Experiments at the ESR storage ring at GSI (Darmstadt, Germany) have demonstrated the power and the potential of laser cooling of bunched relativistic ion beams, using either continuous or pulsed UV laser light. Based on this, a novel 3-beam concept was developed using three separate highly tunable UV laser systems. There will be two powerful pulsed laser systems with MHz repetition rates and...
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...
Transverse deflecting cavity (TDC) has been used in longitudinal injection design for fourth generation light sources with quite small dynamical aperture. This scheme typically consists of four kickers, one septum and one or two TDCs, which takes considerable longitudinal space. Long straight section design may be required for some facilities, which consequently demands extra efforts on linear...
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...
A novel structure-based wakefield accelerator is proposed. This accelerator uses the structure that simultaneously acts as a slow-wave medium stimulating Čerenkov radiation of electrons propagating the structure and suppresses the beam breakup instability. Examples of the structure are presented alongside of the calculations demonstrating the feasibility of this novel approach.
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. A superconducting RF electron gun is technically suitable for high-quality high-current beam generation, but there are not many examples in practical use, such as the ELBE RF...
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 school...
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...
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...
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 CLEAR (CERN Linear 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 conditions...
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...
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...
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) aims at training 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 across a number of research projects, including the optimization of X-band low-level radio frequency (LLRF)...
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...
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 beamline inside the TPS tunnel at the National Synchrotron Radiation Research Center is transmitted through stainless steel pipes. However, part of the pipeline in TPS24 is exposed to the atmosphere, without full connection. It is suspected that a chemical substance or radiation has led to corrosion at some flange areas, resulting in the formation of white crystals.
Ozone readily reacts...
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 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...
The stability of electron beams in storage rings is vital for precise synchrotron radiation experiments. However, external vibrations, such as earthquakes, ocean waves, and human activities, often disrupt beam stability. This study analyzed low-frequency(~0.3Hz) disturbances in the beam orbit systems of the Taiwan Photon Source (TPS) and Taiwan Light Source (TLS). Using Fast Fourier Transform...
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...
Work continues on the magnetic design for an APPLE-KNOT that is in development for the BESSY III successor facility. BESSY III is planned to operate at a higher energy of 2.5 GeV in comparison to the current BESSY II energy of 1.7 GeV. This necessitates the development of a long period undulator to provide access to photons down to 5 eV, with suppressed on-axis power as made possible by the...
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 superconducting 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,...
In the storage ring of the Taiwan Photon Source (TPS), we have installed 172 Beam Position Monitors (BPMs) to continuously monitor the electron orbit. We have developed an automated monitoring tool that extracts BPM data from the database at scheduled intervals and calculates the standard deviation for each BPM over a specified period to quantify its stability. The system identifies the ten...
The Electron Ion Collider (EIC) will collide high energy and highly polarized hadron and electron beams with luminosities up to 10^34/cm^2/s. In the Conceptual Design Report baseline scope, the electron beams, accelerated in the Rapid Cycling Synchrotron (RCS), are vulnerable to the outside magnetic field due to its low injection energy at 400 MeV. In addition, when the Hadron Storage Ring...
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 collision in the energy range 1-4.5 GeV/u. The experiments relating tonuclear and hadron physics require a more powerful longitudinal and transverse cooling that stimulates searching new technical solutions.Such beam quality may be realized with stochastic and electron coolingat...
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...
We evaluate several key performance metrics of the Proton Storage Ring (PSR) at the Los Alamos Neutron Science Center (LANSCE) for a potential upgrade from a single harmonic to a dual harmonic RF system. The instability caused by space charge effect is a common limitation for high-intensity proton ring, like the PSR, an accumulation ring for 800 MeV protons. While an upgrade to the present RF...
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...
Normal-conducting accelerating structures capable of supporting GV/m-scale electric fields offer a promising pathway to compact accelerators. Similarly, achieving such high fields in photocathode guns is critical for the generation of bright electron bunches. Our group has demonstrated the generation of ~0.4 GV/m electric fields on a photocathode surface in an X-band (11.7 GHz) photoemission...
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...
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 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 and 2.5 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...
Oriented crystals create a unique environment for high-energy charged particles and photons. When charged particles undergo channeling * , they are guided by atomic electric fields with angstrom-level precision, similar to accelerator optics and achieving effects equivalent to magnetic fields exceeding 100 T. This process also generates intense X-ray and gamma radiation due to transverse e+/e-...
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 for this 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...
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...
Mu2e experiment, searching for a super rare mode of the CLFV decay of muon into an electron is in preparation for data taking at Fermilab’s Muon Campus facility. The experiment requires the 8 GeV proton beam continuous delivery aided by the Slow Extraction (SX) from the Delivery Ring. The first full beam commissioning of the SX has begun in Summer 2024. Here we will present and discuss our...
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...
Between 2016 and 2026 four new insertion devices will be installed in the storage ring for the BioSAX, MX3, ADS and Nano Beamlines*. The latest ID to be commissioned is the U17 for MX3. The measured fields and spectra of U17 will be presented indicating that the RMS phase error of < 2.6° was achieved.
In the process of optimising the characterising the photon beam from U17 a technique using...
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. Photoinjector were developed to generate these bright beams. Since then, research and development of high accelerating gradient photoinjectors has been an important topic to generate even brighter electron beams. However, high gradient...
Medical accelerators are playing a more and more important role in contributing to radiotherapy. So far, the medical accelerators are still too large and too expensive to be afforded by most hospitals. This paper introduces a conceptual study aiming to develop a compact hybrid medical accelerator by taking advantage of advanced beam dynamics concepts, new RF structures, and state-of-the-art...
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...
The CAMD light source was proposed 40 years ago and reached its best performance and application at the end of last century. Many upgrades for current light source were made, including 7.5 T wiggler and 7 T WLS; and new light sources have been discussed since then. The outcome of the activity is not perfect for a new modern light source nowadays. Authers will survey CAMD-based users, propose a...
Linear accelerators offer significant advantages over circular accelerators in hadrontherapy by enabling rapid energy modulation of the output beam, facilitating efficient treatments without scattering or activation. In this work, we investigated the key geometrical features of 3 GHz Side-Coupled Drift Tube Linac (SCDTL) structures to optimize energy efficiency and the maximum achievable...
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...
Crystal shadowing is a very promising technique for improving the Slow Extraction efficiency that has been successfully demonstrated at CERN with 400GeV proton beams. It remains to be demonstrated at low energies, where it has both new challenges and advantages. The beam studies for crystal shadowing are under preparations at the Fermilab Delivery Ring, which is being commissioned for the 8GeV...
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...
The MYRRHA (Multi-purpose hYbrid Research Reac-
tor for High-tech Applications) project is a planned accel-
erator driven system (ADS) for the transmutation of long-
living radioactive waste. A critical passage for the beam
quality and especially for the emittance is the injector,
which for the MYRRHA project consists of a 4-rod RFQ,
two Quarter Wave Rebunchers (QWR) and a total of...
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...
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...
The main accelerator of the Shanghai Soft X-ray Free-Electron Laser (SXFEL) facility utilizes C-band traveling wave accelerator tubes to accelerate electrons. At the end of the traveling wave accelerator tube, a load is required to absorb the residual power. To this end, a high-power stainless steel load operating at a frequency of 5712 MHz has been developed. The microwave model of the load...
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...
This study presents the design and fabrication of a fully 3D-printed Crossbar H-mode (CH) cavity operating at 350 MHz, optimized for continuous-wave (CW) operation. The cavity is manufactured using a 1.4404-grade stainless steel additive manufacturing process, followed by electrochemical polishing and galvanic copper plating to enhance surface conductivity and reduce power losses. The...
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 nonlinear kicker injection scheme is a potential option for the future Taiwan Photon Source. Compared to the current four-bump injection scheme, which occupies the entire 12-meter-long straight section, the nonlinear kicker requires only a few tens of centimeters in length. A new booster-to-storage-ring transfer line has been designed to create additional space for installing more...
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.
Standing wave linacs with energy from 4 MeV to 20 MeV were used or proposed for FLASH Radiation Therapy (RT), due to easy fabrication and low cost. We proposed an X-band beam generation module based on a multi-beam klystron and a standing wave linac. This module can be used for the FLASH RT as well as traditional Intra-Operative Electron Radiation Therapy. The klystron generates RF pulses with...
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...
The X-band deflecting cavity is one of the critical components of the microwave systems for the Soft X-ray Free-Electron Laser (SXFEL) and the Shanghai High Repetition Rate X-ray Free Electron Laser and Extreme Light Facility (SHINE). It necessitates a pulse compressor to achieve high pulse power. Traditional designs involve two cavities connected by a specialized waveguide. Such designs are...
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...
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...
Monte Carlo simulations are a powerful tool for modeling photoemission from photocathodes, enabling the prediction of key parameters such as quantum efficiency, mean transverse energy, electron spin polarization, and photocathode response time. However, these simulations require material band structure parameters, which are not always available from experiments. This work aims to establish a...
Accurate beamline simulations are necessary for optimal operation of accelerator facilities, however many electrostatic accelerators are operated on the basis of operator intuition. In Australia, DC electrostatic accelerators are used to produce light and heavy ion species for many applications, ranging from quantum computing to nuclear physics. Here, we initiate the development of a modular...
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...
The ELI Beamlines (ELI-BL) facility is the Czech Republic based pillar of ELI ERIC. It is a new-generation high-power high-brilliance laser facility that offers its lasers to users worldwide. Among others, ELI-BL has a 1 PW (L3) and a 10 PW (L4) class lasers that can be used for laser wakefield electron acceleration.
It has been already demostrate that 1 PW lasers are able to accelerate...
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...
In recent years, the Solid-State Power Amplifier (SSPA) has become a popular RF power source in accelerator applications. Previously, the low output efficiency of solid-state transistors meant that most RF power sources in accelerators relied primarily on klystron equipment. However, with advancements in transistor technology, solid-state amplifiers can now achieve output levels in the...
The large gradients of plasma-wakefield accelerators promise to shorten accelerators and reduce their financial and environmental costs. For such accelerators, a key challenge is the transport of beams with high divergence and energy spread. Achromatic optics is a potential solution that would allow staging of plasma accelerators without beam-quality degradation. For this, a nonlinear plasma...
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,...
Center for Accelerator and Beam Applied Science of Kyushu University has been established to promote activities in scientific, medical, educational and engineering fields at Kyushu University. An accelerator facility, consist mainly 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 developments...
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...
Superconducting insertion devices are now an established technology used in 3rd generation light sources. During the last years, progress has been achieved in making the devices “cryogen-free”, i.e. without liquid cooling, and in industrial production processes. Present developments aim at achieving even higher performance in magnetic field, homogeneity, repeatability and magnetic length,...
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 aptly named “Leda,” after the Greek “Mother of Light.” 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...
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,...
The Scorpius linear induction accelerator (LIA) will utilize solid-state pulsed power (SSPP) to generate accelerating fields for a multi-pulse intense relativistic electron beam. By optimizing the trigger on and off times of the linear transformer drivers that make up the SSPP system, the accelerating field amplitude can be flattened to reduce unwanted effects. Circuit modeling suggests that...
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.
We consider an isochronous permanent magnet cyclotron capable of accelerating protons to 18 MeV, within which the permanent magnet is distributed about the cyclotron return yoke above and below the midplane. With an outer radius of 1.36 m and height of 1.22 m, the design can replicate the field strength (up to 2.3 T peak) and pole gap of the Cyclone(R) Kiube. We consider the most effective...
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 widely used in synchrotron light sources to produce elliptically polarized light. However, manufacturing imperfections in EPUs can introduce a skew quadrupole component that varies with different gap and phase settings. This skew quadrupole component couples horizontal betatron motion and dispersion into the vertical plane, increasing...
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...
In Accelerator Mass Spectrometry (AMS) laboratories, chemical pretreatment is vital for reducing sample contamination and improving the accuracy of the data. Specifically, in radiocarbon dating with AMS, chemical pretreatment is used to eliminate carbonates and humic acids, leading to more precise measurement results. This technique has been traditionally method applied to ancient...
Electron beam radiation is advantageous for coating preparation due to its rapid curing and environmental benefits, but its energy and dosage are crucial for crosslinking. Overdosing can degrade the coating and substrate, while underdosing results in poor crosslinking. Traditional optimization of electron beam parameters is inefficient. This study combines FLUKA simulations with EBlab-200...
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...
The Los Alamos Neutron Science Center (LANSCE) accelerator complex delivers both protons and negative hydrogen ions and provides various beam patterns simultaneously to multiple users. The LANSCE linac front end is still based on Cockcroft-Walton voltage generators. An upgrade of the front end to a modern, RFQ-based version – a part of the LANSCE Modernization Project (LAMP) – is now in the...
A muon collider will require short, intense proton bunches on a high-power target to generate the initial muon beam. Current designs leverage charge-exchange injection and accumulation in a ring, followed by compression using a single-harmonic radiofrequency cavity. We are pursuing an experimental study of this bunch compression scheme at the Spallation Neutron Source (SNS), an operational...
As part of a research collaboration between MedAustron and TU Wien, the feasibility of delivering mixed helium and carbon beams for online range verification during carbon ion treatment is investigated. This includes the generation of mixed 4He2+ and 12C6+ beams within a single ion source. While generating and extracting such beams is possible, the beam composition cannot be determined with...
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...
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 laser-plasma accelerator-like bunches into the VLA-cSR (Very Large...
Radiotherapy can be performed using a high-energy electron beam (several hundred MeV) tightly focused on the tumor area, offering a relatively simple approach to beam generation and handling while achieving a favorable energy deposition profile in tissue-like materials. However, traditional beam focusing relies on quadrupole magnets, which add complexity and pose significant engineering...
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 taking place 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 FINEMET technology successfully implemented in the CERN PS...
It has recently been demonstrated that, as is the case with GaAs, photoemitted electrons from Negative Electron Affinity (NEA) GaN can be spin-polarized. Leveraging the many decades of research performed on NEA GaAs to increase spin-polarization, quantum efficiency and robustness in this proceeding we apply analogous approaches to GaN. In particular we present the development of strained GaN...
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...
CLARA at STFC Daresbury laboratory is undergoing an upgrade to phase-II to deliver a 250 MeV electron beam comprised of ultrashort, low emittance electron bunches for wide ranging user experiments from medical to laser plasma acceleration at designated beam areas via the FEBE arc and as a precursor to a possible phase-III FEL upgrade. Here we report on the high power RF conditioning of CLARA’s...
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...
H₃⁺ ions have attracted interest in application to cyclotron to overcome intensity limitation by using stripping extraction. Meanwhile, when accelerating different ion species with varying mass-to-charge ratios in a single beamline and a synchrotron, using H₃⁺ ions instead of protons simplifies the design and allows for three times the number of ions compared to proton beams at the same...
The ALS-U septum kicker is a large impedance source although beam only goes through it once. The monopole wakefield and dipolar wakefield are considered, with the effect to the bunch train kick and the project emittance increment.
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...
The National Synchrotron Radiation Research Center (NSRRC) currently operates the TLS and TPS accelerators, along with approximately 40 end stations, about 10 of which are dedicated to biology-related experiments. These include the Protein Microcrystallography Beamline, which focuses on the analysis of 3D biostructures; the BioSAXS Beamline, designed to study non-crystalline structural...
We Sumitomo Heavy Industries, Ltd. developed the superconducting azimuthally varying field (AVF) cyclotron SC230 for proton therapy in 2021. Superconducting coils and new RF cavities have achieved energy-saving operation with power consumption of 200 kW or less, reduced to 3/5 times of conventional cyclotron P235. It delivers the highest intensity beam of 1 µA among all accelerators for proton...
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...
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...
The third-integer resonant extraction of the proton beam from the Super Proton Synchrotron (SPS) at CERN is a technique used for slow extraction of the circulating beam, providing a constant spill of protons to the North Area experiments.
Currently, this method deploys an electrostatic septum (ZS) to separate the extracted particles from the proton beam circulating in the ring. However a...
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator*. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. PAX has completed the installation of a spectrometer system able to measure radiation...
A 2.5 MeV proton injector has been 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...
At the Los Alamos Neutron Science Center (LANSCE), the injection system of the Proton Storage Ring (PSR) utilizes charge exchange via a stripping foil that converts H- into H+. While the beam losses due to partially stripped H neutrals are one of the primary focuses to reduce beam losses, the interaction between the circulating beam and the foil plays an important role as well. On average,...
Intrinsic emittance is an important figure of merit for determining the photocathode performance in accelerator applications. In this work, we present the design and fabrication of an emittance measurement system for alkali-based photocathodes that incorporates an MCP-YAG detector. Simulations are performed by Possion/Superfish and SIMION software to optimize the design parameters and...
A high gradient in the accelerating structure enhances beam quality and accelerator efficiency but may also lead to the "dark current" issue. In high-gradient SRF photoinjector, dark current represents an "unwanted beam". It arises from field emission in the cavity and the photocathode, which is subsequently accelerated through the gun.
In the operation of the ELBE SRF gun-II, a correlation...
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...
Plasma-wakefield acceleration shows great promise as a next-generation accelerator technology, able to sustain strong accelerating and focusing fields. This significantly reduces the required length of the accelerator compared to radiofrequency accelerator technology. Electrons are expelled transversely by the electric field of an intense electron bunch, forming a plasma wake that is devoid of...
The IOTA proton injector (IPI) has recently been installed and commissioned at the Fermilab Accelerator Science and Technology (FAST) facility. The IPI provides 2.5 MeV protons for injection into the to the Integrable Optics Test Accelerator (IOTA), a 40-meter-circumference storage ring also capable of accepting 150 MeV electrons from a superconducting radio-frequency (SRF) linac originally...
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...
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. The CSNS design beam power is 100 kW, with the capability to upgrade to 500 kW. By February 2020, the beam power had reached 100 kW, and through improvements, the beam power was...
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...
Lattice design for a transport line of the storage ring is introduced in this paper. The lattice of transport line is presented, and beam optics will be described. This paper will introduce the results of simulation, and the errors with orbit correction will be discussed.
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 (ECR) 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). The 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...
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...
Recent results of production of the medical radionuclides 67Cu, 225Ac 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...
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...
The Hefei Advanced Light Facility (HALF) is a fourth-generation synchrotron radiation light source based on a diffraction-limited storage ring, which has been recently approved for construction in China. Its beam energy is 2.2 GeV, the target emittance is 86 pm·rad, and the circumference of the storage ring is 479.86 m. The micro-vibration control indicator for the foundation of the Hefei...
Simulations, analysis, and measurements are performed on the BNL Booster’s third integer resonance extraction to the NSRL line, which uses a constant optics slow extraction method. In this method, ring dipoles and quadrupoles are changed synchronously for a coasting beam, which aids in maintaining a fixed separatrix orientation through the spill. Simulations show that the outgoing beam has a...
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...
We tried to obtain longitudinal phase space tomography in LINAC by using the information of energy spread due to chicane magnets. The motion in the bending plane is governed by energy spread and betatron motion. Thus, at first, we used transverse phase space tomography to obtain betatron motion information and then calculated the energy spread. The longitudinal phase space is rotated by...
There are numerous injections schemes into storage rings, and implementations, exist for 4th generation light sources. In 2023 a Ti coated chamber was installed in the storage ring to enable such an injection scheme using the 8-wire design modeled after MAX/Bessy-II/Soliel. The injection requirements and basic design of the nonlinear kicker is described in Ref *. Two approaches to the magnet...
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...
Electron beams with energies of 100 MeV and above, commonly referred to as Very High Energy Electron (VHEE) beams, offer several properties that might be of interest for radiotherapy such as deeper penetration and insensitivity to inhomogeneity. Numerous studies, both simulations and experiments, have been conducted to verify these purported beneficial properties and assess VHEE beams...
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...
CSNS-II is an upgrade project for the China Spallation Neutron Source (CSNS), aimed at increasing the beam power from 100 kW to 500 kW. To identify an appropriate tuning space in advance and assess the impact of space charge effects and beam instability effects on the Rapid Cycling Synchrotron (RCS) of CSNS-II, we have conducted an evaluation of beam transmission within the transverse tune...
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...
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 rapidly shifted into and out of the bandpass of a monochromator, enabling fast polarization switching for the...
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...
Negative Electron Affinity (NEA) GaAs is presently the most viable option for the production of a spin-polarized electron beam at high average current (> 1 mA). To bring GaAs to an NEA state, typically a mono-layer of Cs and Oxygen are deposited onto the cathodes surface. While this results in a high Quantum Efficiency (QE), the activation layer is extremely fragile resulting in a short...
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,...
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...
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,...
Conventional white beam photon beam position monitors (XBPMs) in light source front-ends detect the beam by measuring the drain current from illuminated metallic material (photoelectric). Another common method is the use of semiconductors like Diamond or SiC (photoconduction) however rarely (if any) for white beam due to the high power density. The latest development has been the GRID-XBPM at...
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...
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 ...
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...
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...
The Hollow Electron Lens (HEL), initially planned for the High-Luminosity project of the LHC (HL-LHC), consists of an electron current in the shape of a cylindrical shell coaxial to the circulating hadron beam for typical distances of a few meters. At injection and extraction of the HEL, the electron beam intercepts the circulating hadron beam, leading to possible losses of the latter (e.g....
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...
RFQ (Radio frequency quadrupole) accelerating structures for RF frequencies lower than 400 MHz have been intensively investigated for decades. To realize modern medical accelerators with more compact layouts, there is an increasing interest to use ultra-high frequencies (UHF: 0.3 - 3 GHz). This study performs R&D towards efficient UHF RFQ structures. The design and simulation results will be presented.
For the past 60 years, the issue of radiation damage to electronics has been a well know problem in satellite and space exploration. In the last 20 years, it has taken central stage at high-energy conventional accelerators.
A large scientific community has coalesced to study this phenomenon and an international network of facilities has been woven to support this research. Nevertheless, the...
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 ion beam therapy. In 2024, a mixed ⁴He²⁺ and ¹²C⁶⁺ beam was extracted successfully for the first time at the MedAustron center for ion beam therapy and research, which was facilitated by a mixed beam generation during two sequential multi-turn injections into the...
This poster will discuss the performance of CsTe photocathodes recently grown for the CARIE (Cathodes and Radiofrequency Interactions in Extremes) project at LANL. CARIE requires a low emittance, high QE photocathode, capable of withstanding challenging vacuum conditions and high fields. CsTe is a natural fit. We will describe recent efforts to optimize the co-deposition process while...
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,...
SLAC Next Linear Collider Test Accelerator (NLCTA) was originally built as a test accelerator for the next generation linear collider. Presently, it is repurposed as an accelerator test facility. NLCTA has an X-band Test Accelerator (XTA) for electron beam experiments, an X-band test area, an S-band test area, with an additional test area planned for cryogenic RF testing at X-band . We give an...
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...
We will describe a design of a novel continuous wave normal-conducting traveling wave accelerating structure to achieve rapid and flexible control of beam compression. This structure will introduce chirp longitudinal energy distribution of the beam. Our development of the 3.9 GHz chirping accelerating structure enables shot-by-shot beam compression control at megahertz repetition rates for...
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...
Recent advancements in radiotherapy have demonstrated that Very High Energy Electron (VHEE) beams with energies of 100 MeV or higher are effective for treating deep-seated tumors, achieving therapeutic outcomes comparable to conventional radiation. This efficacy is further enhanced when electron beam parameters enable Ultra High Dose Rate delivery, operating in the FLASH regime, which...
The concept of the AGU has been proposed for some time*. However, utilizing a permanent magnet-based device complicates the design due to the necessity of independent gap control for each segment and, in the case of an in-vacuum undulator, the requirement for a flexible continuity sheet to mitigate image current heating. The adoption of SC magnets eliminates these concerns.
The SC-AGU...
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...
This poster presents some RF components of the ICONE pilot. The ICONE pilots aims at defining a technical solution for a HiCANS Neutron source that would be built in France. The LINAC part aims at accelerating an 80 mA proton beam up to 25 MeV to the target with a 6% duty cycle.
The poster presents RF and thermal simulations of the RFQ, based on the ESS RFQ design. Then, a design of rebuncher...
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...
In this study, we present a comparative analysis of passive higher-harmonic cavity (HHC) simulations with beam loading compensation using the particle tracking codes ELEGANT and SPACE. By cross-verifying results from both codes, we assess their accuracy in modeling beam dynamics under passive HHC operation for different filling patterns. Our findings demonstrate consistent outcomes between...
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 the drive bunch with high charge....
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...
Undulator misalignments relative to the electron beam are known to cause photon energy shifts and significant reductions in spectral flux. This effect is particularly pronounced in in-vacuum undulators (IVUs), where the magnetic cassettes are positioned very close to each other (4.3 mm in the case of SIRIUS IVUs), making these devices more sensitive to such misalignments. This paper presents...
SPS-II is the fourth generation electron storage ring in Thailand. Medium size ring constructed with Double-Triple Bend Achromat (DTBA) cell provides low emittance and high capacity for beamline. To complement the compact storage ring with DTBA cell, a Non-Linear Kicker (NLK) was chosen for beam injection due to its simplicity and minimal perturbation to the stored beam. In this paper,...
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...
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...
At GSI the design of a prototype electron lens to demonstrate the space charge compensation scheme is being continued. The ultimate goal is to increase the beam intensity for FAIR by compensating for the space charge forces in the synchrotrons operating with high intensity beams by overlapping with an inversely charged electron beam in the electron lens.
The main components of the lens, such...
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...
A compact, low cost and beam parameters flexible hadron accelerator is pursued for the effective hadron radiotherapy all the time. The high gradient technology is promising to realize an ideal linac for radiotherapy. The cryogenic copper cavity was proposed and demonstrated for even higher gradient and lower power consumption with electron linac. In this paper, we proposed to use low beta...
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...
Negative Electron Affinity (NEA) activated GaAs photocathodes are the only one capable of generating spin-polarized electron beam larger than 90%. However, the NEA layer currently made from mainstream cesium (Cs) and oxygen (O) is chemically unstable, the NEA-GaAs photocathode has a rapid quantum efficiency degradation over time or electron beam. As a result, it requires an operating vacuum...
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...
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...
To achieve a high precision experiment, one needs to eliminate the field errors up to certain orders that those field errors wouldn't contribute the systematic effect to the experiment. In this study, we modeled electrode plates of electrostatic deflector with hyperbolic/elliptical shape deformation schemes, investigated the beam dynamics and spin effect caused by these type of high orders of...
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...
The SHERPA (“Slow High-efficiency Extraction from Ring Positron Accelerator”) project aim is to develop an efficient technique to slowly extract positron spills of O(ms) length, with excellent beam energy spread and emittance, from one of the accelerator rings composing the DAΦNE accelerator complex at the Frascati National Laboratory of INFN. SHERPA proposes to use coherent processes in bent...
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,...
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 driving 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...
GaAs photocathodes operated in a negative electron affinity (NEA) state typically achieve 35%-40% photoemitted electron spin polarization (ESP). However, when operated in a slight positive electron affinity (PEA) state, the barrier for electrons to escape into vacuum can cause upwards of 50% ESP electron beams to be photoemitted. In this proceeding, we explore the mechanisms and limitations of...
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 -...
The desired electron beam from the Superconducting Radio-Frequency photoelectron gun (SRF gun) at SEALab has tailored properties for its specific application. There are, however, sources of unwanted electrons from field emission and other processes, that may lead to beam losses and limit the performance of the SRF guns. This paper studies potential unwanted beam generation and transport...
The Illinois Accelerator Research Center (IARC) coordinates with the National Nuclear Security Administration (NNSA) to build a 1.6 MeV 650 MHz 20 kW SRF industrial accelerator. A beam diagnostic system that will later turn into a beam delivery system is under development. We updated the beam dump design. This paper will demonstrate the beam-line and beam dump design.
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...
NFN Milan-LASA has successfully completed its in-kind contribution to the European Spallation Source ERIC, delivering 36 superconducting medium beta cavities for the ESS LInac. These cavities are designed to increase the energy of the proton beam from 216 MeV to 571 MeV. In addition, four spare cavities are being fabricated. This article outlines the performance of the cavities delivered so...
Ultrafast electron diffraction using MeV energy beams(MeV-UED) has enabled unprecedented scientific opportunities in the study of ultrafast structural dynamics in a variety of gas, liquid and solid-state systems. The SLAC MeV-UED program began in 2014 and became an LCLS user facility in 2019. Recent strategic planning efforts, combined with user feedback, have identified critical areas for...
The electron beam linear accelerator at the FEL laboratory of the University of Hawaii at Manoa, originally developed by John Madey, has undergone significant upgrades in 2024 to enable its restart and improve its control systems and operational capabilities. The S-band linac accelerates electrons to 45 MeV, with a pulse current of 200 mA and pulse lengths of 4 to 8 μs, to generate infrared...
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...
