole...
SRF CW accelerator constructed for Coherent electron Cooling project at Brookhaven National Laboratory frequently demonstrated record parameters using 1.5 nC 350 psec long electron bunches, typically compressed to FWHM of 30 psec using ballistic compression. In this paper we report experimental demonstration of CW electron beam with parameters fully satisfying all requirements for hard-X-ray...
The lepton beams of the Future Circular Collider FCC-ee will store 17.5 MJ of energy per beam during Z mode operation. The damage potential of these beams is an essential input for the design of the machine protection system. In this paper, first, the stored energy and energy density of the FCC-ee beams are reported and compared with the values for the Large Hadron Collider (LHC) and the...
A novel damping ring design and related transfer lines for the FCCee are proposed. The presented damping ring layout is optimized for operation at 2.86 GeV to efficiently cool both electron and positron beams and should cool down the transverse emittance of the positron beams by four orders of magnitude. The system accommodates beam trains consisting of 4 bunches separated by 25 ns, with a...
The RF photoinjector in LCLS-II produces several microamperes of dark current via field emission. While the vast majority of this dark current is collimated before reaching the first cryomodule, a small amount (typically less than 1 nA) is transported all the way to the beam switchyard (BSY) dump. In this contribution, we present the results of a start-to-end model of the transport of the dark...
The TWOCRYST proof-of-principle experiment at the LHC is an initiative to demonstrate the feasibility of a double-crystal setup for fixed-target physics experiments. Such a setup could enable spin precession studies of charmed baryons in the TeV energy range in the HL-LHC era. Major milestones in this project have recently been achieved, including the successful construction and testing of...
By designing a C-type nonlinear magnet, low emittance beam injection is realized on HALF.
To realize the matching of RFQ and DTL, it is expected to place a three-gap rebuncher cavity with a frequency of 162.5 MHz in the MEBT section. The dynamics design parameters of the cavity have been determined, so this paper mainly focuses on the RF design and multi-physics field analysis of the cavity. Modeled in CST, the normal temperature CH-type structure is selected, in order to increase...
The electron gun is a crucial component of various vacuum electronic devices, including electron accelerators and electron microscopes. Prior to fabrication, designing and optimizing its geometry is a critical step to ensure optimal performance. In this study, the design and simulation of an electron gun for a linear electron accelerator are presented. The influence of key parameters on the...
Microbunched electron Cooling (MBEC) is a type of Coherent electron Cooling (CeC), suitable for cooling high energy protons; such an electron cooler can be driven by an energy recovery linac (ERL). The beam parameters of this design are based on cooling 275 and 100 GeV protons at the Electron-Ion Collider (EIC), requiring 150 and 55 MeV electrons, respectively. If implemented, a high energy...
This study presents the design of an isochronous FFAG accelerator in the energy range of 3 to 150 MeV. A numerical method for solving the isochronous field is introduced, ensuring constant orbital frequencies across the energy range. The dynamic aperture was evaluated, multi-particle simulations were conducted to assess the impact of space charge effects on beam stability at different beam...
Shenzhen Superconducting Soft X-Ray Free Electron Laser (S3FEL) is a high-repetition-rate and high-brightness soft X-ray facility under construction. It is designed to support multiple user experiments simultaneously, each requiring different undulator lines and FEL parameters. This capability is made possible by the beam spreader system, which plays a pivotal role in transporting the electron...
Laser-plasma accelerators (LPAs) produce high-quality electron beams with the GeV-level of the energy, the high peak currents and low emittance, making them ideal for compact novel free-electron lasers (FELs). However, the large angular divergence and energy spread of these beams pose challenges for efficient beam transport and overall FEL performance. This study explores the use of an active...
The fourth generation HALF light source is a kind of storage ring light source based on diffraction limit. On the one hand, the shielded bellows in the vacuum system is used to compensate the thermal expansion and cold contraction of the vacuum chamber, and to adjust the longitudinal and transverse offset of the vacuum chamber according to the requirements of installation and collimation, on...
A new 4th Generation Storage Ring (4GSR) will be constructed in Ochang, South Korea, by the end of 2029. A technical design review for the Korea 4GSR was completed at the end of 2023. The storage ring has a circumference of 799 meters and is designed for a maximum current of 400 mA at 4 GeV electron beam energy. The target emittance is below 100 pm-rad, with a calculated emittance of 62...
The Super Tau-Charm Facility (STCF) is an electron-position collider proposed in China. The injector of STCF provides high quality electron and position beams at an energy up to 2.5 GeV at a repetition rate of 30 Hz. The beam transport system is composed of the electron bypass transport line, the transport lines from positron Linac to Damping Ring and from Damping Ring to positron Linac, and...
The FCC-ee injector complex aims to deliver tunable, high-charge electrons and positron bunches for injection into a collider operating at center-of-mass energies from 90 to 365 GeV. The injector complex includes multiple linacs that sequentially boost the energy of the bunches to the booster injection energy of 20 GeV. This work addresses the significant challenges posed by the required beam...
The muon collider has great potential for enabling high-luminosity multi-TeV lepton-antilepton collisions provided low-emittance, high-intensity muon beams can be produced. Ionization cooling is the proposed technique to achieve the required muon beam emittance. The International Muon Collider Collaboration aims to demonstrate the integration and reliable operation of a 6D ionization cooling...
The Electron-Ion Collider (EIC) aims at a luminosity of 10^34 cm^-2 sec^-1. Its Electron Storage Ring (ESR), which will be installed in the existing RHIC tunnel, will store electron beams from 5 to 18 GeV with beam currents up to 2.5 A. The design of the ESR has matured substantially. We will report the design status, including beam dynamics and polarization aspects, value engineering...
We have designed three types of septa—thin septum, thick septum, and DC septum—for the Korea-4GSR project, a 4 GeV diffraction-limited storage ring incorporating a 200 MeV LINAC and booster synchrotron. The thin septum is an in-vacuum pulsed septum magnet, the thick septum is an out-vacuum pulsed septum magnet, and the DC septum is an out-vacuum DC magnet. This presentation focuses...
The adoption of Solid State Power Amplifier (SSPA) is rapidly increasing in major accelerators worldwide, replacing tube amplifiers such as Klystron and IoT. This study aimed to develop a High-Power RF system for Multipurpose Synchrotron Radiation Accelerators and to design and implement a GaN transistor-based SSPA. Through this research, we verified control performance equivalent to that of a...
Optical stochastic cooling (OSC) is a recently demonstrated state-of-the-art method for beam cooling and control. The strength and utility of OSC can be greatly extended by the inclusion of a high-gain optical amplifier in the system. The amplifier is necessarily a bespoke system whose design and implementation are highly constrained by the OSC physics and system design. In this report, we...
In the scope of the renewal of its injection systems, the ESRF-EBS has decided to implement a new scheme using Non-Linear Kickers (NLK) magnets. These pulsed octupole like magnets are extremely sensitive to any misalignment of the conductors carrying the currents resulting in a degraded magnetic field quality. It is then important to characterize precisely the transverse magnetic fields of...
The linear accelerators of the Taiwan Photon Source has been fully operating for more than 10 years. Considering components’ aging issues and a shortage of supply chain due to phase-out parts, an alternative solution for these components with the same functionality must be prepared in case of need in order to ensure the TPS Linac’s smooth operation. In this report, a new 6-axis step motor...
In an effort driven by the requests from different physics experiments at CERN, the CERN ion injector complex is looking to expand its capabilities by providing lighter-than-lead ion beams. Argon and xenon were delivered for NA61/SHINE physics in 2015 and 2017, with xenon also reaching the LHC in 2017. Oxygen is foreseen to be collided in the LHC in 2025, with magnesium, boron and krypton...
The compact ERL has been built in 2013 at High Energy Accelerator Research Organization (KEK) to a test machine of an energy recovery linac. Afterwards, two undulators have been installed in the compact ERL and a first light amplification (free-electron laser: FEL) in mid-infrared range has been observed in 2021. However, the intensity of light has not been achieved to the intensity saturation...
A large momentum acceptance (MA) in 4th generation storage ring light sources is paramount to obtaining a long Touschek lifetime. However, the calculation of MA typically requires computationally expensive tracking simulations thereby complicating, or even disabling, the direct optimization of Touschek lifetime using numerical optimization algorithms. Our recent development of Fast Touschek...
Heavily populated transverse beam tails can be an issue for the operation and the performance of present and future particle colliders. In this respect, the tailoring of beam distributions through transverse halo scraping is a powerful technique for limiting beam losses and maximizing beam lifetime. By doing so, a portion of the bunch intensity is sacrificed, to the benefit of a reduced bunch...
A dual-purpose structure has been developed for the NICA collider accelerating heavy multiply charged ions and light polarized nuclei of protons and deuterons. For heavy multiply charged ions, it is necessary to solve the problem of intrabeam scattering, which requires minimal modulation of the envelope and dispersion function. For light particles, the problem of crossing transition energy...
The Ring Electron Cooler is one option to provide cooling to the Electron Ion Collider’s 275 GeV proton bunches. Using traditional electron cooling this racetrack shaped storage ring uses one straight section to cool the protons and the other one to enhance the radiation damping of the electrons using 2.4 T wigglers. These sections comprise the majority of the ring and are connected by short...
The electron-ion collider (EIC), under design at Brookhaven National Laboratory, will consist of two storage rings for collisions of polarized electron and hadron beams. Dynamic aperture (DA) of 10 sigma is required in the electron storage ring (ESR) for the design beam energies from 5 GeV to 18 GeV to ensure an adequate beam lifetime. The DA is limited by chromatic and error effects in a...
Echo-enabled harmonic generation (EEHG) has been proposed as a seeding method for free-electron lasers but can also be employed to generate ultrashort radiation pulses at electron storage rings. With a twofold laser-electron interaction in two undulators ("modulators"), each followed by a magnetic chicane, an electron phase space structure with high harmonic content is produced, which gives...
Crab cavities, operating at 197 MHz and 394 MHz respectively, will be used to compensate the loss of luminosity due to a 25 mrad crossing angle at the interaction point in the Electron Ion Collider (EIC). Both cavities are of the RF Dipole (RFD) type. To meet the stringent impedance requirements for beam stability and quality, the cavity design must incorporate strong Higher Order Mode (HOM)...
Electron beam and laser-Compton X-ray parameters stabilization simulation study at KEK Laser-Undulator Compact X-ray facilityis a normal conductivity multi-bunch electron linear accelerator devoted to develop an intense monochromatic source of laser-Compton X-ray for tomography applications.
The electron beam parameters absolute values and its stability were simulated at the ASTRA tracking...
The Future Circular Collider (FCC), in its leptonic configuration has been chosen by CERN as main proposition for the next high-energy collider. This project aims to achieve luminosities one to two orders of magnitude higher than ever. Feasibility studies have led to the definition of tolerances on magnet imperfections and correction strategies. This is crucial for ensuring the performance of...
During 2022 and 2023 LHC optics commissioning, it was observed that at low-beta small changes in the beam-energy could generate substantial perturbations of the linear beam optics, requiring re-commissioning of local corrections in the experimental insertions. This issue may become even more significant at the very low beta anticipated for operation in the High Luminosity LHC (HL-LHC)....
Enhanced self-seeding (proposed in Phys. Rev. Lett. 125, 044801, 2020) is a concept for more stable, laser-like XFEL operation. The principle of enhanced self-seeding lies in strong lasing on the current spike in the SASE section, and picking the seed pulse with the flat, lower current portion of the beam. Recently, we performed experimental studies of this scheme with the existing hard x-ray...
The existing synchrotron SIS18 will serve as an injector for the FAIR (Facility for Antiproton and Ion Research) complex in booster mode operation. FAIR requires high-intensity beams, placing stringent demands on increasing beam currents in SIS18. Operational experience has shown that significantly increasing beam intensity in SIS18 necessitates both a higher current from UNILAC and improved...
Across its energy range, the beam lifetime at the Future Circular Collider $e^+e^-$ (FCC-ee) will be dominated by radiative processes occurring as a result of the beam-beam collision, namely by beamstrahlung and small angle radiative Bhabha scattering. Although approximate analytical expressions exist for estimating the lifetime, it is most accurately evaluated by performing multiparticle...
Error analysis and estimation of accuracy in the experiment on precise mass measurement of Y(1S)-meson on the VEPP-4M with KEDR detector collider was presented. The resonant depolarization technique with laser polarimeter was used for beam energy calibration.
This paper presents a comprehensive evaluation of the relationship between titanium coating thickness and thermal deposited power in the ceramic chambers of the Nonlinear In-vacuum Kicker (NIK) system, a critical component in synchrotron light sources. The study focuses on optimizing the coating thickness to minimize magnetic field attenuation and thermal load, thereby enhancing the...
This study explores the feasibility of using Compton Backscattering (CBS) as a compact source for generating photons in the extreme ultraviolet (EUV) to soft X-ray range, with potential applications in biological imaging and modern lithography. A CBS experiment was conducted at the AWAKE Run 2c test injector (ARTI), where electron bunches, accelerated up to 6 MeV by a high-gradient,...
Several laboratories and facilities recently started joined efforts towards the realization of a python accelerator middle layer (pyAML) for control, tuning and optimization. This software is intended as a successor to matlab middle layer (MML), inheriting its features but also expanding to new ones (e.g., nonlinear optics and machine learning tools). Presently, several codes are available...
The design of lattice candidates for the Taiwan Photon Source (TPS) upgrade is under investigation, focusing on Multi-Bend Achromat (MBA) and Hybrid Multi-Bend Achromat (HMBA) configurations. A 5BA lattice, which offers relaxed hardware requirements, can achieve a natural beam emittance in the hundred pm-rad range for a 3 GeV storage ring. The 6BA configuration shows promise in achieving phase...
Recently, the Hard X-ray Self-Seeding (HXRSS) setup at the European XFEL has been successfully demonstrated, achieving routinely pulse energies in the seeded signal of several hundreds of microjoules at various wavelengths. However, the shorter wavelengths pose a challenge to the impulse response of crystal, limiting output radiation and spectral performance. To address these challenges, a...
Many different techniques have been investigated at Diamond for optimising sextupole strengths*. One method not previously studied is to exploit the null space of the chromaticity response matrix. By performing a singular value decomposition (SVD) of the chromaticity response matrix, combinations of sextupole strengths are identified which alter the nonlinear lattice whilst keeping the...
The Future electron-positron Circular Collider, FCC-ee, aims at high-precision particle physics experiments with beam energies from 45.6 to 182.5 GeV, corresponding to the Z-pole up to above the top-pair-threshold. These goals demand, among others, a precise knowledge of the center-of-mass energy and, hence, the beam energies. By depolarizing previously polarized pilot bunches and recording...
The proposed FCC-ee machine is a high-energy, high-intensity and high-precision lepton collider which will require to reduce drastically the differential motions of its two beams at the interaction points (IPs). All undesirable effects on the beam parameters must be analysed in detail, especially in the vicinity of the IP but also along the collider. To assess the beam effects due to...
Optics tuning and correction in the Interaction Point (IP) region of the FCC-ee is critical for achieving the target luminosity. By utilizing dedicated IP tuning knobs, lattice errors at multiple IP's are corrected to restore the design optics, enabling dynamic aperture studies on the fully corrected lattice. These studies, conducted using the pyAT optics code, assess the impact of corrections...
The FCC-ee is a future high-luminosity circular electron-positron collider aiming at achieving unprecedented luminosities with beam energies ranging from 45.6 up to 182.5 GeV. FCC-ee demands precise optics tuning to achieve its ambitious performance goals. This study investigates the tuning and correction of FCC-ee optics under simulated magnet misalignments, with a particular focus on the...
The secondary radiation fields generated by synchrotron photons pose a significant challenge for equipment in high energy electron and positron storage rings like the Future Circular Collider (FCC-ee) at CERN. The annual ionizing dose can reach MGy-levels in the FCC-ee tunnel and requires the design of a dedicated radiation shielding enclosing the photon stoppers in dipoles. In this paper, we...
CERN’s Future Circular Collider (FCC) comprises a ~91 km circumference lepton collider and its injector complex. This contribution summarises the feasibility studies performed for the various kicker systems needed to transfer the beam between the different machines. The individual system requirements are reviewed, recent changes are highlighted, and the chosen conceptual design is outlined....
In the context of ongoing research for a future muon collider, one of the primary challenges is the efficient production and cooling of muons. To address this, a proposal is being explored to construct a demonstrator at CERN for testing a cooling cell. This demonstrator would include a target and focusing system, a chicane around a dump, and a cooling channel. A potential site for this...
A phase shifter collocated with an undulator is an efficient method to enhance the lasing performance of free-electron laser (FEL), particularly for seeded FEL. Dalian Coherent Light Source (DCLS) is a seeded FEL facility operating in high-gain harmonic generation (HGHG) mode to produce fully coherent vacuum ultraviolet laser. To achieve high FEL lasing performance, five phase shifters are...
A new lattice for the EBS is proposed as preliminary candidate for the next generation ESRF storage ring. This new optics would feature lower emittance, matched optics at all ID, transparency conditions for insertions and overall a net gain in brilliance coherence and flux. Due to the reduced dynamic aperture, on-axis injection with a low emittance beam would be a requirement in order to...
FLASH, the XUV and soft X-ray free-electron laser at DESY, is currently undergoing the 2nd of two long upgrade shutdowns within the FLASH2020+ project. The 1st half of 2024 was dedicated to user operation. The upgrade shutdown started in June 2024, and we plan to come back to beam operation in August 2025.
Here we will discuss the operational highlights of the first half of 2024,
briefly...
The Energy Recovery Linac (ERL) combines the high repetition frequency of synchrotron radiation with the high brightness of FELs, showing great potential. Despite recent breakthroughs, the electron beam quality still fails to meet the requirements for driving short-wavelength FELs.
The method combining ERL with Angular Dispersion-induced Microbunching (ADM), proposed by the Shanghai Light...
The polarization of the gamma-ray beam plays a critical role in experimental photonuclear research by probing angular momentum. For example, the multipolarities of the 80Se(g,n)79Se reaction can be assigned by measuring cross-sections relative to the plane of polarization*. Dynamic control over gamma beam polarization will open new opportunities in nuclear research, particularly by allowing...
We report the progress made on alternative optics namely low beta and low emittance cases for the DIAMOND-II storage ring upgrade. The results of optimizations of both linear and nonlinear optics as well as impacts of insertion devices on lifetime and dynamic aperture and injection scenarios will be reported.
This study explores the feasibility of generating high-energy photons, reaching up to 150 GeV, at the FCC-ee booster through inverse Compton scattering. The proposed scheme utilizes a laser within a Fabry-Perot cavity, enabling high repetition rates while minimizing recoil effects during individual collisions. This approach supports the potential use of the FCC-ee booster as a high-energy...
Generating few- or sub-femtosecond radiation pulses in a free-electron laser (FEL) requires precise control of the longitudinal phase space density of the driving electron bunch, as the FEL process depends strongly on the bunch current and energy spread profile. In an experiment conducted at FLASH in Hamburg, Germany, an energy modulation with linearly changing amplitude is imprinted onto...
The High Luminosity Large Hadron Collider (HL-LHC) presents significant collimation challenges due to its high stored beam energy. An effective collimation system is critical for ensuring stable operation, protecting the superconducting magnets and minimizing background to the experiments. This paper examines the current baseline collimation configuration and potential changes to the...
With the upgrade from PETRA III to PETRA IV the requirements concerning the beam parameters increase. Thus, a special focus is placed on the suppression of higher order modes (HOMs) in the accelerating systems.
An Investigation of the already presented single mode structure showed the emergence of certain higher order modes. These cavity eigenmodes are now examined by evaluating and...
The international linear collider (ILC) is a Higgs Factory, where electron-positrons are accelerated by the linear accelerators using Superconducting RF (SRF) cavities to 125 GeV. In 2013, the GDE, an international organization of researchers, already compiled the TDR. It is currently being studied under the International Development Team (IDT). Especially, from 2023, the ILC Technology...
The electron positron Future Circular Collider (FCC-ee) is considered the primary contender for the next major particle accelerator within the European Strategy for particle physics, aiming to achieve unprecedented luminosities to enable precise measurements of Z, W, and H bosons along with the top quark. Despite its potential, the FCC-ee project faces significant operational and design...
The Future Circular Collider for electron-positron collisions (FCC-ee) is a proposed next-generation particle accelerator aimed at achieving high luminosity and precision for fundamental particle physics experiments. Its performance is sensitive to environmental factors such as ground motion, which can induce vibrations and misalignments in critical accelerator components. This paper presents...
Muon colliders offer high-luminosity, multi-TeV collisions without significant synchrotron radiation but require further exploration of muon production, acceleration, cooling, and storage techniques. A proposed 6D cooling demonstrator aims to extend the MICE experiment's validation of transverse ionization cooling to also reduce longitudinal emittance, using bunched muon beams and...
Accurate determination of magnet centres seen by beams is the key to a successful commissioning of a particle accelerator storage ring. In this paper, several techniques to improve the beam-based alignment for a circular accelerator storage ring are introduced. Firstly, a formula to propagate the uncertainties from linear fitting is given. Secondly, a reliability weighted averaging technique...
FLASH is an XUV and soft X-ray free-electron laser (FEL) facility that comprises a superconducting linear accelerator with a beam energy of up to 1.35 GeV which drives two FEL beamlines in parallel and the plasma wakefield accelerator experiment FLASHForward. Within the upgrade program FLASH2020+, a laser heater was installed upstream of the first bunch compression chicane to mitigate...
Synchrotron radiation light sources normally operate at a low coupling between the transverse planes in order to achieve flat beams and produce high peak brilliance. Instead, operating at a high coupling has other advantages such as smaller emittance degradation due to intra-beam scattering, improved Touschek lifetime, and lower sensitivity to vibrations of the photon beam. Moreover, it has...
In an FEL oscillator with a planar undulator, odd harmonics appear as either spontaneous emission or as linear and nonlinear harmonics associated with the FEL pulse evolution. Additionally, misalignment of the electron beam or the resonator can lead to off-axis gain, generating even harmonics. We conducted an experiment at KU-FEL, operated at 5 µm, to measure the 6th- and 7th-harmonic spectra...
The Future Circular Collider of electrons and positrons (FCC-ee) is designed to achieve high luminosity at center-of-mass energies ranging from the Z boson peak to the top quark threshold. During the commissioning phase, specialized optics are essential to accommodate the dynamic needs of machine tuning and beam stabilization. This paper investigates the role of sextupoles in the various...
The GSI Facility consists of several accelerators, offer-ing the distinctive capability to provide different ion beams with varying characteristics to a range of experi-ments simultaneously. In order to facilitate the monitor-ing of machine performance across diverse beam produc-tion chains and experiments, a Key Performance Indica-tor (KPI) metrics has been introduced. The CRYR-ING@ESR team...
Currently, SuperKEKB faces the challenge of sudden beam loss (SBL), which occurs with almost no prior sign. The causes of SBL are not fully understood. A damaged collimator reduces its ability to suppress beam background noise compared to an undamaged one. In cases that the beam background noise reduction decrease, it is necessary to stop the operation and replace the collimator jaw....
During operation for luminosity production, the LHC runs with very strong Landau octupoles to ensure the collective stability of the beams. A disadvantage of this is that these octupoles can drive resonances which can be detrimental to beam lifetime. Recently, a special optics configuration has been utilised to reduce the impact of the main octupoles on lifetime. This design relies on...
The current achieved highest luminosity at SuperKEKB is only one-tenth of the design value, and beam injection is one of the most serious issues in achieving the target luminosity. Recent operations in both the HER and LER rings have shown insufficient injection efficiencies and detector backgrounds. The achieved injection efficiency falls short of the required level, sometimes leading to...
Attosecond x-ray pulses play a crucial role in the study of ultrafast phenomena involving inner and valence
electrons. Especially isolated attosecond pulses with high photon energy and high peak power are of great
significance in single-shot imaging in the soft x-ray region, life sciences, and attosecond pump-probe experiments. In modern accelerators, laser manipulation of electrons can be...
In this study, we explore the application of laser-driven Compton backscattering (CBS) as a method to precisely adjust and regulate the intensity of colliding particle bunches in the Future Circular Collider (FCC-ee). Maintaining a tightly controlled charge balance between collision partner bunches within a 3–5% tolerance is critical for mitigating the impact of beamstrahlung on bunch length...
Precise determination of the center-of-mass energy at the Future Circular Collider (FCC-ee) operating at the Z and W resonance energies relies on resonant spin depolarization techniques, which require a sufficient level of transverse beam polarization in the presence of machine imperfections. In this study, the FCC-ee lattice is modeled and simulated under a range of realistic imperfections,...
The HALF storage ring is a 2.2 GeV diffraction limited storage ring, with radiation photons mainly in the vacuum ultraviolet (VUV) to soft X-ray wavelength ranges. In order to meet the demand for high brightness hard X-rays, HALF plans to replace 0.9 T normally bending magnet with 6 T superbend. This paper reports two lattice design schemes, replacing one bend and two bends respectively. The...
SLAC’s LCLS-II is advancing towards MHz repetition rate attosecond X-ray pulses, creating opportunities to optimize X-ray generation through machine-driven controls and diagnostics via start-to-end simulation. Advanced laser shaping and upconversion techniques at the photoinjector, such as spatial light modulator-based pre-amplifier pulse shaping linked to nonlinear methods such as...
The ESRF booster has been built more than 30 years ago as injector of the first ESRF storage ring and it is still used to inject in the EBS. Several components of the booster have been updated in the years and it is now operated off-energy and with emittance exchange at extraction, however the lattice has not been modified since the '90s. A project to reduce the equilibrium emittance and...
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...
SuperKEKB is a double ring collider consisting of a 7 GeV electron ring and a 4 GeV positron ring with a circumference of 3 km built 11 m below the ground level.
SuperKEKB was constructed by reusing the KEKB tunnel, which was originally excavated for TRISTAN accelerator in early 1980s. SuperKEKB utilizes “large angle nano-beam scheme,” where two low emittance beams collide with a large...
For diffraction-limited storage rings, the triple radio-frequency (RF) system has been proposed to achieve further bunch lengthening or to meet specific requirements for longitudinal injection. The choice of RF cavity parameters for the triple RF system has a significant influence on the longitudinal beam dynamics. Macroparticle tracking simulation is commonly used to accurately analyze this...
The intra-beam scattering in high charge state intense heavy ion beams is a problem worth considering. With the help of controlling the longitudinal distribution of the ion beam, it may be possible to alleviate the ion beam loss and to improve the ion beam lifetime caused by intra-beam scattering. Unlike the traditional cooling process of direct current electron beams or longitudinal uniform...
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...
The influence of longitudinal wakefields on the beam dynamics in electron-positron colliders, particularly their role in beam instabilities such as Transverse Mode Coupling Instability (TMCI) and other transverse-longitudinal effects, necessitates a robust approach to accurately model these effects. This work focuses on the implementation of wakefield effects in the Circulant Matrix Model...
The Muon Collider is a proposed future accelerator for very high energy muon collision. Since muons are heavier than electrons, the synchrotron radiation is negligible at this high energy, allowing to build a compact machine able to deliver Multi-TeV c.o.m. energy collisions, enabling precision measurements of the Standard Model quantities and search for new physics. A challenge of a muon beam...
At HZB / BESSY II the first in-vacuum APPLE II undu-lator is under construction. The design includes three magnet arrays for each of the four magnet rows for an efficient force compensation. The support and drive sys-tem has been delivered. Currently the magnets for the 10-period prototype are fabricated by Vacuumschmelze. Within the project IVUE32 a new soldering technique based on reactive...
Electron storage rings based on multi-bend achromat (MBA) lattice can achieve very low natural emittances. Several fourth generation light sources have been built and operating, the natural emittances of which are a few 100 pm or even lower than 100 pm, providing high brightness photon beams to users. Since the lattice of MBA storage ring tends to be highly compact, the field of a magnet may...
The muon collider represents a transformative approach in particle
physics, offering a pathway to achieve high energy and luminosity with
reduced environmental impact compared to other collider technologies.
Central to its feasibility is the development of advanced magnet systems
capable of supporting the stringent requirements of muon production,
acceleration, and collision. The key...
The ALS-U project, aimed at enhancing the Advanced Light Source’s capabilities, is currently in the manufacturing, assembly, and construction phases. The construction of the accumulator, a crucial component, is nearing completion, with commissioning expected towards next year. ALS-U promises to deliver diffraction-limited performance in the soft x-ray range by significantly reducing the...
The MAX IV 3 GeV storage ring in Lund, Sweden, was the first implementation of a multibend achromat (MBA) lattice fourth-generation light source. Since it started delivery of light in 2016, three succeeding MBA-based rings and variants have come on-line: ESRF-EBS, Sirius and APS-U. Several others are being planned, designed, built or commissioned. All of these capitalize on the MBA concept and...
Aramis, the hard-X-ray undulator line at the free-electron laser SwissFEL at the Paul Scherrer Institute, has been in user operation at full beam energy since the end of 2018. After steady improvements of the performance until 2022, it proved difficult to maintain the achieved performance level in recent years. Now, after a systematic re-alignment and recalibration of the undulator line and a...
SuperKEKB, located at KEK, is a second generation B-factory, providing beam to the Belle-II experiment. Optics design and simulation of SuperKEKB were previously performed using the optics code SAD, developed at KEK. In this paper, we present a new model of SuperKEKB using the tracking code Xsuite, developed at CERN. An alternative strategy for modelling the interaction region, with...
For the FCC-ee collider it is planned to, in regular intervals (minutes), measure the average beam energy of the circulating electron and positron beams with a relative precision of $10^{-6}$ or better, using the method of resonant depolarisation with pre-polarized pilot bunches. In this article, we study basic systematic effects and ultimate uncertainties that may arise in this kind of...
High-dimensional phase space reconstruction is an important tool for achieving precise beam simulation and optimization. We adopt a machine learning approach with a polarizable transverse deflecting cavity to reconstruct the multi-dimensional phase space of electron beam. By scanning the strength of the quadrupole magnets and the polarizations of the deflecting cavity, projections of the...
The design performance of the 3.5 GeV Diamond-II low-emittance electron storage ring has been studied as a function of the linear and nonlinear lattice tuning parameters. A Multi-Objective Genetic Algorithm (MOGA) has been implemented to optimise both the beam lifetime and the injection efficiency for off-axis injection. The simulations have been run on 5 machine error seeds, including...
Abstract—A SCILAB Xcos model, developed using SCILAB software version 6.1.1, was implemented to simulate the on-axis radiation intensity of a helical undulator, (undulator parameter= 1, undulator wavelength 5cm, number of periods= 10, device length 0.6 m) with an electron beam (1, 2, & 3 GeV) and beam current as Ib = 3–6 × 10⁻⁶ Ampere. A numerical approach is utilized to perform the undulator...
The Large Hadron Collider (LHC) features a collimation system that protects the machine against beam losses that may induce the loss of superconductivity in some exposed lattice magnets. Thus, optimal cleaning performance must be ensured at all times. The collimation system encompasses more than 100 collimators whose settings are organised in a well-defined transverse multi-stage hierarchy. A...
Following the LHC Injector Upgrade programme (LIU) there has been a gradual ramp-up of the intensity of LHC beams in the CERN Super Proton Synchrotron (SPS). This was initially hampered by vacuum issues in several critical components, such as RF cavities and kicker magnets, requiring extensive scrubbing campaigns to condition these components. This paper reviews the current status of the high...
In view of the unprecedented beam intensities expected in the High-Luminosity era of the Large Hadron Collider (HL-LHC), an upgrade of the LHC injection kickers (MKIs) is currently underway. This upgrade aims to mitigate excessive beam-induced heating of the MKIs and to limit resulting vacuum activity. The first MKI Cool was installed in the LHC during the Year End Technical Stop (YETS) in...
Every high-energy beam dump event at the Large Hadron Collider (LHC) is analysed to assess the performance of the machine protection system and to identify anomalous behaviour. Analysing the loss pattern of nearly 4000 beam loss monitors, which depends on beam parameters and machine settings, can be time-consuming and requires expert knowledge. Therefore, an automated beam loss analysis tool...
The baseline design for the high-energy complex of a muon collider consists of a chain of pulsed synchrotrons spanning an energy range from 63 GeV to the target collision energy of 5 TeV. This chain incorporates both normal and hybrid synchrotrons, featuring a combination of fixed-field superconducting magnets and pulsed normal-conducting magnets. Initial optics designs for the chain of...
The compact ERL has been operated at the various beam optics as a test facility for industrial applications, such as the future EUV-FEL for a lithography. The short bunch length is the key for the high intensity SASE FEL therefore a tunable R56 of the arc optics is necessary for the bunch compression. We demonstrate the two kinds of arc optics: one is easy optics matching and another one is...
The Future Circular Collider, FCC-ee, is a proposed next generation electron-positron collider aiming to provide large luminosities at beam energies from 45.6 up to 182.5 GeV. This collider faces a major challenge to deliver the design performance in the presence of realistic lattice errors. A commissioning strategy has been developed including dedicated optics designs, efficient beam-based...
As new synchrotron light sources push for lower emittances, intra-beam scattering (IBS) becomes an increasingly more important factor in determining the final beam distribution properties. Because IBS depends strongly on beam energy, in the regime of ultra-low emittance rings, beam energy is a parameter to be optimized for best beam performance. In this report, we study the optimal beam energy...
Additive manufacturing is a now-powerful tool for the rapid prototyping and manufacturing of complex geometries. A proof-of-concept 433 MHz IH-DTL cavity was constructed for direct additive manufacturing of linear accelerator components. The CFD analysis of the initially designed cooling for the drift tube revealed a design with insufficient heat dissipation; this can lead to thermal...
PLS-II has been faithfully fulfilling its role for 13 years since it launched its user service in 2012. As the 4GSR project is currently underway in South Korea, upgrading PLS-II to PLS-III is expected to take a significant amount of time. Therefore, how PLS-II can be optimized and used well over a significant time in the future is an important question. In this presentation, we present how to...
At the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), a scheme for generating attosecond XFEL pulses in the soft X-ray undulator line is under development using the Enhanced Self-Amplified Spontaneous Emission (E-SASE) method with an external laser pulse. To account for the slippage effect in the soft X-ray region, a mid-wavelength infrared (IR) laser pulse will be...
The pulse duration of the X-ray free-electron laser (XFEL) relies on the pulse duration of the electron bunch. The energy distribution of the electron bunch can be manipulated by using the laser heater in the purpose of generating attosecond pulse duration electron bunch current profile. Therefore, the resultant electron bunch current profile after the bunch compressor chicanes is programmable...
A recent simulation study demonstrated the potential to achieve high 4D-emittance using an emittance exchange (EEX) beamline integrated within a photoinjector. This EEX beamline enabled to achieve the final normalized longitudinal emittance of 0.44 micron, which corresponds to rms bunch length of 7micron and energy spread of 32keV. These results are noteworthy for a 60-MeV photoinjector...
The measurement of electron Yukawa coupling ($y_{e}$) via direct s-channel Higgs production at $\sim$125 GeV centre-of-mass (CM) energy is significantly facilitated at the FCC-ee, provided that the CM energy spread can be reduced to a level comparable to the natural width of the Higgs boson. This reduction is possible through the “monochromatization” concept, which involves generating...
The increased beam intensity during the high lumionsity LHC era is expected to impose tight margins on the operation of the LHC RF system. The larger momentum spread from the injectors together with twice the bunch charge requires a higher RF voltage at injection to avoid beam losses. However, the peak RF power due to the increased beam loading must be kept below the saturation level of the...
The PITZ facility at DESY in Zeuthen has demonstrated the first operational high peak and average power THz self-amplified spontaneous emission (SASE) free electron laser (FEL). The current setup displays the onset of saturation at a central frequency of 3THz using a 3.5m long LCLS-I undulator. However, the THz user community has expressed the need for carrier-envelope phase (CEP) stability...
Orbit alignment plays an important role in free-electron laser (FEL) facilities, particularly in the collimation section, where multipoles are strategically positioned near the collimators as part of the specialized optics design. At the European XFEL, a strong dependence of lasing performance on the orbit in the collimation section has been observed. This study focuses on calibrating the...
PERLE (Powerful Energy Recovery LINAC for Experiment) is a high-power Energy Recovery LINAC (ERL) facility with 20 mA beam current and 500 MeV final energy, initially operating at 250 MeV, through three accelerating and three decelerating passes. Operating in the high-power regime of 10 MW brings challenges in beam steering and control. This work studies optics misalignments and their impact...
The user operation of the Extremely Brilliant Source (EBS) since August 2020 has opened a new era of high energy fourth generation synchrotron radiation light sources. During the following four years of operation, the EBS accelerator has sustained user operation with high availability, reliability, and stability, and has continued to improve beam performance by reducing injection...
Off-momentum losses at the start of the LHC acceleration ramp in proton runs gave rise to multiple beam dumps by exceeding Beam Loss Monitor (BLM) thresholds in the momentum cleaning insertion (IR3). Accurately estimating the power deposition profiles in IR3 is necessary to determine where BLM thresholds can be optimized, thereby reducing unnecessary beam dumps and improving machine...
In preparation for the 2026 Update of the European Strategy for Particle Physics, various options are being proposed for a future circular hadron collider, FCC-hh. Here, we discuss a few operational scenarios spanning c.m. energies from about 70-120 TeV, which correspond to the arc dipole field strengths ranging from 12 to 20 T. We present the respective integrated luminosity forecasts,...
The CERN-SPS beam dump system (SBDS) is equipped with a dilution kicker system, the so-called MKDH. During the 2022 and 2023 beam commissioning, the vacuum rise in the MKDH became a concern for reaching the anticipated higher beam intensities. Dedicated conditioning of the SPS kickers enabled successful attainment of High-Luminosity (HL) beam intensities during 2024 operation. However, the...
A 90-mA and 52.5-keV negative hydrogen ion (H⁻ ion) beam has been extracted from the J-PARC Radio Frequency (RF) H⁻ ion source. The 90-mA beam phase-space distribution at the entrance of the Radio Frequency Quadrupole (RFQ) cavity was measured at the test stand. Compared with the 60-mA beam condition for the present J-PARC user operation, reasonable increase in the operation parameters (the RF...
The Hefei Advanced Light Facility (HALF), a soft X-ray and VUV diffraction-limited storage ring light source, started construction in 2023. This paper describes the physics design progress of the HALF storage ring over the past year.
To avoid unacceptable proton emittance growth via beam-beam interaction, the EIC electron storage ring (ESR) requires very stringent tolerances for beam position and size stability at the interaction point. These tolerances imply tight specifications for several accelerator systems, including magnet power supplies (PS). While the magnetic field ripple requirements are most stringent at the...
A 100-MeV proton linac has been operated for over 10 years at KOMAC and used for proton beam services. We are planning to upgrade the linac energy to 200-MeV. By increasing the linac beam energy, we expect the machine to be capable of serving wider application fields including space radiation tests of semiconductor devices and material tests by using high-energy neutrons generated by...
The utilization of plasma devices in beam transport is slowly being accepted as a worthy alternative thanks to its potential in maintaining or even reducing particle beams emittance but also for its compactness which supplements the recent advances in compact laser plasma acceleration systems. However, their use can go beyond the substitution of magnets. In this work, the utilization of a low...
The surface muon beamline at J-PARC provides high-intensity muon beams that are essential for advanced materials science research, particularly in techniques such as muon spin rotation/relaxation (μSR). However, positron contamination in the beam poses a significant challenge by introducing background noise that affects the measurement precision. Therefore, achieving high-purity muon beams is...
The Future Circular Collider (FCC-ee) at CERN requires a betatron and momentum collimation system for reducing particle backgrounds in the detectors, and for protecting the machine in case of excessive beam losses. The system is composed of primary and secondary collimators, which will be housed in one of the technical insertions of the 91 km ring. In this paper, we present a first assessment...
The Canadian Light Source does not currently correct beta beating driven by its insertions devices. However, it has been known for some time that insertion device correlated vertical beam size changes can cause large reduction in flux at the VESPERS beamline. In this work we discuss our preliminary explorations to control the vertical beam size and correct beta beating.
Plasma lensing provides compact focusing of electron beams, since they offer strong focusing fields (kT/m) in both planes simultaneously. This becomes particularly important for highly diverging beams with a large energy spread such as those typically originating from plasma accelerators. The lens presented here is a nonlinear active plasma lens, with a controlled focusing-strength variation...
The Large Hadron Collider (LHC) can operate with high intensity proton and heavy ion beams, both of which require a collimation system to ensure an efficient operation and to protect against damage to sensitive equipment along the ring. The crystal collimation scheme using bent silicon crystals as primary collimators was therefore introduced to improve the collimation efficiency for heavy...
A new high-intensity Beam Dump Facility (BDF), hosting the SHiP (Search of Hidden Particles) experiment, is set to begin operation in CERN’s North Area (NA) in Run 4. To meet its physics goals, SHiP aims at accumulating 4$\times$10$^{19}$ protons on target per year, which will require approximately 10$^6$ high intensity cycles from the SPS with $4.2\times10^{13}$ p$^+$ per cycle (as...
Kyoto University Free Electron Laser (KU-FEL) has been developed for promoting energy related researches in Institute of Advanced Energy, Kyoto University. Currently two accelerator based infrared light sources, a mid-infrared FEL (MIR-FEL) and THz coherent undulator radiation (THz-CUR) are available. MIR-FEL covers the wavelength region from 3.4 to 26 micro-m and THz-CUR covers the frequency...
Cavity-based XFEL - CBXFEL - is an ongoing experiment at SLAC Accelerator National Laboratory. It utilizes first seven LCLS hard x-ray undulators, wrapped into a rectangular Bragg cavity. CBXFEL is expected to operate at 9.831 keV, and serve as a proof-of-principle device for future large scale cavity-based systems. We report on the recent status and preliminary experimental results.
A new lattice configuration is being developed for a compact,isochronous ring for the ISRS project, as an innovative spectrometer at HiE-ISOLDE. The design incorporates ten combined-function, canted cosine-theta (CCT) superconducting magnets, enabling the ring to fit within a constrained 5x5 meter hall space. This design presents significant challenges, particularly in accommodating the...
A 10 TeV center-of-mass muon collider could serve as a next-generation high-energy lepton collider with substantial physics potential while offering a more compact footprint than other proposed machines. However, this collider presents unique challenges, largely due to the short lifetime of muons and their decay products. Specifically, the collider ring requires specialized designs to protect...
The 2023 P5 report and recent long-term planning efforts in high-energy physics emphasize the need for a future discovery collider operating at 10 TeV parton center-of-momentum (pCM). A promising candidate is a wakefield-based linear collider, offering various beam options. While conventional electron-positron collisions using flat beams are preferred, challenges with accelerating such beams...
Interactions of dust grains with the LHC beams cause beam losses that can
trigger premature beam aborts or even quenches of superconducting dipoles.
While the simulated
motion and ionisation of dust grains inside the proton beam are in good agreement with measured beam-loss data, a direct measurement of the dust movement is not available.
A novel method was developed that reconstructs...
Electron-positron ERL colliders at the Z pole are proposed as a sustainability near future collider.The components are similar to the ILC accelerator, which consists of the linac with the 9 cell superconducting cavities, the 5 GeV damping ring, the beam delivery system for the final focus, and the electron and positron injectors. The recirculation loop is added to the ERL scheme. To fit it in...
Gamma-ray induced nuclear physics experiments rely on good signal-to-noise ratio, requiring accurate rejection of detector background. One source of this background is the interaction of cosmic rays with nuclear detectors. The Duke High Intensity Gamma-ray Source (HIGS) is typically operated in quasi-CW mode, requiring background measurements to be conducted independently of data production...
The lepton Future Circular Collider (FCC-ee) at CERN provides electron-positron collisions at four interaction points (IPs) along a 91 km ring, with beam energies spanning from 45.6 GeV (Z pole) to 182.5 GeV (ttbar threshold). The radiation showers produced by these collisions can reach sensitive components of the surrounding machine elements, possibly affecting their performance and lifetime....
In the period from October 2021 to August 2024, a cavity was developed for the 3rd harmonic system of PETRA IV. The development has progressed so far that a complete CAD model already exists. The cavity design has been reviewed by an external expert and approved. The project team is now working on clarifying the final details of the design and preparing all the technical documentation for the...
Optical Stochastic Cooling (OSC) is a state-of-the-art beam cooling technology first demonstrated in 2021 at the IOTA storage ring at Fermilab's FAST facility. A second phase of the research program is planned to run in 2025 and will incorporate an optical amplifier to enable increased cooling rates and greater operational flexibility. In addition to beam cooling, an OSC system can be...
The compact ERL (cERL) is a test accelerator operating at KEK. Its main purposes are to develop key technologies related to energy-recovery linacs and high-current superconducting accelerators for industrial applications. An important goal of our activity is to realize a high power FEL source for future EUV lithography.
In recent years, we have been working on demonstrating high current beam...
The KOMAC (Korea Multi-purpose Accelerator Complex)of the KAERI (Korea Atomic Energy Research Institute) has been operating 1.7 MV and 3 MV Tandem accelerators for many years. Recently, in the fields of cultural heritage research and semiconductor device development, there have been strong demands from users for precise composition analysis and large-area & uniform irradiation of proton beam...
The dynamic aperture is a key metric for assessing the stable phase space of particle accelerators and evaluating their overall stability. However, in highly damped accelerators such as high-energy electron synchrotrons like the Future Circular Collider (FCC-ee), the rapid amplitude variation of tracked particles over a few turns introduces significant sensitivity to initial conditions and the...
The scheme with quadrupole lenses is presented for realization relativistic strophotron type Free electron laser. Equations of motion are solved and trajectories are found. It is shown, that movement of electrons in presented scheme is stable in both transverse directions.
The accelerator and free-electron laser (FEL) laboratory at the University of Hawai’i at Manoa (UHM), established by John Madey, has been in standby since his passing in 2016, with operations further paused during the pandemic. Recent efforts aim to recommission the facility, which includes a thermionic gun, an S-band linear accelerator reaching 45 MeV, and a Mark III undulator FEL oscillator...
The Super Tau-Charm Facility (STCF) is a new generation of electron-positron colliders being planned with a design center of mass energy of 2-7 GeV. In the concept design, the positrons produced by electron targeting are accelerated to an energy of 200MeV by three large-aperture accelerating structures, and then to 3.5GeV by several conventional accelerating structures. The aperture of...
The Relativistic Heavy Ion Collider (RHIC) Run 24 was 27 weeks, operating with collisions at the STAR and sPHENIX detectors. The secondary running mode was gold at 100 GeV/u, where there was 3 weeks of operation. The goals of this run were to: reach an intensity of 1.8e9 ions/bunch and fully commission the 56 MHz cavity, ensure sPHENIX systems are ready for Run25,and deliver 1-2e9 minimum bias...
Here I will showcase the advanced precision instrumentations involved at the Veritas beamline dedicated to high resolution soft X-ray resonant inelastic X-ray scattering (RIXS) experiments. Following this, I will unveil the unique science cases one can attempt here.
In 2024 DAFNE successfully completed the data delivery for the SIDDHARTA-2 detector largely exceeding the integrated luminosity requested by the experiment. This has allowed allocating the machine time for several dedicated beam dynamics experiments useful for both the collider characterization and for the design of future electron-positron colliders based on the crab waist collision concept.
TWOCRYST is a machine test designed to demonstrate the feasibility of an in-vacuum fixed-target experiment for the first direct measurement of the magnetic and electric dipole moments of short-lived charm baryons. This setup exploits crystal channeling using two bent crystals. The first one is similar to the existing crystals used in the LHC for beam collimation, deflecting the beam halo...
A circular waveguide lined with a thin dielectric layer enables electron bunches propagating within the structure to radiate light in the (sub-)THz regime. In this work, we perform simulations of low-energy electron beams traversing extended waveguides to analyze the dynamics of beam bunching and lasing within the structure. By exploring the free-electron laser (FEL) process in this context,...
Bent crystal collimators (BCC) are a promising technology for halo collimation in high-power synchrotrons. To investigate their performance, a BCC module has been integrated into G4PyORBIT, leveraging Geant4's precise modeling of crystal channeling and PyORBIT's beam dynamics simulation capabilities. This study applies the tool to the rapid cycling synchrotron (RCS) at the China Spallation...
During the 2023 ion run at the LHC, where crystal collimation was regularly adopted for the first time, strong background levels were observed at the Inner Tracking System (ITS) of the ALICE detector. Some of the readout chips became saturated, causing losses of angular acceptance. This background was mitigated using a dispersion knob in the beam optics, letting some residual background...
Ion profile monitors (IPMs) provide a non-destructive means of measuring the transverse beam size of a passing ion beam in a particle accelerator. The Alternating Gradient Synchrotron (AGS) at Brookhaven National Lab is equipped with two types of IPMs: ion-collecting and electron-collecting. While ion-collecting IPMs are susceptible to significant distortions in the measured beam size due to...
The neutrinos from Stored Muons (nuSTORM) experiment aims to create neutrino beams through muon decay in a storage ring, targeting %-level precision in flux determination. With access to two neutrino flavors, it enables precise measurement of $\nu$-A cross sections and exhibits sensitivity to Beyond Standard Model (BSM) physics. With muons in the 1-6 GeV/c momentum range, it covers neutrino...
PAL-XFEL (Pohang Accelerator Laboratory X-ray Free Electron Laser) is a facility that generates high-brightness FEL for users to perform the FEL-based sciences. Currently hard and soft X-ray (HX/SX) beamlines are operational, but the parallel operation can be done with less than 60 Hz using a single electron bunch from the electron injector. Therefore, for the user service with maximum...
Beam based alignment (BBA) plays an important role in the commissioning of the light sources. To speed up the BBA, a BBA method using AC excitation, called fast BBA (FBBA), has been proposed and is tested in several existing light sources. In the FBBA, the beam orbit is sinusoidally modulated at around 10Hz by AC correctors, and the change in the beam response when a target quadrupole magnet...
Modern injection schemes for light sources seek to explore the full 6D phase space in order to find creative ways of top-up injection with minimal perturbation to the stored beam. The longitudinal injection scheme is considered for the SLS 2.0 storage ring and, hence, the longitudinal profile of the injected beam becomes highly relevant for the injection efficiency. We simulate possible ways...
The electron-positron Future Circular Collider (FCC-ee) is a proposed high-energy lepton collider that aims to reach unprecedented luminosity and precision in the measurement of fundamental particles. To fully profit of such performance, it is crucial to keep detector backgrounds under control and operate the machine safely. Due to the high stored beam energy and to a number of complex...
We have started single electron storage experiments since 2021 at the UVSOR-Ⅲ storage ring with the aim of conducting fundamental research on electromagnetic radiation. At BL1U, which is a beamline dedicated to light source developments, we extracted undulator light in the UV wavelength range into the air and observed its intensity by a photomultiplier tube, as decreasing the electron beam...
We report the generation of single spike hard x-ray pulses at the Linac Coherent Light Source enabled by temporal shaping of the photocathode laser. The pulses were produced with typical pulse energies of 10 uJ and full-width at half-maximum spectral bandwidths averaging 30 eV, corresponding to a 60 attosecond Fourier-limited pulse duration. These pulses open new doors in...
The Swiss Light Source, SLS, storage ring has been rebuilt as SLS2.0, to improve the radiation brightness by about two orders of magnitude. All components of the storage ring lattice and its supporting infrastructure are newly constructed and were installed during a 15-month shutdown that began in October 2023. The linac and booster synchrotron received only small modifications with the...
SOLEIL II is the French upgrade project to build the science of tomorrow with synchrotron light radiation. Providing the highest brilliance in its class while maintaining the radiation range from IR to hard X-rays, the project is an ambitious triple upgrade of the SOLEIL facility: accelerators (new booster and storage ring), 29 beamlines and 3 laboratories, and an information technology...
The synchrotron SOLEIL is France's 2.75 GeV third-generation synchrotron light source and serves as a cutting-edge research laboratory dedicated to advanced experimental techniques for matter analysis at the atomic scale. It also functions as a service platform accessible to both scientific and industrial communities. This abstract highlights the performance of the accelerators, which deliver...
Transmission Electron Microscopes (TEM) require high voltage DC electron sources, which can quickly grow in size and cost at the higher energies required for standard TEM imaging. We present the progress on a low cost, compact solid-state-driven RF linac to replace high power electron guns in micro-crystal electron diffraction setups. The system accelerates electrons to 50 keV electrons with a...
With the adoption of multi-bend achromat lattices and the aim for diffraction limit, the state-of-the-art light sources are approaching a point where their emittance becomes so small that the effects of space charge can no longer be ignored. Space charge produces a significant betatron tune spread that affects many aspects of beam dynamics: single particle dynamics to collective beam...
Highly polarized MeV gamma rays, produced by Laser Compton Scattered (LCS) of a polarized laser with an electron beam, offer a unique probe for basic and applied physics research. As the polarization characteristics of these gamma rays vary with the position of the beam cross section, it is essential to understand the polarization properties when using polarized gamma rays * . However,...
SPS-II was designed for low emittance storage ring with
compact Double-Triple Bend Achromat (DTBA) cell. To
ensure sufficient machine performance, realistic machine
imperfections were simulated and incorporated into the optimization
process.Thus the lattice solutions were made robust
against imperfections, thereby reducing the machine’s sensitivity.
The solution with sufficient dynamic...
This paper presents comprehensive start-to-end commissioning simulations for the SOLEIL II storage ring upgrade, demonstrating the feasibility of achieving an ultra-low emittance of 84 pm-rad at 2.75 GeV. We detail a multi-step correction strategy addressing challenges posed by the dense magnet arrangement and limited number of BPMs and correctors. Our simulations encompass first turn...
This paper presents statistical uncertainty studies on data analysis methods employed for the alignment of induction voltage adder (IVA) cell magnets in the Scorpius Injector. The Stretched Wire Alignment Technique (SWAT) was utilized to precisely locate and align the magnetic axis of beamline solenoid magnets. A current pulse with duration of approximately 100 µs was propagated through a...
LumiBelle2 is a fast luminosity monitor used for beam parameter tuning and feedback at the interaction point of SuperKEKB. It uses sCVD diamond detectors placed in both the electron and positron rings to measure the rates of single bremsstrahlung events. Luminosity signals are provided both for averaging all bunches and for each bunch crossing at 1 Hz. The averaged luminosity signal over all...
Recent years have seen growing interest within the laser particle acceleration community in laser sources operating at wavelengths substantially longer than the ~1 µm typical of present-day facilities. This renewed focus is fueled by recent advancements in powerful mid- and long-wave infrared (M/LWIR) laser sources. While fundamental advantages, such as the λ2-scaling of ponderomotive...
The construction of the new FAIR heavy ion accelerator facility at GSI is progressing well. With the start of installation of SIS100 an important new milestone in project execusion has been reached. SIS100 is the first superconducting, fast ramped synchrotron with special design features dedicated to the acceleration of high intensity, low charge state heavy ions. The full performance of the...
SIRIUS is a state-of-the-art synchrotron light source facility, featuring a 3 GeV electron storage ring with a 518 m circumference and 250 pm·rad emittance. Built and operated by the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, Brazil, SIRIUS has undergone significant upgrades over the past year. These include the installation of a cryogenic plant, superconducting RF cavities,...
PERLE (Powerful Energy Recovery Linac for Experiments) is a three-turn, high power Energy Recovery Linac under construction at IJCLab, France. It emerged from the design of the LHEC and FCC-eh and will serve as a hub for the validation of several technical choices and exploration of a broad range of accelerator phenomena in an unexplored operational power regime (up to 10 MW in its final...
DELTA, a 1.5-GeV electron storage ring facility operated by TU Dortmund University in Germany, celebrated its 30th anniversary in fall 2024. During its time in operation, the facility has been continuously developed to provide synchrotron radiation (SR) users with the most reliable and attractive radiation source possible. This includes continuous improvements of electron beam stability and...
FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a new compact versatile linear accelerator at KIT. Its main goal is to serve as a platform for a variety of accelerator studies as well as a generation of strong ultra-short THz pulses for photon science. Also it will be used as an injector for a Very Large Acceptance compact Storage Ring (VLA-cSR) which will be realized at KIT in the...
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...
SILA (Synchrotron Laser) is a project of the National Research Center Kurchatov Institute (NRC KI) planned for the period 2022-2033. It is aimed at creating a 4th generation synchrotron radiation source and a free electron laser. The storage ring is divided into 40 periods, the perimeter (SR) is 1103 m, the electron energy is 6 GeV, the horizontal emittance is 70 pm∙rad. The free electron...
The VEPP-5 injection complex was put into operation as a source of electronic and positron beams for the VEPP-2000 and VEPP-4M colliders at the end of 2016. To date, an operating energy of 430 MeV and a positron accumulation rate of 3.5 nC/s have been achieved. Options for improving the complex for working with promising installations are being considered. The latest results and prospects of...
The study of beam-cavity interaction is an essential step towards achieving the design objectives of high-intensity storage rings, particularly in the rapidly advancing fourth generation of synchrotron light sources, which rely on the strategy of bunch lengthening with harmonic cavities. Assessing the effectiveness of harmonic cavities typically requires self-consistently solving bunch...
The autonomous alignment and optimization of syn-chrotron beamlines pose significant challenges. Tradi-tionally, manual alignment is a time-consuming and ex-perience-dependent process, often requiring extensive diagnostic efforts and data collection. With the construc-tion of the Hefei Advanced Light Facility (HALF) under-way, the development of a virtual platform for beamlines will be an...
PETRA IV is the storage ring light source currently under design at DESY in Germany. The baseline injector is a 6-GeV synchrotron DESY IV, an upgrade to the existing injector DESY II. Even if the project progresses in developing the DESY IV, we studied the intensity limit of DESY II to investigate the feasibility of reusing the existing injector chain, in view of a possible upgrade to a laser...
The H6BA lattice is now considered as the baseline design for PETRA-IV light source. It is required that the ring can be operated with and without damping wigglers, resulting in two sets of natural equilibrium beam parameters. This paper analyzes the single-bunch effects due to impedance in the H6BA lattice of PETRA-IV. We will show the influence of the impedance on the electron beam in both...
This work examines the dominant coherent head-tail type (< x-z >) instabilities in the vertical plane of the FCC-ee collider, focusing on a mode analysis method with the Circulant Matrix Model (CMM) to assess instability mechanisms under the influence of beam-beam effects and transverse wakefields. While the impact of vertical plane instabilities have been already studied, different...
We propose a phase jump method to improve the electron beam conversion efficiency in FEL oscillator. A fast phase shifter is put between two undulator segments to kick the phase of the electron beam at saturation. The theoretical and simulation results are given based on FELiChEM which is built in Hefei. They indicate that a phase jump value of approximately π at saturation can significantly...
Laser ion sources can produce a very high pulsed beam current, but still more than 90% of the beam is lost. In order to further increase the beam current of the laser ion source, this study installed a solenoid in the ion source target chamber and investigated the relationship between the solenoid and the generated beam current.
PAL-XFEL comprises two lines: Hard X-ray (HX) line for 2.5-15 keV FEL and Soft X-ray (SX) line for 0.25~1.1 keV FEL. Both lines share accelerator sections L1, L2, L3A, and two Bunch Compressors (BCs). The electron bunch is accelerated to 2.8 GeV and compressed to a peak current of 400-500A using accelerators and two BCs, then it is directed into either the HX or SX line at the branch line....
We have been studying about a pre-bunched FEL in the THz region. In the pre-bunched FEL, the electron bunches being compressed shorter than the oscillation laser wavelength, it is expected that we can generate short-pulse THz laser pulses with high peak intensity. A broadband spectrum and high-intensity characteristics, which cannot be realized by conventional FEL, are expected. The...
Understanding the characteristics of the beam source is crucial for designing optimal beamline optics. During the construction of PAL-XFEL, simulation studies on the characteristics of the XFEL beam source were conducted in advance to aid in the design of beamline optics and experimental instruments. However, since the facility began providing user services in 2017, the performance of PAL-XFEL...
As proposed in Ref[1], a fully coherent synchrotron light source requires a high-current, low-emittance storage ring with very short damping time to deliver a high-quality beam for the bypass line, ultimately producing high average power EUV radiation. The initial design adopts 8 TBA (Triple Bend Achromat) cells, with four cells forming one superperiod. The straight sections on either side of...
Recent progress on the experiments of Inverse Compton Scattering (ICS) at Brookhaven National Laboratory Accelerator Test Facility (BNL ATF) is introduced. Nominal e-beam parameters utilized are electron beam energy of 70 MeV, charge per pulse of 0.5 nC with normalized emittance of 2 mm mrad. Use of long wavelength TW CO2 laser, and short wavelength Nd: YAG or Ti: Sapphire lasers allows us to...
X-ray vortices carrying tunable Orbital Angular Momentum (OAM) are an emerging tool for X-ray characterization technology. However, in contrast to the generation of vortex beams in the visible wavelength region, the generation of X-ray vortices in a controlled manner has proved challenging. Here, we demonstrate an X-ray free-electron laser oscillator (XFELO) can adjust only the kinetic energy...
THz sources are typically very limited in power, making high-power sources scarce. One of the most promising THz sources are the Free Electron Lasers (FELs), which can generate high-power THz radiation using an undulator structure. Undulator radiation is an incoherent synchrotron spontaneous emission whose energy is proportional to the number of particles in the beam (𝑁). By longitudinally...
The electron-positron Future Circular Collider (FCC-ee) is designed to operate at four beam energies, from 45.6 GeV to 182.5 GeV. At such energy levels, the circulating beam loses a significant fraction of its energy via synchrotron radiation. As a single RF insertion is foreseen in the ring, large closed-orbit shifts featuring a typical sawtooth pattern and optics distortions are induced....
VEPP-2000 electron-positron collider operating in the beam energy range of 150-1000 MeV is the only machine originally designed to exploit Round Beams Concept which results in significant beam-beam limit enhancement. After long shutdown for injection chain upgrade VEPP-2000 resumed data taking with luminosity limited only by beam-beam effects.
Thanks to extensive and thorough machine tuning...
High-brightness and high-average current electron sources with excellent beam quality hold significant potential for applications in fields such as ultrafast electron diffraction (UED), free-electron lasers (FELs), and energy recovery linacs (ERLs). However, when the electron beam is initially generated, it typically exhibits large energy spread, beam size, and relatively low energy. During...
The purpose of this paper is evaluating vibration status for cooling water pump system in TPS. The utility systems operate continuously since TPS commission in 2014. The predictive maintenance based on vibration level and spectrum became more important, especially for those unstoppable operate water pump systems. The vibration monitoring system started to construct in 2017 and upgraded in...
After 31 years of serving the user community with excellent results, on July 2nd 2025 the removal of the Italian third generation synchrotron light source Elettra (www.elettra.eu) will start to be replaced by Elettra 2.0 a fourth-generation one. The project is in full development and, being a diffraction limited light source, Elettra 2.0 will provide ultra-high brilliance and coherence to the...
The goal of the ESSnuSB project is to precisely measure neutrino Charge-Parity Violation (CPV). The construction of the European Spallation Source, ESS, represents an outstanding opportunity for such project to take place. ESSnuSB has been funded from EU in the framework of H2020 (2018-2022) and Horizon Europe (2023-2026) to make feasibility studies. The aim of the first phase was to...
The field of ultrafast science has seen substantial growth over the past decade. High-power, ultrafast free-electron lasers (FELs) have become essential tools across various scientific disciplines, including physics, chemistry, and biology. The shorter pulse durations enable enhanced temporal resolution in pump-probe experiments. This paper introduces methods for generating ultrafast seeded...
The synchrotron radiation generated by storage rings offers numerous advantages, including high stability, a broad photon energy range, and the capacity to support multiple users simultaneously. However, one notable limitation is its poor radiation coherence. Achieving coherent harmonic generation (CHG) in storage rings would not only significantly enhance the coherence of the emitted light...
We present the lattice design features and performance evaluation of the Korea-4GSR storage ring. This greenfield ring has a 4 GeV beam energy, an 800 m circumference, and 28 cells. A natural emittance of 62 pm is achieved through the implementation of four longitudinal-gradient bends and six reverse bends within the hybrid multi-bend achromat unit cell. The ring includes two high-beta...
Currently the HIAF Project at IMP has reached the construction phase. The BRing is one of the key systems of HIAF, which is used to capture, accumulate, accelerate and extract the heavy ion beam injected by iLinac. The quadrupole magnets in BRing have large aperture (Ф260&Ф180) , large axial length(the total length of the magnet is reached 1140mm) and high integration field uniformity...
SKIF (Russian acronym for Siberian Circular Photon Source) – fourth-generation light source under construction in Novosibirsk. Natural emittance (at zero beam current and absent betatron coupling) of the SKIF is 72 pm at 3 GeV beam energy and 476 m circumference. Only two families of sextupoles provide horizontal and vertical dynamic apertures of 12 mm and 3.5 mm, respectively, and energy...
Recently, Optical Stochastic Cooling (OSC) became the first demonstrated method for ultra-high-bandwidth stochastic cooling. The initial experiments at Fermilab’s IOTA ring explored the essential physics of the method and demonstrated cooling, heating and manipulation of beams and single particles. Having been validated in practice, with continued development, OSC carries the potential for...
A fixed-target experiment using two bent crystals is proposed to study the magnetic and electric dipole moments of short-lived charm baryons with unprecedented precision in the LHC. This will be achieved exploiting crystal channeling into a first crystal to extract the beam halo and then into a 7 cm long silicon crystal capable of inducing a measurable spin precession to the particles of...
Fixed Field Accelerators (FFAs) are a promising candidate for future high intensity machines such as ISIS-II. It follows that the largely unexplored topic of coherent transverse beam instabilities in these machines is of increasing importance. Transverse instabilities, such as head-tail, can be mitigated in synchrotrons by adjusting the chromaticity appropriately. However, in scaling FFAs,...
The intrinsic emittance obtained from radio-frequency (RF) photoinjectors is notably reduced by increasing the launch field at the cathode. Moreover, cryogenic RF guns offer the possibility of producing stronger fields, due to the higher bulk conductivity, while lowering the mean transverse energy (MTE) of near-threshold photo electrons. Such devices thus constitute an ideal tool for driving...
The High Luminosity LHC (HL-LHC) project aims to increase the integrated luminosity of CERN’s Large Hadron Collider (LHC) over its exploitation era up to the end of 2041 by an order of magnitude compared to the initial LHC design value. This requires doubling the bunch intensity along with several other important changes to the LHC configuration. Dedicated beam experiments in the LHC and its...
The Accelerator Test Facility 2 (ATF2) serves as a critical platform for testing technologies and techniques aimed at advancing the next generation of linear colliders. The ATF2 is composed of a linear accelerator (LINAC), a damping ring, and an extraction line that includes a high-precision final focus system designed to achieve the small beam sizes necessary for future collider experiments....
The free-electron laser (FEL), powered by an accelerator and equipped with an undulator, produces intense coherent radiation at ever-shorter wavelengths. Whilst the hard x-ray regime represents the current state of the art, the gamma-ray regime remains the next objective. Gamma-ray lasers, deemed one of the most profound and intriguing challenges in physics by the 2003 Nobel Laureate, hold the...
Laser-Assisted Charge Exchange (LACE) is being developed at the Spallation Neutron Source (SNS) as a potential replacement for injection foils, which are not expected to endure in the 10 MW beam power regime. Previous experimental demonstrations have achieved highly efficient charge exchange of H⁻ ions to protons for beam durations of up to microseconds. A refined method, capable of scaling to...
Experimental programs entrusted to the Franco-British EPURE facility require more and more flexibility with regard to the operation of different functioning points for our two Linear Induction Accelerators (LIA). In 2023, UPRX work (presented at IPAC'24) demonstrated our ability to control both reliability and repeatability of our first radiographic axis performances at high current (2.6 kA)....
Single-sextupole and single-octupole lattices ``exhibit .. all the typical properties of more complicated mappings and dynamical issues'', including horizontal resonances of all orders $N$ with island tunes $Q_I$. In general both island tune response spectra and tune modulation drive spectra have multiple lines. Stable motion in transverse phase space is compromised when a pair of drive and...
As one of the most important frontiers of international science and technology, the development of ultrafast science has provided important research tools for many disciplines. Free-electron laser (FEL) has the unique advantages of high power and short wavelength in generating ultrafast pulses. In this paper, the theoretical simulations were performed to produce the ultrafast pulses, utilizing...
Helmholtz Zentrum Berlin is engaged in the conceptual design of the BESSY III facility. The BESSY III storage ring will be a fourth generation synchrotron light source with an emittance of about 100 pm rad and an energy of 2.5 GeV. It will be equipped with advanced undulators to provide users with tailor-made light. So far cryogenic permanent magnet undulators, hybrid planar undulators and a...
A high electron current is often needed in modern electron accelerators. To achieve this, an energy chirp must be imposed on the bunch so the electrons will compress when they pass through a chicane. This energy chirp is usually imposed by accelerating the beam off-crest from the peak fields of RF cavities, which increases the total length and power requirements of the linear accelerator...
Determining Yukawa couplings of the Higgs boson is one of the most fundamental and outstanding measurements since its discovery. The FCC-ee, owing to its exceptionally high-integrated luminosity, offers the unique opportunity to measure the electron Yukawa coupling through s-channel Higgs production at 125 GeV centre-of-mass (CM) energy, provided that the CM energy spread can be reduced from...
In the era of the High-Luminosity Large Hadron Collider (HL-LHC), the main RF system will be limited in voltage and power on the injection plateau due to strong beam loading. At the same time, significant start-of ramp losses, that are originating from capture and flat bottom losses, are expected and can severely impact machine availability or even prevent the beam from reaching the collision...
Brookhaven's Accelerator Facilities Division provides users with access to cutting-edge research tools, including the Accelerator Test Facility (ATF) and the Ultrafast Electron Diffraction (UED) facility. The ATF features an RF photocathode electron LINAC, a femtosecond Ti:Sa laser, and a high-peak-power LWIR laser, all capable of synchronized or independent operation. These tools enable...
As an option to control the vertical emittance a beam shaker will be implemented at the planned upgrade of the synchrotron light source at DESY, Hamburg. We evaluate the electron beam dynamics for a simple sine-wave and a noise band excitation and present the expected equilibrium vertical emittances.
Accurate characterization of radiation pulse profiles is crucial for optimizing beam quality and enhancing experimental outcomes in Free Electron Laser (FEL) research. In this paper, we present a novel approach that employs machine learning techniques for real-time virtual diagnostics of FEL radiation pulses. Our advanced artificial intelligence (AI)-based diagnostic tool utilizes longitudinal...
A novel soft X-ray BPM (sXBPM) for high-power beams of synchrotron undulator radiation has been developed through a joint effort by BNL/NSLS-II and Stony Brook University. In this approach, custom-made multi-pixel GaAs detector arrays are positioned in the outer portions of the X-ray beam, with beam position inferred from the pixel photocurrents. The first R&D device was installed in the 23-ID...
Optical frequency comb (OFC) technology provides precise measurement tools for optical frequencies, leading to revolutionary changes in the field of optics.OFCs consist of a series of uniformly spaced spectral lines resembling the teeth of a comb, and they have found widespread applications in timing, precision spectroscopy, and fundamental physics.Extending this technology into the EUV to...
X-ray Laser Oscillator (XLO) is an ongoing project at SLAC National Accelerator Laboratory. The project aims to construct world's first population inversion x-ray laser, using LCLS XFEL as a pump. XLO also utilizes the multi-bunch mode of LCLS copper linac, and a Bragg cavity arranged in a bow-tie configuration. When built, XLO will be able to generate x-ray pulses of very high quality. In...
Xsuite is a comprehensive simulation toolkit for accelerator physics, with Xcoll serving as the dedicated module for collimation studies. These studies involve tracking particles through an accelerator and simulating their interactions with matter, taking into account non-linear elements and large betatron and off-momentum deviations. Particle-matter interactions can be modeled using an...
A new high precision measurement of the Y(1S)-meson rest mass is being carried out at the VEPP-4M collider using the KEDR detector. The resonant depolarization method with the laser polarimeter has been employed for the absolute calibration of the beam energy. In the paper resent status of the experiment is discussed.
The pursuit of optimal beam quality and stability in linear accelerators (Linacs) stands as a cornerstone of accelerator physics. However, the presence of High Order Modes (HOMs) within Linacs, particularly in the context of energy recovery (ERLs), presents formidable challenges to beam quality and stability. In response to this challenge, the development of the Compact HOMEN (High Order Mode...
Safety is one of the main concerns in accelerator society. The key FRIB strategies and experience can be shared, leading to the successful FRIB operations with no safety-related incidents and meeting stringent standard in a university area.
Personnel protection and machine protection are key to high power frontier facilities like FRIB. For a facility built in the middle of university campus...
This study presents 2D approximated expressions for eddy currents in the Ti-coated layer of a nonlinear kicker and compares them with numerical simulations. Nonlinear kicker-based injection schemes have be-come popular in recent years and are used at several facilities. Eddy currents, which depend on both the applied magnetic field and the chamber’s geometry, can create unwanted field...
The Japan Proton Accelerator Research Complex (J-PARC) has achieved stable 1 MW operation test on its neutron target and is advancing toward higher power levels of 1.5 MW to support high-power MR operations and a second target station. This progression presents challenges, including increased intra-beam stripping (IBSt) of H⁻ ions, chop leakage from higher beam currents and emittance,...
Our studies indicate that parametric instabilities except the envelope instability are unlikely to be observed in actual linear accelerators unless waterbag or KV distributions are generated. Furthermore our studies and previous literatures indicate the dominance of particle resonances over parametric instabilities in high-intensity linear accelerators. Any counter evidence has not been found...
Accelerator-based boron neutron capture therapy (BNCT) has been studied worldwide for a novel cancer therapy using neutrons generated by an accelerator system. The iBNCT (Ibaraki BNCT) project began in collaboration with KEK, the University of Tsukuba, Ibaraki Prefecture, and private companies in Japan. The iBNCT project aims to realize linac-based BNCT with a compact and low-activation...
Higher harmonic cavities (HHCs) play a critical role in storage rings by extending the bunch length, thus mitigating beam instability and increasing the beam lifetime. This study investigates the influence of Robinson instability on the bunch lengthening performance for both active and passive HHCs. A detailed comparison is conducted to analyze the Robinson instability thresholds* and the...
An Accelerator Physics Experiment (APEX) was conducted in the Relativistic Heavy Ion Collider (RHIC) to verify the formation, rotation, and size of resonance islands.The experiment provides lattice parameters to be used to facilitate an alternative method of transition crossing in the Hadron Storage Ring (HSR) of the Electron Ion Collider (EIC) project by producing a non-adiabatic kick to the...
The Electron-Ion Collider (EIC), which is being designed by BNL, JLab and other partners, will be a particle accelerator that collides electrons with protons and nuclei to produce snapshots of those particles' internal structure. It will collide polarized high-energy electron beams with hadron beams in the center-of-mass energy range of 20-140 GeV. The electron beam, employed as a probe, will...
Next generation heavy ion accelerators such as HIAF (High Intensity heavy ion Accelerator Facility), FRIB (Facility for Rare Isotope Beams), SPIRAL2, and so on strongly require high intensity highly charged ion beams. The production of intense highly charged heavy ion beams such as U3n+ is a worldwide challenge for the community. ECR (Electron Cyclotron Resonance) ion source is the most...
In this contribution we report on the experimental generation of high energy (10 GeV), ultra-short (fs-duration), ultra-high current (∼ 0.1 MA), petawatt peak power electron beams in a particle accelerator. These extreme beams enable the exploration of a new frontier of high intensity beam-light and beam-matter interactions broadly relevant across fields ranging from laboratory astrophysics to...
TThe Large Hadron Collider (LHC) operation began in 2008. Its superconducting equipment requires a cool-down/warm-up cycle lasting several months to access some key elements such as superconducting magnets, making annual shutdowns impractical and obliged for a change in programmed stops paradigm. A new lifecycle management approach for programmed stops was therefore necessary. The large...
The Relativistic Heavy Ion Collider (RHIC) Run 24 was 27 cryo weeks, operating with collisions at the STAR and sPHENIX detectors. The primary mode was polarized protons at 100 GeV, where there was 22 weeks of physics production. sPHENIX continued commissioning, becoming fully operational after 13 weeks and the addition of isobutane to their TPC gas mixture. STAR had a low luminosity run...
This talk will report on the status of commissioning of the Cathodes And Radio-frequency Interactions in Extremes (CARIE) C-band high gradient photoinjector test facility and other high-gradient C-band research activities at Los Alamos National Laboratory (LANL). The construction of CARIE began in October of 2022. CARIE is powered by a 50 MW 5.712 GHz Canon klystron and will house a high...
We review the 2024 Pb-Pb ion run at the Large Hadron Collider (LHC), in terms of the operational experience, the problems encountered and the main results. This run was the second heavy-ion physics period of LHC Run 3 at 6.8 Z TeV. With only 18 days scheduled for physics data-taking, the key objective was to address the problems encountered in the 2023 Pb-Pb run and establish stable and...
The Korea-4GSR is a next-generation diffraction-limited light source designed to provide beam brightness up to 100 times greater than existing facilities. Chromatic aberrations from strong focusing fields in quadrupoles are corrected using sextupoles and octupoles. However, these sextupoles and octupoles introduce nonlinear effects, causing electrons to follow nonlinear trajectories,...
Carbon ion therapy is gaining popularity due to its unique physical and radiobiological properties, such as a lower oxygen enhancement ratio (OER) than photon and proton therapy, indicating that efficacy is not limited by hypoxic tumor microenvironments. It also has a Its superior anticancer effect on hypoxic tumor cells, which are resistant to chemotherapy, radiotherapy, and immunotherapy. It...
The shortening of the FEL pulse length is an important subject, and especially reducing the FEL pulse length down to a few-cycle duration is a great challenge. However, there exists a theoretical limit that disturbs the realization of few-cycle FELs, which is known as the slippage effect. Recently, the author proposed a novel idea to overcome this difficulty and experimentally demonstrated...
CERN Linac4 was formally approved in 2007 in the framework of the LHC Injector Upgrade Project with the purpose of removing the first intensity bottleneck in the chain of CERN LHC injectors. Linac4 was inaugurated in 2017 and became the sole proton injector at CERN in 2020. The experience and know-how built over a decade through the Linac4 project has subsequently been applied to accelerators...
Siam Photon Source II (SPS-II) is a 4th-generation synchrotron light source set to be constructed in Thailand, aimed at becoming a major synchrotron facility for Southeast Asia. It is designed with a 3 GeV low-emittance electron storage ring, featuring a DTBA lattice and a circumference of 327.6 meters. Recently, the design and machine parameters have been carefully revised, with a particular...
In the coming decades, numerous designs for new accelerator-based facilities, or potential upgrades to current facilities, have been proposed to support the next generation of scientific advancement. While these facilities have significant scientific, economic, and societal benefits, they also require considerable resources to operate effectively. Amid the ongoing climate crisis, these...
Two synchrotron radiation sources, the 2.5 GeV Photon Factory Storage Ring (PF ring) and the 6.5 GeV Photon Factory Advanced Ring (PF-AR), have been in stable operation at the High Energy Accelerator Research Organization (KEK) for over 40 years. This paper first describes the current operational status and recent developments at the Photon Factory. Next, a new concept of hybrid light source...
The Advanced Photon Source (APS) recently completed a transformative upgrade, replacing its 25-year-old storage ring with a state-of-the-art hybrid seven-bend achromat lattice with six additional reverse bends. The new design features a low natural emittance of 42 pm-rad, enabling productions of X-rays up to 500 times brighter than the original APS. The upgrade introduced a pioneering swap-out...
Carbon nanotubes (CNTs), known for their versatility as 2D materials, are key to advancing quantum technologies such as qubit fabrication and magnetic data storage. In this study, multi-walled carbon nanotubes (MWCNTs) doped with magnetic impurities (Fe and Co) were exposed to swift heavy ion (SHI) irradiation to explore induced structural modifications. SHI beams transfer energy to the carbon...
The South African Isotope Facility (SAIF) is a radioisotope production facility based around a 70 MeV Cyclotron from IBA. SAIF was commissioned at the end of 2023 and commenced commercial isotope production in 2024. The facility is located in three vaults at iThemba LABS in Cape Town. The vault design, radiation modelling, and an overview of construction are presented. The designs and...
Unlike the situation under the third-generation light sources, we will have to pay more attention to control electron beam loss under the fourth-generation ones. The main causes of the beam loss are (i) a beam dumped by switching off RF cavities and (ii) electrons lost by electron-electron scattering (the Touschek effect). Due to the low emittance, if the highly-dense dumped beam directly hits...
Accurate characterization of plasma density profiles is vital for optimizing plasma-based accelerators, as density directly affects beam acceleration and quality. Plasma capillaries also serve as lenses and for beam guiding, highlighting their role in advanced accelerators. This study measures longitudinal and transverse density profiles of plasma capillaries, achieving 3D characterization...
Particle accelerators have long been instrumental in advancing scientific research, medical treatments, and industrial processes. However, traditional radio-frequency accelerators are encumbered by their size, expense, and reliance on external microwave sources.
In this paper, we propose a novel linear accelerator concept that integrates a high-power microwave source directly into the...
In the frame of the Next Ion Medical Machine Study (NIMMS) collaboration based at CERN, a compact synchrotron for radiotherapy with high-intensity helium beams is designed. Interest in helium ions is growing in the major treatment centers, since they provide superior accuracy compared to protons, thanks to their sharper lateral penumbra, and higher linear energy transfer. Their properties lie...
Structure-based wakefield acceleration, using dielectric-lined or corrugated waveguides, is a novel acceleration method currently being explored by several research groups globally. This technology facilitates the transfer of energy from a high-charge drive beam to a lower-charge main bunch with high accelerating gradients. In this study, we propose an energy booster for the Compact Linear...
As accelerators and electron microscopes become more advancement, high-performance photocathodes are required. In particular, CsK$_2$Sb photocathode is of interest because of its low emittance, excitability in visible light, and high quantum efficiency (QE). Two challenges with CsK$_2$Sb photocathodes are (1) the lack of a universal deposition recipe to achieve crystal stoichiometries and (2)...
Muography is a useful technology for non-destructive inspection of a large-scale structure. Muography with cosmic ray muons has limitations such as low rates, particularly low muon rates in the horizontal direction, and energy spreading, which require long observation times and limit its resolution. Worldwide, large structures such as bridges built during the economic development period of the...
A superconducting accelerator is an excellent technology that can efficiently accelerate high-current beams and is being applied to free electron lasers and next-generation linear electron-positron colliders such as ILC. Not only for the fundamental science, but also the high current electron beam plays a rather important role in industrial and medical applications. This is because the demand...
ISBA24 (The 7th International School of Beam Dynamics and Accelerator Technology) was held in Chiang Mai, Thailand, jointly hosted by Chiang Mai University, Hub of Talents in Particle Accelerators (operated by the Thailand Center of Excellence in Physics), Synchrotron Light Research Institute (Public Organization) and Hiroshima University. ISBA is a series of international accelerator schools...
The radio frequency quadrupole (RFQ) is known for bunching, focusing and acceleration of ion beam and more importantly, it does not require transverse focusing element like quadrupole magnets between accelerating cells compared to drift tube linacs. By pushing the limits of handling surface electric field between RFQ vanes, it is possible to make a standalone 352 MHz RFQ reaching 1.8 MeV/u...
In the PAL-XFEL system, an X-ray free electron laser facility, 51 modulator power supplies in total have been operated with thyratron tubes as the high voltage pulse switch devices in order to drive an X-band linearize and 50 S-band klystrons for a beam energy of 10 GeV. PAL-XFEL requires beam energy stability of less than 0.02% and very tight control of the klystron RF phase jitter. The...
We introduce ABEL, the Adaptable Beginning-to-End Linac simulation framework developed for agile design studies of plasma-based accelerators and colliders. ABEL’s modular architecture allows users to simulate particle acceleration across various beamline components*. The framework supports specialised codes such as HiPACE++, Wake-T, ELEGANT, GUINEA-PIG and CLICopti, which facilitate precise...
Acceleration by the wakefield in the plasma can provide compact sources of relativistic electron bunches of high brightness. Free electron lasers and particle colliders, for using plasma wakefield accelerators, require high efficiency and bunches with low energy spread. The best way to achieve low energy spread is using profiled bunches which form plateau on the wakefield. However, in...
To prepare the Super Proton Synchrotron (SPS) as an injector for the High Luminosity Large Hadron Collider (HL-LHC), its Radiofrequency (RF) system was majorly upgraded. The 200 MHz travelling wave structures were rearranged, adding two solid-state power amplifiers and a new Low-Level RF (LLRF) system. The increase in RF power and reduction of the beam coupling impedance at the fundamental...
GaAs cathodes with thin-film Negative Electron Affinity (NEA) surfaces affixed have been used to generate spin-polarized electron beams for decades, but still suffer from short lifetimes. Heterojunction NEA surfaces have shown promise in improving cathode lifetimes, but further optimization of cathode activation and surface deposition is possible. Here we report the results of cathode...
The properties of the photoemitting electron sources are the determining factors contributing to the performance of the most advanced electron accelerator applications such as particle colliders, X-ray free electron lasers, ultra-fast electron diffraction and microscopy experiments. Therefore, low mean transverse energy (MTE), high quantum efficiency (QE) along with long operational lifetime...
Accelerator Driven Advanced Nuclear Energy System (ADANES) is to realize the transmutation of nuclear waste and the regeneration of nuclear fuel. ADANES can flexibly connect with the existing nuclear power system to achieve the goal of continuous and minimum waste discharge for the nuclear power system. A new sub-critical reactor concept is proposed as high power beam with one accelerator...
Heavy ion therapy (HIT) is a transformative approach to cancer treatment offering precision to target tumors minimizing damage to surrounding normal tissue cells. This study explores the feasibility of applying the particle-in-cell (PIC) method to evaluate and optimize the clinical therapy of HIT. The PIC models ion beams & dynamics by tracking their motion with electromagnetic interaction and...
The EuPRAXIA Doctoral Network (EuPRAXIA-DN) trains the next generation of scientists in plasma-based accelerator technologies, addressing challenges in laser-plasma interactions, advanced beam diagnostics, and novel applications.
This contribution highlights progress made in three critical areas: ) real‑time characterization of capillary discharge plasmas to stabilize laser‑wakefield...
Bead-pull method is a commonly used approach to test and tune the structures of accelerator. Traditionally, this method has been time-consuming. An automated paltform has been developed in this paper, which significantly reduces the time required for the bead pull method and enhances its accuracy. This method has been implemented in the testing of the Hefei Advanced Light Facility (HALF) and...
Muons have important applications in both scientific research and industry. In order to produce muons, an effective way is to use a high-power proton beam interacting with a targeting material. After the interaction, the proton beam is disposed of for other purposes. In this paper, we propose a new type of proton accelerator, an energy recovery proton linear accelerator, so that the...
Jefferson lab is considering an energy increase from current 12 GeV to 22 GeV for its CEBAF accelerator. This will be accomplished by recirculating 5-6 additional turns through two parallel CEBAF LINACs using an FFA arc at each end of the racetrack. The total recirculation turns would be 10 times, the first four turns use present conventional arcs to make the 180-degree bends from one LINAC to...
The International Linear Collider (ILC) is a next-generation electron-positron collider based on the superconducting linear accelerator. Many positrons are required for the ILC because beams are not reused in linear colliders. Therefore, the ILC electron-driven (E-driven) positron source system should be designed to optimize efficient positron generation. In this study, we optimize the...
Inspired by the progress of surface plasmon research and the rapid development of nanotechnology, we embarked on an endeavor aiming to improve the GaAs-based photocathode performance by patterning semiconductor wafer surfaces with pillar arrays on the scale of hundreds of nanometers. Over the past a few years, extensive research effort involving both simulation and experimental studies have...
This project describes the source for a neutron facility to produce 99Mo for Medical Diagnostics through the irradiation of natural
Molybdenum by means of a 14 MeV neutron source based on the Deuterium
Tritium fusion reaction.
The Relativistic Ultrafast Electron Diffraction and Imaging (RUEDI) facility is an approved project to provide ultrafast capability to UK researchers. The current design involves two separate beamlines for diffraction and imaging but with shared infrastructure including laser pump sources. This presentation describes recent progress in the design of the diffraction line.
The diffraction line...
In this contribution, we present advancements in upgrading the employed normal-conducting electron beam transport line at the JETI laser facility, University of Jena. To address spectral broadening caused by the large energy spread in Laser-plasma accelerators (LPAs), a transverse gradient undulator (TGU) with an energy acceptance of ΔE/E0 = ±10% has been developed. Although efficiently...
STFC Daresbury laboratory has developed a suite of analysis equipment for characterisation of photocathode materials. This includes the TESS spectrometer for measuring the mean transverse energy and a multiprobe surface analysis system for measuring the chemical and physical properties of samples*. Recently, the multiprobe system has been upgraded to include a monochromated X-ray source...
The plasma wakefield excited by highly asymmetric drivers has recently been the subject of extensive study. Unlike the case of axisymmetric drivers, the transverse focusing and longitudinal fields exhibit coordinate dependencies. There are still open questions regarding the longitudinal characterization of this blowout regime. In this work, we analyze the transverse dependence of the...
Recent studies explored a novel storage ring light source using steady-state microbunching (SSMB). Existing investigations predominantly focused on single-particle and pure-optics phenomena. Many SSMB schemes employ laser modulators, comprising an undulator and copropagating laser beam, to manipulate electron longitudinal bunch length. Electron bunch traversing the undulator emits coherent...
This study focuses on the detailed analysis of signals generated by the newly implemented klystron modulator system in the Taiwan Light Source (TLS) booster linac, aiming to identify optimal operation points. Key parameters under investigation include the forward signals of the Low-Level RF (LLRF) SSA, klystron forward signals, and variations in electron bunches. Additionally, the relationship...
Bayesian optimization is an effective method for designing complex systems with costly, non-analytic black box objective functions. It enables efficient exploration of the parameter space, making it well-suited for challenging problems in accelerator design which involve computationally intensive simulations such as FLUKA.
This study presents a framework to apply Bayesian optimization...
The storage ring of Taiwan Photon Source (TPS) at the National Synchrotron Radiation Research Center (NSRRC) will utilize up to four cryogenic supercon-ducting radio frequency (SRF) cavities. These cavities require significant liquid helium cooling to maintain their superconducting state at approximately 4.5 K. Thus, the TPS Liquid Helium Manufacturing System (TPS LHe system) is crucial for...
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 two 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, and a maximum voltage per gap (E0L) of 55 kV. The detailed RF and thermal design...
Complementing its contributions to the JT-60SA and ITER fusion reactors, Fusion for Energy contributes to the R&D for material characterization facilities. Under the Broader Approach agreement, Europe and Japan are developing the Linear IFMIF Prototype Accelerator (LIPAc) in Japan, a deuteron accelerator demonstrator producing neutrons by nuclear stripping reactions on a liquid lithium target,...
Ion accelerators use electron cooling to improve luminosity and beam lifetime. However, extremely low momentum spread in a cold beam weakens Landau damping, enabling the development of instabilities and potentially decreasing lifetime. To combat this, the NICA Booster electron cooling system allows to generate electron beams with oscillating energy to increase the momentum spread in ion beams....
The project NICA (Nuclotron-based Ion Collider fAcility) aims to provide colliding beams for studying heavy ion collisions in the energy range 1-4.5 GeV/u. Obtaining maximum luminosity of the collider requires powerful longitudinal and transverse cooling at collision energy. That will be achieved with usage of both stochastic and electron cooling. The 2.5 MeV electron cooling system (ECS)...
Off-axis top-up injection into 4th generation storage ring light sources is complicated due to the transverse acceptance, which is typically in the order of a few millimeters. Therefore, the characteristics and control of the incoming beam from the transfer line plays an important role in achieving successful injection. SLS 2.0, the storage ring upgrade of the Swiss Light Source, is among the...
At PITZ, a comprehensive study is conducted to analyze the factors influencing emittance growth in the European XFEL (EuXFEL) continuous wave (CW) setup. Emittance growth due to space charge effects can be mitigated using advanced photocathode laser pulse shapes. To optimize beam quality, multiobjective optimization studies using ASTRA are performed, focusing not only on minimizing emittance...
The performance results of a new super-conducting booster for the CEBAF injector at Jefferson Lab, could be of interest for other similar electron injectors. A recent addition of this new booster has provided us the ability to achieve a more adiabatic acceleration and therefore an improvement to the beam dynamics and beam brightness. It has also simplified the design and operation of the...
The MITHRA facility being commissioned at UCLA, will be capable of producing low emittance beams with 100s pC of charge with bunch lengths in the 100s of fs range having an energy of 60 MeV. This can be used to drive plasma wakefields and the long bunch length compared to the plasma skin depth allows us to create a beam with a broadband energy spectrum. The energy spectrum resembles the...
Laser plasma accelerators (LPAs) can produce high-energy electron bunches from short distances. Successfully coupling these sources with dedicated compact storage rings tuned to quasi-isochronous conditions would demonstrate the capture and storage of ultra-short electron bunches in a circular accelerator. Electron bunches generated from LPAs can have a correlated distribution in longitudinal...
Beyond 1 MW operation of the J-PARC RCS
The 3-GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has already been achieved the designed 1 MW operation to the Material and Life Science Experimental Facility (MLF). However, to cope with the gradually getting faster operation cycle of the main ring synchrotron sharing more beam requires RCS to...
To help master student understand the basic principles of a particle source, we have built a simple thermionic source with cathodes made of incandescent light bulb and other simple materials. We present here the main features of this source.
This paper presents turn-by-turn observations of internal and external filamentation within the Poincare contours of a fourth order resonance during an Accelerator Physics Experiment (APEX) in the Relativistic Heavy Ion Collider (RHIC). Beam position monitors measured the turn-by-turn evolution of the center-of-charge of the captured beam. The fraction of beam outside the island soon comes to...
The 3GeV Rapid-Cycling Synchrotron (RCS) at J-PARC supplies the beam to the Main Ring (MR). Under the current operating conditions, there is the longitudinal beam mismatch between RCS and MR. To improve the RCS-MR longitudinal matching, a method for the bunch lengthening of RCS at the extraction is proposed. The method is based on introducing a second harmonic RF voltage at beam extraction and...
The Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research continues work on the reconstruction of the U400 cyclotron into a new U400R accelerator complex designed to produce accelerated ion beams with an atomic mass in the range of A = 4 ÷ 209 and an energy of 0.8 ÷ 25 MeV/nucleon. The intensity of accelerated ions will be about 2.5 μA particles for 48Ca ions. The...
A new QWR SRF electron gun has been designed as a low-emissivity light injector for LCLS-II-HE, and a prototype is currently being developed in collaboration between SLAC, FRIB, HZDR, and ANL. The new gun will use an HZDR-type cathode, which includes a cathode load-lock (cathode stalk) developed by FRIB and a complex cathode exchange system designed by HZDR. A dedicated alignment process...
The MEDICIS facility is a unique facility located at CERN, dedicated to the production of non-conventional radionuclides for research and development in imaging, diagnostics and radiation therapy, and based on offline mass separation. It exploits a classified area for handling of highly radioactive open sources, a dedicated isotope separator beam line, a target irradiation station at the 1.4...
The Second Target Station (STS) at Oak Ridge National Laboratory is designed to produce the world’s highest peak brightness neutron source using a 700 kW proton beam at 15 Hz, which interacts with solid rotating tungsten (W) target segments. The tungsten blocks are encapsulated in a 2-mm thick copper layer that retains the radioactive products generated during the spallation reaction,...
The High-Luminosity LHC (HL-LHC) project foresees nearly doubling the design beam intensity of CERN's Large Hadron Collider (LHC). A particularly pressing issue is the observation of significant beam losses at the flat bottom in the Super Proton Synchrotron (SPS) that delivers these beams to the LHC. These losses arise from multiple factors: uncaptured beam losses that are generated during the...
We conducted time-of-flight (TOF) measurements to characterize the spectrum of a quasi-monoenergetic neutron beam driven by a 30-MeV proton cyclotron at the National Atomic Research Institute in Taiwan*. Neutrons were produced by irradiating 30-MeV protons onto a 1-mm-thick beryllium target. The developed TOF spectrometer comprised two 2-inch EJ-309 organic scintillators positioned 200 mm from...
The EuXFEL R&D project, STERN, aims to provide X-ray users with an accelerator-based THz source synchronized with the X-ray repetition rate. The main proposed THz generation method consists of electron beam wakefield excitation in Cherenkov waveguides. This work focuses on the design of a copper block that holds an array of waveguides to cover the radiation spectrum spanning from 300 GHz to 30...
Active energy compression scheme enables generating laser-plasma accelerator electron beams with a small relative slice energy spread, of the order of 10 ppm. When modulated by a laser pulse, such beams can produce coherent radiation at very high, about 100-th harmonics of the modulation laser wavelength, which are hard to access by conventional techniques. The scheme has a potential of...
The Swiss Light Source (SLS) at the Paul Scherrer Institute (PSI) was Switzerland’s first and only 3rd-generation light source. For the SLS 2.0* upgrade the old 2.4 GeV, 12-fold 3-bend achromat lattice with 5 nm horizontal emittance was decommissioned in September 2023 after 22 years of successful user operation. The new 2.7 GeV storage ring has a 12-fold 7-bend achromat lattice achieving 150...
Our understanding underscores a global demand for affordable, efficient, and compact/mobile electron beam solutions across various sectors, including:1.Replacement of Co60 sources: Co60 radiation sources must be replaced with safer and more efficient alternatives. 2.Isotope production and medical accelerator treatment: Accelerators utilized in isotope production and medical treatments...
Direct laser acceleration with radially polarized lasers is an intriguing variant of laser-based particle acceleration that potentially offers GeV/cm-level gradients while avoiding the instabilities and complex beam dynamics associated with plasma-based accelerators. Currently, the performance of this method is primarily limited by the difficulty of generating high-power radially polarized...
The muon linac has been developed at J-PARC to accelerate muons from thermal energy (25 meV) to 212 MeV using electrostatic extraction and four different types of radio-frequency cavities: RFQ, IH-DTL, DAW-CCL, and disk-loaded structures.
Although some of the technologies employed were relatively novel, most proof-of-principle demonstrations have been successfully completed through prototype...
High brightness electron beams have a wide range of applications ranging from accelerator-based light sources to ultrafast electron diffraction and microscopy. High accelerating gradient photoinjector is an important tool to generate brighter electron beams. However, high gradient photoinjector suffers issues from material breakdown due to extremely high surface electric fields. One possible...
In recent years, proton and heavy-ion therapy has become increasingly widespread in clinical applications, and has emerged as one of the important means for cancer treatment. The commonly used particle types for this therapy are protons and carbon ions. However, further research into the biological effect has found that helium ions have both high biological effectiveness and small penumbra...
Two types of beam abort mechanisms, namely, the External Abort System and the Internal Abort System for the Electron Ion Collider (EIC) Electron Storage Ring (ESR) are devised, designed and compared. Both mechanisms will be located in the Interaction region 2 (IR2). The External Abort System utilizes the ISABELLE Spectrometer tunnel to facilitate an extraction beamline and a beam dump, and the...
IFMIF-DONES is devoted to the irradiation of fusion materials, based on a high energy linear accelerator and a lithium-deuteron stripping reaction, creating the high intensity neutron source which simulates the damage on the 1st wall of the future fusion reactors.
The core of the facility are the Accelerator, Lithium and Test Systems hosted inside IFMIF-DONES Facility, in the so-called Main...
The J-PARC 3 GeV Rapid-Cycling Synchrotron (RCS) delivers the high-intensity proton beam to the 30 GeV Main Ring (MR). The improvement of longitudinal beam matching between RCS and MR is desired to suppress the beam loss in the MR. A scenario to improve the longitudinal beam matching between RCS and MR is designed. For the RCS, the bunch lengthening scheme using the unstable fixed point...
In order to exploit the scientific potential of user-oriented accelerator facilities, it is necessary to provide adequate pump sources to enable pump-probe science. The EuXFEL R&D project, STERN, aims to equip X-ray users with an accelerator-based THz source matching the high repetition rate of the XFEL. The proposed THz radiation generation methods involve Cherenkov wakefield structures and...
In order to achieve polarization control at tender photon energies at a medium energy light source, a cryogenic in-vacuum APPLE device is being developed at Helmholtz Zentrum Berlin. The project builds on the innovative design of the in-vacuum APPLE II IVUE32 also in development at HZB. The state of the magnet and mechanical design is presented, in addition to the expected spectral performance...
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. The 700 keV RFQ has been sucessfully commissioned with a 10 mA proton beam. Conditioning of the subsequent IH-type cavity has been performed up to 10 kW. We also report on RFQ emittance measurements performed with a slit grid emittance device. In...
The development of a 4th-generation storage ring (4GSR)-based light source has been in progress in Korea since 2021, utilizing a linear accelerator (LINAC) and a booster ring as injection systems. The LINAC generates a 200 MeV electron beam using an RF photocathode gun. Electron bunches produced by a UV laser in the RF photocathode gun are focused by a solenoid magnet positioned between the...
As part of the MYRRHA project, which is being implemented in Mol, Belgium, two of the planned 17 normal-conducting CH cavities have been built and tested at several kilowatts of RF power. Since the cooling concept for the stems was revised after their construction, concerns arose that the two existing cavities might have suffered a degradation in performance during high-power testing due to...
A deflecting cavity is an interesting tool providing a coupling between transverse and longitudinal planes. Several methods employing deflecting cavities have been proposed to shape current profiles or adjust longitudinal chirp. Even, a method using deflecting cavities was recently proposed for imparting arbitrary correlation on the longitudinal phase space. In this work, we introduce an...
GL2000 Gabor-lens (GL) is a 2m long device built mainly for focusing and space charge compensation of hadron beams in energy ranges up to GeV. The electron cloud is initially produced by cold-cathode method with gradually ionisation of residual gas and is confined in a cylindrical trap much longer compared to previous constructed lenses. Density measurements were carried out at the test-stand...
Flerov Laboratory of Nuclear Reaction of Joint Institute for Nuclear Research carries out the works under creating of FLNR JINR Irradiation Facility based on the cyclotron U400R. The main systems of U400R are based on the U400 cyclotron. The objectives of this project are:
- to increase the intensity of accelerated 48Ca ion beams from 1.2 puA to 2 puA;
- to expand the energy range of...
This paper presents the design of 750 MHz IH-DTL (Interdigital H-mode Drift Tube Linac) tank, specifically developed to be part of a carbon ion injector for medical treatment applications. These sections provide a highly efficient solution for ion acceleration in the 5 to 10 MeV per nucleon energy range, offering a high shunt impedance. The study includes simulations of electromagnetic fields...
Linear accelerators offer key advantages over circular machines in hadron therapy, such as rapid energy modulation and reduced activation. In this work, we optimized a 3~GHz Side-Coupled Drift Tube Linac (SCDTL) in terms of energy efficiency and the maximum achievable acceleration voltage. Comparative analyses were performed with alternative optimized configurations in TE and TM modes for ions...
This study focuses on the design and simulation of a negative hydrogen ion beam extraction system for the C30 cyclotron accelerator. The filament-driven arc discharge multi-cusp ion source, capable of producing H⁻ ions with 30 keV energy and 2 mA current. The ion source consists of two main components: the driver and the extraction system, with the latter playing a crucial role in ensuring the...
Pohang Light Source-II (PLS-II) is a third-generation synchrotron light source operated by the Pohang Accelerator Laboratory (PAL) since 2012. This study was conducted as a preliminary investigation for upgrading the linac to improve the beam operation efficiency of PLS-II. In this system, beam bunching is initially performed using a pre-buncher operating at the same frequency. To achieve more...
High-brightness, ultra-high peak current electron beams are of significant interest to applications including high-energy colliders, strong field quantum electrodynamics, and laboratory astrophysics. Despite such interest, compressing tightly-focused electron beams to attosecond pulse durations and mega-amp peak currents while preserving beam quality remains a challenge. In this work, we...
The study of high-brightness, low-emission photocathode injectors and high-gradient electron guns is an important topic in the field of linear accelerator. Research has been carried out on cryogenic photocathode electron guns to obtain higher quality beams with shorter driven laser. However, problems such as multipole fields and dark currents have been found in the research experiments. An...
Ultra-High brightness electron sources are enabling technologies for frontier applications of electron accelerators, such as FEL, UED, and UEM. Due to the higher cathode acceleration gradients and lower initial thermal emittance at cryogenic temperatures, cryogenic copper radio-frequency electron guns have the potential to achieve higher brightness. In this paper, a 2.5-cell C-band cryogenic...
In order to fill the gap of X-ray intraoperative radiotherapy technology in China, an X-band standing wave electron linear accelerator with operating frequency of 9.3 GHz was designed for X-ray intraoperative radiotherapy equipment. Using electromagnetic simulation software and beam dynamics simulation software, the outlet energy of the accelerator is 50 keV , and the electron capture...
Astatine 211 is one of the most effective theragnostics isotopes for targeted alpha therapy of cancer. Connected to a carrier that links to cancer cells when injected in a patient, this powerful alpha emitter can selectively destroy cancerous cells.
Accelerator production of 211At requires sending beams of fully stripped helium ions (alpha particles) on a bismuth target at the energy of 7.1...
The planned upgrade of the synchrotron light source at DESY, Hamburg will include an upgrade of the booster synchrotron. We discuss the considerations for the design of a slow resonant extraction from this future machine. The implementation of a bent crystal as a potential septum shadower and/or as a septumless option is considered.
A novel modular electrostatic accelerating tube, free from gap insulators, is designed that addresses the limitations of traditional metal-insulator bonded accelerating tubes*, which are costly and prone to damage from high-voltage discharges and beam impacts. This design uses ultra-high vacuum (UHV) as the insulator, with electrodes placed in series under vacuum. High voltage is coupled...
Certain types of muon experiments, such as muon spin rotation techniques and muon lifetime measurements, require beams with repetition rates around 50 kHz for optimal statistical performance. However, existing facilities are limited to pulsed beams operating at 25-50 Hz or continuous beams, both constrained by the time structure of proton drivers. Despite ongoing efforts to optimize these...
A collaboration is underway to experimentally demonstrate a novel approach using deflecting cavities to control a particle beam’s longitudinal chirp. While a series of deflecting cavities produces negative chirp, the de-chirping process requires additional modification on the beamline. It has been known that inserting negative drift sections between TDCs enables de-chirping. While the original...
NSRRC has developed a superradiant terahertz (THz) free-electron laser (FEL) that utilizes a photoinjector operating in its velocity bunching mode. This system currently achieves a maximum THz frequency of 1.4 THz, constrained by the shortest electron bunch duration of 240 fsec attainable with the photoinjector. To extend the operation THz range to higher frequencies, we are exploring the...
The high current density of HTS material allows electromagnet to induce sufficiently strong magnetic field without relying on any iron core. This permits the design of air-cored cyclotron, where the absence of iron core brings the properties of light-weight and high field reproducibility, making it an ideal medical cyclotron to be installed inside hospitals. However, the cyclotron coil system...
The AWAKE experiment at CERN makes use of a self-modulated proton bunch to excite wakefields and accelerate a witness electron bunch. Run 2c of the experiment will demonstrate stabilization of the wakefield amplitude and control of the witness bunch emittance during injection and acceleration. In this work, we present an overview of the ongoing simulation efforts to support the project as it...
The National Atomic Research Institute (NARI) is developing a 70 MeV proton cyclotron, with construction set from 2023 to 2027. The cyclotron is designed to operate at proton energies from 28 to 70 MeV and a maximum current of 1000 micro-amperes. It will serve three main purposes: (1) medical isotope production, (2) proton irradiation testing, and (3) cyclotron-based neutron source...
Multi-alkali antimonide photocathodes, particularly potassium–cesium-antimonide, have gained prominence as photoemissive materials for electron sources in high-repetition-rate FEL applications due to their properties, such as low thermal emittance and high sensitivity in the green wavelength. To explore the potential of these materials in high-gradient RF guns, a collaborative effort was...
The National Synchrotron Radiation Research Cen-ter (NSRRC) operates the Taiwan Light Source (TLS) and Taiwan Photon Source (TPS) accelerators and approximately 40 end stations, about 10 of which are dedicated to biological research. Biologists from around the world utilize these facilities to investigate the structures and functions of biomolecules and cells, advancing the life sciences....
We have started research and development of a 4K niobium-tin superconducting RF (SRF) electron accelerator system for radioisotope (RI) production. The niobium-tin superconducting RF electron linac can be operated with the compact conduction cooling system without liquid helium and large-scale equipment. The cavity-cryocooler thermal link needs a careful design as its thermal conductance will...
Effect assessments of high-energy radiations on materials and equipment are expected to become increasingly important in near future space developments. We initiated a project to construct an irradiation environment with high-energy radiations using the electron linear accelerator at Nihon University. The advantages of using this accelerator include the accelerations up to 100 MeV for...
This paper introduces the development of a global tune feedback system at the Taiwan Light Source (TLS) to address tune variations resulting from changes in the gap and phase of insertion devices. The system utilizes two families of quadrupole magnets to sustain betatron tunes at their desired working points. Adjustment currents, essential for feedback control, are computed using a tune...
Further development of a cyclotron design concept with advantages, such as energy efficiency and cost-effectiveness, is presented. The concept is optimized for non-superconducting cyclotrons. The main feature of the concept is the operation at high frequency (145 MHz) of the accelerating system.
Scaling the RF-accelerator concept to terahertz (THz) frequencies possesses several compelling advantages, including compactness, intrinsic timing between the photoemission and driving field sources, and higher field gradients associated with the shorter THz wavelength and higher breakdown threshold promising vastly smaller and cost-efficient accelerators. These benefits, however, come at the...
Since 2023, Solid-State Power Amplifiers (SSPAs) have been operational at the Taiwan Photon Source (TPS) of the National Synchrotron Radiation Research Center (NSRRC), Taiwan. The TPS employs two KEKB-type Superconducting Radio Frequency (SRF) cavities, with one cavity powered by a home-made 300 kW SSPA RF power system with a stored beam current of 500 mA. This study presents the design and...
This study presents the development of an automated learning program using Python to optimize the performance of the kicker parameters in the Taiwan Light Source (TLS) storage ring. The research focuses on enhancing storage ring current stability, improving injection current efficiency, and reducing the impact of environmental radiation in experimental areas. Through comprehensive analysis and...
At iThemba LABS proton beams, extracted from an ion source, are pre-accelerated in an injector cyclotron and further accelerated in a K200 cyclotron and transported to various target stations used for radionuclide production. To gain a deeper understanding of the various processes occurring inside the plasma reservoir of the ion source and to support operational adjustments of the ion source,...
The Taiwan Photon Source (TPS) storage ring features 172 strategically deployed Beam Position Monitors (BPMs) forming a high-precision electron orbit monitor-ing network. This paper presents an automated monitoring system that periodically extracts BPM data from the data-base and calculates standard deviations to quantify beam stability through statistical methods. The system employs a...
Center for Accelerator and Beam Applied Science of Kyushu University has been established to promote activities in various fields such as, medical, educational and engineering fields at Kyushu University. An accelerator facility, consist of a 10 MeV proton cyclotron, 8 MeV tandem accelerator and of 150 MeV FFA, has been constructed in the center. In this paper, status of the hardware...
Research on heavy ion linac was began more than ten years ago initially to improve the HIRFL operation at IMP. In China, the first continuous wave (CW) heavy ion linac, SSC Linac, working at 53.667 MHz was designed and constructed as the SSC injector. The ion particles can be accelerated to 1.48 MeV/u with the designed A/q≤5.17. At present stage, this CW linac has been put into operation and...
THz wave is wonderful prove for materials. Additionally new nonlinear phenomena are expected in spintronic devices if the peak electromagnetic field is greatly higher than 10 MV/cm (3.3 T/cm). Although coherent transition radiation from short bunches is intense, it is very difficult to exceed 10 MV/cm. However we found a possibility of which oscillator FEL reaches ~100 MV/cm employing a...
Slow beam the extraction in synchrotrons is utilized for various nuclear and particle physics experiments and radiology. A beam loss at a septum electrode induces equipment activation and damage. We have been developing a non-destructive electrostatic septum. This septum has multiple electrodes, and those are placed around the outside of the beam. Measuring the 2-D electric field distribution...
At UCLA, we’ve developed a versatile capillary discharge plasma source for plasma wakefield experiments at the MITHRA and AWA facilities. This compact device, with an adjustable length and a 3-mm aperture, is designed to transmit high-aspect-ratio beams and generate plasmas across a wide density range. Its tunable density allows us to explore the shift from linear to nonlinear plasma wakefield...
At the Japan Proton Accelerator Research Complex (J-PARC), low-emittance muon beams with a linear accelerator (linac) are proposed as a new approach to precisely measure the anomalous magnetic moment and electric dipole moment of the muon. Low-emittance muon beams can also be employed as new probes for non-destructive imaging techniques to see through structures. In the low-velocity section of...
The Advanced Light Source (ALS) has an in-vacuum undulator named “LEDA”. It was installed in 2019 and provides high-brightness, high-energy photons for the ALS macromolecular crystallography beamline, Gemini. The undulator is a hybrid design with a minimum gap of 4.3 mm, a magnetic period of 15 mm, and a photon energy range of 5–19 keV. When the device was commissioned in the ALS storage ring,...
Interaction Region 3 (IR3) of the Large Hadron Collider (LHC) houses the off-momentum collimation system, designed to remove particles with significant energy deviations. The interaction of the beam with this multi-stage collimation system generates particle showers that impact various elements, including quadrupole magnets in the straight section. Radiation exposure to magnet coils and...
The effectiveness and efficiency of a beam injection scheme is crucial
to achieve high beam intensities while minimizing possible beam losses.
The classical method for injecting from a linac to a synchrotron is
the multi-turn injection. In this scheme the quality of the injected
beam as well as of the injection scheme depends on factors as beam
emittance, type of local bump ramp,...
We present basic analytical studies on the effects of the local transverse plasma density fluctuations. We show that in two acceleration schemes (blow-out regime and hollow plasma channel) transverse plasma density gradient results in a transverse wakefield. This, in turn, may lead to significant limitations in the machine's performance. We consider the classical round driver in the transverse...
KAERI (Korea Atomic Energy Research Institute) has been operating an electron irradiation facility for electron beam application research since 2018. This facility is used for a variety of purposes, from material improvement to the development of Large composite-based products such as wind turbine blades, using electron beams. In order to support this multipurpose electron beam utilization, in...
The Advanced Wakefield Experiment (AWAKE) at CERN uses bunches from the CERN SPS to develop proton-driven plasma wakefield acceleration. AWAKE Run 2c (starting in 2029) plans for external on-axis injection of a 150 MeV electron witness bunch. The goal is to demonstrate emittance control of multi-GeV accelerated electron beams. Prior to injection, the electron witness bunch may have to traverse...
Industrial radiation processing is used on a wide variety of products, including medical devices for eradication of pathogens, food for preservation and safety, and plastics for material property modification. But millions of curies of Co-60 that are still used in some industrial sterilization facilities can pose a significant security risk in an act of radiological terrorism. Lower-cost...
Considered the current Nuclotron structure for precision EDM-experiments as an independent synchrotron storage ring equipped with electrostatic deflectors. In this regard, the design must ensure the preservation and precise regulation of spin dynamics stability. Moreover, the initial purpose of the structure as a booster of polarized beams in the collider has been preserved.
Multi-alkali antimonide photocathodes are selected as candidates for electron sources that can continuously generate electron beams with high average current, high bunch charge, and low emittance. Such electron sources are essential for the current electron cooling scheme in Electron Ion Collider (EIC) to cool the hadron beams and maintain beam luminosity. In BNL, epitaxial growth of...
APPLE-II type elliptically polarized undulators (EPUs) are critical for producing elliptically polarized light in modern synchrotron light sources. However, residual skew quadrupole components from manufacturing imperfections can couple horizontal betatron motion and dispersion to the vertical plane, changing beam size and degraded beam quality. This paper introduces a Bayesian...
The ESSnuSBplus target station will consist of one target-horn system operating under an intense proton beam of 1.25 MW power, derived from the nominal 5 MW proton beam at 14 Hz frequency from the European Spallation Source (ESS) linac. The ESSnuSBplus target features a packed bed of titanium (Ti) spheres cooled with pressurized helium gas to withstand the substantial power deposition expected...
The Taiwan Photon Source (TPS) currently operates at 500 mA beam current, with future evaluations targeting 800 mA to assess the feasibility of high-intensity operation. This imposes significant thermal and mechanical challenges on high heat load (HHL) components, such as premasks, fixed masks, slits, and absorbers, in the storage ring and front end. To systematically evaluate the severity of...
In this paper, the energy and power parameters of the electron beam have been investigated in the range of 0.5 to 3 MeV and 20 to 50 KW, respectively, with the aim of determining the optimal operating conditions to achieve maximum efficiency of industrial wastewater treatment. The findings quantitatively show the effect between the beam power, accelerator efficiency, treatment volume at...
The need for THz pulses with 100 µJs of pulse energies at a 100 kHz (or higher) repetition rate that are well synchronized with X-ray free electron laser (XFEL) pulses is paramount to studying novel ultrafast phenomena. Efficient THz generation (3 – 20 THz), coupling, and transport over long distances has posed several challenge. In particular, THz wavelengths makes it impractical to rely on...
We present an injector simulation study to explore the feasibility of a few pico-Coulombs with nanometer-emittance operation at the Argonne Wakefield Accelerator (AWA) facility. The accelerator community have utilized or explored pico-Coulomb or even lower charges to achieve a nanometer level emittance for various applications such as ultrafast electron diffraction, attosecond pulse...
The Institute for Plasma Research in India set up an accelerator-based 14 MeV neutron generator utilizing Electron Cyclotron Resonance Ion Source technology. This advanced generator can produce 1012 neutrons per second in continuous and pulse modes. By directing deuterons at a TiT target, it generates fast neutrons that are essential for various applications such as fusion experiments,...
We compare radiation from relativistic electrons (γ≫1) in magnetic undulators and ion channel betatron oscillations, addressing limitations in conventional theories for high undulator parameter (K) and K/γ regimes. Differences in magnetostatic and electrostatic oscillations lead to inaccurate trajectory and radiation descriptions. By reformulating key parameters, we enable comparisons of...
In this paper we will report on the recent progress made on FAST-GREENS experiment program at IOTA/FAST facility at Fermilab. FAST-GREENS experiment will take advantage of the superconduct LINAC in IOTA/FAST facility. A 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240...
Feasibility design of THz beamlines for the use of the superradiant THz free electron laser driven by the NSRRC high brightness photo-injector has been studied. The Accelerator Test Area (ATA) building, where the photo-injector installed, will be transformed into a THz user facility that meets radiation safety regulations. Narrow-band intense superradiant THz radiations with pulse energy as...
Plasma-based acceleration technology can revolutionize particle accelerators, enabling the realization of compact systems capable of driving different user-oriented applications.
We propose developing a laser-based, high repetition rate (HRR), highly stable and tunable plasma filament stage for beam-driven plasma wakefield acceleration (PWFA) systems. The plasma filament, generated by a...
The ideal beam coming from an RF photoemission electron gun is composed only of electrons that are produced by the incidence of the drive laser in the photocathode. The timing of the drive laser with respect to the RF fields in the gun is carefully chosen to tailor the beam properties. There are, however, sources of unwanted electrons that degrade the performance of RF photoemission guns....
RadiaBeam is developing and manufacturing a 15mm period, high temperature superconductor undulator using Magnesium Diboride (MgB2) wire at 10K-15K temperature range. This temperature range can be achieved by cryocooler, a simpler and less expensive cryogenic solution compared to a liquid helium approach. After optimizing the thermal-mechanical design, the operating temperature is finalized at...
The European Spallation Source (ESS), currently under construction in Lund, Sweden, is designed to be the brightest neutron source in the world. It will be driven by a superconducting proton linac with a design beam power of 5 MW and energy of 2 GeV. The construction and installation of the linac are completed for the initial user operation envisaged in 2026 with capability of 2 MW beam power...
The next generation of synchrotrons will have undulators with shorter periods, stronger magnetic fields, and thus higher radiation power. Consequently, concepts for reducing on-axis heat load will become more relevant. One possible idea is to introduce so-called APPLE “knot” undulators that shift the main energy peak off-axis. Thanks to almost on-axis injection, APPLE X undulators with a round...
CERN has developed a new fast pulsed septum magnet to replace the aging PS proton extraction septum. The aim is to increase the refurbishment intervals of the magnet and to phase out the old power converter, while allowing energy savings during operation.
The new system includes a novel under vacuum eddy current septum magnet, a new third-harmonic fast pulse generator and dedicated control...
FLUTE is a compact and flexible linac-based accelerator test facility at the Karlsruhe Institute of Technology (KIT) in Germany. It serves as a platform for a variety of accelerator studies and to generate intense short THz pulses for various photon science experiments. Later, FLUTE will be also used as an injector of sub-100 fs bunches into the VLA-cSR (Very Large Acceptance compact Storage...
The Force-Neutral Adjustable Phase Undulator (FNAPU) is set to revolutionize future free-electron laser (FEL) undulator designs. This innovative technology is gaining rapid traction as its compact and lightweight design offers a cost-effective solution for X-ray production. The FNAPU can be efficiently scaled to lengths of 5 meters and beyond and meet the requirements for light production with...
Variable gap undulators require large and complex motion systems to operate, making their tunability to generate specific radiation wavelengths cumbersome, limited, and slow. RadiaBeam Technologies is engaging in a project to advance undulator manufacturing by utilizing force-neutral adjustable phase undulator (FNAPU) technology developed by Argonne National Laboratory (ANL). This innovative...
The ion source at the European Spallation Source (ESS) since its comissioning in 2019 continues to support the beam commissioning phases of the Linac. In order enable comprehensive characterisation and benchmarking of the ion source's performance, as well as to facilitate future upgrades, a dedicated test stand has been constructed and is nearing completion. This test stand features an ion...
Within the framework of the NIMMS (Next Ion Medical Machine Study) initiative at CERN, a comprehensive design study is being performed for the Helium Light Ion Compact Synchrotron (HeLICS), a compact accelerator for hadron therapy. A key component of this facility is the radiofrequency (RF) cavity. Its proposed design is based on the wideband technology successfully implemented in the CERN PS...
We experimentally study the generation of THz coherent undulator radiation by electron beam at NTHZ facility which is located in USTC. Velocity bunching scheme in a travelling-wave accelerating structure is employed to produce the short electron bunch. An undulator which has 20 periods with a period length of 5.8cm and a maximum undulator parameter of 3.95 has been developed to produce intense...
As part of the program of the seventh International School on Beam Dynamics and Accelerators (ISBA'24), we carried out hands-on training with the accelerator simulation code ASTRA. A selection of students used the intensive two-hour daily course to go from learning the basics of ASTRA to designing and optimizing their own accelerators. Here we report the details of training, the student...
Undulators assembled from quasi-helices consisting of readily available magnetized ring rare-earth sectors are proposed. "Radially" magnetized sectors create a stronger field on the axis than longitudinally magnetized ones. The field value weakly depends on the number of sectors per undulator period. An experimentally studied prototype Halbach-type helical undulator of "radially" and...
A highly efficient muonium source will enable fundamental muon and precision measurements, including sensitive symmetry-violation searches. There are no U.S. muonium sources, nor available muon beams. Muonium sources internationally are significantly oversubscribed. The intense 800 MeV PIP-II linac under construction at Fermilab is capable of providing world-class muon and muonium beams with...
The Taiwan Photon Source (TPS) is a third-generation synchrotron light source located in Taiwan. Currently, it operates with two RF stations, each capable of delivering 300 kW of RF power. As the number of beamlines at TPS increases, more insertion devices will be installed, necessitating additional RF power. Presently, each RF station provides approximately 250 kW of power. To maintain...
Acceleration by plasma wakefield accelerators enables compact sources of high-brightness relativistic electron bunches. Applications like free electron lasers and particle colliders require high efficiency and low energy spread, achievable in the blowout regime, where the radial wake force is linear and independent of the longitudinal coordinate over much of the wakefield bubble. However, this...
Abstract
The possibility of charged particle acceleration by a longitudinal wake field excited in plasma by an electron bunch and a train of electron bunches is investigated. The exact solution of the stationary nonlinear self-consistent interaction of a monoenergetic relativistic bunch with cold plasma is obtained. It is shown that under certain conditions a self-acceleration of the bunch...
We present recent impedance modeling studies of the kicker systems developed for the Advanced Light Source Upgrade (ALS-U), including ferrite-loaded kickers, stripline-type fast kickers, and septa. The modeling supports the injection/extraction systems to ensure beam stability in the accumulator and storage rings. In addition, it provides guidance for component fabrication and offline testing...
Beam Delivery Simulation (BDSIM) is a Geant4 based accelerator tracking code which includes interactions of particles with material. BDSIM has become an important code in the accelerator community to simulate beam lines. Since laser and beam driven plasma wakefield acceleration (LWFA/PWFA) is a promising acceleration method we found it important to include related capability in BDSIM. This...
Developing a laser wakefield acceleration (LWFA) scheme by focusing few-TW laser pulses into a thin, dense gas target paves the way for generating high-average-current electron beams driven by a modern high-repetition-rate laser. Our previous study demonstrated that using a sub-mm nitrogen (N₂) gas cell facilitates the routine generation of 10-MeV-scale electron beams from few-TW LWFA with...
National Synchrotron Radiation Research Center (NSRRC) has been advancing its capabilities in producing intense terahertz (THz) radiation from a superradiant free-electron laser (FEL). This system utilizes a photoinjector operating in its velocity bunching mode to achieve ultra-short electron bunches. However, the highest THz frequency from the facility is determined by the shortest achievable...
Betatron radiation is the spontaneous emission of radiation produced by the betatron oscillations of electrons in a plasma during the Laser Wakefield Acceleration (LWFA) process. A high-intensity and ultra-short laser pulse is focused on a supersonic gas jet, simultaneously creating a plasma, injecting, and accelerating electrons, which then emit this radiation. In the framework of the ...
A 2.5 MeV proton injector is being constructed for the IOTA ring at Fermilab to study the interaction of nonlinear integrable optics (NIO) with high space charge beams. Space charge in the transport line from the RFQ to the injection location has a significant current dependent effect on the phase space. Simulation studies to support efficient injection of intense bunches into IOTA are...
Ionetix Corporation has been conducting research and development on compact superconducting cyclotrons for medical isotope production, with multiple Ion-12SC units installed and operated at customer sites in USA. Since 2021, we have also focused on the production of alpha-emitting medical isotopes for cancer therapy, specifically At-211 and Ac-225. As a first step, Ionetix acquired an...
The SMH16 system at CERN is a pulsed septum magnet driven by a single period of a flattened sine wave current with a fundamental frequency of approximately 2.5 kHz and a peak current of 28 kA. The magnet connects to its pulse generator via ten high-voltage, high-power cables, each containing go, return, and ground conductors and coarse shielding. Due to the high currents, magnetic field...
This study deals with the design and performance analysis of H-mode drift-tube linac (DTL) accelerators in the ultra-high frequency (UHF; 0.3 - 3 GHz) range. Simulations of typical application scenarios were performed, including particle velocities from 0.05c to 0.25c and different drift-tube internal structures. The RF efficiency of different H modes was analyzed. In addition to the shunt...
In plasma-based acceleration, an ultra-relativistic particle
bunch—or an intense laser beam—is used to expel electrons
from its propagation path, forming a wake that is devoid
of electrons. The ions, being significantly more massive,
are often assumed to be stationary. However, both theory
and simulations suggest that any sufficiently dense electron
bunch can trigger ion motion, and its...
Realization of high intensity neutrino beam over 1 MW beam power is crucial to search for CP violation in lepton sector. J-PARC Main Ring (MR) accelerator and neutrino beamline are being upgraded toward 1.3 MW beam power for Hyper-Kamiokande experiment, a future long baseline neutrino oscillation experiment in Japan, by shortening repetition cycle (2.48 to 1.16s) and increasing beam intensity...
Recent results of production of the medical radionuclides 67Cu using a laser wakefield accelerator (LWFA) are presented. This emerging technique utilises powerful, ultrashort laser pulses that are focussed into a gas jet to create a plasma wake that traps and accelerates electrons to very high energies with large accelerating gradients. Accelerated electrons interact with high-Z material to...
The Shanghai soft X-ray Free-Electron Laser user facility has open to users since 2023. The electron beam is generated by Cu photocathode, integrated in an S-band electron gun. As the photocathode quantum efficiency drops to less than 10-5, photocathode cleaning technology based on drive laser is used to improve the performance of the photocathode.
The Delhi Light source is a pre-bunched Free Electron Laser facility to generate coherent THz radiation. The electron beam is generated from a normal conducting 2.6 cell RF photocathode (PC) gun operated at 2860 MHz. The RF gun is powered by a high power RF source for a duration of 4 µs at 10 Hz repetition rate. The dark current during the operation of the RF gun has been found to be...
LCLS-II has turned into users operations since 2023 and has gradually ramped the beam rate to 16kHz to date. LCLS-II photoinjector has demonstrated low emittance beam operating at high rate. During operation, we also experienced challenges such as charge production and FEL intensity dependence to the beam rate, beam split, and emittance growth due to unexpected nonlinear field. These problems...
The Paul Scherrer Institute has developed advanced Linac gun driver electronics designed for use in Linear Accelerators, particularly for modern Synchrotron Light Sources. A prototype of this innovative gun driver was successfully evaluated during the final three months of user operations at the Swiss Light Source (SLS). The finalized design is now installed and will be integrated into the...
The University of Sarajevo Physics Department, in collaboration with CERN’s Accelerator Beam Physics group, proposes a compact linear accelerator design for applied physics research spanning from beam dynamics studies to material surface analysis. The Sarajevo Ion Accelerator (SARAI) consists of an electron cyclotron resonance ion source, a low energy beam transport line (LEBT) and a...
A muon linear accelerator is under development at J-PARC for precise measurement of the muon anomalous magnetic moment (g-2) and electric dipole moment (EDM). A disk-and-washer (DAW) structure is employed to accelerate muons from 30% of the speed of light (kinetic energy = 4 MeV) to 70% (40 MeV) at 1296 MHz. The muon DAW consists of tanks accelerating the muons and bridge couplers that couple...
The degree of spin-polarization of electrons photoemitted from unstrained, room-temperature GaAs is usually significantly less than the theoretical maximum of 50%. However, it has been experimentally observed that the degree of electron spin polarization can be increased and even exceed the theoretical maximum when the sample is cooled to low temperatures and in strained-lattice samples. The...
The PS Booster is the first synchrotron in the CERN proton accelerator complex, which delivers both high-brightness and high-intensity beams. Injection to the Booster is at a kinetic energy of 160 MeV, therefore space charge is a main limiting factors for beam quality. Maximising the longitudinal emittance and adding a second, and sometimes third, RF harmonic are measures to decrease the...
Using a Timepix3 radiation monitor, the muon rate at the Scattering and Neutrino Detector (SND) location at the Large Hadron Collider (LHC) was measured during luminosity production at the ATLAS collision point. Filters are applied on the measured data to distinguish between background radiation and the muon signal by analyzing the cluster type, length, and angle. The results were compared to...
Using a Timepix3 radiation monitor, we measured the muon rate at the proposed CODEXb experiment location within the Large Hadron Collider (LHC) during luminosity production at the LHCb collision point. Filters were applied to the data to differentiate the background radiation from the muon signal by analyzing the particle track morphology—specifically cluster type, length, and angle within the...
The Super MuSR spin rotators (SR) are electromagnetic devices with a horizontal dipolar magnetic field to rotate the muon spin by 34o and a perpendicular electric field that operates at +/-192 kV. The electromagnetic design was already presented elsewhere. The mechanical design is now complete, and the manufacturing of components has started, both of which are discussed here. The stainless...
Structured plasma channels are an essential technology for driving high-gradient, plasma-based acceleration and control of electron and positron beams for advanced concepts accelerators. Laser and gas technologies can permit the generation of long plasma columns known as hydrodynamic, optically-field-ionized (HOFI) channels, which feature low on-axis densities and steep walls. By carefully...
Cornell University has been working on developing techniques to grow single crystal photocathodes for electron sources using the Molecular Beam Epitaxy (MBE) technique. As a result, the first single crystal Cs3Sb photocathode was produced, which has shown high quantum efficiency and is expected to have a low Mean Transverse Energy (MTE). Now, other alkali materials are being explored. In this...
Superconducting(SC) radio-frequency(RF) quadrupole (RFQ) integrates the high efficiency of SC technology with the strong focusing and stable acceleration capabilities of RFQ .It is a critical development in next-generation high-performance accelerators.In this study, we present the multi-physics analysis results of a SC RFQ test cavity operating at a frequency of 280 MHz. This test cavity is...
Vertically polarized superconducting wigglers enable unique hard X-ray experiments based on horizontal optical setups. However, their implementation in modern low-emittance storage rings has been limited due to significant emittance growth. We present a vertically polarized superconducting multipole wiggler designed to reduce the impact on beam emittance. By limiting the magnetic field to 2-3...
A new design for in-vacuum undulators has been developed for the upgraded SLS 2.0 at the Paul Scherrer Institute (PSI), combining several new, beneficial concepts: modular, compact construction, integrated keepers for automated field optimization, and magnetic force compensation. This enables a scalable and relatively lightweight realization. The basis is solid aluminum vacuum chamber modules...
As the International Muon Collider Collaboration advances the conceptual design for a multi-TeV muon collider facility, new technical constraints continue to arise in the muon production stage, where a high-power proton beam interacts with a target. Achieving the required muon bunch intensity may necessitate increasing the primary beam power up to 4 MW. Consequently, the shielding design must...
High Energy Sources R&D group at Varex Imaging has developed several Accelerator Beam Centerline (ABC) and Linear Accelerator (linac) designs in the past 8 years. Here we present a summary of our recent progress. M9V linac, featuring our new ABC, is being developed to further improve characteristics of 9 MeV accelerator. The new ABC is shorter than the standard 9 MeV linac, and the focusing...
The Next Linear Collider Test Accelerator (NLCTA) facility at SLAC National Accelerator Laboratory provides unique capabilities for conducting accelerator research and testing technology with accelerator applications, as well as beam time for experiments using the X-band Test Accelerator (XTA). Test areas in the facility support high power RF testing over a range of frequencies and operating...
Accelerator-driven systems (ADSs) can accelerate high intensity ions to generate high flux of neutrons to transmute the long-lived species in used nuclear fuel (UNF) from nuclear reactors. A typical specification would be for a 1-2 GeV proton beam, comprising multi-MW-level power load on a spallation target. An alternative approach could be to produce the neutrons via breakup of 40-MeV...
In the AWAKE Run 2c experiment, two electron beams are injected into two separate rubidium (Rb) vapour sources. The first electron beam initiates the self-modulation of a proton bunch in the first vapour source, while the second electron beam serves as a witness beam for plasma wakefield acceleration with low energy spread in the second vapour source. This setup requires the precise...
Very high energy electron (VHEE) beams, with energies of 100 MeV and above, offer favourable properties for radiotherapy, such as deep penetration depth and reduced sensitivity to tissue heterogeneity. Numerous simulation and experimental studies have investigated these properties for clinical application. In this study, we use Monte Carlo simulation using TOPAS to obtain the depth-dose...
Nanostructures based on carbon nanotube arrays are emerging as promising media for achieving ultra-high acceleration gradients in laser wakefield acceleration (LWFA). In this study, we design and optimize plasmas with hexagonal lattice structures, where the lattice parameters directly define the nanostructure's properties. Using WarpX, a state-of-the-art particle-in-cell (PIC) simulation...
Photoinjector performance is a key to accessing to the sub-angstrom operation regime of the European XFEL. Optimization of the photoinjector determines the lowest possible emittance along the long accelerator beamline, thus strongly influencing the lasing performance at a given electron beam energy and undulator settings of the user facility. In this paper, an injector optimization approach is...
Plasma Wakefield Acceleration (PWFA) is a method of accelerating charged particles using a plasma. It has the potential to produce exceptionally large accelerating gradients on the order of 10’s of GeV/m. The FACET-II test facility accelerates pairs of 10 GeV electron bunches to study the PWFA process—a drive bunch to produce a wake in the plasma in a lithium-ion oven, and a witness bunch to...
Magnetic tunnel junctions (MTJs) formed by CoFeB and MgO are key components to form memory elements in magnetic random access memory (MRAM) for high-density data storage applications. A thorough understanding of the relation between properties such as magnetic anisotropy (MA) and tunnel magnetoresistance (TMR) is crucial for optimizing the performance of these devices*. These properties have...
The J-PARC main ring has three linear sections, and one have a beam collimator system downstream of the injection devices to localise beam losses. In September 2024, the seventh collimator unit was installed, completing an upgrade of the collimator system that has been underway since 2012. The system was changed from one that scatters and captures the beam halo to one that draws the jaw close...
Alkali photocathodes are vital for generating high-performance electron beams in accelerator technologies, but their production remains challenging. Current in-house fabrication methods are complex, costly, and unreliable, limiting the potential of these materials for bright electron sources. Our innovative approach seeks to commodify photocathodes, offering a ready-to-use product for...
PEEK is an advanced polymer known for its exceptional mechanical strength, thermal stability, and radiation resistance, making it a promising candidate for applications in extreme environments. This study explores the viability of PEEK as a vacuum window material in high-power radio frequency (RF) couplers. Traditionally, materials such as ceramics are employed for this purpose; however, they...
National Institute of Advanced Industrial Science and Technology (AIST) has collaborated with Nihon University to study generation of high-intensity terahertz waves using coherent radiations at the Laboratory for Electron Beam Research and Application (LEBRA) at Nihon University. In a straight section for parametric X-ray (PXR) generation, developments of various types of coherent radiation...
Since 2023, the hydrotest Epure facility, located at Valduc, Burgundy, operates as a dual-axis radiographic system for French and British nuclear deterrence programs.
Each of the two axes is a single pulse electron linear induction accelerator rated nominally at 20MeV, 2kA and driving an X-ray conversion target. The first one is in use since 2013 at Valduc, and the other since 2023. Both...
High-field micro-undulators are one of the key elements in most compact Terahertz and X-ray FEL projects. In our works, helical undulators of several helices, each made of a single piece of rare-earth magnet, are proposed for this purpose. We demonstrated previously the possibility of high-precision manufacturing helices with centimeter periods using the Wire Electric Discharge Machining. In...
Methods for medical isotope production using electron liner accelerator have been investigated in past studies. The accelerators used for medical isotope production increasingly demand high-power electron beams. In this article we present the physical design of a compact superconducting accelerator capable of providing a high average current electron beam with a current of 10 mA and an energy...
Shenzhen Superconducting Soft X-Ray Free Electron Laser (S3FEL), a continuous-wave superconducting facility aimed at providing soft X-ray FEL pulses with a repetition rate of 1 MHz, is currently under construction. These FEL pulses originate from the electron beam generated in a superconducting linear accelerator (linac). This paper comprehensively describes the physics design of the linac,...
This study develops a gas-filled plasma-discharge capillary system for laser wakefield acceleration (LWFA). Using an external high-voltage source for pre-ionization enhances plasma formation, operational stability, and laser propagation over extended Rayleigh lengths, enabling high-energy electron beams. The uniform plasma environment improves beam charge, consistency, and energy spread,...
Muons, Inc. is developing a conceptual design for a UNF Transmutation Facility that is a MuSTAR Nuclear Power Plant (NPP). It is based on a 50 MW superconducting RF proton accelerator that drives a number of subcritical molten-salt (MS) small modular reactors that each have an internal spallation neutron target. The starting points for the components are the ORNL SNS Linac and the ORNL MSRE...
The ESRF mid-term plan for the upgrade of the injection complex foresees a full energy linac option. Given the space limitations of the site, compactness is a strong design constraint and high gradient technology is a potential candidate to fulfill this goal. Beam dynamics simulations have been performed for several different accelerating structures in the S-, C- and X-band frequencies to...
Korea Multipurpose Accelerator Complex (KOMAC) proposes an energy upgrade of the 100 MeV proton linac. The design of the extended linac is based on a normal-conducting separated-DTL (SDTL) structure which has several advantages over other accelerating structures. The SDTL structure is the same as the DTL, however, unlike the general DTL, the quadrupole magnet is not placed inside the DT but is...
The injector test facility for PAL-XFEL project has been evolved into R&D facility named e-labs, where a preliminary test of MeV ultrafast electron diffraction (UED) was carried out. MeV-UED provides similar scientific opportunities as femtosecond time-resolved XRD experiments at XFEL facilities, and would be a useful tool to overcome a limited beam time problem of XFEL. MeV-UED is a...
J-PARC MR delivers 30 GeV proton beams to the neutrino facility and the hadron experimental facility, and an upgrade plan is underway to increase beam power by shortening the MR cycle time and increasing the number of particles per bunch. As a result, the beam power for neutrino experiments has achieved its original design value of 750 kW in 2023 and reached 800 kW in 2024. The target beam...
The Japan Proton Accelerator Research Complex (J-PARC) has achieved stable 1 MW operation test on its neutron target and is advancing toward higher power levels of 1.5 MW to support high-power MR operations and a second target station. This progression presents challenges, including increased intra-beam stripping (IBSt) of H⁻ ions, chop leakage from higher beam currents and emittance,...
In the J-PARC main ring (MR), a project to increase the beam power with higher repetition rates and higher beam intensities is now in progress, aiming to achieve 1.3 MW in the fast extraction (FX) mode and >100 kW in the slow extraction (SX) mode. Beam power has generally been increasing as planned with progress of hardware upgrades and beam dynamics tuning; beam powers of 800 kW (FX) and 80...
The Optically Pumped Polarized Ion Source (OPPIS) has been providing polarized H- ions to the injector chain of the Relativistic Heavy Ion Collider (RHIC) since 2000. The OPPIS has undergone several upgrades. The latest upgrade, completed in 2022, included several improvements. Optimizing the Rb and Na cells has mitigated vapor dispersion in the beamline, resulting in a significant reduction...
At European XFEL up to six superconducting undulators with 18 mm period and 1.83 T magnetic field are planned to enlarge the hard X-ray photon range above 30 keV. Currently, S-PRESSO, a prototype with 2x 2m long undulator sections plus phase shifter in a 5m long cryostat is being produced.
The SUNDAE2 (Superconducting UNDulAtor Experiment 2) magnetic field test facility aims to perform...
An emittance exchange (EEX) beamline may provide a unique capability in transferring a transverse beam density modulation into longitudinal bunching. This process can be advantageous for generating coherent radiation below the micron level, through super-radiant emission in a radiating system, or by providing a large input signal for a high gain FEL. Indeed, this mechanism has been proposed...
An accelerator-based mid-infrared (MIR) and terahertz (THz) free-electron laser (FEL) light source has been developed at Chiang Mai University, Thailand, along with experimental stations for high-field irradiation, spectroscopy, and ultrafast interaction studies. The 25-MeV linear accelerator system, serving as the electron beam injector, has been extended to support two newly developed...
A wakefield experiment at the Argonne Wakefield Accelerator (AWA) facility employs flat electron beams with highly asymmetric transverse emittances to drive plasma wakefields in the underdense regime. These beams generate elliptical blowout structures, leading to asymmetric transverse focusing forces. The experiment features a compact 4-cm-long capillary discharge plasma source developed at...
With the aim of maintaining transparent and efficient injection during top-up, a kick-and-cancel injection scheme has been developed for Diamond-II. In this, stripline kickers are used with 3 ns pulses to deflect individual bunches, with the stored bunch receiving two kicks separated by 180 degrees phase advance to leave it on-axis and the injected bunch timed to arrive at the second kick. In...
Future colliders with discovery potential for particle physics rely on increasing the parton centre of mass (pCM) energy, with the recent P5 report calling for a 10 TeV pCM collider. However, the development of such schemes using conventional accelerator technology would result in ever-larger facilities. High-gradient plasma wakefields driven by proton beams allow the transfer of energy to a...
One of the possible proofs of CP violation beyond the Standard Model may be the discovery of permanent Electric Dipole Moments (EDM) of elementary particles. To search for the EDM of charged particles, the Frozen Spin (FS) concept was first proposed at BNL. The implementation of the latter involves the creation of a special storage ring in which the spin vector is preserved along the momentum...
A prototype Beam Gas Curtain (BGC) monitor was installed on beam 1 at the Large Hadron Collider (LHC) at CERN to provide 2D images of the transverse beam profile during the ongoing Run 3 (2022 - to date) and in view of the High Luminosity LHC upgrade (HL-LHC). By design, the BGC operation generates collisions between the beam particles and an injected gas jet proportionally to the beam...
The Hefei Advanced Light Facility - Accelerator Test Facility (HALF-ATF) is equipped with a linear electron accelerator capable of achieving a maximum energy of 120 MeV, which is utilized for the debugging of the pre-injector and essential equipment. The electron beam is produced by an electron gun and subsequently accelerated to 120 MeV via a buncher and accelerating tubes, ultimately being...
The HEARTS@CERN activity in the framework of the HEARTS (High-Energy Accelerators for Radiation Testing and Shielding) EU project is targeted at enhancing Europe’s high-energy (>100 MeV/n) heavy ion electronics irradiation capability through the development of an irradiation beam combining unique penetration and ionization characteristics. These types of tests are essential for exploiting...
The Advanced Photon Source (APS) continues developing novel SCUs, several of which have operated for a decade, delivering high-brightness, hard X-ray beams for scientific research. As part of the APS Upgrade, eight new NbTi SCUs were planned. While cryogenic and support systems were in place, challenges in scaling magnet lengths and reducing periods led to magnet failures and fabrication...
Simultaneous irradiation with mixed helium and carbon ions is being proposed for online range verification in carbon radiotherapy. In 2024, a mixed $^4$He$^{2+}$ and $^{12}$C$^{6+}$ beam, generated by sequential injection of helium and carbon ions into the synchrotron, was extracted successfully for the first time at the MedAustron ion beam therapy and research center. This double injection...
Radiation processing technology started in Tunisia by the installation of a pilot plant gamma irradiator in 1999 and an electrons beam accelerator in 2009 at the National Centre for Nuclear Science and Technology CNSTN. These facilities are established with the support of the International Atomic Energy Agency IAEA. The electrons-beam facility is equipped with CirceIII Linac accelerator, 10...
At J-PARC MR, proton beams are supplied to the neutrino facility via fast extraction (FX). The beam power, which was 500 kW in 2021, reached 800 kW by June 2024, with further upgrades planned. This increase in power has led to a rise in beam loss in the FX section, necessitating countermeasures. Residual doses are high at positions where the FX beam orbit closely approaches the aperture, and...
Most muons injected into a muon collider decay into an electron (or positron) and a neutrino-antineutrino pair, producing a narrow disk of high-energy neutrinos emitted tangentially to the beam in the collider plane. These neutrinos reach the Earth’s surface at distances far away from the collider. Vertical diffusion of the neutrino cone, reducing integrated neutrino flux at any surface exit...
To realize high-precision single-ion irradiation or implantation, we have proposed a nanobeam formation scheme where single cold ions selectively separated from a two-component Coulomb crystal in a linear Paul trap (LPT) are accelerated to 100 keV and focused on the nanometer scale using electrostatic bipotential lenses. The entire process of laser cooling of trapped ions in the LPT,...
A stored proton beam may become unstable when the horizontal tune slowly approaches a quarter integer resonance.This paper discusses this phenomenon in the context of an Accelerator Physics Experiment that was conducted in the Relativistic Heavy Ion Collider, in which the horizontal tune was ramped through a fractional tune of 0.75 in the presence of strong octupolar fields.
After more than 40 years of services the 2856~MHz linac injector of The Canadian Light Source (CLS) has been retired to leave space for a new 3000.24~MHz linac injector, the frequency of which is a multiple of the 500.04~MHz CESR-B type superconductive radio frequency cavity. The new CLS linac injector has been designed and built by RI Research Instruments GmbH. The design is based on their...
Polarized electron beams play critical role in fundamental physics research by providing additional observables and opening new channels of discoveries. T GaAs crystals illuminated by circular polarized IR lasers remain the best choice for generating polarized electrons. All current polarized sources are an electrostatic electron guns providing necessary extreme (XUV) vacuum conditions for...
The Variable Energy Gamma (VEGA) system is under implementation in Bucharest-Magurele (Romania) as one of the major components in the project of Extreme Light Infrastructure Nuclear Physics (ELI-NP). Photon beams will be resulting from the Inverse Compton Scattering of laser photons off relativistic electrons. VEGA is dedicated for photonuclear research both in applied and fundamental physics...
Stable peak surface electric fields in excess of 200 MV/m are achievable at cryogenic temperatures in test cavities due to emprical reductions in RF breakdown rates. In order to fully capitalize on these effects, the complex physics at RF cavity interfaces in extreme conditions must be further understood from a basic physics perspective. Even before the onset of RF breakdown several precursor...
The CERN Super Proton Synchrotron (SPS) Radio Frequency (RF) system was upgraded as part of the Large Hadron Collider Injector Upgrade (LIU) project, and now comprises six 200 MHz travelling wave structures, each fed by a separate RF power amplifier. While the upgrade was targeting the peak power for capture and acceleration of the beams for the High Luminosity LHC, it also brought an increase...
In general, it is not easy to measure the drifting RF properties of a device during its operation. If the scatter matrix changes depending on the temperature, the vector network analyzer provides only a static or a starting point of the thermal development. In particular, it is impossible to fully characterize the component that has more than two ports only by the online measurement. So, in...
THz technology being a highly growing and potent field, finds use in a wide range of research applications. Delhi Light Source (DLS) at IUAC, New Delhi is at final stage of commissioning to produce intense and coherent THz radiation based on pre-bunched Free Electron Laser principle. As an addition to the narrowband undulator radiation, broadband Coherent Transition Radiation (CTR) will also...
The PAL-EUV storage ring has been designed to provide extreme ultra violet (EUV) beams, and is currently under commissioning. With a circumference of 36 m and an electron beam energy of 400 MeV, injection from the booster to the ring is achieved using a nonlinear kicker. Successful injection requires precise tuning of the kicker’s timing delay and maximum strength to match the injected beam’s...
A tandem accelerator is a type of electrostatic accelerator that utilizes the high-voltage terminal twice to achieve higher ion energy. In this accelerator, a charge exchange cell is positioned between the low-energy and high-energy sections of the accelerating tube, converting the negative ion beam into a positive one. The charge exchange cell can be categorized into two types: gaseous charge...
CEA is committed to delivering a study for a warm linac in the frame of the ICONE project. It aims at accelerating an 80-mA beam of protons up to 25 MeV, with a 6% duty cycle. The LINAC consists of: a proton source with low-energy beam transport line, an RFQ, a medium-energy beam transport line, and a warm DTL. All these components must be tuned at 352.2 MHz, to reach the required output...
Reducing beam loss during slow extraction remains a critical challenge for the J-PARC Main Ring, which aims to enhance beam power for its 30 GeV proton beam. Since beam loss during slow extraction mainly occurs at the electrostatic septum, it is important to reduce beam loss at this location. Researchers at CERN SPS have recently reported that beam loss can be reduced by installing bent...
The Compact Linear Accelerator for Research and Applications (CLARA) is an electron test facility capable of delivering tunable 250 MeV electron beams with up to 250 pC charge to the Full Energy Beam Exploitation (FEBE) experimental area . In this study, we investigate the feasibility of conducting beam-driven plasma wakefield acceleration (PWFA) experiments using the CLARA beam and...
We present an electromagnetic characterization and beam dynamics study of nanostructured plasmonic copper photocathodes for electron gun applications. The study concentrates on photocathodes operated at ultraviolet and infrared wavelengths. Various types of nanopatterns are explored in order to understand how different geometrical parameters affect light reflectance. Optimized nanostructure...
AWAKE (Advanced Wakefield Experiment) is the world’s first proton-driven plasma wake field acceleration experiment and has demonstrated the acceleration of electrons to several GeV’s in its first Run. The goal of Run2 is acceleration of a witness bunch whilst preserving beam quality and experiment scalability. AWAKE drives high gradient plasma wake fields using a proton beam, then a secondary...
Within the realm of general relativity, the measurement of signals coming from relativistic celestial bodies have offered great insights. However, the relatively low frequency of these signals and the lack of control over their source may make the creation of well-controlled laboratory environments desirable. One possibility is to measure the relativistic beams in the Large Hadron Collider...
Thermionic cathodes are well known as a robust source of electrons for a wide range of accelerator applications. In the case of Barium Oxide cathodes the low work function that allows emission at modest temperatures is achieved through a surface coating. This coating can be damaged from both ion bombardment and, in the case of RF sources, electron bombardment. Lifetime models that predict the...
A high-power 3-GeV proton beam from a rapid cycling synchrotron (RCS) is transported to targets for muon and neutron production at Materials and Life Science Experimental Facility (MLF) by a 3-GeV RCS to Neutron facility Beam Transport (3NBT) line in J-PARC. Recently, the design power of 1 MW has been achieved, which has initiated a future plan of MLF second target station (TS2). For the...
Laser Wakefield Accelerators (LWFA) offer a promising solution for producing high-energy electron beams in compact setups. Beyond obtaining the required energy, the beam quality (emittance, energy spread, intensity) must also be optimized for LWFA to be considered an alternative to conventional accelerators. Achieving precise control of the transverse beam dynamics is one of the key...
Novel acceleration schemes aim to address the need for higher acceleration gradients which enable to minimise the size and costs of particle accelerators. One of these novel accelerator schemes is the dielectric wakefield acceleration (DWA), where an electron bunch is accelerated by the longitudinal wakefields generated within a dielectric lined waveguide by a leading drive bunch with higher...
The information on phase space in all six dimensions is required for various accelerator experiments. We developed an algorithm based on Convolutional Neural Network (CNN) that can be used instead of the traditional back projection techniques because it is less computationally intensive and has a simple architecture. Our method has shown consistency with the simulation, and we plan to validate...
The pioneering ORION project will integrate a biosafety level 4 (BSL-4) laboratory with the SIRIUS synchrotron light source. The project includes three beamlines: TIMBÓ, HIBISCO, and SIBIPIRUNA, optimized for X-ray microscopy on biological materials. This study focused on evaluating Insertion Devices (IDs) for the TIMBÓ and HIBISCO beamlines, which demand high photon flux in the ranges of 3–20...
Recently, two SIRIUS beamlines, EMA and PAINEIRA, received their definitive insertion devices (IDs). Both IDs are in-vacuum devices (IVUs), the first of this kind at SIRIUS. Due to the proximity of the IVU cassettes to the electron beam, the spectrum emitted by these devices is highly sensitive to misalignments of the ID magnetic center. Such misalignments can result in photon flux losses,...
Resonant slow extraction is routinely used to provide ion beams to various users. At GSI SIS18, two extraction methods are implemented: quadrupole-driven and Radio Frequency Knock Out (RF-KO) extraction. In either case, delivering a defined beam intensity (spill) without fluctuations or drifts is desired for an efficient beam usage. The Spill Optimization System (SOS) was developed to address...
SPS-II is the fourth generation electron storage ring in
Thailand. The medium-sized ring constructed with a Double-
Triple Bend Achromat (DTBA) cell provides low emittance
and high capacity for the beamlines. To complement the
compact storage ring with DTBA cell, a Non-Linear Kicker
(NLK) was chosen for beam injection. This approach not
only simplifies the injection system by reducing...
The construction of a low-emittance 3-GeV linear accelerator as an injector system of a new high-brilliance synchrotron radiation facility “NanoTerasu” was completed in January 2023. After beam commissioning of the accelerator complex for several months, the synchrotron radiation for user experiment was provided in April 2024 as planned [*]. The 3-GeV compact linear accelerator consists...
A Dielectric Disk Accelerator (DDA) is a metallic accelerating structure loaded with dielectric disks to increase coupling between cells and group velocity, while still maintaining a high shunt impedance. This is crucial for achieving high efficiency, high gradient acceleration in the short pulse acceleration regime. Recent research of these structures has produced traveling wave structures...
The Japan Proton Accelerator Research Complex supplies a high-intensity proton beams for the physics experimental programs in the Material and Life Science Facility (MLF), the Hadron experimental facility and the neutrino target. In such a high-intensity hadron accelerator, losing less than 0.1% of the beam can cause several problems. Such lost protons can cause serious radioactivation and...
Up to six superconducting undulator modules are foreseen to be installed downstream with respect to the permanent magnet undulators of SASE2, one of the two hard X-ray lines at European XFEL. Aim is to provide users with photon energies above 30 keV. The superconducting undulator pre-series module (S-PRESSO) is currently under production.Before installation in the tunnel, the magnetic...
The 1st article NbTi SCU consists of two 1.5 m-long superconducting undulators (SCU) installed in a single cryostat that will occupy an entire straight section in the upgraded storage ring at the Advanced Photon Source. Installation is planned during the winter shutdown of 2025/2026. The initial design of the magnets proved to be difficult to successfully implement and a new design was pursued...
The operation of the specifically upgraded pulsed gas stripper development setup for the user beamtime lasted until July 2024. It was very successful in terms of both providing stripped ions and gaining valuable experience in the long-term operation of the pulsed stripper. The long periods of high duty nitrogen operation revealed a severe service life issue of the fast injection valves, which...
At the Joint Institute for Nuclear Research (JINR), we use an RF photo-gun generating electrons via UV laser-driver and accelerating them up to 5 MeV to make a source of the so-called vortex electrons with a quantized orbital angular momentum projection onto the propagation axis. Such electron beams with a low current have previously been obtained only at electron microscopes with the highest...
The Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is a transformative approach to ion-beam therapy and radiobiological research. Serving the Ion Therapy Research Facility (ITRF), LhARA proposes to use a laser-driven proton and ion source, combined with advanced beam delivery systems, to provide highly flexible, high-repetition-rate, and ultra-short ion bunches suitable for...
Laser-plasma accelerators have demonstrated the ability to accelerate high-energy electrons but require improved beam stability and repeatability for practical applications. Pre-formed plasma channels enhance the stability in Laser-Wakefield Accelerators by maintaining laser focus over longer distances, increasing energy transfer efficiency. The characteristics of such channels are highly...
The PITZ accelerator comprises a radiofrequency photogun and an RF booster cavity, capable of generating electron beams with bunch charges of several nC and momenta of up to ~24 MeV/c. To achieve higher beam currents which is a key parameter for the single-pass high-gain THz FEL, a four-dipole chicane is installed upstream of the undulator. Given the low beam energy and high bunch charge,...
Korea Multi-purpose Accelerator Complex (KOMAC) has been preparing 200 MeV energy upgrade. As a possible upgrade choice, separated drift tube linac (SDTL) type is considered in this study. From 2D analysis, optimum cell design deriving maximized effective shunt impedance and minimized Kilpatrick number is obtained. Then, final tank parameters considering stems, slug tuners, vacuum ports are...
The development of high-intensity, high-quality ion sources is essential for advanced applications such as particle beam therapy and nuclear physics experiments. The aim of this study is to integrate the Laser Plasma RF Ion Source (LaPRIS), currently under development, into the cyclotron at the Research Centre for Nuclear Physics (RCNP) in order to accelerate ion bunches with high precision...
The traditional APPLE-KNOT undulator forms composite magnetic fields by superimposing APPLE fields and KNOT fields with the period ratio of 2:3. The APPLE field serves as the main component to approximate the target photon energy, while the KNOT field acts as an additional component to transversely deflect the electron beam away from axis. Variable polarization states can be generated with a...
Currently, in the J-PARC linac, beam commissioning between the ion source and RFQ mainly involves adjusting the extraction voltage of the ion source and the two solenoid magnets in the Low Energy Beam Transport line (LEBT) installed between the ion source and the RFQ. These parameters are determined to maximize the measured beam current at the current monitor (SCT) downstream of the RFQ....
Cs-Sb compound thin-film photocathodes are an excellent candidate to produce bright electron beams for use in various accelerator applications. Despite the virtues of these photocathodes being known, the mechanics that govern their photoemission are not well-understood. Crystalline and other material properties affect the mean transverse energy (MTE) and quantum efficiency (QE) and, thus, the...
Acceleration by the wakefield in the plasma can provide compact sources of relativistic electron beams of high brightness. Free electron lasers and particle colliders, using plasma wakefield accelerators, require high quality bunches with predictable profile. Previous studies showed that the resonant sequence of electron bunches appears to be unstable due to the destruction of the bunches. In...
Magnesium (Mg) has been demonstrated to be a safe, stable, and reliable photocathode for both normal-conducting and superconducting RF guns.
Pure magnesium, with its low work function of 3.6 eV, exhibits significant quantum efficiency (QE) improvement — by up to two orders of magnitude — following appropriate surface cleaning procedures. This study investigates the chemical processes...
Alkali antimonide photocathodes exhibit high efficacy as photoemissive materials in electron sources. This proceeding explores the fabrication of thin, ordered films of sodium potassium antimonide via molecular-beam epitaxy (MBE) at the PHotocathode Epitaxy Beam Experiments (PHOEBE) laboratory at Cornell University. Utilizing a sequential deposition technique, the photocathodes are...
FRIB is the first linac to deploy a large number of half-wave-resonators (220 HWRs) and the first heavy ion linac to operate at 2 K. Such key technology has enabled FRIB to operate as the world’s highest energy continuous-wave hadron linac and highest-energy heavy ion linac delivering world’s highest uranium beam power (>10 kW) on target. The key technological experience may be shared with our...
Pyroelectric neutron generators have been one of the research hotspots in the field of neutron generation due to their advantages of compact structure and controllable intensity. A novel laser pyroelectric neutron generator was proposed by utilizing 1064nm wavelength pulsed laser irradiation on LiTaO3-Mo-TiDx for simultaneous heating and ionization. The laser irradiation on the pyroelectric...
The linac refurbishment program is an initiative to modernize the linear accelerator (linac) at the Advanced Photon Source (APS) for the APS Upgrade (APS-U). This program addresses critical operational challenges, including obsolete components and the need for higher beam energies. Key projects involve upgrading RF stations to 50 MW capacity using modern klystrons , solid-state modulators, and...
The University of Melbourne's Xband Laboratory for Accelerators and Beams (XLAB) is collaborating with CERN on the design and testing of high-gradient accelerating structures. Together with the Australian Synchrotron (ANSTO), we are developing the X-Band Electron Test Accelerator (xBeta), a compact high-gradient electron accelerator.
The system will feature a photogun to generate short...
The Experimental Storage Ring (ESR) at GSI Darmstadt, Germany is the core instrument for unique physics experiments. It is operated for accumulation, storage, cooling and deceleration of a wide range of heavy ion beams in the energy range from 4-400 MeV/u coming from the synchrotron SIS18 via the FRagment Separator (FRS) or a direct transport line. Low energy decelerated beams can also be fast...
The CERN Linear Accelerator for Research (CLEAR) is a versatile 200 MeV electron linac followed by an experimental beam-line, operated at CERN as a user facility. Its user community includes research groups working on beam instrumentation R&D, advanced acceleration techniques and irradiation studies, including medical applications. A recent internal review has confirmed the excellence of its...
The ENUBET and NuTAG projects propose the measurements of the $\nu_e$ and the $\nu_\mu$ cross sections at the relevant energies of Hyper-Kamiokande and DUNE. While ENUBET focuses on a fully instrumented decay tunnel to achieve a precise flux measurement, NuTAG proposes the use of silicon-pixel detectors to achieve the \textit{full tagging} of the parent meson and the daughter lepton. Both...
Super Tau Charm Facility - Beam Test Platform (STCF - BTP) is a verification facility for Super Tau Charm Facility. A complex radiation environment consisting of particles with different types and energies will be produced. An advanced monitoring system is being developing to measure the radiation dose rate for STCF - BTP. The radiation monitoring system combines the function of data...
Plasma acceleration is a rapidly maturing technology, but is not yet ready for large-scale applications such as linear colliders. The SPARTA project aims to develop a near-term, medium-scale plasma-accelerator facility to enable new experiments in strong-field quantum electrodynamics (SFQED)—an application that requires solving two of the most important remaining challenges in plasma...
The Shanghai Proton Therapy Device (SAPT) is the first domestic proton therapy system, and China has a truly self-developed and marketable domestic high-end proton therapy device. The gantry is an important part of the proton therapy device, which has the characteristics of large inertia, large size, and large weight, and at the same time requires high motion positioning accuracy and...
Understanding performance and limitation of CsTe photocathodes under high field gradients in a radio-frequency gun requires adequate theoretical models for material properties, photoemission and surface morphology. We are developing a suite of models based on Density Functional Theory (DFT), moment and Monte-Carlo (MC) photoemission models, and meso-scale material surface model informed by DFT...
Tomographic reconstruction of beam distribution using four wirescanners has been carried out and a comparison is made with the Allison scanner data at the RAON. Tomography technique which is valid under strong space charge effect is applied in the LEBT, MEBT and SCL sections. Also comparison is made with method to get beam parameters using wirescanner rms beam sizes
Axions, originally introduced to solve the strong CP problem, are leading dark matter candidates appearing in various Standard Model extensions. At low masses, axion-like particle (ALP) dark matter behaves as a classical field, potentially detectable when its frequency resonates with a beam's spin-precession frequency.
The JEDI collaboration's proof-of-principle experiment at COSY set upper...
Superconducting radio-frequency (SRF) electron linear accelerators (e-linacs) provide significant advantages over conventional room-temperature accelerators, especially in their capacity to accelerate high-intensity continuous-wave (CW) beams. Recently, the first liquid helium-free (LHe-free) Nb₃Sn SRF cavity was successfully operated at the Institute of Modern Physics of the Chinese Academy...
The time-of-flight (nTOF) facility at CERN uses neutrons produced by a proton beam interacting with a fixed target. To prevent target damage, an upper bound on the peak energy density has been imposed. Adhering to this constraint requires a large beam size. Similarly, at CERN’s North Area, a large beam size is required at the septa splitting the beam towards different experiments. However,...
Irradiation with mixed helium and carbon ion beams is emerging as a promising approach to treatment monitoring in ion radiotherapy. In contrast to mono-isotopic beams, the full characterization of the mixed beam requires distinguishing ion species of almost identical charge-to-mass ratio, which is not feasible with most conventional beam diagnostic devices. This proceeding proposes a...
Plasma wakefield acceleration in the filament regime can provide wakefields suitable for high-gradient, high-quality positron acceleration while maintaining stability. However, the energy that can be extracted by the positrons is limited. Recent works have proposed accelerating a supplementary electron recovery bunch along with the positron bunch to extract more energy from the wake and...
We report on recent progress in transverse instabilities and transverse tolerances for plasma-wakefield accelerators in the blow-out regime. In this regime, the transverse fields provide both strong focusing and strong deflection via transverse wakefields. The deflection effect of the wakefields on the main beam leads to limitations on the acceleration efficiency, if not mitigated. Based on...
The energy layer switching time is a limiting factor for hadron therapy, precluding fast beam delivery and reducing treatment efficacy. For rapid energy switching the beam delivery system must be achromatic with zero dispersion over a large energy range. At the University of Melbourne, the TURBO project will utilise Fixed Field Accelerator techniques to demonstrate transport of a ±42% momentum...
Twin electron bunches accelerated by high-energy linacs are attracting increasing interest especially in twin free-electron laser (FEL) pulse generation and beam-driven plasma wakefield acceleration (PWFA) studies. High-energy linacs may benefit from plasma accelerators, where a trailing bunch is accelerated in GV/m fields in a plasma wave driven by the leading bunch. This could facilitate...
The Shanghai Synchrotron Radiation Facility (SSRF) project team developed two in-vacuum undulators (IVUs) with a period length of 18.5 mm and a gap of 4 mm for the SIRIUS. This paper introduces the design and magnetic field measurements. The results indicate that with a gap range of 4-20 mm, the phase error is less than 3°, the quadrupole field is less than 37 Gs, the sextupole field is less...
As a new scheme, High Energy Electron Radiography (HEER) was considered as one of the novel mesoscale diagnostic methods for high energy density matter (HEDM) because of powerful penetration, high space-time resolution and large density dynamic diagnosis range. In this work, we R&D a practicle cascade HEER composed of a electromagnetic beamline and a permanent magnet HEER in High Energy...
At the MAX IV 1.5 GeV ring, two APPLE II undulators with period lengths of 84 mm (Bloch) and 95.2 mm (FinEstBeams) cover minimum photon energies of 7 eV and 4 eV, respectively. Operating below 80 eV, the polarization state is distorted significantly by the beamlines' optical elements. A combination of helical and linear inclined modes during undulator operation - the so-called universal mode -...
In the slow extraction operation of the J-PARC Main Ring (MR), ensuring the uniformity of the extracted beam's time structure (“spill structure”) is crucial. One primary factor distorting the spill structure is the random fluctuation of the horizontal tune caused by current ripples in the main magnet power supplies. To address this issue, a system called the "tune ripple canceller" has been...
The ThomX Compact Compton Source comprises an electron linac, an electron storage ring and a Fabry-Perot cavity. The electrons interact with laser photons at the intersection of the storage ring and the Fabry-Perot cavity. The facility started its commissioning in 2021 and the first X-rays were observed in June 2023. The operation energy was increased from 50 MeV to 70 MeV in 2024. We present...
Muons, Inc. and its collaborators propose to improve solid uranium spallation targets to provide more neutrons per incident proton, longer lifetime, and corrosion control for:
The design of Muons Subcritical Technology Advanced Reactor (Mu*STAR) combines two remarkable ORNL accomplishments: the 1 GeV Superconducting Proton Linac of the Spallation Neutron Source (SNS) and the 1965-1969...
Single crystal alkali antimonide photocathodes have been shown to produce brighter beams than their polycrystalline counterparts. These single crystal semiconductors require a lattice matched substrate to be grown, but current INFN plugs lack the capability for this growth. To relieve this issue, we modified the INFN plug to hold a disk 1cm in diameter. This allows for studies of a wide range...
The elliptical in-vacuum undulator (IVU) IVUE32 is being developed at Helmholtz-Zentrum Berlin (HZB). The APPLE-II design allows for not only gap changes but also longitudinal shift movements, putting additional design challenges on the tapers at the entrance and exit of the undulator. The chosen design philosophy separates the gap and shift movement compensation into two assemblies...
We present the analytical solution for the transverse and longitudinal wakefields in a perfectly conducting elliptical cavity following from a conformal mapping formalism. These closed-form results are corroborated by numerical calculations. Simple representations of the dipole and quadrupole modes as a function of the cavity dimensions then precipitate, permitting the analyses of the beam...
To study the electric dipole moment of light nuclei, it is necessary to maintain the direction of the spin along the particle's motion along the ring. The first obvious solution to this problem is to use elements with an electric field that rotates the spin in the direction opposite to the spin rotation in a magnetic field. The most successful solution in this case is the Wien filter, which...
In this paper, we present an experimental demonstration of the high-gradient operation of an X-band, 11.424 GHz, 20-cells linear accelerator (linac) operating at a liquid nitrogen temperature of 77 K. The tested linac was previously processed and tested at room temperature. Low-temperature operation increases the yield strength of the accelerator material and reduces surface resistance, hence...
The KEK injector linac injects high-charge electron and positron beams into the high-energy-ring and low-energy-ring of SuperKEKB respectively. The linac also injects electron beams to the two light source rings, PF ring and PF-AR. We operate simultaneous top-up injections into the four rings by using many pulsed magnets. We have been upgrading the linac to attain the higher-quality beam...
The Canadian Light Source (CLS), a 3rd generation synchrotron light source, has operated the CESR-B type superconducting radio frequency cavity since 2005. We report on 20 years of operating experience of the facility with this type of accelerating cavity.
This work presents techniques for non-invasive transverse profile measurements of high-intensity proton beams using an Electron Beam Profile Scanner (EBPS). The EBPS utilizes low-energy electrons as a probe to analyze the transverse size of proton beams, allowing for potential analysis on a single-bunch basis. Recent upgrades to the Fermilab Main Injector have enhanced beam power on target to...
Magnetic hysteresis and eddy current decay continue to challenge beam quality and operational consistency in multi-cycling machines like the Super Proton Synchrotron (SPS) at CERN. Building on our previous work, this paper presents improvements in the data-driven approach for magnetic field modelling to enhance the reproducibility of SPS dipole and quadrupole fields and thus maintain stable...
Superconducting materials such as niobium have been extremely useful for accelerator technology but require low temperature operation ~2 K. The development of high temperature superconductors (HTS) is promising due to their operating temperatures being closer to that of liquid nitrogen ~77 K. This work aims to determine the high-power RF performance of these materials at X-band (11.424 GHz)....
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 as a proof of concept for direct additive manufacturing of linac components. In this design, the internal drift tube structure has been produced from pure copper using AM. We present the most recent results from high-power tests with...
To ensure patient safety, treatment effectiveness, and facility efficiency, each ion beam therapy facility requires a complete online characterization of the charged particle beam. Existing dosimetry methods are either limited in the information they provide or invasive to the beam, highlighting the need for new in-vivo dosimetry solutions. Since 2015, the QUASAR Group at the Cockcroft...
The long term sustainability of future accelerators is now a crucial problem for our community. Many groups and collaborations are actively working in this area (e.g. European projects included IFAST and iSAS, RUEDI (STFC) has recently published a case study for the project lifecycle, Centre of Excellence in Sustainable Accelerators is now being vigorously pursued in the UK with CERN backing,...
EM (electromagnetic) field around a relativistically ac-celerated charged particle is known to be squeezed longi-tudinally. This behavior is called the Lorentz contraction, and no inconsistent phenomena have been found. How-ever, an experiment has not directly confirmed the Lo-rentz contraction of the EM field. The first direct observa-tion of the Lorentz contraction of the EM field was...
Cryogenics is a key enabling technology for present and future particle accelerators and detectors, providing the conditions required for the operation of superconducting magnets, superconducting RF cavities, vacuum systems, and particle detection devices. However, extracting heat at very low temperatures requires large amounts of energy, often representing a major share of the total energy...
Xsuite is a Python toolkit for modelling and simulation of particle accelerators, which has been developed at CERN together with collaborators from other institutes over the past four years. The code has reached a mature development stage and has become the workhorse for several studies and applications, allowing the gradual replacement of legacy tools like Sixtrack, COMBI, PyHEADTAIL. This...
The auto differentiable simulation is a type of simulation that outputs of the simulation contain not only the simulation result itself, but also its derivatives with respect to many input parameters. It provides an efficient method to study the sensitivity of the simulation result with respect to the input parameters and can be used in some gradient based optimization methods for fast...
ALBA is a 3rd generation synchrotron light source located in Barcelona, Spain. The circumference is 268.8 meters and electrons are stored at 3 GeV. In the framework of the upgrade towards the 4th generation light source ALBA II, an active 3rd harmonic RF system at 1.5 GHz is foreseen to increase the Touschek lifetime component. The system will be installed and available for operation in the...
In this study, we designed a hybrid dipole magnet that integrates both permanent magnet and electromagnet technologies. The primary magnetic field is generated by the permanent magnets, while the coils enable fine-tuning of the field. The design carefully considers the placement of the permanent magnets and coils to optimize performance. Additionally, an outer plate mechanism is incorporated...
Round beam operation offers significant benefits for synchrotron radiation experiments and reduces intra-beam scattering effects in diffraction-limited light sources. This paper proposes a method for round beam generation based on global skew quadrupole settings and the application of the Non-Dominated Sorting Genetic Algorithm (NSGA). Two coupling schemes, large emittance coupling via...
High-resolution X-ray spectroscopy in the sub-nanosecond to femtosecond time range requires ultrashort X-ray pulses and a spectral X-ray flux considerably larger than that presently available. X-ray free-electron laser (XFEL) radiation from hard X-ray self-seeding (HXRSS) setups has been demonstrated in the past and offers the necessary peak flux properties. So far, these systems could not...
LCLS-II first stage commissioning is completed in the summer of 2023, with demonstration of 93 kHz electron beam and 1 kHz FELs using the superconducting CW linac. Operation-based electron beam and FEL commissioning has been continued with the goal of ramping up beam rate, improving the FEL performance, and developing advanced FEL operation modes. We started 33 kHz x-ray FELs to user...
To introduce the Heavy Ion Therapy Center of Taipei VGH and share the experience of its construction, installation and commissioning.
The recent P5 Report calls for a 10 TeV parton center-of-mass (pCM) collider, for which advanced wakefield accelerators are a candidate technology. Design studies are being developed including particle sources, damping rings, and linacs based on plasma and structure-based wakefield accelerators. Compact Beam Delivery Systems may be possible using plasma lenses, requiring understanding of their...
The SLS consists of a 100MeV linac, a 2.7GeV booster synchrotron with 9nm horizontal emittance and the storage ring (SR). The old 12-TBA SR with 5nm horizontal emittance operating at 2.4GeV was turned off in 09/2023 after 22 years of successful user operation. In course of the SLS 2.0 upgrade project the 288m circumference SR has been replaced by a 2.7GeV 12-fold 7-bend achromat lattice with a...
The versatile 1.3 GHz superconducting radio-frequency (SRF) gun at HZB succesfully generated first photoemission beam from a high quantum efficiency (QE) multi-alkali photocathode. This demonstrates worldwide first beam operation of a SRF gun at high repetition rate and with a robust multi-alkali Na-based photoemissionn source. The setup of the test and all sub-systems is described. The latest...
We will review interesting advances we have been able to perform in the domain of laser-driven generation of proton and neutron beams, using the new ultra-high power Apollon laser facility (France)*. Thanks to the ability to tailor the ultra-short timescales of the temporal pedestal of the laser pulse, we have notably been able to accelerate protons in a “lighthouse” fashion, whereby the...
In ultra-low-emittance synchrotron light sources, the bunch-lengthening technique is useful to mitigate harmful effects due to the intrabeam scattering. The perfomacne of the bunch lengthening can be degraded by the transient beam loading (TBL) effect induced in the cavities. To mitigate the TBL effect, we proposed a TBL compensation technique using a wide-band longitudinal kicker cavity. In...
Compensation of the 3Qy resonance at injection energy in the LHC is of significant interest, given its potential to degrade the lifetime of high-intensity beams. In the absence of dedicated corrector circuits for the 3Qy compensation of each beam at low energy, an alternative approach is needed. Using skew-sextupoles in the four common experimental insertions it has been possible to develop a...
The Radiofrequency Quadrupole (RFQ) is the initial accelerating device in many modern linear accelerators (linacs), such as the European Spallation Source (ESS), where it accelerates protons from 75 keV to 3.6 MeV. Due to its complex geometry, RFQ beam dynamics are typically studied using finite element solvers, which, while accurate, are computationally intensive and unsuitable for online...
HEPS is a nearly finished fourth-generation photon source with a 6 GeV energy storage ring. When machine protection is activated in the storage ring, the low beam emittance causes most particles to deposit nearly vertically on the collimator. This can result in concentrated heating, potentially leading to material melting of the collimator. Thereby, two pre-kickers are used to generate 4.52 µs...
Radio frequency quadrupole (RFQ) is one of the first cavities in a protons or ions accelerator. It aims to focus, bunch, and accelerate the beam, using a high-intensity electric field concentrated between rods or vanes. At CEA, similarly to other labs, a method to evaluate the inter-vane voltage and to tune the cavity (usually with 4 vanes) has been developed, based on the bead pull...
Intra-Beam Scattering (IBS) remains one of the primary mechanisms of emittance blow-up and performance degradation in the Large Hadron Collider (LHC) accelerator chain. The phenomenon is particularly relevant following the recent injector upgrades to achieve the high-brightness beams required for the High Luminosity LHC (HL-LHC) era. Traditional IBS models, as those already implemented in...
The Institute for Nuclear Physics of the University of Mainz operates the accelerator complex MAMI. Outstanding qualities are the continuous beam with an excellent beam quality, a very low energy spread, as well as its extremely high reliability. All kinds of channeling experiments require such a high quality beam with a low divergence. Positrons, however, are more preferable because they have...
The application of a 10 Hz repetitive induction synchrotron (IS) to the next generation of heavy ion therapy drivers is under investigation *. The IS is characterized by the use of a pulse voltage to accelerate the beam, but until now, due to technical limitations, the magnitude of the pulse voltage could not be perfectly matched to the acceleration conditions. Instead, a pulse density...
TM020-mode cavity with a higher quality factor and a lower R/Q as compared to TM010 cavity is an attractive candidate for RF system of Super Tau-Charm Facility. However, the symmetrical electromagnetic field distribution at radial nodes is diluted by the introduction of a high-power input port and cavity frequency tuners. This results in the leakage of the accelerating mode and a weak damping...
To meet the requirements of collider rings of Super Tau-Charm Facility (STCF) with a beam current of up to 2 A, a TM020-mode cavity with improved performance is designed in this paper. In order to address the issues of leakage of accelerating mode into the slots which has dampers inside, a choke geometry is introduced for this cavity. Through optimizations on this choke, the accelerating mode...
The SEALab facility in Berlin is home to an R\&D superconducting radio-frequency (SRF)photoinjector setup and beamline. Designed to support multiple varied applications - ranging from Energy Recovery Linac (ERL) to Ultrafast Electron Diffraction (UED) and Electron-Beam Water Treatment (EBWT) - SEALab requires flexible, high-precision tuning to support these diverse beam modes. These...
Accurately simulating the thermal and mechanical effects of undulator power density distribution in high heat load components requires precise power implementation in finite element analysis (FEA) models. This study presents a novel methodology utilizing intermediate programming to efficiently map complex undulator power density distributions onto FEA models. The approach enables the placement...
For years, Instrumentation Technologies and ScandiNova have developed advanced products to optimize RF performances in LINAC applications. In 2024, the companies began integrating the Libera LLRF system into ScandiNova modulators during assembly. This innovation enables the modulators to offer enhanced operational flexibility and improved performances.
This paper will focus on mechanical...
The Karlsruhe Research Accelerator (KARA) has undergone a significant modernization of its power supply infrastructure, including dipole, quadrupole and sextupole magnet systems. These updates, completed by replacing the storage ring quadrupole power supplies in summer 2024, introduce improved stability, reduced energy consumption, and advanced control capabilities.
The new controls and...
Dynamic aperture (DA) is a crucial metric for understanding nonlinear beam dynamics and particle stability in circular accelerators like the Large Hadron Collider (LHC) and its future High-Luminosity LHC (HL-LHC) upgrade. Traditional methods for DA evaluation are computationally intensive, requiring extensive tracking of large particle ensembles over many turns. Recent advances in machine...
This study explores beam dynamics in the development of high intensity cyclotrons, focusing on the challenges posed by space charge effects at high beam intensities. Space charge forces, which become significant in high-current operations, can lead to emittance growth, beam loss, and instability, compromising cyclotron performance. Advanced modeling techniques are employed to analyze and...
The KIT cSTART project (compact STorage ring for Accelerator Research and Technology) aims to demonstrate the injection and storage of a high intensity ultra-short electron bunch in a large acceptance storage ring using the FLUTE linac and a laser plasma accelerator (LPA) as injectors. Amongst the unique features of the cSTART project is the wide dynamic range of machine and beam parameters to...
Manipulation of an electron beam by Laguerre-Gaussian (LG) modes is investigated using finite-difference time-domain particle-in-cell (FDTD-PIC) simulations. The azimuthal velocity profiles of macro-particles exhibit a 3-D spiral pattern with the number of strands equal to a sum of the state number of spin angular momentum and the orbital angular momentum of LG modes. These spiral patterns...
The transverse beam halo population in the Large Hadron Collider (LHC) has been found to carry a significant fraction of the total stored beam energy, potentially reaching several percent. With the anticipated increase in beam brightness for the High Luminosity LHC (HL-LHC), this poses an increasing risk to machine safety, particularly during abrupt orbit shifts or critical component failures....
The low-frequency components of the impedance drive coupled-bunch instabilities in electron synchrotrons. In the Diamond-II storage ring, the geometric component of the impedance of some vacuum vessels is comparable in strength to the resistive-wall impedance. This study compares the growth rates of all coupled-bunch modes obtained through simulations and analytical calculations....
This paper presents observations collected during the LHC operation with proton beams in 2024. In particular, a systematic analysis of the beam and machine parameters along the run reveals that the emittance evolution at the LHC injection plateau and during collisions cannot be fully explained by Intra-Beam scattering, synchrotron radiation and electron cloud effects, thus indicating that some...
The Hefei Advanced Light Facility (HALF) storage ring employs a hybrid six-bend achromat lattice with long and short straight sections. In this paper, main resonance lines of on- and off-momentum dynamic apertures (DAs) of the HALF lattice are analyzed by using frequency map analysis and considering $\beta$-beat. The combined effect of a fifth-order structural resonance and a half-integer...
In the present study we provide a simple model and a physics insight into the recently discovered Skew Wakefield Effect*. We show that the effect posses certain complexity as along with the rotation of the principle axis of the quadrupole wake there exist an overall increase in the wake transverse wake amplitude.
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. In this work we present the current status of the development of the nonlinear EM solver, in ACE3P which includes nonlinear material with application to quantum nonlinear...
Total electron emission yield (TEEY), defined as the number of electrons emitted per incident electron of a given energy, is potentially the source of two major problems: electrostatic discharges (ESD) in vacuum and multipacting effect. To mitigate these risks, a possible solution could be to coat the surfaces prone to ESD or multipacting originate with a thin film with tunable TEEY and...
AtomicAndPhysicalConstants.jl is a Julia package designed to provide atomic and physical constants including the speed of light, subatomic particle properties, atomic isotope properties, etc. Values are obtained from CODATA (Committee on Data of the International Science Council), NIST (National Institute of Standards and Technology), and PDG (Particle Data Group) datasets for physical...
A novel wireless method for beam coupling impedance measurements is currently under development, with preliminary measurements on beam pipes serving as proof of concept for its validity. This innovative approach overcomes the limitations of existing methods by not only evaluating impedance with high accuracy but also enabling the characterization of an unknown Device Under Test (DUT) as it...
The side-coupled standing wave accelerator tubes have a wide range of applications in linear electron accelerators due to their relatively high acceleration gradient and relatively low sensitivity to manufacturing errors. In the NSTRI-eLinac project, a dual energy electron linear accelerator is defined for cargo applications. In this accelerator, a side-coupled standing wave tube accelerates...
Developing medical accelerators for clinical use presents significant challenges, particularly for FLASH radiotherapy, where specific beam parameters are essential to activate the FLASH effect. At Sapienza University, a new electron FLASH LINAC is being developed, designed to deliver FLASH electrons and adaptable for very high-energy electron (VHEE) applications. This work focuses on...
A series of experiments has been carried out at CERN to derive the damage limits of superconductor strands and sample coils. The latest experiment was designed to characterize the limits of Nb3Sn racetrack sample coils impacted by a 440 GeV/c proton beam at cryogenic temperature. The effect of a beam impact on superconducting coils aged by long-term radiation exposure, however, is currently...
In view of ensuring the successful completion of the third operational run of the Large Hadron Collider (LHC) and preparing for the High-Luminosity LHC era, a systematic assessment of the risk of failure of all the vacuum interconnection modules installed in the accelerator is being carried out. This was prompted by a significant pressure rise in 2023, localized near an interconnection module...
The J-PARC Main Ring achieves a high extraction efficiency of 99.5% during 30 GeV slow extraction at the current beam power of 80 kW. However, at beam powers above 30 kW, we observed ring-wide beam losses due to transverse beam instability associated with vacuum pressure rises and electron cloud effects, which are believed to be triggered by longitudinal microwave structures. To achieve stable...
The main ring synchrotron (MR) of the Japan Proton Accelerator Research Complex (J-PARC) provides high power proton beams to neutrino and hadron experiments. Since we are planning to increase the beam intensity from current $2.3 \times 10^{14}~$protons per pulse (ppp) to $3.3 \times 10^{14}~$ppp, we need to reduce the beam loss. In the J-PARC MR, the space charge is one of the main causes of...
The components of the SIS100 synchrotron (FAIR facility) are presently under installation in the accelerator tunnel. The superconducting dipole magnets have been produced and the magnet field errors up to 7th order have been measured for all magnets. The superconducting quadrupole magnets are under production, the field error data for a part of the magnets is available. As a part of the magnet...
The PUMA (antiProton Unstable Matter Annihilation) experiment at CERN aims to explore the interaction of antimatter with exotic isotopes, utilizing the unique capabilities of CERN’s ISOLDE facility and Antiproton Decelerator. This contribution presents recent advancements in the beam transfer lines optics studies relevant to the success of the experiment, and to ISOLDE’s operation in general....
The Delhi Light Source is an upcoming user facility for coherent THz radiation and electron beam. Electron beam of energy upto 8 MeV generated from a RF photo-cathode gun will be used for coherent THz generation from a planer undulator. The beam after passing through the undulator field will be separated from the THz and THz line by a $60^{o}$ achromatic section and delivered to electron...
Optics studies in the LHC are generally performed on low-intensity, non-colliding beams. Understanding the optics perturbation from beam-beam effects however, is of significant interest. This was particularly true for the LHC in 2024, where the 3Qy resonance driven by the long-range beam-beam (LRBB) contributed to breaking of the collimator hierarchy, limiting beta* reach and luminosity. By...
SIRIUS is the 4th generation synchrotron light source of the Brazilian Synchrotron Light Laboratory (LNLS). In mid 2024 the storage ring had a major upgrade on the rf system, with the replacement of the PETRA 7-Cell rf cavity by two superconducting (SC) CESR-B cavities. It was antecipated that after the upgrade the longitudinal coupled-bunch instabilities (LCBIs), previously driven by the...
To achieve the design luminosity of $1 \times 10^{35}\ \text{cm}^{-2}\text{s}^{-1}$, the Super Tau-Charm Facility (STCF) adopts an extremely low $\beta_y^*$ and a crab waist (CW) collision design. The extremely small vertical beam size at the interaction point and low vertical emittance required to achieve a beam-beam parameter of around 0.1 make the CW colliders highly susceptible to beam...
Effect of the transverse instability driven by the resistive wall impedance in the PF-HLS (Photon Factory Hybrid Light Source) 2.5GeV storage ring are investigated and compared with three methods: an analytical method with azimuthal modes, a Vlasov solver DELPHI and beam tracking code MBTRACK2**.
The PF-HLS is proposed as the successor machine to the PF-2.5GeV ring and the PF...
Intra-beam scattering (IBS) has recently gained significant interest in the community of free electron lasers (FELs), as it is believed to produce an increment in the sliced energy spread (SES), which is detrimental to FEL performance. To control and contain this phenomenon, it is important to include IBS in the design phase of an FEL through appropriate numerical simulation. Most existing...
Observations of betatron tune evolution during LHC beam injection have revealed a significant tune error, strongly correlated with beam intensity. This finding highlights limitations in the existing feedforward corrections based on Laslett coefficients. A dedicated machine development study was conducted to refine intensity-dependent tune corrections. Utilizing high-precision, per-bunch tune...
The 4th generation synchrotron light source, BESSY III, is expected to enable high-impact applications for users in life science, material science, energy and catalysis materials, and more. Currently in its Conceptual Design Report (CDR) phase, the feasibility of BESSY III's ambitious parameter range necessitates a thorough assessment of "collective effects". These phenomena can either...
Currently in its Conceptual Design Phase (CDR), the 4th generation light source BESSY III aims to become a world-leading soft X-ray source, enabling numerous applications in metrology, life sciences, energy and catalysis materials, and many more. Its performance relies on ultra-low transverse emittances, achieved through the use of strong focusing magnetic elements that are sensitive to...
The CERN-SPS transverse impedance model plays an important role in predicting beam stability and guiding machine operation. This work advances the benchmarking of the SPS vertical impedance model through experimental investigations of mode-zero instability growth rates and intensity-dependent tune shifts as a function of chromaticity. Building on insights from previous measurement campaigns,...
Controlled longitudinal emittance blow-up is indispensable for the operation of the Large Hadron Collider (LHC) to counteract single-bunch loss of Landau damping during the acceleration ramp. The blow-up is performed by injecting RF phase noise in a narrow frequency band into the beam phase loop, with bunch-length feedback regulating the noise amplitude. In 2024, the variation of the bunch...
Study of bunch lengthening effect in SSMB storage ring using STABLE program.
Relativistic vortex electrons carrying orbital angular momentum (OAM) may provide a novel tool for applications in atomic, nuclear, and particle physics. A straightforward approach to produce such particles involves generating vortex electrons using conventional methods, such as fork-like holograms or magnetic monopoles, followed by their acceleration in a linac. While the azimuthal symmetry...
The CERN Proton Synchrotron Booster (PSB) delivers a wide variety of high-intensity and high-brightness proton beams to several destinations, including operations at the Large Hadron Collider (LHC) and various fixed-target experiments. Following the Long Shutdown 2 (LS2) upgrades, discrepancies between beam measurements and macro-particle simulations were observed, highlighting the need for a...
To enhance the performance of superconducting radiofrequency (SRF) cavities, a promising solution involves depositing a superconducting material onto copper RF cavities. A prerequisite for this process is the electropolishing of the copper cavities. At Jefferson Lab (JLab), a modeling study of the electropolishing process for 1.3 GHz copper cavities was conducted. This paper focuses on two...
The 5 MeV beamline of Phase B+ which is an intermediate commissioning stage of the Linear IFMIF Prototype Accelerator (LIPAc) consists of an MEBT, an MEBT Extension Line (MEL) where the SRF will be installed, a HEBT, and a beam dump. It has 17 quadrupole magnets, and some quads have small aperture-to-length ratios and are also densely installed in the MEBT and HEBT sections. In the early...
The purpose of this research is to characterize proton beam properties - beam energy, energy spread, beam size, and transverse emittance - to establish the initial setup for simulation in planning cancer cell culture experiments at the Cyclotron Medical Accelerator at King Chulalongkorn Memorial Hospital in Bangkok, Thailand. The characterization was performed using GEANT4 Monte Carlo (MC)...
We study the coherent synchrotron radiation instability in a novel synchrotron light source concept, steady-state microbunching storage ring.
One of the major goals of the cSTART project (compact STorage ring for Accelerator Research and Technology) at KIT is injecting and storing ultra-short bunches from the FLUTE linac into a very large-acceptance compact storage ring. To cope with the spatial constraints of the injection line connecting FLUTE with the storage ring three meters above, compact quadrupole-sextupole magnet units were...
The analysis and mitigation of collective beam effects, such as coherent synchrotron radiation (CSR), is a significant challenge in the generation of high-brightness beams. To this end, considerable effort has been invested in the development of simulation tools to accurately characterize the CSR generated by a bunch following a curved trajectory. In particular, with codes like LW3D and CoSyR,...
Superconducting radio frequency (SRF) cavities are, along with superconducting magnets, indispensable technologies for modern particle accelerators. The current cooling method for SRF cavities is immersion in liquid helium bath, which is ideal in terms of cooling because the entire outer surface of the cavity can be maintained at liquid helium temperature. On the other hand, using helium has...
Superconducting magnets, RF cavities, undulators and wigglers are widely employed for particle accelerators and cooled under the cryogenic condition below 100 K. This paper describes the cryogenic cooling schemes of superconducting devices and the sources of the cooling power capacities: refrigerators, cryoplants, and cryocoolers. Their main features, such as temperature, pressure, and cooling...
In 2023 the beam commissioning of low energy superconducting linear accelerator (SCL3) of a heavy ion accelerator, RAON have been finished in Daejeon, Korea by Institute for Rare Isotope Science (IRIS) in Institute of Basic Science (IBS). The purpose of this accelerator is the generation of rare isotope by ISOL (Isotope Separation On-Line) and its acceleration for the nuclear physics...
Beam-Beam simulations are currently being studied in preparation for future EIC experiments to study beam-beam effects and, in turn, maximize luminosity. Weak-strong methods are studied for single-particle dynamics during collision. 1 million macro-particles for 1 million turns are typically tracked, corresponding to only 10 seconds in the EIC. The goal of this study is to predict beam...
The SHINE project requires more than six hundred of 1.3GHz cavities and sixteen 3.9GHz cavities for the superconducting accelerator. These cavities are from both domestic and foreign companies. Surface defects, such as cat-eyes, aluminum inclusions and scratches, are one of the most important factors strongly related to RF performance of cavities. The multiplicity of sizes, depths and...
In recent years, several new beam manipulation techniques have been proposed that exploit the crossing of nonlinear resonances and the use of stable islands of the transverse phase space. One such manipulation is a novel approach to slow extraction, which combines particle trapping in stable islands with the use of bent crystals to reduce losses on the extraction septum. As a first step...
The permanent-magnet in-vacuum undulator technique is critical for the Taiwan Photon Source(TPS) at the National Synchrotron Radiation Research Center(NSRRC). Before installing the magnet arrays in the vacuum chamber, the phase error of the undulator is optimized by adjusting the magnetic field. Optimizing phase errors is a complex and time-consuming task. The conventional measurement method...
SCK CEN is developing MYRRHA, a large-scale Accelerator Driven System. MYRRHA shall be a subcritical nuclear reactor driven by a high-power linear proton accelerator, which sustains the nuclear reaction. In the initial phase, known as the MINERVA project, the goal is to demonstrate the high reliability requirements on the accelerator. The two primary end users of the MINERVA project are the...
This paper presents the design and implementation of a power distribution and monitoring system for a high-power RF solid-state amplifier (SSPA) system at the Taiwan Photon Source (TPS). The system consists of four SSPA towers delivering a combined RF power of 300 kW. Given efficiency and safety considerations, a robust distribution and protection architecture was implemented. The system...
The RF window has to withstand several megawatts of RF power without experiencing any physical deformity to maintain the pressure difference between vacuum and isolate gas sides. It must also have suitable and acceptable RF performance with minimum reflection and insertion loss. The design of an RF window depends on the window materials' dielectric characteristics, such as dielectric constant,...
For multi-unit RF amplifier systems, a 2300 W solid-state RF power amplifier module with integrated EtherCAT and USB interface has been developed. The RF amplifier section is constructed from the latest LDMOS from Ampleon with a power of 2300 W at an efficiency of 72 % and is fully shielded and offers space for adding a driver amplifier or phase shifter circuit. The module is equipped with a...
RF loads are critical components in any high-power rf system. There are two types of commonly used rf loads in multi-megawatt systems: water loads and dry loads. Water loads have a ceramic window separating vacuum from the water. Use of water loads in large scale rf systems is risky because of the possibility of water leaking into vacuum. At SLAC multi-megawatt dry loads were developed and...
The Super Tau-Charm Facility (STCF) project plans to use 12-15 TM020-mode cavities for each collider ring to compensate for the beam energy loss. Each cavity is designed to provide a voltage of 0.5 MV and a power of 250 kW for the beam. Therefore, an online adjustable waveguide coupler with a power capacity of CW 300 kW has to be developed for each cavity. This input coupler has a waveguide...
In the J-PARC muon g-2/EDM experiment, a three-dimensional beam injection scheme will be adopted to inject a 300 MeV/c muon beam into a compact storage orbit. In this scheme, a low-emittance muon beam with X-Y coupling is injected from the edge of a solenoidal magnet and guided to a compact beam storage region where the magnetic field is precisely tunned for a muon g-2 measurement with a good...
LhARA, which stands for “Laser-hybrid Accelerator for
Radiobiological Applications”, is a novel and flexible facil-
ity dedicated to research in radiobiology. A proton beam
of energy up to 15 MeV can be produced by a laser driven
source, the beam then enters a Fixed Field Alternating (FFA)
gradient accelerator for acceleration to produce a variable ex-
traction energy between 15-127 MeV....
The grid control power supply of the electron gun of the free electron laser (FEL) is a high frequency pulse power supply (HF-PPS), which has a special time structure. The macro pulse repetition frequency of the HF-PPS designed in this paper is 10 Hz, and the micro pulse repetition frequency is 476 MHz.
The high broadband field-gradient RF system based on direct oil-cooling magnetic alloy cavity for High Intensity Heavy-ion Accelerator Facility (HIAF) Bost Ring (BRing) has been successfully reached and developed in Oct. 2022. The RF system consists of a three gaps cavity which loaded by 24 domestic nanocrystalline soft magnetic alloy (MA) ring cores, a RF power amplifier with an output power...
A non-linear kicker (NLK) is designed for the beam injection into the storage ring of Siam Photon Source II. The required deflection angle is 4 mrad, the effective length is 400 mm and the peak field is 100 mT at the horizontal position of 9 mm from the magnet center. The design is based on 8-wire configuration where the conductor position is symmetric along the xz and yz planes. The vertical...
The interaction region IR6 in the Electron Storage Ring of the planned Electron Ion Collider facility at Brookhaven National Laboratory includes a section to rotate the electron spin into or out of the longitudinal direction. This section consists of superconducting solenoids, and normal conducting dipoles and quadrupoles. The geometry and field gradient requirements of the quadrupoles pose a...
Fixed Field Alternating gradient accelerators (FFA) hold
promise for pulsed high intensity applications. No such
FFA has been constructed to date; therefore a prototype -
the Front End Test Stand-FFA (FETS-FFA) has been pro-
posed to explore the feasibility of using FFA technology for
the next generation spallation neutron source, ISIS-II. A key
component of this prototype is its main...
The Siam Photon Source II (SPS-II) represents Thailand’s second synchrotron light source, designed to enhance the region’s scientific capabilities by providing high-energy, high-intensity synchrotron light for both academic and industrial research. The SPS-II will be situated in the Eastern Economic Corridor of Innovation (EECi) in Rayong Province. The SPS-II accelerator complex comprises...
RadiaBeam has designed and manufactured a fast-ramping alpha magnet (FRAM) that is developed for interleaved operation at the Advanced Photon Source (APS) at Argonne National Laboratory. This interleaving operation requires the alpha magnet to stably complete a 5 s long cycle with a 100 ms ramp-up, 1s nominal field output and a 100 ms ramp-down. A laminated yoke is used to minimize eddy...
From 2010, the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) carried out the relevant testing and research work on the RF Cavity loaded magnetic alloy materials firstly, and explored the development process of high-performance magnetic alloy (MA) cores with domestic manufacturers and research institutes jointly. Through the long-term exploration from small...
To perform high electric field experiments for evaluating the vacuum breakdown characteristics of accelerator materials, we have developed a high-voltage pulsed power supply capable of providing a 10 kV peak voltage, 1 µs pulse width, and 1 kHz repetition rate. This system is designed to reliably apply intense fields to metallic electrodes with load capacitances up to 650 pF. To ensure...
We have been developing a compact pulse power supply with output pulse waveform specifications of 75kV/40A/50us/25Hz. This power supply is used to drive klystron for muon linac, which requires high stability and reliability. Next-generation power semiconductor SiC-MOSFETs with excellent characteristics of ultra-high breakdown voltage and low loss at 13kV, which were realized through the...
This study presents a multi-module parallel current output system based on the correction magnet power supplies (CMPS) of the TPS storage ring. An N+1 re-dundant control interface card was designed to enable high-current, bipolar modular parallel output. The system integrates external DCCTs and current feed-back signals from the internal module. After PI com-pensation, these feedback signals...
The R&D of the radio frequency (RF) power distribution system (PDS) for the International Linear Collider is ongoing. The PDS is designed to drive 39 superconducting RF (SRF) cavities by a 10 MW multibeam klystron. The key feature of the PDS is the usage of power dividers and phase shifters, which allow driving all cavities below their respective operational limits over the whole flattop. This...
The China Spallation Neutron Source Upgrade Project (CSNS-Ⅱ) will use two debuncher cavities to supplement the beam energy at the end of the linear accelerator. The PI mode structure operating at room temperature is chosen, and each debuncher cavity is equipped with an online adjustable waveguide coupler. The main body of the coupler is the WR1500 waveguide, and a hole on the narrow wall of...
Our 6 MeV medical C-band accelerating structure is assembled using the disk-stacked method, where multiple oxygen-free copper components are stacked along the beam axis. The design incorporates the side-coupled (SC) structure and the re-entrant structure with an accelerating gap at the center of the cavity. Due to the complex shape and the large nunber of components, there are challenges in...
Currently, pulsed power supply systems with output power of several GW, output voltage of several hundred kV, and pulse width of 100 ns are difficult to miniaturize and portability is a limitation for industrial applications. We are developing a pulsed power supply with an output power of 4 GW, an output voltage of 200 kV, and a pulse width of 100 ns, which is 1/20th the mass of conventional...
We have been developing an X-band transverse deflector system (XB-TDS) with sub-fs time resolution, which will be installed after the undulator sections at SACLA. A sub-fs XFEL pulse is desirable for user experiments such as the measurements of structural disordering in an XFEL interaction with a matter, as the degree of damage depends on the pulse duration. The demand for a shorter and...
Hefei Advanced Light Facility (HALF) consists of two main components: the injector and the storage ring, the core of the facility includes nearly one thousand magnets, of which there are more than one hundred conventional dipole magnets and longitudinal gradient bend magnets.The longitudinal integral field and its uniformity of these dipole magnets are typically measured by the Hall probe...
A stretched wire measurement system was developed for magnetic field measurement of magnet prototype for Siam Photon Source II. It is used for magnetic field integral measurement for characterization of multipole field errors, magnet centering and fiducialization of multipole magnets. The wire trajectory across magnet aperture can be either linear or circular. The maximum wire movement is ±100...
The power coupler is one of the most important components for superconducting cavities. Different from the normal conducting cavity, the superconducting cavity has to keep an ultra-high cleanliness environment for operation. As the vacuum barrier, power couplers are welded by many different materials and maybe the gas source since they are installed to the cavities after vertical test,...
We have developed a new SLED-type RF pulse compressor for powering ultra-high gradient X-band photoinjectors with pulse lengths shorter than 10 ns. Klystrons capable of generating these short pulses at multi-MW levels are non-existent. However, RF pulse compression is an alternative technique used to increase klystron output peak power at the cost of pulse length. Over the years, we have...
In the International Linear Collider (ILC) main linac, superconducting quadrupole (SCQ) magnets combined with dipole correctors, together with superconducting radio frequency (SRF) cavities, will be used to transport and accelerate electron and positron beams to the collision point. The SRF cavity accelerates the beam up to 125 GeV per side, the SCQ focuses the beam, and the dipole collectors...
Coherent Synchrotron Radiation (CSR) plays a critical role in beam dynamics, significantly influencing beam shape and energy characteristics in particle accelerators. This study investigates the CSR effect through a comprehensive numerical approach, starting from the fundamental Lienard-Wiechert equation and utilizing an explicit, non-approximated methodology to explore beam energy dynamics....
The evaluation of dynamic aperture (DA) under time-dependent variations of lattice parameters is essential for understanding the long-term stability of particle motion in the Large Hadron Collider (LHC) and enhancing the future performance of the High-Luminosity LHC (HL-LHC). In this work, we develop DA models that address the complexities introduced by time-varying effects, with a focus on...
The dynamic aperture(DA) is one of the most important parameters of nonlinear beam dynamics in storage rings. It describes the transverse phase space region where the motion of a particle can remain stable. In the design and optimization of storage rings, long-term particle tracking is usually required to ensure an sufficient DA. However this process is very time consuming. This study explores...
We simulated the dynamic problems in the SSMB storage ring, such as TMCI, through the dynamic simulation software elegant and discovered its instability threshold current intensity.
C-band technology holds the potential to generate a high-energy, high-brightness electron beam by elevating the peak field of both the cathode and cavity within the machine. This proposed injector offers a promising avenue for achieving kHz operation. The conceptualization of this injector draws inspiration from the EuPRAXIA@SPARC_LAB S-band injector, wherein the gun is replaced with a...
Coupled bunch instability was observed during beam commissioning of CSNS/RCS. The instability was successfully suppressed by installing sextupoles to control chromaticity. The instability exhibits characteristics influenced by the strength of space charge. We conducted a theoretical study on the effects of chromaticity and space charge on coupled bunch instability and compared results with...
The behavior of high gradient rf cavity is improved via the reduction of RF breakdown rates by operating at cryogenic and temperatures. These studies are largely empirical but they present a new paradigm in the future of high gradient capital operation. Peak electric fields >200 MV/m are sustainable at S and C band frequencies. These fields while sustainable produce more dark current than is...
Recently, two SIRIUS hard X-ray beamlines, EMA and PAINEIRA, were upgraded by replacing their previous insertion devices (IDs) with SIRIUS’s first in-vacuum undulators (IVUs). These new IDs have a period of 18.5 mm and can achieve a peak magnetic field of 1.24 T at a minimum gap of 4.3 mm. This paper reports on the effects of these new light sources on the electron beam, including static and...
For the upgrade of SOLEIL II a new booster with reduced transverse and longitudinal beam sizes is required. The new booster follows a 16 BA Higher-Order Achromat lattice with a reduced emittance to about 5 nm rad at 2.75 GeV. At the end of the ramp an emittance exchange is foreseen to allow for more flexibility in the injection parameters into the storage ring. In order for a good efficiency...
Fast orbit feedback systems are an important component in fourth-generation synchrotron radiation sources such as PETRA IV at DESY in Hamburg, Germany. These control systems are designed to stabilize the particle orbit, i.e., to correct deviations from the design orbit due to various disturbances. To that end, such a system employs fast orbit corrector magnets, which must be powered at...
Recently, artificial intelligence and machine learning are actively discussed in the particle accelerator community. The physics-informed neural network (PINN) method, which is a powerful approach for solving differential equations with deep neural networks (DNN), has been successfully applied to the calculation of electromagnetic fields and beam coupling impedances in particle accelerators....
The Future Circular Collider (FCC)-ee is a planned electron-positron collider under development. The future collider would be built in an about 91 km ring-shaped underground tunnel located beneath the French departments of Haute-Savoie and Ain, and the Swiss canton of Geneva. The FCC-ee may face challenges from electron cloud (e-cloud). The strongest effects are foreseen for the Z...
The Taiwan Photon Source (TPS) booster ring accelerates electron beams from the linear accelerator (lin-ac) output energy of 150 MeV to 3 GeV for storage ring injection. In the event of partial RF station failure in the linac, the available beam energy may be reduced to 100 MeV. Preliminary machine tests have demonstrated multi-turn beam circulation in DC mode and successful acceleration from...
Graphical user interfaces (GUIs) are sought to support particle accelerator and beamline modeling for both conventional and advanced accelerator concepts. Downloaded over 1500 times in the last 22 years, G4beamline (available gratis from Muons, Inc.) has been used for diverse applications in science and industry, representing over 50M$ of economic activity. Its strengths include ease of use...
Recently, many new light source projects have been developed based on the Multi-Bend Achromat (MBA) magnet lattice. In general, the dynamic aperture and transverse emittance of synchrotron light sources are sensitive to errors in magnet fields, alignment, and momentum. A realistic estimation of error tolerances is crucial for the successful construction of a fourth-generation synchrotron light...
The first section of the ESS superconducting linac is the Spoke Linac, which raises the beam energy from 90 MeV to 216 MeV. This is achieved by 26 superconducting spoke cavities, housed in 13 cryomodules. These cavities are powered by Spoke RF Power Stations (RFPS), each delivering a maximum power output of 400 kW at 352 MHz. This power is generated by combining the outputs of two tetrode...
The European Spallation Source (ESS) superconducting linear accelerator (linac) represents a key component in delivering high-intensity proton beams for cutting-edge neutron science research. This paper details the first cold technical commissioning of the superconducting linac in 2MW configuration, focusing on the performance validation of cryomodules, superconducting radio-frequency (SRF)...
At the large synchrotron radiation facility SPring-8, the upgrade project “SPring-8-II” is underway to increase the radiation brightness by 100 times. In SPring-8-II, the beam energy will be reduced from 8 GeV to 6 GeV and the beam current will increase from 100 mA to 200 mA. The bell-shaped 509 MHz cavities will remain in place at SPring-8-II, with the number of cavities reduced from 32 to...
In a collaborative work between ALBA and KEK the computation of the microwave instability threshold of the current ALBA ring was initiated. This analysis involves solving the dispersion relation equation and conducting simulations using a Vlasov-Fokker-Planck (VFP) solver. The longitudinal wake fields of geometric origin of all vacuum elements were computed with GdfidL** using a bunch...
The J-PARC Main Ring (MR) RF system has been undergoing upgrades in preparation for the Hyper-Kamiokande (Hyper-K) neutrino experiment, which is scheduled to begin receiving a 1.3 MW proton beam in 2028. The beam will be accelerated from 3 GeV to 30 GeV within the MR over a reduced cycle time of 0.58 seconds, down from the current 0.65 seconds. Additionally, the number of protons will be...
In a linear accelerator (linac), having a reliable model of the accelerating cavity is critical, as it is the primary element influencing particle dynamics. At the European Spallation Source (ESS), the TraceWin software is used for linac design, implementing thin-gap and multi-cell models, with both linearized matrix-based and field-map solvers. However, these models cannot be used online, as...
Longitudinal emittance growth is a significant challenge in RF linacs, especially for poorly bunched beams. This stems from particles occupying outer synchrotron oscillation orbits in the LBET, causing unwanted bunch-bunch interactions and degraded beam quality. To address this, we proposed using temporally spaced laser pulses to selectively photo-detach electrons from the longitudinal head...
The Karlsruhe Research Accelerator (KARA), a synchrotron light source and test facility, at the Karlsruhe Institute of Technology (KIT), offers excellent conditions for testing different Beam-Based Alignment (BBA) approaches. Classical BBA approaches estimate the offset between the magnet and the closest BPM for one magnet at a time, and the required time for the BBA scales linearly with the...
Hefei Advanced Light Facility (HALF) is a 2.2 GeV diffraction-limited storage ring designed with a modified hybrid six-bend achromat (H6BA) lattice. The present baseline lattice has a relatively large dynamic aperture and a reasonable Touschek lifetime. But it is better to further improve the nonlinear dynamics performance when considering the effect from errors and insertion devices. For a...
Symplecticity of the transfer maps is important for reliable evaluation of space-charge dominated beams in accelerators. Unfortunately, most simulation codes that include collective effects, such as space charge, do not use canonical phase-space variables and therefore are not symplectic in the presence of electromagnetic fields. In this paper, we present a numerical method to extract...
Magnetic fields play an important role in many physics studies, and many measurement items in physics experiments require control of micro magnetic fields. Although superconducting accelerating cavities can generate high electric fields at low power, the material niobium is a type-II superconductor, and trapping the ambient magnetic flux during the superconducting transition increases the...
Structure-based wakefield accelerators (SWFA) have been identified as a candidate technology for future applications ranging from free electron lasers to colliders. However, achieving the desired beam energy and quality requires meter-scale structures with tight tolerances, placing constraints on structure and beam characteristics to minimize emittance growth and combat transverse...
Superconducting undulators (SCUs) may be capable of generating stronger magnetic fields at shorter periods than can be achieved using permanent magnet undulators. Therefore, the range of x-ray wavelengths that an XFEL facility can generate for users could be expanded by exploiting SCU technology.
Prototyping work is ongoing at STFC to build a helical superconducting undulator (HSCU) with 13...
The Future Circular Collider (FCC) study is developing designs for higher performance particle colliders that could follow on from the Large Hadron Collider once it reaches the end of its high-luminosity phase. In particular, the FCC-ee is a proposed electron-positron collider that may face challenges from the electron cloud (e-cloud). Specifically, the Z configuration foresees the highest...
Superconducting radiofrequency cavities made of bulk Nb are reaching their theoretical limits in the maximum accelerating gradient, Eacc, where Eacc is limited by the maximum magnetic field, B, that can be applied on the surface of the accelerating cavity wall. To increase Eacc, the maximum B field, Bmax, which can be applied to the surface, must also be increased. The A15 materials or...
The first experimental observation of a 10 $\mu$m crabbing orbit at 1~$\sigma_z$ induced by head-on collisions with a non-zero crossing angle ($\theta_c$) in a high-energy proton beam at the LHC is presented. This challenging measurement required both the design of a dedicated experiment and a careful calibration and optimization of the beam instrumentation to produce and detect such a subtle...
The microbunching instability (MBI) has long been a persistent issue in high-brightness electron beam transport. The dogleg structure, a dispersive configuration composed of two quadrupole magnets and dipole magnets, has drawn attention in recent studies. It has been pointed out that the Landau damping effect can be enhanced to effectively suppress the microbunching instability by adjusting...
Oriented bent crystal planes can deflect charged particles as strongly as a magnetic field exceeding 100 T. As a result, beam extraction from an accelerator using oriented crystals offers significant opportunities for diverse applications, ranging from beam tests for particle detector R&D to high-energy fixed-target experiments. However, designing these applications requires a universal...
Longitudinal tomography is widely used in the CERN synchrotrons as an essential beam diagnostics tool. In recent years, more complex applications of phase space tomography, such as voltage calibration and multi-bunch tomography, have been explored. For these applications, large numbers of reconstructions are required, and computation time has a significant impact on usability. The current...
Longitudinal single-bunch instability caused by high-frequency impedance poses a major challenge for achieving optimal performance in fourth-generation synchrotron light sources and future electron-positron colliders. Accurate simulations of this instability are critical but computationally intensive, requiring millions of macro-particles and dense slicing to resolve bunch density...
We present a method of constructing a nonlinear accelerator lattice that has at least one approximate integral of motion that is given upfront. The integral under consideration is a Hamiltonian in normalized (canonical) coordinates that is preserved by a lattice with a given accuracy. A connection between the integrator of a Hamiltonian in normalized coordinates and a real lens arrangement is...
After the magnet is magnetized, due to the characteristics of the magnetization curve, there will still be residual magnetism in the magnetic field even after the magnetizing power supply is turned off. When measuring the same magnet multiple times, the residual magnetism not only affects the measurement of the magnetization curve but also impacts surrounding devices and instruments. In the...
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. In this talk, we show the progress of developing a 1.3 GHz HEIOT in...
As the High Luminosity LHC (HL-LHC) era approaches, precise control of the accelerator becomes increasingly critical. Machine studies are essential to address the forthcoming challenges and develop correction strategies based on experimental measurements. Although the upgraded inner triplets are not yet available, key features of the HL-LHC optics can still be investigated. This includes...
The high-frequency cavity system of the Wuhan Advanced Light Source (WALS) utilizes a normal temperature single-cell cavity with heavily damped higher-order modes. The operating frequency of this cavity is 499.654 MHz. Power from a solid-state power source module passes through a circulator and then is fed into the main cavity via a waveguide. The coupler is designed to be compatible with both...
A pulsed power supply (PPS) using SiC-MOSFETs is an essential component in the camshaft-bunch system at KEK-PF *. The system requires the PPS to generate half-sine pulses with a peak current of 500 A, a pulse width of 200 ns, and a repetition rate (rep-rate) of 800 kHz. We have developed a prototype PPS consisting of a resonant circuit (RC) to generate half-sine pulses with a SiC-MOSFET...
The X-LAB has been commissioned at the University of Melbourne. A key project within this laboratory involves rehoming half of the CERN high-gradient X-band test stand, XBOX3, now known as Mel-BOX. This initiative aims to validate the performance of high-gradient traveling wave accelerating structures operating at a frequency of 12 GHz. Mel-BOX is employed to evaluate the performance of these...
SuperKEKB is a high-current machine for high-luminosity.Eight higher order mode (HOM) damped single-cell superconducting cavities accelerated an electron beam in the main ring since KEKB.
A strong dependence of the absorbed power of the ferrite HOM dampers on
the number of bunches was observed in 2022 operation. One of the reasons for this is thought to be a build-up effect of some parts of...
We have introduced new 476MHz solid-state pulsed amplifiers to the X-ray Free Electron Laser facility, SACLA. The 476 MHz booster cavity requires high stability and reliability with a 100 kW power for 50 us pulse width. Previously, an Inductive Output Tube (IOT) was employed for this purpose. However, due to the reduced operational range caused by aging of IOT components and increasing...
The SRF community has shown that high temperature annealing can improve the flux expulsion of niobium cavities during cooldown. The required temperature will vary between cavities and different batches of material, typically around 800 C and up to 1000 C. However, for niobium with a low residual resistance ratio (RRR), even 1000 C is not enough to improve its poor flux expulsion. The purpose...
Unipolar and bipolar High Power Impulse Magnetron Sputtering (HiPIMS) are widely used techniques for depositing superconducting thin films, utilizing various magnetron configurations such as planar and cylindrical. In this study, ion energy and flux were measured from both planar and cylindrical magnetrons under varying pressure and power conditions, using mass spectrometry and Retarding Field...
Magnetic field measurements have been performed after fabrication of new separation dipoles for the low beta-star insertion regions of the High Luminosity LHC project*. In this paper, the effect of the linear imperfections of these magnets on coupling, beam size and beta-beating are evaluated using MAD-X simulations. The results indicate that the impact of normal-oriented quadrupole errors are...
Since the start of the third operational run of the CERN Large Hadron Collider (LHC) in 2022, multiple observations have highlighted the significant influence of non-linearities within the accelerator on the collimation loss patterns of circulating beams. Understanding this phenomenon is particularly relevant for qualifying and validating collimation performance for machine operation at high...
The combination of a compact storage ring and a laser-plasma accelerator (LPA) can serve as the basis for future compact light sources. One challenge is the large momentum spread (about 2%) of the electron beams delivered by the LPA. To overcome this challenge, a very large acceptance compact storage ring (VLA-cSR) was designed as part of the compact STorage ring for Accelerator Research and...
Beam stability in the FCC-ee collider is strongly influenced by transverse and longitudinal beam coupling impedance. Developing a flexible and comprehensive impedance model is crucial for accurately evaluating and mitigating instabilities as machine parameters evolve. This study investigates the effect of the FCC-ee collimation system, identifying it as a dominant source of total machine...
To mitigate the risk of radiation damage induced failure while operating the LHC beyond its initial integrated luminosity target, changes to the triplet polarity and crossing angles have been applied in the two main experimental interaction regions of the LHC. This allows for a more distributed radiation deposition in the insertion region magnets, which should allow their survival until they...
The PF Hybrid Light Source (PF-HLS) has been proposed in the High Energy Accelerator Research Organization (KEK), capable of utilizing both high-quality beams from a superconducting linac and beams from a low-emittance storage ring. The coupling impedance will cause beam instability, which must be carefully handled. It is essential to benchmark impedance models using analytical methods and...
Korea-4GSR is a future light source in Korea with a circumference of 800 m, an energy of 4 GeV, and a maximum current of 400 mA. Due to the small aperture of the vacuum chamber (12H x 9V octagonal) and the large number of normal-conducting cavities and beam position monitors (BPMs), impedance-induced instabilities are expected to pose challenges at 400 mA operation. In this study, we estimated...
Over the past year, we have conducted comprehensive impedance optimization calculations for the vacuum components designed for the Hefei Advanced Light Facility (HALF) storage ring. Our calculations indicate that specific components, which have a cavity-like or tapered structure, possibly exhibit a relatively strong trapped-mode impedance in the longitudinal or transverse directions. In order...
The beam wire scanners are instruments for precise transverse beam profile measurements by detecting the secondary particles generated from the interaction of the beam with a moving carbon wire. Following a completely new design of this device for the Large Hadron Collider (LHC), a detailed impedance calculation has been performed already in the design phase. This contribution presents the...
The High Intensity ECN3 (HI-ECN3) project aims to increase the number of protons per pulse delivered to a new experimental facility in CERN’s North Area up to $\sim 4 \cdot 10^{19}$ per year. Such an upgrade requires the reduction of the beam loss at SPS electrostatic septum (ZS) by at least a factor of four, since the activation of this device is the main factor constraining transition to the...
We investigated the effects of low-temperature baking, a standard treatment for superconducting radiofrequency (SRF) cavities, on niobium samples using synchrotron X-ray photoelectron spectroscopy. The study examined the chemical state of the niobium surface after chemical treatment with a buffered etching solution, which leaves a native oxide layer, fluorine impurities, and surface...
This paper reports the status and recent progress of INFN LASA’s in-kind contribution to the PIP-II project at Fermilab, with updates on key activities and major procurements. Production efforts for the 38 INFN LASA-designed, 5-cell cavities (β=0.61) for the LB650 section of the linac are underway and two pre-series prototypes are being realized as a first step to validate the manufacturing...
The ALBA synchrotron light source is undergoing a transformative upgrade to become a state-of-the-art fourth-generation facility, known as ALBA II. This upgrade will reduce the electron beam emittance to approximately 200 pm·rad, achieving a twentyfold improvement over the current performance. A key goal of the project is to maintain the existing source points for the insertion device...
Synchrotron light sources worldwide are transforming into next-generation facilities with ultralow transverse emittances at the diffraction limits. With these parameters, intrabeam scattering (IBS) becomes significant and can spoil the light quality by increasing emittance. A harmonic cavity can be installed to mitigate this effect by increasing the bunch length. Another way to reduce the...
SKIF (Russian acronym for Siberian Circular Photon Source) – is a new fourth generation synchrotron light source under construction in Novosibirsk, Russian Federation.
One of the most important characteristics of the synchrotron radiation source SRF "SKIF", which in turn determines its brightness, is the ultra-low emittance of the electron beam, which depends on the operating regime and...
The determination of electromagnetic wakefields and their impact on accelerator performance is a longstanding challenge in accelerator physics. These wakefields, induced by the interaction between a charged particle beam and the surrounding vacuum chamber structures, significantly affect beam stability and power dissipation. Accurate characterization of these effects via beam-coupling...
The Future Circular Collider is an ambitious international proposal for a next-generation particle accelerator complex, building upon the successes of CERN’s Large Hadron Collider. Specifically, the FCC-ee is a future circular lepton collider. The baseline design for the FCC-ee features four modes of operation, with beam energies ranging from 45.6 GeV to 182.5 GeV. Electron cloud (e-cloud)...
The long injection segment (flat bottom) of the cycle in the Super Proton Synchrotron (SPS) used for filling the Large Hadron Collider (LHC) with Pb ion beams, exhibits strong beam losses and transverse emittance growth. During the 2024 run, large improvements of the beam transmission could be made such that record intensities could be delivered to the LHC. In particular, these improvements...
Alternative configurations around the ATLAS experiment are investigated aiming to reduce muon rates at forward physics experiments such as FASER and SND@LHC. The Geant4 toolkit BDSIM is used to propagate muons through a model of a section of the LHC and the TI12 tunnel, where the FASER experiment is located. We compare the muon rates in BDSIM with FASER data collected during dedicated tests in...
With the increasingly challenging parameters in 4th generation synchrotron light sources, collective effects causing instabilities are putting even stronger limitations on the area of stable operation. The microwave instability (MWI) is a longitudinal single-bunch instability driven by the geometric and the resistive-wall impedances. While the instability typically does not result in a beam...
Space charge limited (SCL) emission is of fundamental importance to vacuum electronic devices, where the self-field of emitted charges limits the maximum current density being emitted from a cathode surface. Traditional modeling of SCL emission using the Child-Langmuir law primarily focuses on electron dynamics, neglecting the role of ions, which can significantly influence emission dynamics....
The variation of polarized light is a critical characteristic of synchrotron radiation sources. To accommodate diverse user needs and enable helicity switching, a soft X-ray beamline has been designed to alternate the helicity of polarized undulator radiation. This is achieved by switching between two undulators, configured to provide right and left circularly polarized radiation,...
Carbon ion therapy is one of the most effective radiotherapy methods for cancer treatment, offering superior dose conformality compared to conventional radiation therapies. The combination of carbon ion treatment with a gantry further enhances treatment effectiveness and safety. When designing a gantry, the magnet aperture must consider both the beam envelope and the beam position errors all...
The mitigation of long-range beam-beam interactions remains a critical challenge for maximizing the luminosity performance of the Large Hadron Collider (LHC). Previous experimental studies have demonstrated that long-range beam-beam wire compensation can effectively counteract long range beam-beam interactions, leading to enhanced beam lifetime and increased integrated luminosity. A...
The measurement of the integral magnetic field in accelerator magnets is crucial for the precise control and operation of particle accelerators. Traditional methods often rely on a fixed distribution of magnetic field sensors or long integral coils. Nonetheless, integral coils are sometimes unavailable in the magnet bore.
This study presents an approach to enhance integral magnetic field...
Addressing electromagnetic compatibility (EMC) issues at the design stage is important. However, for a prototype like the Linear IFMIF Prototype Accelerator (LIPAc) and its RadioFrequency (RF) system providing over 2 MW of RF power, problems during the commissioning have to be expected. Random interlocks and probability of occurrence increasing with the number RF modules, the power level or...
The High-Luminosity LHC (HL-LHC) project aims at increasing beam intensity, hence posing tight constraints on its injector chain. A critical issue in the Proton Synchrotron (PS) is the contribution of numerous pumping manifolds to the longitudinal beam coupling impedance at high frequencies. It causes microwave instabilities that particularly affect ion beams and limit the longitudinal density...
Longitudinal microwave instability has been observed in the J-PARC Main Ring. The longitudinal microwave instability was observed during the debunching process for the slow extraction. This led to electron cloud formation, which can cause transverse beam instability and beam losses. Longitudinal microwave instability was also observed during the latter part of the acceleration for the fast...
The LHC luminosity model is a powerful tool for studying the evolution of beam and machine parameters during the LHC operation. The model includes important effects that are present in LHC operation such as Intra-Beam Scattering, synchrotron radiation and burn-off. By comparing model predictions with experimental data, the presence of additional emittance blow-up and intensity loss mechanisms...
Symplectic simulation of space-charge effects is important for high-intensity particle accelerators. In this work, we propose to use a generative model to efficiently simulate space-charge effects in JuTrack, a Julia-based particle tracking code. The one-step symplectic transverse transfer map of the particles is obtained by differentiating the predicted space-charge Hamiltonian. This model...
In order to develop a lightweight gantry for proton therapy, the canted–cosine–theta (CCT) superconducting magnet was considered to apply in the gantry development. The code MagCCT intended for magnetic field calculation and analysis for CCT magnet is described. The main features of the MagCCT are that it can calculate the magnetic fields of 3 different magnets: curved CCT, straight CCT and...
The National Synchrotron Radiation Research Center (NSRRC) is focused on the application of 2G high-temperature superconducting tape (2G-HTS) for the insertion device in the Taiwan Photon Source (TPS) synchrotron ring. A preliminary design for a 2G-HTS wiggler (HTSW) is being developed, with considerations for sharing the SRF straight-section to make efficient use of space. The target field...
The KIT project cSTART (compact STorage ring for Accelerator Research and Technology) aims to store ultra-short electron bunches in a very-large-acceptance compact storage ring. The magnetic lattice of the storage ring is laid out for a variety of beam optics, including ultra-low positive and negative alpha as well as isochronous optics. These put high demands on the magnet quality and...
The Canadian Light Source has decommissioned three insertion devices in recent years, replacing each with upgraded devices. The decommissioned devices are planar undulators that have seen approximately 15 years of operation in a 2.9 GeV storage ring, two being out-of-vacuum devices with 45 mm and 185 mm periods and one being an in-vacuum 20 mm device. In this paper we present magnetic...
We systematically investigated the effects of various thermal treatments on the superconducting properties of niobium. In this study, niobium is utilized for fabricating nine-cell 1.3 GHz cavities used in particle accelerator facilities. Cylindrical niobium samples underwent the same chemical and thermal treatments applied to superconducting radiofrequency (SRF) cavities, including buffered...
We describe a program to develop 805 MHz magnetron power sources to enable a cost effective one GeV Linac that is capable of CW operation at greater than 50 MW beam power. Compared to the klystrons now used at the ORNL SNS, magnetrons have about a factor of ten lower capital cost ($1/W vs $10/W) and much higher wall power to beam power efficiency (almost 90% vs 50%).
Two applications under...
Past measurements* of coherent synchrotron frequencies at the Photon Factory storage ring revealed that the behavior of measured coherent frequencies could not be well explained with standard 4th-order characteristic equation under conditions close to the Robinson limit. To investigate whether similar phenomenon occurs in other storage rings, we measured the coherent synchrotron frequencies at...
In order to explore an efficient and accurate method for measuring the magnetic field information of accelerator magnets, this paper used the stretched wire system to measure a quadrupole magnet prototype of Hefei Advanced Light Source. In the measurement process, the integral field of the magnet at multiple points was first measured to calculate the magnetic center and multipole components of...
Charged particle bunches traversing cavity-like discontinuities in the beam pipe at relativistic velocities excite electromagnetic resonant modes that can detrimentally affect the dynamics of trailing bunches. This beam-cavity interaction, characterized in the frequency domain through the concept of beam-coupling impedance, poses significant challenges for beam stability and performance in...
Many accelerators have to take microbunching gain into consideration during both design and operation; this typically involves beam parameters where space charge is negligible. However, there are some accelerator designs which involve bunch compression of low energy beams with very low slice energy spread - conditions which may be prone to both microbunching considerations as well as space...
Vacuum vessels of the Diamond-II storage ring feature non-evaporable getter (NEG) coating which cause a resonator-like peak in the longitudinal impedance. This work demonstrates how different parameters of NEG can increase momentum-spread growth. It is shown that the spread of the coating-layer thickness amongst vacuum vessels results in significantly reduced momentum-spread growth. Insertion...
This study presents a multi-objective optimization scheme for ring cyclotron RF cavities, leveraging a neural network ensemble surrogate model. The cavity geometry is parameterized using Non-Uniform Rational B-Splines (NURBS), with control points and weights as design parameters. To reduce the computational cost of direct eigenmode simulations, an ensemble of neural networks trained using...
Elliptical cavity geometries are typically parameterised using a canonical set of variables that define the shape of the cavity half-cells. In multicell cavity optimisation, the mid-cells are modelled with identical dimensions, while the end-cells are optimised to ensure good field flatness. However, manufacturing tolerances can introduce slight variations between individual half-cells, as...
SuperKEKB, a double ring circular collider with 7 GeV electron and 4 GeV positron beams, utilizes “nano-beam collision scheme” in which low emittance beams collide at large crossing angle. Positional fluctuations of the colliding beams are predicted to have a deleterious impact on luminosity; therefore, it is important to measure position oscillation of its superconducting quadrupole Final...
Nonlinear integrable optics is a promising design approach for suppressing fast collective instabilities. To study it experimentally, a new storage ring, the Integrable Optics Test Accelerator (IOTA), was built at Fermilab. IOTA has recently completed its fourth electron run, achieving the design 150 MeV energy and optimal beam parameters. This report presents the results for the...
The Landau states of electrons with orbital angular momentum in magnetic fields are important in the quantum theories of synchrotron radiation at storage rings and in many other areas. In realistic scenarios, electrons are often born inside the field or injected from a field-free region, requiring nonstationary quantum states to account for boundary or initial conditions. This study presents...
The Radio-Frequency (RF) system of the CERN Proton Synchrotron Booster (PSB) features Finemet-loaded cavities that cover a wide range of frequencies. This system generates a significant broad-band longitudinal impedance, which must be mitigated to maintain beam stability, particularly at higher beam intensities. To counteract the induced voltage, a direct RF feedback is employed over the...
The presence of third order horizontal resonance island buckets at the ESRF EBS has been observed in simulations and in the machine. The islands appear at a few mm distance from the core with a specific horizontal tune and octupole setting. When the electrons are kicked with an injection kicker, a fraction of the beam can be captured in the island. The procedures to send the beam into the...
Helmholtz-Zentrum Berlin plans to construct a fourth-
generation greenfield synchrotron light source in the early
2030s to replace BESSY II, a 1.7 GeV machine that has been
running since 1998. The optimization of the linear lattice
already considers non-linear aspects, such as minimizing
the necessary sextupole strength and, for the minimal case
of two families of sextupoles, phase...
Vertical tests of single-spoke resonator type 1 (SSR1) superconducting cavities were conducted in conjunction with high-pressure rinsing (HPR) simulations to assess and improve cavity performance. The quality factor (Q) was evaluated as a function of the accelerating field (Eacc), Lorentz force detuning (LFD), and pressure sensitivity. In the HPR simulations, water droplet dynamics emitted...
The beam lifetime in synchrotron light sources is critically influenced by nonlinear beam dynamics, particularly in low-emittance storage rings where the Touschek effect dominates. At the Taiwan Photon Source (TPS), a third-generation 3 GeV storage ring, optimization of harmonic sextupole magnet strengths has been conducted using Bayesian Optimization (BO) techniques to minimize beam loss...
SuperKEKB continues the operation with the aim of achieving high luminosity. The beam current has already exceeded 1.3 A in the electron ring and 1.6 A in the positron ring. Eight superconducting RF (SRF) systems are operating in the electron ring. The SRF system including cavities, input couplers, HOM dampers, and so on was designed for KEKB and modified to handle the higher beam current of...
Determining the betatronic waist shift and the $\beta^*$ at the interaction points through K-modulation in the Large Hadron Collider presents considerable challenges. This paper introduces a novel method for the measurement of these quantities, based on luminosity measurements and the van der Meer technique for reconstructing transverse bunch profiles.
The strategy involves colliding...
Optimization of dynamic aperture is a challenging aspect of low emittance storage ring lattice design. A large dynamic aperture is favourable for efficient injection and long beam lifetime. Several methods like simple scanning of sextupoles and octupoles strength and genetic optimization with different configurations have been successfully combined to enlarge the dynamic aperture of Elettra...
Initial experimental investigations of transverse beam splitting, carried out at the CERN Proton Synchrotron, have demonstrated that transverse feedback is highly effective in controlling the characteristics of the transversally split beam. The feedback notably improves the intensity distribution among the beamlets and the emittance of the core, which is the portion of the beam remaining near...
In this study, superconducting Nb3Sn films were synthesised on different substrate such as sapphire, diamond turned copper and polished Nb, by DC magnetron sputtering from a single stoichiometric alloy Nb3Sn target. The structural, morphological and superconducting properties of the films were investigated. The effect of different deposition and substrate was examined. The film properties are...
High-power attosecond X-ray pulses play a critical role in many areas of research like ultrafast nonlinear spectroscopy, structural and electronic damage-free X-ray measurements. For free-electron laser facilities, the self-chirping operation mode has been demonstrated as an effective method for generating terawatt-level X-ray attosecond pulses. To compress the bunches under this mode, the...
The optimization of LHC operation is focused on achieving the highest possible integrated luminosity to maximize experimental data collection. Given the limitations of current detector systems, maintaining a constant level of integrated luminosity has become more critical than achieving a high peak luminosity. Techniques such as beta-leveling and separation levelling have already been...
The Helium Light Ion Compact Synchrotron (HeLICS) is an innovative synchrotron design for cancer treatment currently under development in the context of the Next Ion Medical Machine Study (NIMMS) at CERN. As part of the lattice design, the beam size around the HeLICS circumference is evaluated and the optics functions optimized in order to meet the aperture requirements imposed by the magnet...
In low-energy FEL beamlines, like SXFEL-SBP at the Shanghai Synchrotron Radiation Facility and FLASH1 and FLASH2 at DESY, SASE undulators with perfectly reasonable strength may dynamically affect the optics of the Focusing-Undulator-Defocusing-Undulator (FUDU) cells, pre-matched for a given fixed set of undulator parameters, so violently that a dynamical re-adjustment of the FUDU quadrupoles...
Since its official operation in 2016, the Taiwan Photon Source (TPS) has been dedicated to providing a stable and high-quality synchrotron radiation light source. The TPS storage ring is divided into 24 sections, each equipped with 7 sextupole power supply units, totaling 168 units. These power supplies are responsible for delivering precise and stable current to drive the sextupole magnets....
Throughout 2023 and 2024, higher-order mode (HOM) dampers were designed, manufactured and installed on the 100 MHz RF cavities in the 3 GeV ring at MAX IV Laboratory. Cavity HOMs have been the main driving source of longitudinal coupled-bunch modes (LCBM) in the ring. This contribution presents the impact of the HOM dampers via measurements performed on the cavities at different operating...
The main source of beam instability in the J-PARC 3-GeV RCS is the impedance of the eight installed kickers. This arises because one end of each kicker magnet is shorted while the other end is left open during beam acceleration. The shorted-end configuration provides the benefit of power savings during beam extraction from the RCS. However, it also excites beam instability. To retain the...
The Linear IFMIF Prototype Accelerator (LIPAc) in Rokkasho, Japan, designed to accelerate p+ to 4.5 MeV and D+ to 9 MeV at 62.5 mA and 125 mA in Continuous Wave (CW) mode, respectively, is under commissioning and about to enter into its final stages. A high-power test bench was developed for the testing and conditioning of the Radio-Frequency (RF) couplers of the RF Quadrupole (RFQ) cavity....
A 4th generation storage ring based light source is being developed in Korea since 2021. It features <60 pm rad intrinsic beam 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. To optimize the beam emittances, longitudinal gradient bending magnet is applied in the...
Beam halo formation is a significant challenge for high-intensity accelerators, as it can lead to performance degradation and radiation safety risks. This study investigates the formation and mitigation of beam halos caused by a picosecond time-delayed laser pulse, which generates a secondary electron bunch in the same RF bucket as the main bunch. The energy difference between the two bunches...
The Hefei Advanced Light Facility (HALF) storage ring employs more than 200 photon masks to shield thermally sensitive vacuum components from synchrotron radiation. The impedance introduced by these masks is highly dependent on their intrusion depth. This paper presents a straightforward method for assessing the requisite intrusion depth and the shielded photon power for individual masks....
Plasma treatment has proven effective in recovering and reducing field emission in the affected superconducting radiofrequency (SRF) cavities. A joint effort is underway between CEA, ESS and INFN to apply this technique to the treatment of elliptical cavities in the ESS linac. This paper presents the work done so far, which aims at both the development of the plasma process for cavities in the...
Beam production through the LANSCE accelerator is currently disrupted due to lack of critical klystrons spares that power the Side Coupled Cavity Linear accelerator (SCCL). The situation is so dire that the facility had to compromise running beam at 100MeV for 2024 run cycle instead of its nominal 800MeV. This project aims to predict the future performance of those critical klystron units...
The efficient transfer of protons from the Proton Synchrotron (PS) to the Super Proton Synchrotron (SPS) is crucial for beams in the Large Hadron Collider (LHC). A particular challenge at the intensities required for the High-Luminosity LHC is the handover from a 40 MHz to a 200 MHz RF system. This requires a non-adiabatic bunch shortening in the PS triggered by a fast RF voltage jump....
The National Synchrotron Radiation Laboratory is constructing a 2.2 GeV diffraction-limited storage ring, the Hefei Advanced Light Facility (HALF), using the modified hybrid 6BA lattice, which consists of a total of 20 cells. The synchrotron radiation primarily covers the vacuum ultraviolet (VUV) to soft X-ray bands. To extend the photon energy into the hard X-ray range, two 0.9 T...
The presence of the electron cloud inside the chamber of high energy accelerators with positively charged circulating beams has been reported and studied by several facilities. Those studies intend to describe and predict which scenarios may present a mayor risk to operating the machine.
The electron cloud build-up inside the vacuum chambers might generate critical effects that diminish the...
This report details the mechanism design and heat load budget for a cryostat that replace liquid helium and liquid nitrogen with commercially available cold heads (cryocoolers). However, to ensure the proper functioning of cryogenic superconducting magnets with the limited cooling capacity of cryocoolers, careful management of heat transfer, insulation, cooling, electrical power, and vacuum...
Higher-Order Modes (HOMs) in superconducting radiofrequency (SRF) cavities are traditionally considered detrimental to efficient operation. They are often associated with beam instabilities and are actively damped. However, these “harmful” HOMs, if used strategically, can be transformed into a tool for providing extra control over the beam, which can introduce new opportunities that are not...
High-current and low-energy storage ring is an essential part of accelerator for industrial application. However, high intensity poses great challenge to beam stability through collective effects, which can be exacerbated at low energy. In this paper, we present a preliminary study on various collective effects in an application-oriented storage ring. The classical theory is reviewed, and...
The High Luminosity-Large Hadron Collider (HL-LHC) project at CERN aims to increase the integrated luminosity of the Large Hadron Collider by an order of magnitude compared to the LHC original design performance. To achieve this, the existing magnets surrounding the CMS and ATLAS experiments will be replaced with next-generation, high-performance superconducting magnets featuring larger...
BDSIM (Beam Delivery Simulation) is a Monte Carlo particle tracking tool for accelerator beamline modelling. It integrates particle transport with detailed geometry and physics using Geant4 for precise modelling of particle-matter interactions in 3D models of particle accelerators. Primarily for energy deposition studies and beam loss simulations, BDSIM allows a high degree of control and...
A collaboration is underway to investigate the impact of CSR and shielding on the beam of various shapes as it passes through a chicane. Experimental efforts are being made at the Argonne Wakefield Accelerator (AWA) facility. Currently, the facility is equipped with two identical doglegs with reversing quadrupoles that allow doglegs to function as a chicane, and manually adjustable shielding...
ALBA-II is progressing in the definition of an upgrade lattice that meets the requirements of the beamlines and perform well in terms of dynamics aperture and lifetime. The last changes were focused on further decreasing both the emittance (200 pm*rad) and the beta functions at the straight sections (around 2 m) for the improvement of the beamlines performances. The efforts to guarantee a good...
In the current and most evolved design concept of a muon collider, there exists two long (~1 km) channels for cooling newly created muons and anti-muons. Termed the `6D cooling channels', the beam is cooled in momentum and position space using a series of alternating polarity solenoids, which create an oscillating field in the beam direction, absorbers and radio-frequency cavities. In total...
FLUKA simulations of beamlines are important for un- derstanding numerous different aspects of accelerators, in- cluding beam losses, particle backgrounds, activation and shielding. Creating a beam-line simulation using FLUKA is a time consuming and potentially error prone process. This paper describes a set of python tools called pyflubl (Python FLUKA beam-line) which can create a FLUKA...
Quadrupole pumping is a longitudinal manipulation technique for bunch shortening, which works by modulating the RF voltage at twice the synchrotron frequency to excite bunch length oscillations. These controlled oscillations rotate the bunch in longitudinal phase space, with extraction set for when the bunch is shortest. Higher RF harmonics can also be used to linearise the synchrotron...
The National Synchrotron Radiation Research Center (NSRRC) has been at the forefront of advancing synchrotron radiation technologies, including the development of advanced magnet systems. We integrated a wiggler magnet utilizing 2G High Temperature Superconductor (HTS) tape into a cryogen-free system. The wiggler, an essential component for enhancing radiation output, operates effectively...
As part of its ongoing and future contributions to high-Q/high-G activities in major international projects such as PIP-II, ILC Technology Network, and the European Strategy for Particle Physics, INFN-LASA is upgrading its experimental facility for vertical cold tests of superconducting cavities. This upgrade will enable cavity performance characterization in a low residual magnetic field...
Irradiation-induced damage to undulators has become a critical problem in the operation of synchrotron radiation facilities and free-electron laser facilities. During the commissioning and light output phases of the Shanghai Soft X-ray Free Electron Laser facility, the performance of the radiation deteriorated. The main reason for this problem is the impact of high-energy particles on the...
Systematic research work including coating process optimization of Nb3Sn thin film on single cell cavity, quality control before and after coating Nb3Sn thin film on multi-cell cavity, and the construction and operation of LHe-free Nb3Sn SRF demo electron accelerator was carried out at IMP. The evolution of Nb3Sn thin films in the whole growth cycle was tracked by experiments, and the...
Accurate knowledge of wake functions is crucial in accelerator physics, serving as the cornerstone for understanding intra-bunch interactions and for controlling or mitigating instabilities that limit accelerator performance. Haissinski distributions, which describe the steady-state longitudinal bunch density, are intrinsically determined by the wake function experienced by the bunch. While...
The 7th International School on Beam Dynamics and Accelerator Technology (ISBA24) held in Chiangmai University during November 1-9, 2024, encompasses seven days opportunities where the foundation of accelerator physics is applied during hands-on sessions with simulation software including ASTRA, ELEGANT, Opera-3D and CST Studio Suite. Opera-3D, a finite element-based Maxwell’s equations...
The 7th International School on Beam dynamics and Accelerator technology (ISBA24) took place over nine days, from November 1 to 9, 2024 at Chiang Mai University in Thailand. The school, part of the KEK-IINAS-NX series, was jointly hosted by Chiang Mai University and the Synchrotron Light Research Institute (SLRI). Out of 115 applicants who had submitted resumes and recommendation letters, 64...
I show analytical expressions of the longitudinal and transverse impedances of a two-layered circular pipe and their practical expressions at high frequencies derived by using asymptotic expansions of the Bessel functions. These expressions are applied to resistive-wall impedance calculations of NEG-coated insertion-device(ID) pipes for the PF-HLS ring*, which is proposed as a 2.5/5.0 GeV...
The VEPP-2000 collider is a compact machine, which uses the round-beam concept to achieve high luminosity. Its compact size (24 m in circumference) limits the free space between the magnetic elements. Only 4 BPMs are installed in the ring with large phase advance between them (~2 pi). The key to improve its luminosity is to reduce the power of resonances. The implementing of the RDT...
The LHC is approaching the end of its third operational run, with machine protection and performance having demanded an excellent control of the single-particle dynamics. Additionally, the requirement to rapidly commission multiple diverse sets of optics configurations within each year and from year-to-year, placed clear demands on the measurement and correction methods employed. Tight...
The Quadrupole Resonator (QPR), originally developed at CERN, is a dedicated radio-frequency characterization equipment for evaluating superconducting material. It employs the calorimetric compensation technique and has a surface resistance resolution of less than 1 nOhm, operaing over a wide range of parameters, such as tem-peratures, resonant frequencies and magnetic fields. As a part of R&D...
The ASTERIX project, funded by CSN5 and proposed at INFN-LNF, aims to demonstrate a practical, meter-long X-band RF structure for linear accelerators made of hard copper and divided into four quadrants. The prototypes will be constructed by TIG welding. In the first year of the feasibility study, we will design the RF cavities for two full structures working at single-bunch and multi-bunch...
In this paper, we present the RF design of a mode-launcher integrated with an open-type, multi-cell 12 GHz 4-sector structure. The electromagnetic design is carried out using the 3D full-wave electromagnetic solver CST-Microwave Studio. To ensure compactness, a key focus of the integration process is the minimization of the distance between the coupler cell and the accelerating open structure....
The RF window acts as a barrier between the vacuum and air, gas, or water while allowing RF power to pass through with minimal loss. Resonant modes (called "ghost modes") can occur within the ceramic disk of a window. The frequencies of these modes depend on the material and size of the ceramic. Ceramic disk dimensions must be carefully optimized to minimize reflections and avoid ghost mode...
The Electron-Ion Collider at BNL requires several crabbing systems that will be operating at 197 MHz and 394 MHz to compensate for the loss of luminosity due to the large crossing angle of the colliding beams. Two 197 MHz crab cavity cryomodules containing two cavities each will be installed in the Hadron Storage Ring (HSR) at the IP6 interaction region. Due to its large size compared to...
Coherent electron cooling plays an important role in the Electron Ion Collider (EIC) by providing a fast cooling rate at collision energy to counter the emittance growth driven by intrabeam scattering effects. In this paper, we report on the high-fidelity simulation of the electron beam transport through the amplification section of the cooling channel. We will show the amplification of the...
A novel storage ring is proposed in which the bunch maintains a fixed orientation relative to the outside world (does not rotate with the ring as usual). In this geometry, magnetic focussing can confine all three dimensions of the bunch without RF. The application of this ring to ultra-low emittance Coulomb crystals is investigated, where the focussing force balances the space charge to give...
Capability for generating an attosecond bunch can provide interesting opportunities to wakefield accelerator research. We have been studying requirements and challenges in beam dynamics to produce an attosecond bunch using an existing beamline at Argonne Wakefield Accelerator (AWA) facility. One unavoidable limitation of this study is that conventional C-typed chicane is not available. Thus, a...
In the SuperKEKB electron-positron collider, the coupled-bunch instability caused by the accelerating mode of RF cavities becomes severe in high beam current. To suppress it, the ARES cavities have been used. The accelerating cavity is coupled with an energy storage cavity via a coupling cavity between them. While the beam is accelerated by the π/2 mode, the parasitic 0 and π modes are damped...
The compact STorage ring for Accelerator Research and Technology (cSTART) project at the Karlsruhe Institute of Technology (KIT, Germany) aims to explore non-equilibrium electron beam dynamics and injection of laser-plasma accelerator (LPA) bunches. The Very Large Acceptance compact Storage Ring (VLA-cSR) is also filled by a second injector that delivers ultra-short bunches from the...
In ultrafast electron diffraction experiments, the scattering cross-section, q-range, and space-charge effects are critically influenced by the electron beam energy, which is constrained by the high-voltage breakdown. By integrating a 100 kV DC electron gun with a 3 GHz radiofrequency cavity powered with a 400 W amplifier, we demonstrate a net energy gain of up to 31 keV. Here we present...
The GALACTIC Vlasov solver can be used to study the impedance-induced transverse coherent instabilities, considering any longitudinal distribution function, describing the beam with transverse coherent oscillation modes in the frequency domain and ending up with an eigenvalue system to solve. In this paper, the effect of the transverse coherent direct space charge is added, considering a...
A five-year project (MEXT advanced Accelerator element Technology Development (MEXT-ATD)) funded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) began at KEK in FY2023. The goal is to manufacture and construct a cryomodule (CM) that satisfies the ILC (International Linear Collider Project) specifications and conduct cooling tests. The 3D model of the cryomodule...
PAL-XFEL is planning to install second hard X-ray undulator line (HX2) to meet the high beamtime demand from the users. The photon energy range for the second hard X-ray beam line is from 2~ to 11 keV which is lower than the first hard X-ray photon energy range (2 ~ 20 keV). The required undulator parameters are 35 mm period, max Keff=3.48 at 9.00 mm gap, ~ 3.0 m magnetic length with phase...
Since the completion of Taiwan Photon Source (TPS) commissioning in 2015, we have developed and constructed nine APPLE-II undulators of various designs to provide users with soft X-ray sources, particularly for circularly polarized light. To optimize the use of straight-section space, the lengths of the APPLE undulators range from 4.4 to 0.8 meters to accommodate installation constraints....
STFC is responsible for delivering 20 high-beta 650 MHz cavities for the PIP-II project, with industry partners now producing series cavities. Both pre-series cavities have set world records in performance and cleanliness, meeting the project’s stringent requirement for field emission-free operation, accelerating gradient, and Quality factor. Achieving this milestone required an...
With a change in the LHC machine optics foreseen for 2025 and the possible reduction of beta-star, optics commissioning will become even more of a challenge for the CERN Optics Measurement and Correction (OMC) team. In particular, the increased sensitivity of the optics to non-linear imperfections, requiring a plethora of accurate measurements, is expected to be a time consuming task. In...
The superconducting cyclotron SC240 is used to accelerate proton beams to 240 MeV for proton therapy. The SC240 is an isochronous 4 sectors compact cyclotron with a central magnetic field of 2.5 T. Particles acceleration is performed under the second harmonic mode of the radio-frequency (RF) system, consisting of two independent cavities located in the cyclotron valleys. Block on the chimney...
The FCC-ee booster injection kicker, will be injecting 4 particles bunches per single kick. The bunch separation in the booster ring is 25 ns and therefore requiring a faster kicker rise and fall time to not perturb injected or already circulating bunches. The wakefield impedance of the stripline is also important to not perturb the stored beam as well as it is necessary to ensure a good...
Space charge effects in combination with betatron resonances limit the performance of high-brightness LHC beams in the CERN Super Proton Synchrotron (SPS). Here we report on experimental studies performed with single-bunch proton beams, monitoring transverse emittance evolution and particle losses while performing tune scans across the horizontal and vertical planes. Two significant resonances...
SIRIUS, the Brazilian 4th-generation synchrotron light source, operates in top-up mode at a current of 200 mA. Despite previous optimizations, the storage ring injection system still requires improvements in efficiency, to attend the tight demands in terms of repeatability and charge per pulse. In this context, this work investigates the large residual horizontal orbit distortion in the...
Recently proposed transverse wiggler is an intriguing tool for imparting designed correlations in phase space. While several simulations have demonstrated its feasibility, the method using the transverse wiggler has several concerns need to be addressed. Beam evolution along the wiggler can introduce errors in the designed correlation. Wiggler fields have strong vertical position dependence,...
Over the past two decades, very high-energy electron (VHEE) beams ranging from 50 to 250 MeV have been explored as a potential technology for treating deep-seated tumors. FLASH radiation therapy (FLASH-RT) delivers ultra-high dose rates (UHDR) within a few milliseconds, suggests the possibility of enhanced cancer cell lethality while reducing damage to normal tissues. Combining VHEE with...
The cERL injector objective is to produce and deliver a high-quality electron beam to the recirculation loop. However, a recent observation of an anomalous "triangle beam" profile just after the first solenoid presents significant challenges. This distorted beam profile can lead to inaccurate parameter measurements, reduced focusing and collimation efficiency, and increased sensitivity to...
In the 3-GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the beam power ramp-up aiming to surpass the design of 1 MW enhances the space charge effect. It pushes the beam toward the structure resonance. To mitigate the beam loss, the operating point is required to be apart from the structure resonance as the beam power ramp-up. However, large beam...
A 162.5 MHz, optimal beta = 0.19 pure niobium half-wave resonator (HWR) called HWR019 for the superconducting driver linac of the China initiative Accelerator-Driven subcritical System (CiADS) has been designed and analyzed at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). The linac requires 24 HWR019s to accelerate protons from 6.8 MeV to 45 MeV. This paper mainly...
After the great success of KEKB asymmetric-energy collider achieving the world highest luminosity, the ambitious upgrade SuperKEKB collider aims to take the positron-electron colliders to the next level by achieving 40 times higher luminosities. However, this represents a huge challenge, requiring of a highly precise way to control the beams to suppress emittance growth and to assure their...
NSRL recently proposed a future plan to further upgrade the HLS to an EUV diffraction-limited storage ring, named HLS-III. In this paper, a symmetric double-double bend lattice with long and mid-straight sections is studied as a highly promising design for the HLS-III storage ring. The design achieves an ultra-low natural emittance of 2.82 nm·rad at 800 MeV, while maintaining the current eight...
Recently, KEK PF has started developing a superconducting multipole wiggler (SC-MPW) for an application in next-generation light source ring. The SC-MPW is expected to be a key insertion device for the light utilization of a wide wavelength region by aiming at high-brightness and high-energy X-ray production while keeping the stored beam energy as low as 2.5 GeV. In addition, the short period...
Accelerator kicker magnets, which commonly use ferrite and other insulating materials, can encounter High Voltage (HV) performance limitations due to interactions with the particle beam. These interactions, can lead to electron cloud buildup and charging phenomena on exposed surfaces, negatively impacting kicker performance, particularly at high beam intensities. To mitigate these effects,...
A single-aperture two-layer Canted-Cosine-Theta (CCT) sextupole magnet using as conductor high-temperature superconducting (HTS) ReBCO tape has been developed for the short straight sections (SSS) of the FCC-ee study. Manufacturing details, including paraffin wax impregnation and cryogenic temperature measurements, are presented. This demonstrator represents the first CCT magnet constructed...
NSRRC builds four home-made solid state power amplifier towers to provide 300 kW for one superconducting RF cavity at TPS. The power combining tree of one tower is two-stages structure with a complex wire connection. In order to simplify the wire connection and increase the power combining efficiency, we devote resources to develop the cavity combiner. In this study, a 21-ports cavity combiner...
This study investigates the influence of insertion devices (IDs) on the optical properties of the Solaris electron storage ring through a combination of experimental measurements and simulations. The effects of various ID settings were analyzed using tune measurements and the Linear Optics from Closed Orbits (LOCO) method. These results were compared with simulations performed using the Python...
The design of the ALBA upgrade forsees the use of an active harmonic cavity system for bunch lengthening. The resulting RF-potential will be a combination of a harmonic and a quartic potential. The corresponding stability diagram will be computed and compared to the stability diagram based on a pure quartic RF-potential. It will be checked if an already existing HOM in the DAMPY cavities and a...
The eddy current type septum magnets (Eddy-septa) are used for fast extraction in J-PARC MR from 2022. Currently, the operation of the Eddy-septa is very stable. However, we have some still technical issue. One is an output pulsed current measurement by current transfers. The peak value of the output pulsed current is measured pulse by pulse and the measured value is used for a feedback system...
The Electron-Ion Collider (EIC) is being designed by BNL in collaboration with Jefferson Lab. The Phase-I design includes the installation of two cryomodules of 197 MHz crabbing cavities installed at the Hadron Storage Ring (HSR) at the interaction region, IP6 that has a crossing angle of 25 mrad. Each cryomodule consists of two 197 MHz RFD type crabbing cavities. The first article cavity has...
In the Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), to address the issue of resonance correction for third-order resonances in both on- and off-momentum particles, an upgrade project utilizing 24 Trim-S units has been proposed based on numerical simulations. As a first step in verifying its effectiveness, four additional Trim-S (new Trim-S) power supplies, configured with...
Multi-bunch instabilities, often driven by narrowband impedance sources such as higher-order modes, present significant intensity limitations in synchrotrons. One approach to mitigate these instabilities is applying a double harmonic radio frequency (RF) system, which can increase the intensity threshold by enlarging the synchrotron frequency spread. In this study, intensity thresholds are...
Super Charm Tau factory is a proposed electron-positron double ring collider with crab waist collision scheme operating in wide beam energy range from 1.5 GeV to 3.5 GeV with peak luminosity of 10^35 cm^(-2) s^(-1). The polarized electron source and three Siberian Snakes provide 80% longitudinally polarized electron beam at 2 GeV. Superconducting wigglers decrease damping times, effects of...
The collective effects observed in storage rings with high-intensity beams are numerous and diverse. One such effect is that of periodic beam loading of accelerating RF cavities. This effect is contingent upon the impedance of the fundamental mode of the RF cavities and the mode of filling pattern. In a multitude of configurations, the periodic beam loading effect in storage rings leads to a...
The results of Run 24 experiments at Relativistic Heavy Ion Collider (RHIC) for improving luminosity using optics tuning are presented in this study. In the first experiment, MADx matching was used to output magnet strengths corresponding to specific s star movements around Interaction Region 8 (IR8). The corresponding Zero Degree Calorimeter (ZDC) signal was measured in place of luminosity,...
In the CERN Super Proton Synchrotron (SPS), a new AC dipole excitation functionality has been implemented with the aid of the Beam-Based Feedback and Diagnostic Systems. This feature facilitates precise and systematic optics measurements, presenting a robust alternative to the conventional single-kick excitation method. Comparative studies of AC dipole and single-kick excitations have been...
A three-dimensional spiral beam injection scheme* has been developed to realize very precise measurement of the muon spin precession frequency in the level of sub-ppm. A 300MeV/c muon beam is injected into a precisely adjusted storage magnet of sub-ppm uniformity by applying medical MRI magnet technologies for J-PARC muon g-2/EDM experiment. A strongly X-Y coupled beam is required to deliver...
Ongoing conceptual studies for a 10TeV muon collider identified rapid cycling synchrotrons as major engineering challenge. Due to the muon’s short lifetime of only 2.2µs at rest, normal-conducting bending magnets with field rise rates of well beyond 1kT/s are indispensable to support accordingly fast acceleration cycles. Energies of 100MJ will be interchanged between magnets and capacitor...
The Taiwan Photon Source (TPS) of the National Synchrotron Radiation Research Center (NSRRC) in Taiwan has integrated Solid-State Power Amplifiers (SSPAs) into routine operations since 2023, supporting a stored beam current of 500 mA. In response to the phasing out of Ampleon's BLF578 and the growing demand for improved energy efficiency, a new SSPA was developed based on the existing module...
The proton driver of a future Muon Collider complex is designed to deliver a multi-GeV, short and high-intensity proton bunch to a target in order to maximize the muon yield. In the International Muon Collider Collaboration (IMCC), two high power H- Linac configurations are studied: a 2 MW with a beam energy of 5 GeV, and a 4 MW with a beam energy of 10 GeV. The Linac is followed by an...
Collective effects can have a strong influence on the beam stability and performance in synchrotron light sources. Landau cavities or RF harmonic cavities are a tool that is employed at 4th generation storage ring light sources to reduce the impact of or even prevent instabilities arising from collective effects. The positive effect of Landau cavities is based on the lengthening of the...
Superconducting cavities are indispensable elements in modern particle accelerators, utilizing the ultra-low sur-face resistance of superconductors to achieve exceptionally high quality factors. In this work, we apply the least action principle to derive an equivalent RLC circuit model, offering a unified theoretical framework to describe the electromagnetic behavior of superconducting...
We present updated simulation results on the maximum brightness achievable by a 1.6-cell cold copper C-band photoinjector, designed for testing and commissioning as part of the Cathodes and RF in Extremes project at Los Alamos National Laboratory. Previous simulations highlighted the high brightness attainable with a 250 pC bunch charge, attributed to the high accelerating gradients and the...
This work presents the results of single-bunch-instability measurements in the Diamond storage ring. A streak camera was used to measure the bunch lengthening with current, whilst transverse multi-bunch feedback (TMBF) was utilised to quantify the charge-dependent betatron tune shifts and the head-tail instability thresholds. The results show that increasing chromaticity can be used to...
The design and operation of modern accelerators demand advanced simulation tools capable of addressing complex challenges. Differentiable simulations are particularly valuable, as they enable gradient-based optimization techniques that significantly reduce computational costs and efficiently tackle high-dimensional problems. The PyTorch-based simulation code Cheetah was developed to combine...
The radio-frequency quadrupole test stand (RFQ-TS) was prepared for conditioning the spare RFQ in the J-PARC Linac. Additionally, the RFQ-TS is used for the development of accelerator components and the acquisition of beam parameters. The digital feedback system of the Low-Level RF (LLRF) in the RFQ-TS was previously using the discontinued cPCI system, which had been in use for 20 years since...
The European Synchrotron Radiation Facility (ESRF) has built and characterized many insertion devices and magnets over the past decades. The magnetic measurements rely on dedicated benches, based on stretched wire for integral measurements and on hall probes for local measurements. A major upgrade of these benches is being developed. It includes new features such as coordinate measurents,...
LC resonant circuit is widely used in all kinds of pulse power supply because of its simple structure and reliable performance. Among them, the scheme with thyratron as the main power device has been verified for a long time in the BEPCII injection system. With the continuous improvement of the technical requirements of all kinds of accelerators, the performance of the pulser has become...
The goal of the ASTERIX project, proposed at INFN-LNF and funded by the CSN5, is the first-time demonstration of a practical, meter-long X-band RF structure for real linear accelerators made of hard copper and four quadrants. Our joining technique will be the TIG welding for the prototype. During the feasibility study, in the first year, we will proceed to the RF cavity design of two full...
In order to achieve the necessary bunch charge, the Rapid Cycling Synchrotron utilizes bunch merging. The altered longitudinal motion during merges has the potential to reduce dynamic aperture and cause emittance growth. Tools for analyzing the effects of merging have been developed for the AGS using Bmad and a simplified tracking code in Julia. These tools are applied to the merges of the...
Nonlinear effects in particle accelerators have historically been treated as harmful influences that necessitate various mitigation schemes. Therefore, the simulation tools available are largely focused on identifying and correcting resonances. However, recent advances proved that nonlinear beam dynamics enables new techniques for manipulating particle beams and can characterise diffusion and...
A new approach that demonstrates the guiding of relativistic electron beams over curved paths by means of a plasma-discharge capillary is presented. The magnetic field produced by the discharge current is used to deflect and focus the beam along a curved capillary, showing that the guiding can be made dispersion-less, i.e. not affected by chromatic dispersion. This proof-of-principle...
Improving the performances of modern circular particle accelerators requires a tight and solid control of its linear optics. Decades of developments provided invaluable tools towards this end. This talk will review the historical milestones and the most recents novelties in this field.
Measurements of the transverse beam-halo population at large amplitudes in the Large Hadron Collider (LHC) provide crucial insights into the stored beam energy near the LHC collimators. These particles do not contribute significantly to the luminosity but their loss could impose limitations on accelerator performance through sudden loss spikes or even collimator damage in case of fast beam...
A collaboration is underway to develop and demonstrate GW-level power generation in the sub-THz frequency range. Two key components--wakefield structure and electron bunch train--were prepared for the demonstration. A 5-cm long corrugated structure was fabricated using two thin metallic plates with through-holes of different inner diameters. The plates were fabricated by lithography and bonded...
The Advanced Wakefield (AWAKE) experiment is a proof-of-principle accelerator facility at CERN (Geneva, Switzerland). Proton bunches from the CERN Super Proton Synchrotron are used to drive wakefields in 10 metres of laser-ionised rubidium plasma, over which externally injected 19 MeV electrons are accelerated. Run 1 of AWAKE successfully demonstrated the self-modulation of the long proton...
Employing octupole magnets for Landau damping of transverse single-bunch instabilities in synchrotrons often restricts the dynamic aperture due to the excitation of betatron resonances. The situation complicates in the presence of strong direct space charge fields. A notable case is the 1-second accumulation plateau of the heavy-ion synchrotron SIS100 at the Facility of Antiproton and Ion...
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.
We have developed the electron source system, i.e....
Eddy currents induced by rippling magnets in axially asymmetric vacuum chambers are known to generate magnetic multipoles of higher orders, with a dynamic sextupole driven by a time-varying dipole being a common example. However, the inverse phenomenon—lower-order multipoles created by an oscillating higher-order multipole magnet, though consistent with Maxwell’s equations—has not been...
The GSI facilities of CRYRING and HiTRAP are used for decelerating ion beams to low energies. This deceleration phase is preceded by the generation and acceleration of those ions. CRYRING and HiTRAP operate at the junction between accelerator science and atomic physics. The scientfic motivation, the operation principle, the state of the art and future outlooks are presented.
Reinforcement learning (RL) is a unique learning paradigm inspired by the behaviour of animals and humans to learn to solve tasks autonomously. Learning occurs through interactions with an environment, exploring, and evaluating strategies under various conditions. RL excels in complex environments, can handle delayed consequences, and is able to learn solely from experience without access to...
With a total project cost of $272 million the recently completed Proton Power Upgrade at the Spallation Neutron Source increased accelerator capability from 1.4 to 2.8 MW, and the first target station from 1.4 to 2.0 MW. 700 kW of beam power will eventually be sent to the Second Target Station. PPU installed 7 high-beta cryomodules, and HPRF to increase the H- linac energy from 1.0 to 1.3 GeV,...
We are developing a low-level RF (LLRF) controller based on RF System on Chip (RFSoC) for an electron linac. The AMD Zynq RFSoC was employed for this controller, which has a large-scale high-speed FPGA together with high-speed ADCs and DACs (8 channels each). The RFSoC also has an application CPU for Linux and a real-time CPU for time-critical tasks, capable of a 1 kHz repetition rate. A...
We report our latest progress developing diagnostics using quantum optics-based detection method for determining the spatial properties and current of electron beams. As electrons pass through a dilute vapor of rubidium atoms, their electric and magnetic field perturb quantum states of Rb atoms and change their optical properties. By measuring the polarization rotation due to electron current,...
The international Facility for Antiproton and Ion Research (FAIR) is under construction at the GSI Helmholtz Centre in Darmstadt. The first project stage includes the superconducting 100 Tm heavy-ion synchrotron SIS100, the Super Fragment Separator, and associated beam transport lines. Part of GSI’s existing accelerator chain, comprising UNILAC and SIS18, will serve as injector. Installation...
Xie Jialin Prize
The ACFA Xie Jialin Prize for exceptional work in the accelerator field has been given to Hitoshi Tanaka, deputy director of RIKEN SPring-8 Center, for his many contributions to linear and circular accelerator-based photon sources. Examples of his works include: girder-based magnet alignment suppressing COD sensitivity against magnet mis-alignment; achievement of the...
Nishikawa Tetsuji Prize
Nishikawa Tetsuji Prize for his significant contribution to high performance high charge state ECR ion source development, especially in the domain of the next generation ECR ion source development, superconducting ECR ion source high performance operation and key technologies development.
Hogil Kim Prize
Riccardo Pompili got his PhD in Physics in 2013 at the University of Rome “Tor Vergata” with a thesis related to the development of an Electro-Optical Sampling diagnostics conceived for beamdriven plasma wakefield accelerators. For his PhD thesis he was awarded in 2014 by the “Young Scientist Prize” of the Italian Synchrotron Light Society. Currently he is the scientific...
Mark Oliphant Prize
Adam’s work focuses on the application of Fixed Field Accelerator technologies to hadron therapy, investigating novel techniques for beam extraction, transport, and delivery. He completed the initial design study for a large energy acceptance beamline technology demonstrator as part of the ‘TURBO’ project at Melbourne University, looking at both beam optics and magnet...
This study introduces a multi-objective Bayesian optimization framework to enhance the performance of electron linear accelerators in Fourth Generation Synchrotron Radiation facilities. By focusing on minimizing horizontal and vertical emittances and energy spread at the linac exit, the approach targets improved beam quality essential for advanced synchrotron applications. Traditional methods...
A new digital beam position and phase measurement (BPM) system was designed for the ion-Linac (iLinac) accelerator in the High Intensity heavy ion Accelerator Facility (HIAF). The fundamental and the second harmonic signals are retrieved from the BPM electrodes to simultaneously calculate their respective beam positions and phases. All data acquisition and digital signal processing algorithm...
CERN’s upcoming SPS Beam Dump Facility (BDF) will host a production target designed to manage challenging thermal and mechanical conditions while providing the physics output required by the Search for Hidden Particles (SHiP) experiment. It must fully absorb 400 GeV/c protons and dissipate up to 305 kW. The baseline design consists of water-cooled tantalum-alloy clad TZM and tungsten (W)...
The FRANZ linac, consisting of a coupled RFQ-IH cavity and a subsequent CH rebuncher, requires an LLRF system with moderate performance demands. These include amplitude control to maintain a constant field in the cavity, constant phase synchronization between the accelerator and rebuncher, and plunger control to stabilize the cavities frequency at 175 MHz. Given the dead time from LLRF RF...
In the frame of the High-Luminosity LHC (HL-LHC) project at CERN, a series of sensor solutions based on Frequency Scanning Interferometry (FSI) has been proposed for the alignment and monitoring of accelerator components along a total length of more than 800 m. The adoption of FSI technology reduces the overall cost of alignment installations, mitigates the impact of environmental noise, and...
A Low-Level RF and Power Control system based on EPICS has been developed for the new H¯ RF Ion Source on the Pre-Injector Test Stand at ISIS Spallation Neutron and Muon source, UKRI-STFC Rutherford Appleton Laboratory. The Ion Source LLRF system provides a 2 MHz signal to a Solid-State 100 kW RF Amplifier that drives the Ion Source Plasma, the changing Plasma load requires fast Frequency...
Non-destructive measurement of low-intensity charged particle beams poses significant challenges in beam diagnostics. At the Heavy Ion Accelerator Facility in Lanzhou (HIRFL), beams with currents below 1 μA are frequently used in experiments, which fall below the detection threshold of standard beam current transformers. To address this, a low-intensity monitoring system was developed,...
The quality of slow extraction from the SPS (Super Proton
Synchrotron) to the North Area is critically influenced by
the straightness tolerance of the electrostatic septum. Past
observations have identified a degradation of the anode body
straightness, resulting in an increased beam loss during ex-
traction. A new metrology bench including optical sensors
has been developed to cope with...
The High Luminosity-Large Hadron Collider (HL-LHC) is an ambitious project aiming to upgrade the LHC to achieve substantially more collisions to increase its potential for new discoveries after 2030. As part of this upgrade, 220 m of new components will be installed on both sides of the interaction points of the ATLAS and CMS experiments. The upgrade includes the installation of over 300 Wire...
Optical Fibre Sensors (OFS) possess unique features, such as high sensitivity, versatility, and the ability to operate in harsh radiation environments. Distributed OFS are notable for enabling real-time monitoring over large-scale facilities, making them ideal for applications in particle accelerators. Their distributed measurement capabilities provide comprehensive monitoring while offering a...
The digital LLRF controller for the Facility for Rare Isotope (FRIB) project was designed to accommodate various cavity types with six distinct frequencies ranging from 40.25 to 322 MHz. The cavities also adopt different types of tuners, e.g. stepper motor, pneumatic, water flow, etc. A common hardware platform with design choices such as direct sampling of RF, compatible footprint for RF...
An auto-scanning vibrating wire system for magnets centering alignment was developed at NSRRC. It is prepared for the replacement of magnets on the girder of TPS storage ring in case of malfunction and also as a pre-study topic of the TPS upgrade. With this system, both quadrupole and sextupole magnets were tested in the laboratory. This paper presents the system configuration and testing results.
The Accelerator Test Facility* (ATF) is the DoE Office of Science User Facility aimed to provide users with a high brightness electron beam, near-infrared (NIR), and long-wave infrared (LWIR) laser beams. The unique capabilities at the ATF include the possibility to combine the electron beam with synchronized high-power laser beams.
It is planned to upgrade the facility to have enhanced...
In the SXFEL injector, the beam stability achieved superior performance, maintaining fluctuations below 0.01% after passing through four S-band accelerating units. However, the stability deteriorated to 0.02% upon exiting the X-band linearizer. To mitigate this degradation, a series of targeted enhancements were implemented, including an extensive upgrade of the low-level RF system’s front-end...
The Bunch Shape Monitor (BSM) is a versatile diagnostic device designed to measure longitudinal beam parameters, which are essential for the operation and development of high-intensity linear accelerators. However, these measurements remain challenging for proton and ion beams at non-relativistic energies. RadiaBeam has developed an enhanced BSM prototype with several key innovations to...
A laser-wire-based method for a direct measurement of bunch profiles of an operational H- beam has been developed at the SNS. In this talk, we report recent advancements on the bunch profile measurements using a customized picosecond pulsed laser with giga-watt peak power and a user-defined macro-pulse structure. The modified system enables fast and precise tracking of the bunch profiles over...
The Liverpool Centre for Doctoral Training in Innovation in Data Intensive Science (LIV.INNO) has made significant progress in applying data-intensive methods to accelerator research. This contribution presents research outcomes from the center with a focus on two key projects.
The first focuses on optimizing 3D imaging for medical and industrial applications, integrating Monte Carlo...
There are 32 electron beam position processors used for beam position measurement in the storage ring of Hefei Light Source(HLS II), the crossbar-switch(CS) of processors must be operation for RF channels compensation and long-term stability. The turn-by-turn(TBT) and fast acquisition(FA) beam position signals would suffer from the CS interference like harmonics and artifact when the CS is...
In the context of the High Luminosity Large Hadron Collider (HL-LHC) project, two configurations of collimator settings are being considered. A set of relaxed settings were conceived to address potential limitations due to the impedance contribution of the collimation system with the initially foreseen settings, and to increase the
primary betatron cut in case of over-populated beam tails. A...
Previous work has shown the efficacy of using machine learning for removal of noise in LLRF signals when operating in an industrial environment. Here we extend the analysis to include different noise power spectra. Specifically we analyze the impact on denoisig when correlated noise power spectra are used. Four different noise spectra are analyzed including red, pink, violet, and blue noise....
To coat the inner surface of antechamber type vacuum chamber for Hefei Advanced Light Facility (HALF) with nonevaporable getter material (NEG), a dedicated magnetron sputtering setup has been prepared at National Synchrotron Radiation Laboratory (NSRL). The magnetron sputtering device and the coating method are introduced in this paper. The properties of the films were tested. This coating...
Bayesian optimization is a method for performing global optimization on black-box functions using Gaussian processes and an acquisition function. In accelerator parameter tuning, when the number of adjustable parameters is large, finding the global optimal parameters can be time-consuming and often relies on the operator’s experience. Bayesian optimization is well-suited for such scenarios. In...
High-energy accelerators like CERN’s Large Hadron Collider (LHC) present hazards characterized by temperature variations such as cryogenic leak or fire. Considering that LHC tunnels are large, underground, and radioactive areas, alternatives to traditional systems are explored to improve hazard detection. CERN is investigating the feasibility of installing a large-scale temperature monitoring...
The large set of technical documentation of legacy accelerator systems, coupled with the retirement of experienced personnel, underscores the urgent need for efficient methods to preserve and transfer specialized knowledge. This paper explores the application of large language models (LLMs), to automate and enhance the extraction of information from particle accelerator technical documents. By...
The role of large particle accelerators in basic research and applied research is becoming increasingly important. In recent years, which have put forward higher requirements for the accuracy and efficiency of particle accelerator alignment measurement. The vibrating wire pre-alignment system measures the magnetic center position of the magnet through the amplitude information of a beryllium...
The TPS (Taiwan Photon Source) control system is a critical component of the accelerator and beamline. Since the TPS control system is based on the EPICS framework, which communicates through a network, any failure in the control network may result in communication loss between EPICS IOCs, ultimately affecting accelerator operation. To ensure stability, it is necessary to monitor the network...
The retrieved waveform data include pulse magnet power supply waveforms, fast current transformer waveforms, wall current monitor waveform, RF power waveforms, beam signals, and more. These waveforms are crucial for diagnosing subsystem abnormalities and for long-term observation during routine beam operations. Various types of digitizers, capable of remotely accessing waveforms, have been...
Particle accelerator control rooms rely on fixed workstations with multiple monitors and on-site personnel, limiting operational flexibility. When experts connect remotely—whether for troubleshooting, monitoring, or collaboration—current setups often lack sufficient screen space, forcing users to toggle between interfaces and reducing situational awareness. Recent advancements in augmented...
The Crocker Nuclear Laboratory at UC Davis operates a 72-inch isochronous cyclotron capable of accelerating protons, deuterons, and alpha particles to variable energies up to a maximum of 67.5 MeV for protons. The cyclotron is primarily used for proton therapy, conducting radiation effects testing, and supporting academic research. We describe the upgrade of its original analog control system...
The commissioning phase of short-wavelength FEL is often lengthy due to the optimization of thousands of control variables. These variables are frequently interdependent and have non-linear correlations with FEL performance, which makes optimization of such a complex system challenging, particularly for soft XFEL. Additionally, FEL inherently suffers from shot-to-shot intensity jitter, which...
Neutron scattering experiments are a critical tool for the exploration of molecular structure in compounds. The TOPAZ single crystal diffractometer at the Spallation Neutron Source and the Powder Diffractometer at the High Flux Isotope Reactor study these samples by illuminating them with different energy neutron beams and recording the scattered neutrons. Aligning and maintaining the...
This article provides an overview of various software tools developed by operators to enhance TPS operations. The primary functionalities of these tools include real-time monitoring and notification of light source statuses, as well as data analysis. The tools covered include the TPS alarm system, LINE notification system, real-time orbit deviation display, real-time fast corrector output...
The Future Circular Electron-Positron Collider (FCC-ee) is CERN’s leading proposal for the next generation of energy-frontier particle accelerators. At 91 km long, it is ambitious in size, complexity and technical objectives. Availability is a main challenge. This paper presents results from a Monte Carlo simulation that extrapolates reliability and maintain-ability from systems in current...
In particle accelerators, accurate and stable beam parameters are crucial for experimental success. Traditional methods for measuring parameters like beam energy often rely on invasive techniques that disrupt experiments. This paper presents a novel, non-invasive machine learning-based approach to predict beam energy using parasitic measurements, enabling real-time estimation without...
We will present the status of the beam instrumentation at MESA. To put MESA into operation various diagnostic systems are necessary. To optimize the beam the position and phase with respect to the accelerating RF needs to be optimized to be able to recirculate the beam for multi-turn operation or ERL mode respectively. On the other hand, an absolute beam current measurement is necessary. This...
The online optimization and debugging of particle accelerator devices have always been a challenging task. Traditional manual debugging is time-consuming and labor-intensive, and there is a phenomenon of slow drift in the machine's operating state after debugging, requiring experts to repeatedly debug. With the improvement of computing power, machine learning has developed rapidly in recent...
Transverse beam profile diagnostics for high intensity beams are very challenging as material inserts are untenable. An alternative single shot beam diagnostic was studied, and developed, that consists of a thin sheet of gas. When a charged particle beam traverses the gas sheet, the neutral particles are ionized. The ionization products are then imaged on a monitor and the time of flight is...
A recent analysis of emittance measurements highlighted the limited reliability of tools for precise method evaluation and error calculations. In this paper, a new analysis method is presented with its associated errors calculations. It is evaluated using realistic beam simulations and compared to the linear regression method commonly referenced in the literature. This new analysis method is...
Cavity beam position monitors (CBPMs) are very high-precision devices that, in recent years, have progressed from experimental equipment to standard linac diagnostics in many prominent facilities, most notably free electron lasers. However, the high sensitivity of these devices comes at the cost of a limited measurement range, even with high dynamic range electronics. Furthermore, CBPMs need...
The ALBA Synchrotron is currently designing its new version to become a 4th generation particle accelerator. In this new scenario, ALBA would produce a brighter and more coherent photon beam. As a result, ALBA would provide capabilities hitherto inaccessible in terms of resolution, detection levels and understanding of chemical and electromagnetic properties.
In this context, the thermal and...
The KIT cSTART project (compact storage ring for accelerator research and technology) aims to demonstrate injection and storage of a high intensity ultra-short bunch using the FLUTE LINAC, as well as a laser-plasma accelerator (LPA).
cSTART is planned to operate with a wide range of demanding parameters, such as bunch charge, bunch length and energy spread (from the LPA), making it extremely...
A new Beam Profile Monitor (BPM) system has been recently developed at the IRRAD Proton Facility to monitor the high-intensity 24 GeV/c proton beam from the CERN Proton Synchrotron accelerator. Thanks to the use of a new sensor manufacturing technology based on the microfabrication of metal nano-layers and updated readout electronics based on a Charge-Sensitive Amplifier with integrated 20-bit...
Transverse phase space (x, x’, y, y’) measurement is crucial in beam physics to optimize the beam parameters. Typically, the phase space information of space charge-dominated beams can be characterized using well-established methods such as pepper-pot and movable slit-based scans. In addition, recent studies show that calibration of transfer matrix with considering space charge forces provides...
Outgassing rate is one of the most important criteria for vacuum acceptance of various components used in ultra-high vacuum (UHV) systems. There are numerous methods to measure the outgassing rate of UHV components. One of the most common techniques is the so called ‘pressure-rise’ method. In this method the component under test is enclosed in a system and disconnected from the pump. The...
The ISIS-II Neutron and Muon Source, the proposed successor to the ISIS Neutron and Muon Source at the Rutherford Appleton Laboratory, UK, presents a unique opportunity to integrate environmental sustainability practises from its inception. A Life Cycle Assessment (LCA) was performed during the early feasibility and design stage to evaluate the potential environmental impacts across...
The negative impacts of global warming and continuously rising energy costs emphasize a need for sustainable and cost-effective operation also for accelerator facilities. This necessitates optimization of accelerator operation, which then requires a comprehensive profiling of accelerator facilities for power consumption patterns to break down the consumption trends of the whole facility. At...
Beamstrahlung radiation represents a new challenge at CERN's lepton Future Circular Collider (FCC-ee), specifically for electron-positron collisions. At each interaction point, its unprecedented beam intensities give rise to two photon beams with a power of several hundred kW each. Liquid lead, known for its high density and Z and relatively low melting point, is proposed as a beam dump...
The Karlsruhe Institute of Technology (KIT) operates research accelerator facilities for the development of new technologies for future compact light sources at the Institute for Beam Physics and Technology (IPBT). Within the cSTART project (compact STorage ring for Accelerator Research and Technology), a Very Large Acceptance compact Storage Ring will be realized to...
The FCC-ee, a 90.7 km circumference e+ and e- collider under study at CERN, will require a transverse feedback system capable of handling risetimes as fast as four turns for the lowest order coupled-bunch modes. This can be realized by a distributed system of pick-ups and kickers in more than one location of the ring. The advantages are weighed with respect to the flexibility to respond to...
Personnel Safety Systems provide prevention and mitigation barriers to protect personnel, users, equipment, and the environment against the risks associated with the operation of the CERN Accelerators and Experiments, such as Radiation, Fire, Gas and Oxygen Deficiency Hazards. Due to the obsolescence or ageing of technology, evolutions of the facility and the Safety rules, it is now time to...
The premise of the stable operation of charged particles in the accelerator storage ring is a stable and clean vacuum environment, and the level reached by the vacuum system is directly related to beam intensity, beam quality and beam lifetime. Therefore, the design of vacuum system is an indispensable part of accelerator engineering. HALF is a fourth generation advanced synchrotron radiation...
The existing room temperature heavy ion synchrotron SIS18 at GSI will be used as booster for the future SIS100 at FAIR. One of its features the the generation of high intensity heavy ion beams. In order to create such beams, medium charge states are used, which have a lower space charge limit and can be created with less stripping losses. Unfortunately, such heavy ions have very high...
One possible future for Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) lies in upgrading its maximum nominal energy using Fixed-Field Alternating-gradient (FFA) technology for its recirculating arcs. The current proposal aims to use permanent magnets to supply the fixed fields. One concern among reviewers is the degradation of these permanent magnets during operation due...
Starting with user delivery it was noticed that the FEL intensity performance varied by up to a factor of two during the day. Three injector RF phases for the laser, the gun, and the buncher were not stabilized with a forward and reversed reference signals like the rest of the RF feeding the Cryo-Modules, making them the prime candidates for daily phase drifts. Combining the signals in...
To damp undesired longitudinal oscillations of bunched beams, the main synchrotron SIS100 of FAIR (Facility for Antiproton and Ion Research) will be equipped with a bunch-by-bunch longitudinal feedback (LFB) system. It will consist of new broadband kicker cavities and a dedicated low-level RF (LLRF) system. The LFB helps to stabilize the beam, to keep longitudinal emittance blow-up low and to...
The construction of fourth-generation accelerators, represented by free-electron lasers and diffraction-limited storage rings, is increasingly popular, which sets higher standards for the installation precision of insertion devices. Large-scale insertion devices are installed using two laser trackers, but a rigorous system has not been established. To enhance installation accuracy, we propose...
The precise modelling of magnetic fields in particle accelerator magnets is essential for optimizing their performance and ensuring the accurate control of particle beams. Traditional modelling approaches require extensive multi-physics simulations and electrical and magnetic measurements. In this study, we explore using data-driven artificial intelligence models to predict the magnetic field...
The next generation Australian Synchrotron project (AS2), is a proposed 4th generation light source, aims to deliver ultra-low emittance $\sim$100 pm-radians and highly coherent, bright light. Constraints on emittance place tight demands on beam optics correction techniques like linear optics of closed orbit (LOCO) and consequently constraints on accurate estimation of the beam centroid along...
The Booster Ring (BRing), which requires an average vacuum to be better than the 10-10Pa，is the key part of the High Intensity Heavy Ion Accelerator Facility. The total length of BRing is 569.0985 meters, the characteristics of long circumference, large cross-section and a large amount of gas load, pose great challenges for on-site installation and achieving the vacuum index. Therefore,...
Increasingly, synchrotron facilities are being developed as green accelerators focused on energy efficiency and low-emittance rings to achieve high brilliance. The emittance size of the electron beam is closely related to the number of bending magnets used. To economically upgrade and optimize the current synchrotron facility, it is crucial to minimize revisions to the existing infrastructure....
This paper presents the development of a beam scraper system for the 3 GeV storage ring of Siam Photon Source II (SPS-II). Beam scrapers are essential for removing halo particles, protecting accelerator components, and managing aperture limitations. The scraper blade material is carefully chosen for its superior thermal conductivity and mechanical strength. The design prioritizes considering...
The ALS-U project at LBNL is a major upgrade of the ALS involving a new Accumulator Ring (AR) and an upgraded Storage Ring (SR). The new AR RF System has one operational mode with beam and three test modes without beam. Another upgraded overarching Ring Personnel Protection Systems (PPS) covering both AR and SR ring enclosure areas is in place for personnel protection from ionizing radiation...
Permanent magnet-based dipoles will be an essential part of the future PETRA-IV light source at DESY. The bending magnets are combined-function DQ-magnets, which provide moderate focusing with a B/G ratio of about 0.03m. Each DQ consists of several C-shaped modules, one of the three types additionally having a stepwise longitudinal gradient. Several prototype modules have recently been...
As important parts of the High Intensity Heavy Ion Accelerator Facility(HIAF), the Chopper and the Kicker play an indispensable role in controlling the operation mode of the beam and the protection of the machine. Accurate timing control is the key technical requirement and difficulty of this type of equipment, and it has a profound impact on the injection and extraction efficiency and beam...
The Proton radiation effects facility (PREF) was designed and constructed by the Institute of Modern Physics, which can provide high-quality proton beams with continuous and accurate tunable energy range, high current intensity, high duty cycle and large scanning area of 10-60MeV energy range. which consists of a proton source, RFQ linac injector, synchrotron and irradiation terminals. The RFQ...
Designing a vacuum chamber for the Elliptically Polarized Undulator (EPU) in the SPS-II storage ring presents challenges due to a constrained bore aperture, minimal clearance between magnet poles, and requirements for synchrotron radiation delivery. This study focuses on a vacuum chamber design that accommodates the large opening angle necessary for EPU operation. A complex transition...
The High-Luminosity Large Hadron Collider (HL-LHC) project at CERN aims to enhance the LHC's performance and increase its discovery potential. As part of this upgrade, new components will be installed and must be aligned with an accuracy of 0.17 mm vertically and 0.33 mm radially (1σ) over a length of 420 m.
To achieve such requirements in harsh conditions, CERN has developed a range of new...
The CSNS RCS (Rapid Cycling Synchrotron) is a proton accelerator designed to achieve a target beam energy of 1.6 GeV, with a typical operating intensity of 140 kW, which is expected to increase to 500 kW after the CSNS II upgrade. However, a significant current instability has been observed during the 100 kW beam operation. To mitigate this instability, techniques such as operational tuning...
In this paper, a multi-layer ionization chamber is designed for the measurement of 250MeV proton beam profile. The chamber is equipped with 128 X and Y channels, allowing for high-resolution profiling of the proton beam across both transverse axes. Each channel is capable of detecting ionization events, providing precise dose measurements and spatial distribution information. The design...
A novel high-precision beam diagnostic system has been designed for slice emittance and energy spread measurements. The 20-meter diagnostic platform integrates eight quadrupoles, a deflecting cavity, and an energy spectrometer, achieving 100fs temporal resolution in both operational modes through the same beamline layout. The emittance measurement mode provides 50-fold horizontal...
The Siam Photon Source II (SPS-II) is a fourth-generation synchrotron light source designed to provide high-brightness, low-emittance, high-energy electron beams for advanced synchrotron applications. SPS-II is equipped with a 150-MeV linear accelerator, a 3-GeV booster synchrotron, and a 3-GeV electron storage ring, enabling the production of high-quality synchrotron radiation for a wide...
The Hefei Advanced Light Facility (HALF) is positioned as an internationally advanced fourth-generation synchrotron radiation light source in the low-energy range, based on a diffraction-limited storage ring. The stainless steel vacuum chamber is a key component of HALF, with 316LN stainless steel chosen as the primary material. Its mechanical strength, corrosion resistance, low outgassing...
The ANTHEM (Advanced Technologies for Human-centered Medicine) research project will establish a Research and Clinical Center in Caserta, Italy, for the study and application of Boron Neutron Capture Therapy (BNCT). The INFN (LNL, Pavia, Napoli, Torino) has in charge the design and construction of the epithermal neutron source, that will assure a flux of $10^9\ n/(s\ cm^2)$ with...
The ANTHEM (Advanced Technologies for Human-centered Medicine) research project will establish a Research and Clinical Center in Caserta, Italy, for the study and application of Boron Neutron Capture Therapy (BNCT). The Radio-Frequency Quadrupole (RFQ), designed by INFN, produces proton beam of 30 mA at 5 MeV, impinging on a beryllium target. A 12 m long Medium Energy Beam Transport (MEBT)...
The design study of a distributed pumping system using NEG (Non-Evaporable Getter) strips for the slender beam pipes of the Hefei Advanced Light Facility (HALF) is presented. To achieve a high pumping speed and pumping capacity in a limited pumping space, a NEG strip with distributed pumping capacity was considered. A prototype of HALF vacuum chamber, which can be inserted into NEG strip and...
The advancement of broadband terahertz (THz) sources has become increasingly important for various scientific and technological applications, including those in particle accelerators. To enable tunable and flexible THz source development, components capable of selective THz spectrum filtering are essential. In this work, we investigate the use of 3D-printed photonic crystal structures,...
The CERN accelerator complex relies critically on fast injection and extraction processes to transfer particle beams between accelerators via fast pulsed magnets, or kickers. Ensuring high availability is paramount, as the reliability of these systems directly impacts the large number of experiments conducted at CERN. In this paper, we propose to explore Continual Learning (CL) methods,...
At the Taiwan Photon Source 13A experimental station, the detector is prone to noise interference in a vacuum environment ranging from 750 torr to 7 mtorr, which can lead to malfunctions. Therefore, a rapid automatic power-off system has been designed to immediately shut down the detector's power when it is in an abnormal vacuum range, reducing the impact of noise on the detector and thereby...
This work investigates the potential of using synthetic images generated from CAD models to train an object detector for identifying components of a particle accelerator. The study focuses on magnets within the new ALS Accumulator Ring at Lawrence Berkeley National Laboratory. Generating large volumes of real-world training data is often challenging in such complex systems. To address this,...
We present the development and laboratory testing of a precise alignment setup for the STERN experimental area at the European XFEL, aimed at exploring beam-based THz radiation generation methods using Cherenkov waveguides. The setup employs an alignment laser to simulate the electron beam trajectory, enabling the accurate positioning of critical components, such as a copper block housing...
The paper presents a design of an autocorrelator manufactured to measure the duration of infrared picosecond pulses of radiation from the 3rd laser of the Novosibirsk Free Electron Laser facility, as well as the results of testing the autocorrelator when measuring the duration of picosecond pulses in the visible range. The results and future plans for future experiments using developed autocorrelator
ALBA Low-Level RF (LLRF) system has provided over a decade of reliable operation and has been adopted by other synchrotron facilities. To meet the evolving requirements of ALBA and ALBA-II, a new LLRF system has been developed. This system features FPGA and ADC/DAC MTCA boards designed by SAFRAN, enabling direct 500 MHz signal sampling without down/up-conversion. These enhancements reduce...
In this paper, a multipurpose beam diagnostic system based on a YAG:Ce scintillator is presented. This system was developed in order to measure beam profile, transverse parameters, momentum spectrum, and current of the electrostatic accelerator. The concerning issues in the beam profile monitor design such as image resolution and scintillator temperature distribution have been discussed. In...
This paper presents the design and implementation of a long-term operational monitoring and control module, planned for deployment after 2026 at the base of a 1.5 GHz superconducting passive harmonic cavity (SRF HC) in the TPS storage ring. The proposed system, known as the Break Out Box (BOB), consolidates multifunctional measurement and control capabilities into a compact, modular platform....
The controls system for the ISIS accelerator is being migrated from using the commercial software Vsystem to EPICS which is open source. The primary protocol used for transporting process variables (PVs) across the network is pvAccess and the Python-based software p4p is used to create servers that provide access to process variables (PVA servers). A custom wrapper for p4p is being...
A cavity beam position monitor (cBPM) developed by
CEA Saclay was installed at the end of the Accelerator Test
Facility (ATF) linac to evaluate the combined performance
of the monitor and its associated signal processing system.
The setup incorporates a down-conversion architecture inspired
by Royal Holloway, University of London (RHUL),
and employs a digital down-conversion (DDC)...
These days designing an accelerator consist of prototyping and testing adequate commissioning software. Digital twins serve as natural test benches for validating and monitoring the required physics software stack. These twins must align with the current design state of the accelerator from the project's inception to the machine's commissioning. The authors have developed a modern digital twin...
The Taiwan Photon Source (TPS) is a 3 GeV synchrotron radiation facility located at NSRRC. Superconducting RF cavities have been installed in the booster and storage rings to ramp and refill electron beam energy. In order to measure the bunch phase of each bunch relative to the RF clock of the accelerator, a bunch phase detector (BPD) system was constructed to support measurement experiments....
An integrated concept is presented to design a permanent quadrupole magnet (PQM) using tunning modules simultaneously for varying magnetic field gradient. It is anticipated that this design will be utilized for Hefei Advanced Light Facility (HALF) in the future. This design leverages symmetry to achieve both a broad range of magnetic field gradient tunning and a narrow range of precise...
The multipurpose synchrotron radiation accelerator (4GSR), currently under development at the pohang accelerator laboratory (PAL), offers exceptional performance with 100 times higher brilliance and an ultralow emittance of 58 pm·rad compared to third-generation synchrotron light sources. The storage ring includes 344 quadrupoles, 168 sextupoles, and 56 octupoles, most of which are designed...
Among the advanced approaches in Laser Wakefield Acceleration (LWFA), the use of tapered plasma density and extended acceleration lengths—demonstrated through gas jet experiments—has proven effective for generating high-energy beams. However, gas jet sources often fail to ensure stable beam quality and high repetition rates, limiting their applicability. Addressing these limitations within...
The TPS storage ring utilizes a standard four-kicker bump off-axis injection system, which is known to cause disturbances to the stored beam during injections. To address this issue, an in-vacuum non-linear kicker has been developed. This kicker features zero Bx and By fields at its center and an off-axis By, providing a potential solution to facilitate top-off injection while minimizing...
The FETS-FFA will be a proof-of-principle Fixed Field Alternating gradient accelerator (FFA), to demonstrate the feasibility of these machines to drive megawatt-class spallation neutron sources, such as the proposed ISIS-II. It will accelerate protons from 3 to 12 MeV, and demonstrate high-intensity operation through large space charge tune shift. Beam stacking takes advantage of the static...
Hefei Advanced Light Facility (HALF) is a fourth-generation synchrotron radiation source based on diffraction limited storage ring. It comprises a 180-meter injector and a 480-meter storage ring. The injector incorporates a digital low-level radio frequency (LLRF) control system based on MTCA.4, ensuring a stable and adjustable microwave field for the acceleration structure. This article...
HIAF-BRing, the booster synchronous ring of the High Intensity Heavy-Ion Accelerator Facility, is rapid cycling synchrotron. It requires a vacuum pressure of 5 ×10 -10Pa and a vacuum pipeline that generates small eddy currents under high-frequency magnetic fields of 12 T/s. A new type of vacuum chamber has been successfully developed to reduce effectively the eddy current effect. It also...
The MADOCA control system was developed for the present SPring-8 in 1997. Nowadays we faced problems of outdated technologies of the MADOCA. In 2025, SPring-8 upgrade project "SPring-8-II" will be started. Toward to the SPring-8-II, we decided to renovate the MADOCA control system. The new control system inherits former MADOCA's concepts, which are characterized by SVOC-style messaging,...
Residual Gas Analyzers (RGA) are widely used to mon-itor gas composition in vacuum systems. However, they are typically limited to high-vacuum environments and cannot be used directly in processes that operate at higher pressures. To solve this problem, we developed a modular and easy-to-build differential pumping system that allows an RGA to monitor vacuum environments up to 10 Torr. In this...
Construction of the COMET experimental facility is underway to explore the muon-electron conversion process at the J-PARC Hadron facility. An 8 GeV proton beam supplied from the main ring irradiates a target in a superconducting capture solenoid magnet, and the produced pions and muons are transported to the experimental area. In the beam line, the muon transport solenoids are composed of...
To meet the beam commissioning requirements of the High Energy Photon Source (HEPS), a brand-new framework called Pyapas was developed using pure Python. All high-level applications (HLAs) for the HEPS are being built upon this framework. The beam commissioning of the Linac started on March 9, 2023, and the HLAs performed excellently, helping the Linac to successfully complete the test and...
The Direct Diode Detection (3D) method for transverse tune measurement, which was developed at CERN, has been implemented in numerous hadron machines and has recently been tested in electron machines. This method can provide orders of magnitude greater sensitivity to betatron oscillations than conventional beam position measurement approaches, which is particularly useful in fast-ramping...
In the SuperKEKB/Belle-II experiment, various new physics searches are conducted by colliding 4 GeV positrons and 7 GeV electrons. Future plans aim to significantly increase luminosity, targeting an integrated luminosity 100 times higher than current levels. However, the realization of this goal is challenged by the phenomenon of "Sudden Beam Loss" (SBL), characterized by the abrupt...
Accelerators are complex systems composed of tens of thousands of individual components requiring continuous maintenance. Aging facilities such as LANSCE face an increased rate of equipment failures, resulting in costly unscheduled shutdowns for maintenance. Early identification and localization of problems along the accelerator can mitigate future failures during scheduled maintenance periods...
SLAC’s upgraded Linac Coherent Light Source (LCLS-II) promises transformative 1 MHz attosecond X-ray pulse generation. To meet the demands of high-rate attosecond characterization across multiple operational modes at LCLS-II, we showcase the data processing chain for the Multi-Resolution COokiebox (MRCO) detector--a circular array of 16 multichannel plate time-of-flight spectrometers optimized...
Tuning injectors is a challenging task for the operation of accelerator facilities and synchrotron light sources, particularly during the commissioning phase. Efficient tuning of the transfer line is essential for ensuring optimal beam transport and injection efficiency. This process is further complicated by challenges such as beam misalignment in quadrupole magnets, which can degrade beam...
Reinforcement learning (RL) is a promising approach for the online control of complex, real-world systems, with recent success demonstrated in applications such as particle accelerator control. However, model-free RL algorithms often suffer from sample inefficiency, making training infeasible without access to high-fidelity simulations or extensive measurement data. This limitation poses a...
The Coupling-Loss-Induced-Quench (CLIQ) concept is an integral part of the quench protection system for the High-Luminosity Large Hadron Collider (HL-LHC) Inner Triplet superconducting magnets at CERN. Since the discharge of the CLIQ unit induces a change of the magnetic field in the low beta quadrupoles, a spurious trigger during operation could deflect the beam, potentially causing critical...
This work demonstrates electronic logbook (eLog) systems leveraging modern AI-driven information retrieval capabilities at the accelerator facilities of Fermilab, Jefferson Lab, Lawrence Berkeley National Laboratory (LBNL), SLAC National Accelerator Laboratory. We evaluate contemporary tools and methodologies for information retrieval with Retrieval Augmented Generation (RAGs), focusing on...
Beam manipulations require precise control of phase space correlations. Gwanghui's previous work introduced a method for generating arbitrary correlations using Fourier series and cosine sums with transverse wigglers. However, accurately controlling the wigglers to match a desired correlation curve remains challenging, as it involves optimizing parameters like amplitude, phase, and period....
This study presents a data-driven methodology aimed at enhancing the performance and reliability of the injector at ALS. We show a data acquisition system for capturing and analyzing the parameters affecting the injection process to find patterns and improve reliability. We analyze the recorded injection parameters to find key correlations and patterns within the multidimensional parameter...
This poster presents an overview of the efforts to resolve niobium quality issues, specifically surface pits and delamination, encountered during cavity manufacturing for the PIP-II project. Initial surface quality problems led to a temporary suspension of production. Additionally, delamination was later discovered in both formed and unformed sheets, raising concerns about the material's...
Detecting anomalies in superconducting cavities at the EuXFEL is essential for reliable operation. We began with a model-based anomaly detection approach focused on residual analysis. To improve fault discrimination, particularly for quench events, we augmented the detection with a machine learning-based classification. Key challenges are posed by the transition to real-time operation,...
Shanghai Synchrotron Radiation Facility/Shanghai Soft X-ray FEL Facility has developed an advanced transverse deflecting structure TTDS (two-mode transverse deflecting structure), using two different rf power sources to deflect beam in any angle. Bandpass filter is a key component in the TTDS, designed to pass low-frequency signals while blocking high-frequency ones. This study uses an...
The demand for cost- and time-effective and customizable components for High Vacuum (HV) and Ultra-High Vacuum (UHV) has prompted exploration into the application of 3D-printing technology. This study investigates the viability of utilizing 3D-printed plastics in UHV by evaluating their outgassing. An extensive evaluation of 3D-printing materials was carried out, highlighting the best polymer...
EuPRAXIA, the "European Plasma Research Accelerator with eXcellence In Applications," represents the next generation of free-electron lasers (FEL). It aims to develop a compact, cost-efficient particle accelerator using innovative wake-field accelerator technology. High-energy physics often demands higher acceleration voltages, and X-band technology offers high gradients in compact structures....
Since 2020 LINAC4 provides the protons for the entire CERN accelerator complex. It accelerates H- ions to a kinetic energy of 160 MeV and injects them into the Proton Synchrotron (PS) Booster using a charge exchange injection mechanism. The performance requirements have been successfully met since 2021. This paper presents the operational experience gained, together with availability and...
Accurate knowledge of the Thermal Contact Conductance (TCC) between surfaces is of great importance for the design of components in particle accelerators, such as mirrors, monochromators, filters, detectors, among others. The TCC depends on many variables such as surface finish, type of material, pressure between samples, temperature and interface materials. The TCC can be found in specialized...
This theoretical study presents an advanced method for longitudinal phase space tomography in electron storage rings, focusing on reconstructing phase space densities from electro-optical spectral decoding (EOSD) measurements that incorporate crystal geometry effects. The EOSD crystal geometry significantly impacts the measurement signal due to signal integration along its length and...
The Mu2e experiment at Fermilab imposes stringent requirements on the elimination of out-of-time beam in its pulsed proton beam - a requirement known as "extinction". We present a method to measure the out-of-time particle rates to calculate the level of extinction in the inter-pulse gaps. The proposed method utilizes an array of quartz Cherenkov radiators and photomultiplier tubes to detect...
The UC Davis Crocker Nuclear Laboratory houses a 72-inch multi-species Isochronous Cyclotron built in the 1960’s. For many years, previously unexplained beam dynamics have been indirectly observed at the cyclotron by both internal and external experimenters. Investigating these effects within the cyclotron, at the bunch level, has proven particularly challenging due to the cyclotron's harsh...
Function Generator Controllers (FGCs) are key devices used in CERN’s converter control systems to regulate and monitor the power converters that supply current to the magnets in the accelerator complex. To ensure the reliability and enhance the quality assurance of the software that controls these devices, the FGC Test Manager has been developed. It encompasses the Python library...
A homemade permanent dipole magnet with Sm2Co17 is planed to replace the original electromagnet in the TPS transfer line. The prototype of 150 mm length is assembled and measured. This paper will discuss the difference between field measurement and simulation.
This paper presents the first operational experience of the European Spallation Source (ESS) cryomodules in a linac configuration, with a focus on the challenges encountered during the initial integrated cooldown and subsequent stable operation. Key aspects such as thermal stability, cryogenic performance, and system integration are discussed in detail. The paper also highlights lessons...
The 3rd-generation synchrotron light source BESSY II is undergoing a series of modernization measures to maintain its leadership role until BESSY III starts its operation, planned for in 2035. The modernization of the LLRF control systems is one of these measures in the so-called BESSY-II+ project. Prior to the deployment of the new mTCA-based digital systems to control the fundamental...
The future circular electron-positron collider (FCC-ee) is designed for highest luminosity to enhance the precision of high-energy particle physics experiments, spanning energies from the Z pole to the $\text{t}\bar{\text{t}}$ threshold. As outlined in its conceptual design report, high-precision measurements of the longitudinal bunch profile are required across multiple operation modes, which...
KEK ATF is the Accelerator Test Facility devoted to develop an advanced beam instrumentation technologies for ILC (International Linear Collider) project. There are seven main subsystems at the facility: RF-Gun laser, Linac, Beam Transport (BT), Damping Ring (DR), Extraction Line (EXT), Final Focus (FF) and Interaction Point Beam Size Monitor (IP BSM). In order to monitor laser pulse output...
RF measurements are crucial for stabilizing the power source output and extracting beam data. As digital systems evolve, the analog-to-digital converter (ADC) now commonly reaches 16 bits and 100 MHz, enabling multi-channel low-level radio frequency (LLRF) systems to generate several gigabytes of data per second, overwhelming data storage and processing capabilities. This paper proposes a...
During the third run period (2022-2026) of the CERN Large Hadron Collider (LHC), as well as for the future High-Luminosity LHC era, luminosity levelling is key to control the event pile-up in the experiments as well as the heat load to the cryogenic system of the superconducting magnets close to the interaction points. During 2024 proton physics operation, a new luminosity levelling scheme was...
The STAR facility represents an advanced high-energy photon source located at the University of Calabria (Italy). It was conceived to generate high-energy photons through the inverse Thomson scattering process. Following a recent upgrade, the facility features an additional beamline driving the source from 65 MeV electron beam energy up to 140 MeV, leading to a maximum photon energy of 350...
The Mainz Microtron is an electron accelerator, which delivers electron energies up to 1.6 GeV, with a small spread of the energy σ_beam < 13 keV. Besides a small energy spread, the high quality of the beam allows producing high coherent synchrotron radiation. The light from two spatially separated and movable light sources (undulators), can be superimposed to render an interference pattern....
The Advanced Photon Source (APS) facility has just completed an upgrade to become one of the world’s brightest storage-ring light sources. Machine learning (ML) methods have seen extensive use during commissioning. One important application was multi-objective tuning of dynamic aperture and lifetime, a complex high-dimensionality task intractable with classic optimization methods. In this work...
In various of particle accelerator designs, amplitude and phase modulation methods are commonly applied to shape the RF pulses for implementing pulse compressors or compensating for the fluctuations introduced by the high-power RF components and beam loading effects. The phase modulations are typically implemented with additional phase shifters that requires drive or control electronics. With...
Laser field diagnostic has long been limited by dimensions of obtained information and one-shot measurement ability. The term “dimension” refers to spatiotemporal distributions, but also physical quantities completely defining a light field including amplitude, phase and polarization. Conventional diagnostic systems realize multi-shot or incomplete measurements of laser optical field, but are...
We report a novel concept of hybrid semitransparent beamstops for small-angle xray scattering instruments, removing the need for a separate photodiode to monitor the transmitted x-ray intensity. The combination of a semitransparent aluminum core and a highly absorbing steel cover ensures minimal parasitic x-ray scattering from the beamstop itself. The modular design readily enables...
LUXE is an international project that aims to study Quantum Electro-Dynamics processes that occur in the strong field regime. Using the electron beam from the European XFEL, this experiment will perform electron-laser and photon-laser collisions. Beamline simulations are required to understand what beam properties and backgrounds are expected at key locations. The beam optics was design and...
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is an accelerator-based neutron source facility that provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The neutron production occurs when a horizontally injected proton beam strikes the liquid mercury target placed in the center of the target monolith. The...
In synchrotron light sources, coupled-bunch instabilities driven by resonant wakefields in the vacuum chamber pose significant challenges to beam stability and quality. This study presents the implementation and evaluation of a bunch-by-bunch feedback system at the Pohang Light Source-II (PLS-II). Utilizing state-of-the-art feedback technologies, including Dimtel iGp12 baseband processors and...
The EPU66S, an elliptically polarized undulator with a 66 mm period, is a component of the Phase III beamline project at the Taiwan Photon Source (TPS). It was successfully installed in the TPS storage ring in January 2025. The control system for the EPU66S is developed within the EPICS framework, integrating motion controllers and EtherCAT communication. This system also includes a safety...
In synchrotron accelerators, managing the intense photon flux generated by bending magnets is very important for maintaining the accelerator's performance. The emitted synchrotron radiation, characterized by its high intensity and broad spectrum, imposes significant thermal and structural demands on accelerator components. Photon absorbers are essential to effectively block excess photons,...
The Siam Photon Source (SPS) has, for several decades, implemented direct imaging with synchrotron radiation for the measurement of transverse beam size. This paper describes improvements made to the transverse beam measurement system of the SPS storage ring. A synchrotron radiation interferometer system will be integrated for monitoring of beam size alongside the direct imaging system. The...
The FLASH hadron therapy accelerator proposed by Trbojevic requires permanent magnets with nonlinear fields to allow rapid cycling from 10 to 250MeV while keeping the ring tune constant. A test beamline consisting of four cells from this ring is being built at BNL to be tested at the NSRL proton facility. The magnets consist of 24 neodymium-iron-boron (NdFeB) wedges magnetised in different...
Insertion Devices (ID) in particle accelerators introduce orbit distortions that must be compensated. At MAX IV, this compensation traditionally relies on feed-forward tables which are time-consuming to measure, and sensitive to changes in accelerator settings. This study explores the use of machine learning (ML) to automate the generation of feed-forward tables without requiring extensive...
Typical operational environments for industrial particle accelerators are less controlled than those of research accelerators. This leads to increased levels of noise in electronic systems, including radio frequency (RF) systems, which make control and optimization more difficult. This is compounded by the fact that industrial accelerators are mass-produced with less attention paid to...
Advances in fidelity and performance of accelerator modeling tools, in tandem with novel machine learning capabilities, has prompted community initiatives aiming to realize “virtual test stands” that can serve as true analogues to physical machines. Such efforts require integrated, end-to-end modeling capabilities with support for parametric optimization and benchmarking. We present the...
The High Luminosity Large Hadron Collider (HL-LHC) project is a major upgrade of the LHC presently operating at CERN, designed to enhance the performance reach in terms of integrated luminosity collected during its operational era by another order of magnitude. It involves the replacement of the entire machine and services over more than 200 meters on each side of the high luminosity...
The number of motor drivers in the TPS beamline and experimental stations is quite large. Therefore, designing an intelligent monitoring and alert system to monitor the motor control system on the beamline is essential. When the system encounters any abnormal conditions, it can notify engineers to handle the situation. Additionally, it can record usage time to schedule relevant replacement...
To achieve physics performance at the Future Circular electron-positron Collider (FCC-ee), luminosity and beam lifetime must be maintained at close to design specifications. Alongside global feedbacks, a fast feedback system is proposed to mitigate beam offset errors at the interaction points (IP), caused by magnet vibrations or other time-varying errors. In this paper, the FCC-ee luminosity...
The emission of electrons induced by beam interaction with thin targets is a phenomenon used to measure various properties of particle beams. The main processes of electron emission are: secondary emission, delta electron production and thermionic emission. The last one is not desired, because the intensity of thermionic electrons is not directly related to beam density profile. A common...
The Hefei Advanced Light Facility (HALF) is the fourth-generation synchrotron radiation light source based on Diffraction-limited Storage Ring (DLSR) with low beam emittance, high brightness and coherent photon flux. According to the physical design requirements of the HALF, the vacuum chamber structural materials should have low outgassing rate, good electrical and thermal conductivity, high...
CuZr alloy is considered for the structural material of the vacuum chamber of the Hefei Advanced Light Facility (HALF) storage ring. We tested the outgassing rate of CuZr material. The outgassing rate of CuZr alloy can reach 4.93×10^-11 Pa·L/s·cm² after baking at 180°C for 48h, which is more than one order of magnitude lower than that of SS. These results indicate that CuZr alloy is easier to...
The Japan Proton Accelerator Complex (J-PARC) linac is operated with a peak current of 50 mA to deliver the 1-MW beam to the neutron target through the rapid cycling synchrotron (RCS). One of the source of the beam loss to limit the beam power is a leakage beam from an radio-frequency (RF) beam chopper at the frontend of the linac. Since the leakage beam is presented in the unintended RF...
KEK Accelerator Test Facility (ATF) conducts beam instrumentation R&D for International Linear Collider (ILC) project. ATF includes 1.3 GeV normal conductivity S-band Linac and Damping Ring (DR). There are 9 S-band pulsed klystrons at Linac, which supply High-Power RF to accelerate electron beam up to 1.3 GeV, 1 CW klystron at DR. The electron beam is generated by a photocathode irradiation by...
Three Lambertson magnets are utilized in the injection and extraction of the High Energy Photon Source (HEPS) booster. These magnets incorporate an embedded spliced core structure, integrating structural components made from FeCoV alloy (1J22) with a core composed of DT4 material. The 1J22 components are longitudinally segmented according to the core's length, with each segment processed and...
High-power particle accelerators, like the Spallation Neutron Source, require reliable radio-frequency waveguide windows to transmit power while maintaining a vacuum. These windows face performance challenges due to multipacting, an electron cascade disrupting vacuum integrity. Thin TiN coatings can suppress this by reducing secondary electron emission, but traditional methods struggle to...
With increasing operational frequency ($f_R$), the size, weight, and power consumption of linear accelerators (Linacs) decrease, which is why e.g. X-band LinVarious studies show that additive manufacturing (AM) has the potential to significantly reduce the cost of radio frequency cavities (cavities) while increasing performance. With increasing resonance frequency, the size, weight, and power...
The Beam Loss Monitoring System (BLM) of the Large Hadron Collider (LHC) protects the accelerator against energy deposition from beam losses. One of the most critical moments regarding beam losses is the start of the beam acceleration. During this process, particles outside the bucket will not be captured in the first seconds of the start of ramp thus being lost at the machine aperture. This...
The implementation of a new product data management (PDM) and product lifecycle management (PLM) system at CERN has significantly improved lifecycles and workflows for 3D integration studies, thanks to the advanced features and tools of the platform. This new PDM/PLM system has provided an opportunity to reassess and optimize user methodologies, focusing on better organization of 3D CAD data,...
The Novosibirsk Free Electron Laser (NovoFEL) is a facility that consists of three free electron laser (FEL) systems installed on different parts of the Energy Recovery Linac (ERL). These three FELs share the same acceleration system, which enables the generation of high average electron current, typically around 10 mA. Precise measurement of the electron beam parameters is essential for...
We present the experimental results of the longitudinal phase space (LPS) measurement using a corrugated structure at Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The electron beam, passing the corrugated structure, generates the wakefield, which streaks the beam horizontally. The dipole magnet following the corrugated structure disperses the streaked beam vertically. By...
Planned upgrades of the European X-Ray Free Electron Laser (EuXFEL) target higher photon energy and a high duty-cycle operation up to CW operation, critically depending on improvements of the beam slice emittance of the electron gun. We are addressing this challenge by the application of deep learning techniques to create an inverse model that predicts optimal parameter configurations for the...
Superconducting radio frequency (SRF) cavities in particle accelerators rely on accurately calibrated RF signals to assess cavity bandwidth and detuning, ensuring optimal performance. In practice, however, calibration drift due to humidity and temperature fluctuations over time poses a significant challenge, potentially resulting in suboptimal operation and reduced efficiency. This study...
The accurate assessment of beam quality is the most important aspect in the irradiation facilities operation such as IRRAD at CERN. The Beam Profile Monitor (BPM) sensor system developed for the high-intensity proton beam at IRRAD features minimal particle interaction, improved radiation hardness and higher sensitivity and sampling rate than previous systems. It provides a wealth of...
A machine learning-based model predictive control (MPC) application has been developed for the RFQ control at Facility for Rare Isotope Beams (FRIB). In this work, we extend this approach to broader applications at FRIB, the superconducting radio frequency (SRF) control. A machine learning model is trained to learn the correlations between the beam loss and the SRF signals. With the model, a...
The Los Alamos Neutron Science Center (LANSCE) relies on accurate tuning of its Drift Tube Linacs (DTLs) to maintain beam quality and operational efficiency. This work introduces a novel machine-learning-based approach to reconstruct the longitudinal phase space (LPS) at the entrance of DTL Tank 1 using two-dimensional phase scans from Tanks 1 and 2. A Deep Neural Network trained on synthetic...
This study explores the application of machine learning techniques for phase space reconstruction of heavy ion linac beams, a critical aspect of understanding and optimizing beam dynamics for advanced nuclear physics experiments. Modern machine learning methods, including neural networks and differentiable simulations, are employed to reconstruct the multidimensional phase space distribution...
The performance of particle accelerators is critically dependent on the reliability of their power supplies, which can number in the thousands in many facilities. In this work, we present a method for monitoring temperature anomalies in power supplies using infrared (IR) imaging. By applying various machine learning algorithms to the IR imaging data, we develop a reliable anomaly detection...
MedAustron, a synchrotron-based ion therapy centre in Austria, is focused on enhancing cancer treatment performance. A key improvement opportunity lies in the regulation of the main ring bending dipoles, which currently require time-consuming procedures to ensure reproducibility and reliability of the associated magnetic fields (B-Fields). Other therapy centres globally address this through a...
The use of liquid lead as a target material in particle accelerators is of significant interest due to its high density, high thermal power absorption capacity, and resistance to radiation damage. This makes it particularly well-suited for the high-intensity proton beams being studied for CERN’s Muon Collider proposal, with powers ranging up to 4 MW. To minimize shock propagation and manage...
This study investigates the material properties of 3D-printed copper for use in radio frequency (RF) cavities, with a focus on its suitability for high-performance accelerator applications. Key aspects include an analysis of the corrosion and erosion resistance of the printed copper, as well as its electrical and thermal conductivity. Results demonstrate the potential of additive manufacturing...
In this study, we investigated the possibility of using a passive dielectric-lined waveguide structure on slice energy spread measurement of femtosecond electron beam. Such diagnostic setup for a 25 MeV electron beam with a duration of a few hundred femtoseconds is simulated using IMPACT-T. The DLW acts as a passive streaker by generating traverse wakefields that deflect the electron bunch....
The radiation damping time is a crucial parameter that depends on the overall magnetic structure of the accelerator. Accurate measurement of this damping time can provide insights into the fidelity of the accelerator model by allowing for a comparison with calculated damping time values. In this study, we present a series of measurements of radiation damping times at the VEPP-4M and VEPP-2000...
The transition from 3rd to 4th generation synchrotron light sources can primarily be characterized by a significant reduction in horizontal emittance. This enables a nearly uniform transverse X-ray beam profile and a brilliance that approaches the diffraction limit. A consequence of the upgrade to Diffraction Limited Storage Rings (DLSRs) is that the traditional emittance measurement...
The SuperKEKB electron-positron collider, which aims to achieve the world's highest luminosity, has suffered from "Sudden Beam Loss events (SBL)," in which several tens of percent of the beam current is lost and aborted within a few turns (20-30 µs). We have developed a new turn-by-turn beam size monitor to elucidate the cause and time evolution mechanism of the SBL events from a beam size...
Two CLIC TD24 accelerating structures, manufactured by CERN, are being tested on the high gradient 12 GHz RF test stand at XLAB. Installed at the end of 2024, these are the first devices to be tested at XLAB. Testing aims to verify that following conditioning they can be reliably operated at accelerating gradients of 100 MV/m. The conditioning process involves slowly increasing the peak RF...
During the LHC Ion Run in 2023, the ALICE detector observed a high level of background that prevented efficient data taking. This background was caused by different ion species generated in the betatronic collimation region that were intercepted by the Tertiary collimator near ALICE Interaction Point. The mass-to-charge ratio of these generated ions causes them to follow a different trajectory...
The FCC-ee faces challenges in managing radiation from primary synchrotron photons, which can damage machine components and tunnel equipment due to cumulative exposure. Effective shielding is crucial to reduce equipment failure, prevent performance degradation, and limit reliance on costly radiation-hard materials.
The proposed solution involves enclosing photon stoppers with shielding...
The Korea-4GSR storage ring vacuum chamber is composed of materials such as aluminum and stainless steel. Among these, the aluminum extruded chamber for Pill getter insertion undergoes in-situ bake-out and getter activation in the storage ring tunnel at a temperature of 180°C for over 24 hours. The gap between the electromagnet and the vacuum chamber is as narrow as 1–2 mm, which could lead to...
The 13th International Conference on Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation (MEDSI 2025) marks the 25th anniversary since the first MEDSI workshop in 2000. This biennial meeting, hosted by MAX IV Laboratory in Lund, Sweden, from September 15–19, 2025, is expected to welcome over 300 delegates and more than 30 industrial exhibitors. MEDSI is the...
The injector system of SIRIUS, the brazilian 4th generation synchrotron light source, currently operates with non-ideal injection efficiencies, which may impose limits to future top-up operation modes. Within this context, diagnostic techniques to access beam quality in the injector are essential tools for optimizations. In this work, the MENT algorithm was implemented for the reconstruction...
In the field of beam diagnostics for radiotherapy, accurate dose delivery relies on ultra-thin, linear and radioresistant monitors to minimize beam scattering and achieve precise profiling. The first PEPITES prototype monitor features two segmented cathodes, each paired with a high-voltage-biased anode. This latter effectively captures secondary electrons generated by the cathodes when they...
At our institute, we needed a scalable SCADA system for both FRANZ and smaller laboratory test setups. Given the heterogeneity of devices, the system had to be easily extendable to support custom-built hardware, self-made devices, and standard PLC systems. Additional requirements included low maintenance, minimal system demands, and compatibility with various IT environments, operating...
Multi-Turn Extraction (MTE) is a resonance-based technique employed in the CERN Proton Synchrotron (PS) to split the beam in horizontal phase space before extraction to the Super Proton Synchrotron (SPS). The splitting efficiency is evaluated based on the uniformity of intensities across the beamlets, requiring fine-tuning of multiple parameters. In this paper, we investigate the influence of...
Currently, the Flerov Laboratory of Nuclear Reactions (FLNR) is modernizing its accelerator complex, focusing on the development of new facilities and the enhancement of existing ones. Notably, the U400M cyclotron has been successfully modernized. As part of the upgrade of the U400M's main systems, a project for the deep modernization of its Automated Radiation Monitoring System (ARMS) was...
The Taiwan Photon Source (TPS) is an advanced synchrotron radiation light source that provides high-brightness light for scientific research and industrial applications. The insertion device (ID) plays a critical role in controlling the electron beam trajectory to enhance synchrotron radiation intensity. However, due to radiation and signal interference in the operational environment, the...
The ASU cryogenically cooled DC electron gun represents a state-of-the-art platform for testing novel photocathodes at room and cryogenic temperatures. The key electron beam diagnostic tool of this setup is the four-dimensional (4D) phase space reconstruction using the pinhole scan technique. In this work, we use the 4D phase space measurement to extract the Mean Transverse Energy (MTE)...
Diagnostics of charged particle beams is an important area in the field of accelerator technology. Non-destructive methods of beam diagnostics are becoming increasingly popular, as they allow measurements to be taken without changing the beam parameters. This is particularly valuable when studying continuous processes, the results of which can be distorted when using traditional diagnostic...
This study compares Fast Fourier Transform (FFT), Power Spectral Density (PSD), and Wavelet Analysis for detecting tune coupling at the Canadian Light Source (CLS). Data were analyzed for low coupling, 1.4%, and 2.5% high coupling regimes, focusing on frequency identification and amplitude stability in X and Y directions. FFT revealed ~15% amplitude fluctuations, complicating tune...
With the advancement of science and technology, people are more dependent on the Internet and digital technology. We continue to improve our network system to increase speed and security of information transmission at NSRRC. We had established various levels of Information Security System (ISMS) documents and conducted many tasks and obtained the certification of ISO-27001.
Four horizontal paint bump magnets and two vertical paint bump magnets are used for the painting injection to produce a high intensity beam at J-PARC RCS. These paint bump power supplies are composed of the IGBT chopper units, and so the requirement waveforms can be controlled with high precision less than 1%. By using software that automatically creates input voltage (IV) patterns according...
Until recently, the Karlsruhe Research Accelerator (KARA) located at the Karlsruhe Institute of Technology (KIT) was using analog cameras to monitor fluorescence screens. By now all cameras have been replaced by digital cameras directly connected via ethernet, making it possible to directly integrate them into our EPICS-based control system. The new control system integration also provides for...
Aperture measurements at the Large Hadron Collider (LHC) are routine procedures conducted during the early stages of beam commissioning, prior to the injection of high-intensity beams. This is to ensure that the aperture, defining the clearance for the circulating beams, is protected by the LHC collimation system. Local aperture measurements are performed to probe the available aperture at...
The low-level RF (LLRF) systems for S-band linear accelerating structures are typically implemented with heterodyne base architectures. We have developed and characterized the next generation LLRF (NG-LLRF) based on the RF system-on-chip (RFSoC) for C-band accelerating structures and the platform delivered the pulse-to-pulse fluctuation levels considerably better than the requirement of the...
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...
Characterizing the longitudinal bunch profile is crucial for understanding beam dynamics and ensuring optimal accelerator performance. To address these needs, Capacitive Pick-Up type Bunch Shape Monitors (CPU-BSMs) were developed at the Institute for Rare Isotope Science (IRIS). These devices non-destructively measure the longitudinal bunch shapes of non-relativistic, nanosecond-scale ion beam...
We recently commissioned the Next GenerAtion Photocathode Laser system (NEPAL) in Hamburg’s XFEL facilities (FLASH and EuXFEL) and at DESY’s Photoinjector Test Facility (PITZ). The system delivers deep UV pulse trains up to 1 ms long at repetition rates as high as 4.5 MHz, with temporal and spatial shaping capabilities and individual amplitude control for bunch charge manipulation. The shaping...
Taiwan Photon Source (TPS) has been committed to serve users for eight years. In the first and second phases of TPS beamline project, there were 16 beamlines had been in operation. The third phase project had been launched in 2021. Facing the more persons and equip-ment in the experimental hall as well as power saving issue, we applied the computational fluid dynamic (CFD) scheme to simulate...
A novel approach combining online unknown input estimation with reconfigurable control has been developed to enhance orbit stability in the Siam Photon Source (SPS) storage ring. These unknown inputs, representing disturbances or uncertainties in the dynamic system, provide valuable insights for achieving robust control. Disturbances such as noise, temperature changes, and modeling...
The Schottky signals encode various beam and machine parameters, such as betatron tune, chromaticity, momentum deviation and transverse emittance. In this contribution we present the architecture and the performance of the system estimating these parameters in real-time, providing the only non-invasive measurement of chromaticity at the Large Hadron Collider. The obtained results are assessed...
To maintain optimal beam collision conditions and luminosity performance, SuperKEKB requires a fast orbit feedback dedicated to correcting offsets at the interaction point (IP). The 'iBump' feedback system calculates IP beam offset from Beam Position Monitor (BPM) measurements before and after collision and corrects by creating closed orbit bumps in the High Energy Ring (HER). This system has...
At CERN’s Low Energy Ion Ring (LEIR), high beam intensities are achieved through phase space painting with up to eight multi-turn injections from the linear accelerator Linac3. After each injection, the beam is cooled and stacked in longitudinal phase space using an electron cooler. During beam operation, key parameters such as RF cavity phases in the linac, the LEIR electron cooler gun...
We present an overview of recent and upcoming enhancements to the optical electron beam diagnostics stations at the Novosibirsk Free Electron Laser (FEL) facility. These diagnostic stations are designed to measure key beam parameters, including beam energy spread, length and emittance, at the third FEL of Novosibirsk FEL. Currently, the stations for measuring electron beam energy spread and...
Superconducting cavities with high Q-factor require precise tuning to match the RF frequency, ensuring stable electromagnetic fields and minimizing RF power consumption. At the XFEL accelerator, TESLA cavities are tuned using slow tuners (step motors) for coarse adjustments and fast tuners (piezoelectric actuators) for fine-tuning and compensating disturbances such as Lorentz Force Detuning...
Badger is optimization software created for the purpose of real-time accelerator tuning and operation. A range of optimization algorithms are available on this platform, implemented with both graphical and command-line user interfaces. This study shows the improvements in beam size, beam lifetime and related parameters at the Siam Photon Source storage ring following the application of Badger....
Collimators are used to minimize losses and to remove particles that would otherwise get lost downstream and irradiate the machine. Finding the optimal jaw positions is time consuming and with the upstream beam properties changing, the collimation settings would need to be readjusted each time. Therefore, a method to optimize collimator positions and to operate them at full capacity in a short...
To enhance the performance of next-generation X-ray Free Electron Lasers (XFELs), it is crucial to produce high-quality electron beams with low emittance, particularly for attaining emittances below 0.2 mm.mrad for 100 pC bunch charges. This study introduces an emittance measurement method using an orthogonal dual-slit technique, aimed at enhancing measurement efficiency and achieving the...
At the core of IFMIF-DONES is placed the Target System. It generates a high-speed liquid lithium jet (15 m/s, 300°C) acting as the target for a 40 MeV, 125 mA deuterium-based linear accelerator, with the primary aim of qualifying fusion-related materials. The design of the Target System has evolved during the last few years addressing key challenges. Managing the 5 MW of power deposited...
With the increased performance of the High Luminosity Large Hadron Collider (HL-LHC), gas leak detection in the vicinity of the superconducting magnets cooled with cryogenic helium becomes a challenge.
To ensure operational safety and reliable detection of Oxygen Deficiency Hazard (ODH) for the next decade, the entire system will be refurbished during the LHC accelerator's long shutdown,...
PAnTHer (Particle Accelerator on THreejs) is a 3D and 2D map for particle accelerators developed using web and touch technologies. The maps are connected to real-time data from accelerator controls, simulators, and an external component database.
The map is generated from a lattice file in JSON format and a bundle of JavaScript components for the 3D version, and an SVG bundle for the 2D...
The NSRRC is a research facility and currently op-erates two synchrotron accelerators: the Taiwan Light Source (TLS), featuring a beam energy of 1.5 GeV and a circumference of 120 meters, and the Taiwan Photon Source (TPS), with a beam energy of 3 GeV and a cir-cumference of 518.4 meters. There are hundreds of users in 40 beamlines among TPS and TLS experi-mental floors.
The...
In this paper, we investigate statistical and systematic tools to establish performance benchmarks for future beam profile measurement tools, using extensive data from both prototype and legacy Beam Wire Scanners and the Beam Synchrotron Radiation Telescope at the LHC. We detail direct and comparative analyses, including variability in beam size measurements, positioning accuracy, and profile...
This paper presents studies on advanced accelerator technologies conducted under the I.FAST (Innovation Fostering in Accelerator Science and Technology) EU project, focusing on additive manufacturing (AM) advancements. AM, particularly powder bed fusion, is giving unique production capabilities for accelerator components. As a proof-of-principle, a full-size pure copper Radio Frequency...
In recent years, permanent magnet (PM) based multi-pole magnets have become an increasing concern as a replacement for conventional electro-magnets for light sources. The PMs are possible to save both energy and costs for operating and construction the facilities due to the absence of a power supply and cooling system. They have other advantages such as less space without magnetic coils and...
High Temperature Superconductor (HTS) and amorphous Carbon (a-C) thin films, and their combination, are being considered as possible surface coatings for the FCC-hh beam screen (BS) with the aims of reduction of the resistive wall impedance and mitigation of the electron cloud. Along with these required properties, i.e., the high electron conductivity and low secondary electron yield, the...
Permanent-Magnet (PM) magnets combine up to zero power consumption with highly stable magnet operation without ripple and cooling vibration effects for more energy-efficient and stable accelerator operation.
As part of the upgrade program BESSYII+, we will install the B2PT dipole triplet as the first PM-based accelerator magnet. It concludes the BESSYII transfer line, transporting the...
A compact transverse-deflecting system (TDS) is being commissioned at the test facility FLUTE (Ferninfrarot Linac- und Test-Experiment) located at the Karlsruhe Institute of Technology (KIT). It has been proposed for diagnostics of short electron bunches. The idea of the technique is to use terahertz (THz) radiation, produced by the tilted-pulse front method using a part of the facility’s...
NSRRC started its solar energy systems installation project in 2016 and began construction in early 2017. Solar modules have been gradually planned and installed on the rooftops of office, laboratory, and Utility buildings. The total installed capacity has now accumulated nearly 1.2MWp, and the total electricity generated to date has reached 10.8GWh, with a total carbon reduction of 5.7kt....
The storage ring of the Hefei Advanced Light Source includes 120 magnet units, each of which is composed of 4-8 magnets with adjustment mechanisms placed on a rigid support. In order to improve the overall efficiency and accuracy of the alignment installation, we will complete the overall pre-alignment of the magnet unit in an independent laboratory with a good environment based on the...
Achieving precise and real-time diagnostics of electron beam characteristics is critical for enhancing the performance of ultrafast electron diffraction (UED) and electron microscopy (UEM) techniques. Key parameters such as bunch size, emittance, energy spread, and spatial pointing jitter directly influence the quality and accuracy of experimental results. Traditional diagnostic methods often...
China Spallation Neutron Source (CSNS) accelerator complex will employ a new superconducting accelerating section to provide high beam power. To prevent contamination of the superconducting cavity surface caused by sputtering, shedding, or melting of medium materials during interceptive beam measurements, the second phase of the China Spallation Neutron Source (CSNS) superconducting linac...
Hefei Advanced Light Facility (HALF) was the fourth generation diffraction limited storage ring light source under pre-research in National Synchrotron Radiation Laboratory (NSRL) of China. Beam position stability was strictly required with the ultra-low beam emittance. The beam position stability of storage ring was affected by many factors. And the changes of magnetic field center position...
A Terahertz (THz) transition radiation monitor, as part of a Bunch compression monitor (BCM), is implemented for longitudinal bunch diagnostics at FELs such as ELBE, FLASH, or EuXFEL. Pulse energy measurements are typically carried out after each bunch compressor stage using coherent diffraction radiation (CDR) in the THz domain and pyroelectric detectors. For higher repetition rates in the...
Precise measurement of an electron bunch’s longitudinal profile is critical for wakefield accelerators as shaped electron bunches can improve transformer ratios in collinear wakefield acceleration. Electro-Optic sampling of terahertz (THz) radiation from the bunch is one of the most attractive approaches to provide a view into the structure of a relativistic electron bunch due to its...
Non-evaporable getter (NEG) films are ideal for maintaining ultra-high vacuum (UHV) conditions in particle accelerators, owing to their uniform pumping speeds and negligible outgassing characteristics. However, the requirement for thermal activation limits the applicability of NEG films. Prolonged exposure to atmospheric conditions and repeated activation cycles lead to a gradual increase in...
The Samarium-Cobalt (Sm₂Co₁₇) permanent magnet block is a promising material for accelerator applications due to its high radiation resistance, low temperature coefficient, high coercive force, and rust resistance. However, Sm₂Co₁₇ is costly and easily to brittleness. To reduce production costs, a glued Sm₂Co₁₇ block has been developed as a substitute for large blocks, which helps to lower...
The integrated luminosities in each of the ATLAS and CMS experiments at the Large Hadron Collider (LHC) have reached above 120 fb-1 during the proton run of 2024, the highest annual values since the beginning of the LHC operation. The same is true for LHCb, with over 10 fb-1 of integrated luminosity reached during proton operation in 2024. Such high levels of integrated luminosity are...
The application of Raspberry Pi cameras as cost-effective, versatile beam diagnostic tools is currently being explored at the Frankfurt Neutron Source (FRANZ). These compact imaging systems have been deployed to investigate proton beams at energies of 60 keV and 700 keV, including configurations where cameras are installed both externally and directly inside the accelerator’s RF resonator....
This study presents the development and implementation of a reinforcement learning-based algorithm for real-time luminosity tuning in collider experiments. The algorithm is initially pretrained on historical collider data and subsequently fine-tuned online during experiments. By analyzing accelerator measurements collected over several seconds, the model adjusts the magnetic structure to...
This work summarizes the most significant diagnostic upgrades that have been implemented, as well as those currently under development, at the Solaris synchrotron facility. These include the installation, startup, and initial testing of a Bunch-by-Bunch Feedback (BBF) system that is currently being implemented at the Solaris synchrotron. Once operational, the BBF system will provide real-time...
The Low Energy Accelerator Development Facility * is located at the site of the Brookhaven National Laboratory (Upton, NY, USA) and is aimed to run a program specially targeting new collaborations for user-driven research. The facility has two fully radiation-shielded bunkers (153 and 77 sq. m) to where a range of electrical, cooling and RF capabilities are presently being introduced. The...
The Beam Interlock System is a key element of machine protection in CERN’s accelerators. It provides a fast and reliable way to link the accelerator systems to the beam dumping system, which ensures the safe extraction of the beams. This paper presents the reliability study of the new Beam Interlock System, which will replace the current system and will be deployed during CERN’s Long Shutdown...
The new Universal Quench Detection System (UQDS) and Protection Devices Supervision Unit (PDSU) are pivotal elements for the quench protection system of the new HL-LHC inner triplet superconducting magnets as well as for requesting a beam dump upon activation of the active quench protection systems, the novel Coupling Loss Induced Quench System (CLIQ) and the traditional quench heaters (HDSs)....
The distribution of services throughout a large scientific facility like CERN relies on a 14-km-long network of technical galleries. They provide essential utilities to CERN's office buildings and technical facilities, such as hot water, drinking water, compressed air, gas and electrical supply. This network has been gradually expanded or partially discontinued based on the Laboratory's needs....
In the CEPC TDR, the RF beam separating system adopts an electro-magnetic separator scheme. The adverse issues of DC HV as high as hundred kV and beam impedance of the electrostatic separator are inevitable, so an alternative solution using kicker magnets and septum magnets was proposed. Compared with static-electrical separator, kicker magnet is stronger and contributes lower beam impedance....
A three-dimensional spiral beam injection scheme* has been developed since 2014. This scheme is for accumulating a charged particle beam with relativistic energy in a sub-meter storage ring to realize for the J-PARC Muon g-2/EDM experiment (E34). Prior to the E34 experiment, we conducted a demonstration experiment utilizing 80 keV pulsed electron beam generated by an electron gun**. The beam...
The KEK e-/e+ LINAC delivers the beams to four storage rings with the top-up injections by switching the beam mode in 50 Hz repetition rate. The beam charge, energy, and number of bunches (one or two) are different for each ring. Therefore, the RF timing and phase are adjusted to each beam mode independently. To stabilize the RF phase drifts caused by the klystron high voltage, the cooling...
Previous works on reconstructing the 4D phase space using tomography require optimal selection of projection views to achieve accurate reconstruction. In 2D reconstruction, the process is straightforward, as an object can be evenly sampled by dividing the angles evenly. However, extending this concept from 2D to 4D is not intuitive. This work demonstrates that quaternions can be used to more...
A novel service-based EPICS and new front-end data acquisition method based on a high-availability Kubernetes cluster built on the Proxmox VE platform are proposed in this paper to enhance the performance and stability of the data acquisition system. By deploying EPICS services on the Kubernetes cluster, a new efficient front-end data processing and acquisition method is realized. The data...
Non-evaporable Getter (NEG) coating is a breakthrough technology wherein the inner walls of a vacuum chamber are coated with a material that functions as a vacuum pump. This technology is expected to gain widespread adoption across various fields in the future. However, the current coating method, originally developed for long beam ducts, is not adaptable to a wide range of vacuum chamber...
The Cryogenic Current Comparator (CCC) is a superconducting device for measurement of low intensity beams with magnetic fields in the range of fT. It uses a Superconducting Quantum Interference Device (SQUID) as an ultrasensitive magnetometer and an elaborated superconducting shield for its protection from external magnetic fields. The system is operated in a helium bath cryostat, which has to...
This paper presents the strategy for the simultaneous cryogenic operation of the ESS superconducting linac, consisting of 43 cryomodules. It details the process logic required for different operational phases and introduces a novel control system designed to manage these complexities. Key features of the system are discussed, including multiple independent automatic control sequences, a master...
The National Synchrotron Radiation Research Center (NSRRC) is dedicated to enhancing the operational efficiency of its facilities and improving user experience by developing a status and event automatic notification system. This system aims to monitor equipment status in real-time and automatically notify relevant personnel in case of anomalies or significant events. It continuously monitors...
RAON (Rare Isotope Accelerator complex for On-line experiments), a heavy-ion linear accelerator designed to advance basic and nuclear science with rare-isotope beams, successfully completed beam commissioning and, for the first time, provided beam user service for its low-energy section using an argon beam in 2024. The successful operation of such a complex and massive accelerator system...
The impact of high-flux protons on beam loss during slow extraction from the SPS to the North Area has been discussed, and improvements have been proposed focusing on reducing activation, lifetime reduction, and anode body distortion. The conducted studies shall demonstrate the feasibility of replacing the stainless-steel tank, flanges, and anode body with low-Z materials. A reduced-length...
The Korea 4th-Generation Synchrotron Radiation (4GSR) accelerator requires exceptionally high mechanical stability to ensure reliable beam operation with an extremely small beam size. To achieve this, a robust grid-er system is essential for supporting accelerator components such as magnets, vacuum chambers, and beam position monitors (BPMs). The girder system must suppress vibrations...
We have studied classical radiation from relativistic electrons at a facility, test accelerator as a coherent terahertz source (t-ACTS), the Research Center for Accelerator and Radioisotope Science (RARiS), Tohoku University. Cherenkov radiation is generated when a relativistic charged particle passes through a dielectric medium, while Cherenkov diffraction radiation (ChDR) is emitted when the...
In order to achieve laser pulse to electron beam arrival time sub-picosecond stability at the accelerator facilities, a new Low-Level Radio-Frequency system clock generators synchronization architecture is currently under investigation in collaboration between KEK (Japan) and IJClab (France). The system is based on the 10 MHz frequency generator (Stanford Research System), White Rabbit Switch,...
To ensure stable and continuous commissioning of SuperKEKB, the machine protection system (MPS) plays a crucial role in safeguarding the accelerator's hardware from damage caused by beam loss. The response time of the MPS is a critical factor in mitigating hardware damage caused by the radiation of abnormal beams. In this study, we investigate a novel laser fast abort system for the SuperKEKB...
The feasibility of incorporating ozonized water into the ultra-high vacuum (UHV) chemical cleaning process for aluminum vacuum chambers was investigated. The experiments were conducted using custom-designed wet bench equipment under various temperature and time conditions. Auger analysis was used to evaluate the removal of organic contaminants, and TEM analysis measured changes in oxide layer...
A large scientific facility, High Intensity heavy-ion Accelerator Facility (HIAF), was being built to study basic and interdisciplinary sciences. The Booster ring (BRing), as the core device of the HIAF, has a magnetic rigidity of up to 34 Tm，and the field ramping rate of the pulsed dipole magnet is up to 12 T/s. To reduce the eddy current effect and beam loss caused by the rapid ramping of...
The all-optical synchronization system used in many X-ray free-electron laser facilities (XFELs) relies on electro-optical bunch arrival-time monitors (EO-BAM) for measuring the single bunch arrival time with regards to an optical reference. An upgrade of the established EO-BAM is intended to achieve a sensitivity that enables stable operation with bunches down to charges of 1 pC, or to...
Exposure of synchrotron radiation on the vacuum chambers induces high yield of photoelectrons and the consequent increase of pressure from stimulated gas desorption. Characterization of the surface quality of vacuum chambers, either after chemical cleaning or with thin film coating, by synchrotron radiation exposure at a beamline is powerful and sensitive. In this study, analysis of...
Recently, it was found that Pd coating films exhibited ultra-low photon-stimulated desorption and low resistivity values. These advantages suggest that Pd coatings could be applied to small aperture tubes, including undulator vacuum tubes, which have a significant effect on resistive wall impedance.
In previous studies, the DC electrical resistivity of Pd films was measured using the...
The Mainz Energy recovery Superconduction Accelerator (MESA) will be a recirculating electron linear accelerator, capable of delivering beam energies up to 155 MeV and 150 µA in external beam mode or 105 MeV and 10 mA in energy recovery mode. The building consists of a tunnel for the electron guns, spin preparation, and normal conducting pre-accelerator up to 5 MeV and 10 mA. The main...
A bunch-by-bunch synchrotron phase detector system has been implemented to investigate the synchronous phase behavior of the storage ring at the Taiwan Photon Source. This detector employs I/Q demodulation to cal-culate the beam phase on a bunch-by-bunch basis. The acquired data is integrated into the accelerator control system, visualized through a graphical user interface, and made available...
The Karlsruhe Institute of Technology is currently exploring a compact method of longitudinal electron bunch diagnostics with femtosecond resolution that has recently been demonstrated for other parameter ranges. The experimental setup utilizes a THz-based streaking approach with resonator structures, achieving both high compactness and efficiency. In this paper, we report on the experimental...
In particle accelerator complex, measurement of the beam profile monitor is important to mitigate the beam loss in a high-intensity beam linac. However, traditional metallic wires in wire scanner monitor (WSM) face thermal challenges with high energy deposition leads to rapid break. Since the CNT wire has a high-temperature tolerance and a small energy deposit due to the low density compared...
A uniformly moving electron passing through a slab induces electromagnetic
emission known as transition radiation. The generated rays propagate inside
the slab and undergo multiple reflections off the slab boundary. We employ the polarization current method in order to derive the reflectionless
solution for an observed radiation intensity and compare it with that of Pafomov
which accounts...
This report discusses various efforts to improve beam stability at the Taiwan Photon Source. The Fast Orbit Feedback (FOFB) system is essential for maintaining beam stability in the light source. Considering the trade-off between FOFB reliability and performance, we optimize the FOFB parameters to achieve better orbit stability in the TPS. Occasional spikes in the Beam Position Monitor (BPM)...
Two sets of blade-type beam position monitors (XBPMs) are installed in the Taiwan Photon Source (TPS) front-end. The upstream XBPM, referred to as XBPM1, has been calibrated and can calculate the photon beam center position. The downstream XBPM, referred to as XBPM2, encountered difficulties during calibration. It was unable to obtain an effective linear range. Adjustments to the blade spacing...
We present PhysBERT and AccPhysBERT, specialized sentence-embedding models trained on 1.2 million arXiv physics papers and fine-tuned for accelerator physics, respectively. Evaluation across retrieval, clustering, and similarity tasks shows gains of up to 12\% over general-purpose models for physics corpora and 18\% for accelerator-specific tasks. Applications include semantic reviewer–paper...
The installation phase of the European Spallation Source (ESS) linear accelerator is nearly complete. As with other superconducting linacs operating in pulse mode, LLRF systems play a crucial role in controlling accelerating beam parameters.
Modern LLRF systems go beyond providing fast and reliable feedback for RF signal regulation; they also ensure precise, dynamic cavity tuning....
This paper presents the development and implementation of an observer-based estimation method to determine the photon beam position for various beamlines at the Siam Photon Source (SPS). The research, executed over multiple phases, aims to address position drift issues in photon beamlines, particularly those without installed photon Beam Position Monitoring Systems (pBPMs). The method allows...
This study summarizes the X-ray pinhole camera results from two recently constructed diagnostic beamlines. We provide updated emittance and energy spread measurements for the TPS storage ring and implement online measurements for routine operational monitoring.
The Radio Frequency Protection Interlock (RFPI) system main responsibility is to collect predefined set of signals and to protect each RF station. In case of safety limits violations from any of this input signals the RFPI has to instantenously drop permits for the LLRF or RF amplifier (eq. Solid State Amplifier - SSA or klystron) operation.
This paper presents an overview of the final...
The Iranian Light Source Facility (ILSF) Booster, which is currently in the design phase, has a circumference of 504 meters and accelerates electron bunches from 150 MeV to 3 GeV. The RF cavity section of the Booster is a key area, where maintaining ultra-high vacuum (UHV) conditions is essential to ensure stable beam acceleration and minimize beam-gas interactions. This work presents the...
The Iranian Light Source Facility (ILSF) is a 3 GeV synchrotron light source designed to serve as a cutting-edge tool for scientific research, providing high-brightness X-rays for a wide range of applications. In the booster ring, particles are accelerated to a final energy of 3 GeV and then stored in a storage ring with a maximum beam current of 400 mA.
The RF cavity is a fundamental...
In the magnetic field measurement system, a single-core CuZr wire is used in both the stretched-wire (SW) and pulsed wire measurement (PWM) systems. Before measuring the magnetic field of the undulators, the CuZr wire must be aligned with the center of the undulator mechanism. The SW system is then employed to locate the magnetic field center of the undulator. The traditional method involves...
The Korea-4GSR is a fourth-generation synchrotron radiation accelerator with an energy of 4 GeV, a beam current of 400 mA, and a circumference of 800 m. To satisfy the performance requirements of the storage ring, the gap between the electromagnets and the vacuum chamber is designed to be extremely narrow, from 1.5 mm to 2 mmA portion of the synchrotron radiation generated in the storage ring...
The Proton Synchrotron Booster (PSB) receives 160 MeV H- ions, which are converted to protons at injection via a charge exchange mechanism, an upgrade that allows the production of low-loss high-intensity beams (> 10^13 per ring). To mitigate losses due to space charge, horizontal phase-space painting is performed with a system of fours kickers whose pulse is customisable via time and...
A comprehensive program of tracking studies has been carried out to ensure that no train of injected electron bunches can traverse an open beamline during top-up operations at Elettra 2.0. The analysis explored various error scenarios, considering realistic magnetic field variations, trajectory shifts, aperture constraints, and energy deviations. This paper presents the tracking techniques...
Particle accelerators like CLEAR (CERN Linear Accearator for research) are essential tools in advancing various scientific fields. Automating their operation to ensure stability and reproducibility is crucial for future large-scale projects. This paper explores the first steps toward autonomous control of the CLEAR beamline, focusing initially on beam steering and advancing to complex tasks...
We report on tests to achieve low multiplicity (single electron) at the CLEAR facility with a well defined particle energy. This can be achieved by a set of three collimators around a dipole magnet. These collimators reduce the charge of the beam and they give three degrees of freedom, allowing to control the position, angle and energy of the selected particles.
The energy consumption of particle accelerators becomes an important issue nowadays. One option to address this is to employ cavities with a very high quality factor. Despite its energy saving potential, such quality factor poses a serious control problem, because the cavities become very sensitive to noise affecting their resonance frequency. A resonance controller is thus needed. There have...
The slow extracted beams at the CERN Super Proton Synchrotron (SPS) are transported over several 100 m long transfer lines to three targets in the CERN North Area Experimental Hall. The experiments need intensity fluctuations to be entirely eliminated over the roughly 5 s particle spill, requiring full debunching of the extracted beams. In this environment, secondary emission monitors (SEMs)...
The European Spallation Source ESS is a multi-nation, interdisciplinary research facility based on the world’s most powerful neutron source that will operate with high standards of availability and reliability minimizing downtime periods. In order to meet these goals, critical component’s performance and aging need to be constantly monitored and assessed. Transient Grating Spectroscopy (TGS),...
This research investigates the uncertainty in radiation dose measurements utilizing TLD-100 Dosemeters (LiF:Mg, Ti), and a TLD Reader System of Harshaw 6600 Plus present at Nepal Academy of Science and Technology. The calibration of the Dosemeter reader facilitated precise dose determination, resulting in mean calibration and correction factors of 1.052 and 0.003, respectively. Particularly at...
To construct a closed orbit model for an accelerator ring with intrinsic uncertainty quantification from orbit measurements, a physics-informed Gaussian Process model is proposed based on a stochastic ensemble of MAD-X lattices. Key advantages compared to LOCO (Linear Optics from Closed Orbits) include (1.) uncertainty-enabled orbit prediction in between BPMs (beam position monitors), (2.)...
As the design complexity of modern accelerators grows, there is more interest in using advanced simulations that have fast execution time or produce insights about accelerator state. One notable example of additional information are gradients of physical observables with respect to design parameters produced by differentiable simulations. The IOTA/FAST facility has recently begun a program to...
We upgraded the beam abort system at the SuperKEKB positron ring to speed up the abort response and mitigate the damage caused by Sudden Beam Loss (SBL). An SBL event can result in the loss of tens of percent of the beam current within one or two turns. The huge radiation accompanying the beam loss can severely damage accelerator hardware and the detectors at the interaction point. The...
Hefei Infrared Free-Electron Laser device (IR-FEL) is a user experimental device dedicated to energy chemistry research that can generate high brightness mid/far infrared lasers. It is driven by an S-band linear accelerator with a maximum electron energy of 60 MeV. The stability of the final laser output is determined by the quality of the electron beam, and optimizing the Low-Level RF (LLRF)...
After nearly two decades of continuous operation, the Variable Frequency Drive (VFD) of Main Cryogenic Plant 1 (MCP1) experienced a critical failure following a routine shutdown in September 2021. Despite thorough inspection and part replacement, the root cause of the failure remained elusive. Additionally, several seemingly normal spare parts were found to be damaged. Given the discontinued...
The declaration and approval of activities related to CERN's accelerator complex are critical for ensuring safety and compliance. For the past 12 years, the Intervention Management Planning And Coordination Tool (IMPACT) has been the primary system facilitating these processes, enabling approvals by domain and location experts. However, evolving requirements and advancements in technology have...
The Beam Gas Ionization (BGI) instrument provides a non-destructive method for monitoring transverse beam profiles by detecting free electrons produced during beam-gas ionization. Utilizing a Timepix-family detector, the BGI setup at the CERN Proton Synchrotron (PS) includes two instruments dedicated to horizontal and vertical plane measurements. However, the quality of these measurements is...
The Siam Photon Source II (SPS-II) is a new synchrotron light source currently under development in Thailand. Its 3 GeV electron storage ring features a lattice composed of 14 Double Triple Bend Achromat (DTBA) cells, with a total circumference of 327.6 meters. To ensure beam stability and operational reliability, a comprehensive suite of utility systems is required. The design incorporates...
The Karlsruhe Institute of Technology operates the accelerator test facility Karlsruhe Research Accelerator, which also provides synchrotron radiation at 2.5 GeV. Roughly one third of the wall-plug power is used for cooling. Optimizing the infrastructure for cooling has a huge impact on the overall sustainability. To reduce the environmental impact a thermal well system was installed. It...
The pumping speed of pill-type getter pumps for low-temperature activation, fabricated under different sintering conditions, were measured at various temperatures. To reduce uncertainty, the pumping speed measurements were performed on more than 70 getter pumps. This measurement method has limitations: it measures the pumping speed only on one side of the getter and may overestimate the speed...
MAX 4U is an upgrade project of the MAX IV 3 GeV storage ring, to be realized by the early 2030’s in Lund, Sweden. The goal of the upgrade is to reduce the horizontal electron beam emittance to below 100 pm.rad. A new magnet lattice will be used, thus the vacuum system will have to be adapted to follow the new beam orbit of MAX 4U.
Several lattices imposing the most severe changes to the...
With the current availability of cost-effective and compact electron LINACs operating in the 100-200 MeV energy range, there has been a growing interest in using Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment. A particularly intriguing aspect is the Ultra High Dose Rate (UHDR) or FLASH dose regime, which focuses on damaging cancerous cells while sparing healthy...
In accelerators facilities, unexpected failures of water pumps can lead to overheating, unplanned downtime, and costly repairs. In this study, we present a novel approach for real-time monitoring of water pump vibrations to detect anomalies indicative of impending mechanical failures. We employ simple vibration sensors combined with machine learning algorithms to identify patterns and...
The Large Hadron Collider (LHC) Injector Upgrade project has achieved unprecedented beam brightness levels, to fulfill the High Luminosity LHC requirements. This higher intensity has introduced significant challenges for some of the Super Proton Synchrotron (SPS) kickers, specifically concerning beam-induced heating and vacuum rise due to electron cloud.
The primary concern is the integrity...
The ongoing upgrades to CERN power converters pose new challenges to the converter control hardware that require a next-generation embedded control computer: the Function Generator/Controller 4 (FGC4), currently in development. The hardware is based on an AMD Zynq UltraScale+ MPSoC System-on-Chip (SoC), featuring a quad-core A53 ARM-architecture CPU, with one bare-metal core dedicated to the...
Neutron target for high-intensity operation at J-PARC MLF
Beam coupling impedance (in other words, wakefield) causes collective beam instabilities, heating and degradation of components due to the electromagnetic field of the beam, and beam-induced electromagnetic interference. These effects are outlined from an experimental point of view. Examples of beam ducts and kickers are mainly from J-PARC, but examples from other institutions will also be...
The LHC is approaching the end of its third operational run, with machine protection and performance having demanded an excellent control of the single-particle dynamics. Additionally, the requirement to rapidly commission multiple diverse sets of optics configurations within each year, and from year-to-year, placed clear demands on the measurement and correction methods employed. Tight...
The laser-based synchronisation systems for the European XFEL and FLASH provide femtosecond-stable timing references for tens of clients along the accelerator and the experiment halls over many kilometres of optical fibre. Recently, benchmarking experiments revealed a point-to-point timing stability with sub-femtosecond rms timing jitter. At the same time geophysical effects like ocean waves...
Summary: An experiment to fly an accelerator in space recently concluded successfully. Discuss the objectives, differences from terrestrial accelerators, and results from the flight.
Accelerators have the potential to play a major role in space-based activities. These can range from investigation of the Earth’s magnetic field, to helping mitigate the effects of increased solar activity...
The proposed Future Circular Collider (FCC) integrated programme consists of two stages: an electron–positron collider serving as a Higgs-boson, electroweak and top-quark factory,followed by a proton–proton collider operating at a collision energy around 100 TeV. In 2021, in response to the 2020 update of the European Strategy for Particle Physics, the CERN Council initiated the FCC...
An ultrafast strong field terahertz(THz) lightsource will be built at the Hefei National Laboratory. This lightsource aims to characterize the multi-quantum collective behavior of the quasiparticles and enable the cutting-edge exploration of materials for the quantum information technique. To meet these goals, the lightsource needs to cover the electromagnetic spectrum of 0.1-10THz, the...
A novel wireless method for beam coupling impedance measurements is currently under development, with preliminary measurements on beam pipes serving as proof of concept for its validity. This innovative approach overcomes the limitations of existing methods by not only evaluating impedance with high accuracy but also enabling the characterization of an unknown Device Under Test (DUT) as it...
The Hefei Advanced Light Facility (HALF), currently under construction, aims to be state-of-the-art diffraction-limited storage ring light source with a full-energy injector. A grid-controlled electron gun has been chosen as the electron source for HALF. The simulation of the electron source revealed that when using a pulser with width about 1 ns, the parasitic pulses reduce to 8.70%,...
The rapid cycling synchrotron (RCS) of The China Spallation Neutron Source (CSNS) accumulates and accelerates the injection beam from 80 MeV/300 MeV to the energy of 1.6 GeV and then extracts the high energy beam to the target. During each cycle of the RCS ring, beam positions at the same BPM vary over time due to energy and mode transitions. Traditional orbit correction averages turn-by-turn...
Higher-Order Modes (HOMs) in superconducting radiofrequency (SRF) cavities are traditionally considered detrimental to efficient operation. They are often associated with beam instabilities and are actively damped. However, these “harmful” HOMs, if used strategically, can be transformed into a tool for providing extra control over the beam, which can introduce new opportunities that are not...
In this paper we desgin a X-band two-stage pulse compression system based on barrel open cavity (BOC), which is driven by a 6-MW X-band klystron. By utilizing numerous coupling holes surrounding the resonant cavity, a rotating-wave-like mode is excited in BOC, thereby enabling an extremely high Q-factor over 2.3×10$^5$ at 11.424 GHz. A RF pulse can be flattened through the employment of the...
Capability for generating an attosecond bunch can provide interesting opportunities to wakefield accelerator research. We have been studying requirements and challenges in beam dynamics to produce an attosecond bunch using an existing beamline at Argonne Wakefield Accelerator (AWA) facility. One unavoidable limitation of this study is that conventional C-typed chicane is not available. Thus, a...
For the China Spallation Neutron Source (CSNS), the rapid cycling synchrotron (RCS) accumulates and accelerates the injection beam to the design energy of 1.6 GeV and then extracts the high energy beam to the target. As the second phase of the CSNS, CSNS-II will achieve a beam power on the target of 500 kW. The injection energy of CSNS-II will be increased from 80 MeV to 300 MeV and the...
