Normal conducting radiofrequency (NCRF) technology plays a crucial role in the development of more compact and cost-effective linear accelerators with increased energy reach and intensity. Over the past few years, NCRF structures have seen remarkable progress in accelerating gradient, RF-to-beam efficiency and overall performance that could lead to compact linacs for a multitude of...
In this opening plenary talk, the speaker will discuss advances in SRF technologies are enabling PIP-II, the new proton driver for the Fermilab Accelerator Complex currently under construction. This includes advanced cavity processing methods such as nitrogen doping and the mid-T bake and innovations in cryomodule design. He will present an overview of plans to evolve Complex in the PIP-II era...
The SNS H- ion source performance has been improved over many years with main focus on increasing lifetime and availability. Recent R&D efforts achieved dramatic increase of output beam current in excess of 100mA. This talk will discuss the design improvements and diagnostics of the SNS H- ion source.
FLASH is undergoing major modifications in the framework of the FLASH2020+ project.
During the last upgrade phase in 2021/22 alterations to the superconducting linac have been the main priorty. Among other changes two accelerating modules were replaced by modern high gradient versions. This allows to operate FLASH routinely with electron beam energies exceeding 1.3 GeV and thus extends the...
In order to develop a stable LWFA based accelerator and demonstrate FEL generation, the unique LWFA platform was constructed in the RIKEN SPring-8 center and systematic experiments have being conducted financially supported by ImPACT (2013-2018) and JST MIRAI (2018-) programs. Although undulator radiation in an XUV spectral range driven by LWFA electron beams was successfully demonstrated on...
Plasma wakefield accelerators driven by particle beams are one promising method of advanced acceleration, with capable of providing accelerating gradient much larger than RF technology. One of the biggest remaining issues is coupling beams from one stage to another. This novel concept optimizes inter-plasma distances in a staged beam-driven plasma accelerator by drive-beam coupling in the...
Talk will cover state-of-the-art photocathodes for bright-beam and spin-polarized-beam generation.
A multileaf collimator comprising many individually controlled blades has been used to impose predefined transverse beam shapes to an electron beam. Afterwards transverse-to-longitudinal mapping transforms this shape into a longitudinal one. This technique opens a wide field of applications using individually tailored longitudinal beam profiles.
The Proton Power Upgrade (PPU) Project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory will upgrade or replace accelerator components for beam power capability from 1.4 to 2.8 MW and upgrade the first target station for 2-MW beam at 1.3 GeV and at 60 pulses per second. The remaining beam power will be available for the future second target station. PPU scope is...
The European Spallation Source Linac is getting more and more ready. The drift tube linac has produced first beam, and the linac with its cryomodules and also warm units is taking shape. By LINAC 2024 first commissioning results can be expected. Beam on target is expected for 2025.
The Future Ions Working Group at CERN has been mandated to assess production and operation of new ion species in the CERN accelerator complex, to supply fixed target users but also LHC experiments and their potential upgrades (ALICE3). This talk will review the tests carried out at Linac3 (first accelerator in the ion chain) in recent years and overview the latest requests for continuation of...
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped, and reaccelerated rare isotope beams, was successfully commissioned and has been in operation for the past two years. Various ion beam species have been accelerated up to 300 MeV/u and delivered to the target. FRIB routinely provided 10 kW primary beams on target over the past year, a...
The CSNS power upgrade project (CSNS-II) has been launched. It will increase the proton beam power from 100 kW to 500 kW, along with the new construction of 9 neutron instruments. CSNS-II will utilize superconducting accelerator structures to raise the linac energy from 80 MeV to 300 MeV. The pre-research on key technologies has been completed. The newly developed RF ion source is already...
The International Linear Collider (ILC), Compact Linear Collider (CLIC) and C3 are proposed designs for a next-generation high-energy electron-positron linear collider for exploring the Higgs-boson, top-quark and beyond-Standard Model sectors.
An overview and status of each collider project will be given, including the design, key technologies, accelerator systems, energy-staging strategies,...
Corrugated waveguide based colinear wakefield accelerator development at Argonne National Laboratory has been ongoing, achieving significant progress in fabrication and testing of most principal components of the accelerator module. A few 30 cm long corrugated waveguides with a 2 mm ID and short transition sections which provide fundamental mode power extraction and beam offset diagnostics via...
CiADS is the world’s first Accelerator Driven System under construction with a Mega-watt beam power. The linac of CiADS is designed to accelerate a 500 MeV and 5 mA proton beam with five-family superconducting resonators. The facility was lunched from mid 2021 and the hardware has finished the development of the prototype. In this presentation, we will present the physical design of the...
Present status and future prospects of the iBNCT accelerator will be discussed. Several accelerator-based neutron sources for Boron Neutron Capture Therapy (BNCT) have been developed in the world. The iBNCT (Ibaraki, BNCT) is a linac-based BNCT facility which is operated by University of Tsukuba and KEK in close collaboration with the local government, Ibaraki prefecture. The accelerator is...
Linear accelerators for FELs have very high requirements for the accuracy of synchronization. The long and short term stability is influenced by various sources of interference. In this paper it will be shown which methods of stabilization exist and how synchronization accuracies up to the fs-level can be achieved.
Time-resolved diagnostics are fundamental for x-ray free-electron lasers (FELs). Radio-frequency (RF) transverse deflector structures (TDSs) are typically employed to characterize the temporal properties of the electron beams driving FELs. In this contribution, we present time-resolved measurements with a resolution below one femtosecond using a C-band and X-band RF TDS at SwissFEL....
Unlike electron accelerators, hadron machines suffer from sever FE problem. High quality coldmass assembly in clean environment is the key assurance for high performance low beta cavities and cryomodules. However, low beta cavities like QWR, HWR or spoke cavities are much heavier and more difficult to assemble than elliptical cavities. IMP clean room team has introduced both...
Machine learning (ML) tools have been growing in popularity for accelerator applications, but still struggle with time varying systems, for which they require lengthy brute-force re-training. LANL has developed machine learning (ML)-based tools, that utilize adaptive model independent feedback control theory together with hard physics constraints, to make the tools much more robust to...
The International Liner Collider requires a crabbing system to increase the luminosity of the colliding electron bunches. The ILC has a large crossing angle that requires compensation in order to meet the luminosity requirements. There are several frequency options proposed for the crabbing cavity design. Two crab cavity designs were selected to be prototyped in the pre-lab phase, following...
Distributed coupling linear accelerators (DCLs) represent a revolutionary approach to accelerator design, offering significant advantages over traditional standing-wave and traveling-wave linacs. DCLs achieve record-breaking efficiency and gradient while remaining highly reliable, even under extreme operating conditions. These advancements make them ideal for a wide range of applications,...
The DEFT facility at the university hospital of Lausanne (CHUV) is based on a CERN accelerator design, which will be produced and installed by industry (THERYQ). This talk describes the machine design, the collaborative set-up and the planning towards completion.
The Compact X-ray Light Source (CXLS) is a compact source of femtosecond pulses of x-rays that is now commissioning in the hard x-ray energy range 4-20 keV. It collides the beams from recently developed X-band distributed-coupling, room-temperature, standing-wave linacs and photoinjectors operating at 1 kHz repetition rates and 9300 MHz RF frequency, and recently developed Yb-based lasers...
Reliability is an important feature for high power particle accelerators. This is particularly true for Accelerator-Driven Systems (ADS), for that every beam interruption can strongly affect the availability of the nuclear reactor.
Many of these outages come from the loss of accelerating cavities or of their associated systems. Cavity failures can be compensated for by retuning other...
For the time being, determining the cell-to-cell periodic solution for transporting intense beams has been limited to the spatial envelope. Recently, a numerical method for provision of full 4d-periodicity of all 10 beam moments of an intense 4d-coupled beam has been developed and benchmarked with tracking simulations. For instance, it will pave the path towards exploring the potential of beam...
Proposed Abstract: FRIB requires many primary ion species for production of rare isotopes. The beam development time can be significantly reduced by employing surrogate or policy (control) model-based optimization techniques. Sophisticated methodologies continuously evolve within accelerator communities to elevate the performance of beam tuning techniques. In this talk, we aim to explore...
Plasma processing is a common technique where the free oxygen produced in a low-pressure RF plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient of the treated surfaces. Jefferson Lab has an ongoing R&D program in plasma processing. The experimental program investigated processing using argon/oxygen and...
The FRIB diagnostics system covers an extensive range of primary and secondary beam intensities of 14 orders of magnitude and requires continuous improvements. The linac diagnostic system has provided straightforward linac commissioning and supports the development of many primary heavy ion beam species for producing rare isotopes. The diagnostics system for the secondary beam has a unique...
Argon beam was successfully accelerated in the RAON low energy superconducting linac in May, 2023. Neon and oxygen beams are to be accelerated in 2024 providing beam for the experiment systems.
Observation of ultrafast structural dynamics is very important for elucidating functions and creating new materials. We have been promoting research and development of ultrafast electron microscopes by generating relativistic femtosecond electron beam pulses using radio frequency (RF) accelerator technology. So far, we have fabricated the world's first ultrafast electron microscope using a...
We recently demonstrated generation of very high charge (1+ nC), very high energy (10 GeV) electron bunches from a nanoparticle-assisted laser wakefield accelerator [1]. While the experiment did yield record breaking results, the statistics were quite poor due to the very slow repetition rate of the Texas Petawatt Laser system. We are currently on a campaign to repeat and improve upon these...
We will present the results of the commissioning program to establish x-ray lasing and operation of the LCLS-II facility, based on the 4 GeV superconducting accelerator. The commissioning scope included the cryogenic systems, SRF and cryomodules, beam transport and two undulator beamlines serving the hard and soft x-ray programs. The talk will include a discussion of achieved beam performance,...
As an introduction, we will talk about the merit of the superconducting cavity and we about our applied research based on Compact ERL (cERL) in KEK, which uses the Nb superconducting cavity and can make energy recovery operation. The cERL’s characteristic using the high-current beam has a variety of applications; industrial applications using high-intensity terahertz light and mid-infrared FEL...
R&D on laser plasma based accelerators started in India only in the beginning of this century. Both experimental and theoretical studies on laser plasma interaction have been performed at various national labs and universities. High-power Nd:Glass laser systems were developed at RRCAT, Indore. In 2006, a CPA-based 10 TW Ti:Sapphire laser system was set up at RRCAT, for laser plasma interaction...
In 2021, the Chinese ADS Front-end demo superconducting radio-frequency (SRF) linac, known as CAFe, successfully conducted a commissioning of a 10 mA, 200 kW continuous wave proton beam. During this commissioning, it was observed that the SRF cavity fault played a predominant role, contributing to approximately 70% of total beam trips. Upon the detection of fault signals, an acquisition...
Since its completion in 2017, the new 160 MeV proton injector for the CERN accelerator complex Linac4 has undergone some tests to assess and improve reliability, until being connected to the Booster ring during the 2018-22 LHC shutdown. The performance requirements for the LHC high-luminosity upgrade have been successfully met, and during its first two complete years of operation the new...
HIAF is a heavy ion accelerator facility in China for nuclear physics research. The superconducting LINAC was used to accelerating beam energy up to 17MeV/u, then injecting to a Booster Ring. The linac are under construction since 2021, which includes 30 quarter-wave resonator (QWR) and 66 half-wave resonator (HWR). The first-batch production of cavity system have been completed. And the...
We report on the successful test for locating diamonds in ore by using an electron linac to create the 11C isotope atoms via the (gamma,n) reaction which has a large cross-section (8mb) at the Giant Dipole Resonance. The 11C atoms can be detected consequently using the Positron Emission Tomography (PET).
The technology is presently being scaled up for deployment in a mine with the goal of...
The SRF world has made considerable advances in the last 15 years on the performance of bulk niobium cavities. Processing recipes like N-doping and 120C baking are now being accepted as standard and consistently delivered by industry. New treatments like mid-T baking are now being incorporated into some project processing recipes as well. Thin film research is advancing with the mission to...
The 19 MeV electron linear accelerator ELSA at CEA DAM has been in operation for 30 years. A renovation of the RF system was necessary to improve the reliability of the linac. The second part of the renovation deals with the 144 MHz RF amplifier, supplying power to the photo-injector.
The former tetrode based amplifier has been replaced by a 1.6 MW Solid State Power Amplifier delivered by...
The studies commissioned by the U.S. Department of Energy have repeatedly identified electron sources as critical risk area for development of future accelerators including LINAC. To address this challenge, we initiated an effort of integrating 2D materials with cathodes in 2013. The aim was to protect environmentally susceptible but high performing alkali antimonide semiconductor...
Ions have been used in cancer therapy with considerable success in the last couple of decades. Helium and carbon ions have recently become the focus of research for their clinical advantages. The present work has been developed within a collaboration to design helium and carbon pre-injectors as part of an accelerator dedicated to hadron therapy. The subsequent systems in an accelerator depend...
A compact, high-voltage (HV) pulser in the nanosecond regime for transverse electromagnetic (TEM) kickers is presented. TEM kickers are electromagnetic deflectors used in particle accelerators to redirect bunches of particles out of their original trajectory into a new path, such as alternate beam paths, detectors, or other instrumentation devices. The circuit proposed in this design consists...
Accurately assessing the difference between two beam distributions in high-dimensional phase space is crucial for interpreting experimental or simulation results. In this paper, we compare the common method of RMS moments and mismatch factors, and the method of statistical divergences that give the total contribution of differences at all points. We first show that, in the case of commonly...
Efforts aimed at developing klystron parameters have made significant progress in recent years. However, the ultimate parameter list of connected pulse compressors (PCs) has been given insufficient attention. We propose to develop a new high efficiency, high power gain pulse compressor based on the use of a dielectric storage resonator (100% dielectric filling factor) that is operated at a...
Recent developments in laser wakefield accelerators (LWFAs) lead us to consider employing this technology to accelerate electrons at the Advanced Photon Source (APS) facility. Previous experiments using LWFAs were performed at Argonne using the Terawatt Ultrafast High Field Facility. The injector complex serving the APS begins with an electron linac, producing beam energies on the order of 450...
Additive Manufacturing (AM) has the potential to increase the performance of radio frequency (rf) cavity resonators while cutting manufacturing costs. To leverage this potential, AM processes and potentially post-processing techniques must be tailored to cavity requirements. Additionally, conventional manufacturing's quality assurance methods must adapt to the AM case requiring numerous...
Our recent experiments achieved EUV range undulator radiation amplification based on the stable electron beam obtained from laser wakefield accelerator (LWFA). The experiments were conducted on the LWFA platform in RIKEN Spring-8 center supported by ImPACT and JST MIRAI project. By optimizing the driving laser system and gas target, the reproducibility of the acceleration process has been...
The Future Circular Collider electron-positron (FCC-ee) pre-injector complex demands high-performance RF accelerating structures to achieve reliable and efficient acceleration of beams up to 20 GeV. In this study, we describe analytical approach to RF design for the traveling-wave (TW) structures including pulse compression system to meet the rigorous specifications of the FCC-ee pre-injector...
Neutron scattering is an indispensable technique in material science research for providing solutions to major modern engineering challenges, including the ever-growing demand for more efficient batteries and fuel-cells. There are, however, limitations in the access and availability to the necessary neutron beams and this is worsening as nuclear research reactors continue to shut down. As a...
In this paper, we investigate the usage of advanced algorithms adapted for optimizing the design and operation of different linear accelerators (LINACs), notably the superconducting linac ALPI at INFN-LNL and the ANTHEM BNCT facility to be constructed at Caserta, Italy. Utilizing various intelligent algorithms and machine learning techniques such as Bayesian optimization, genetic algorithms,...
Nb3Sn is the most promising alternative material for the future of superconducting radio-frequency (SRF) technology, steadily advancing towards practical applications. Having a critical temperature twice that of niobium, Nb3Sn offers the potential for developing smaller, more powerful, and more efficient accelerators. We present recent developments at Cornell University that address the...
The ISOLDE Superconducting Recoil Separator (ISRS) is based on a very compact particle storage ring of only 3.5 m in diameter. This instrument will be coupled with present and future detector systems of the HIE-ISOLDE facility. The injection of the HIE-ISOLDE beam into this ring requires a more compact bunch structure, so a Multi-Harmonic Buncher (MHB) device is proposed for this task. In...
The ALBA injector consists of a 110 MeV Linac, a Linac-to-Booster Transfer Line and a full energy Booster that further accelerates the electrons up to 3 GeV. The Linac consists of two pre-bunchers, a buncher and two accelerating structures and it is powered by two pulsed 37 MW klystrons at 3 GHz. To overcome an eventual klystron failure the injector has been adapted to keep operative at lower...
The CSNS is an accelerator-based multidisciplinary user facility operates at a stable beam power of 160 kW since March 2024, which is 40% higher compared to the designed value. The upgrading project of CSNS (CSNS-II) is in progress, and the missions associated with linac include increasing the output energy to 300 MeV by employing superconducting accelerator and the peak current to 50 mA. An...
Simulation tools are critical to the prototype and validation of control algorithms prior-to and during commissioning of LLRF systems. Moreover for industrial systems, diagnostics that are available on test systems and in laboratory accelerators are not always available in the field. RadiaSoft has been developing an RF simulator suite that allows for rapid prototyping of control algorithms in...
The 60 kW CW AR RF HPA is critical major equipment in new RF system for ALS-U project at LBNL and so it has been designed & built with a modular redundant topology having large array of 96 RF final PA modules (each delivering ~ 700 W RF output) that are combined in parallel, and large 30 DC PS modules (each ~ 5 kW DC power) operating in parallel for achieving very high reliability (MTBF ~...
The Panofsky-Wenzel theorem states that the change in transverse momentum of an ultra-relativistic particle traversing a TM mode is proportional to integral of the transverse gradient of the longitudinal electric field. The aim of this paper is two-fold: first, to formalise the application of the theorem to azimuthally modulated cavities and, second, to analyse the breakdown of the...
This work presents a semi-analytical model for the calculation of the space charge fields in photo-injectors, which are fundamental to control beam quality. Based on a technique of Green’s functions, the model allows you to calculate space charge fields for different charge distributions. Using a low-energy approximation, the longitudinal and transverse planes are analysed separately. Two...
Recent studies indicate the magnitude of an anomalous decrease in the resonant frequency, so-called frequency dip, near critical temperature of superconducting niobium cavities, Tc, correlates to the cavity quality factor, Q0, and impurities introduced into the superconducting niobium surfaces, such as nitrogen or oxygen. We measured frequency dips in both 644 MHz fundamental mode (FM) and...
The project Anthem, funded within the Next Generation EU initiatives, foresees the realization of an innovative accelerator based BNCT (Boron Neutron Capture Therapy) facility at Caserta, Italy.
The INFN (LNL, Pavia, Napoli, Torino) has in charge the design and construction of the epithermal neutron source, that will assure a flux of 10^9 n/(s cm2) with characteristics suited for deep...
RadiaSoft is developing machine learning methods to improve the operation and control of industrial accelerators. Because industrial systems typically suffer from a lack of instrumentation and a noisier environment, advancements in control methods are critical for optimizing their performance. In particular, our recent work has focused on the development of pulse-to-pulse feedback algorithms...
Sample alignment in neutron scattering experiments is critical to ensuring high quality data for the users. This process typically involves a skilled operator or beamline scientist. Machine learning has been demonstrated as an effective tool for a wide range of automation tasks. RadiaSoft in particular has been developing ML tools for a range of accelerator applications including beamline...
A common challenge in online accelerator operations is aligning beams through a series of quadrupole magnets, especially when in situ beam position monitors are not present. Accelerator operators generally use a trial-and-error approach to solve this problem by sequentially measuring the centroid deflection of the beam as a function of quadrupole strengths. This is a challenging process that...
The superconducting heavy ion HELmholtz LInear ACcelerator (HELIAC) is designed to meet the needs of the Super Heavy Element (SHE) research and material science user programs at GSI in Darmstadt. The beam energy can be varied smoothly between 3.5 and 7.3 MeV/u, with an average current of up to 1 emA and a duty cycle of 100 %.
Recently, the first cryomodule CM1, was fully commissioned and...
A prototype Canadian compact accelerator-driven neutron source (PC-CANS) is proposed for installation at the University of Windsor. The source is based on a high-intensity compact proton RF accelerator that delivers an average current of 10 mA of protons at 10 MeV to the target. This study can serve as a basis for the design of an initial stage of a new high-intensity compact...
The development of a high-repetition-rate infrared terahertz free-electron laser (IR-THz FEL) is advancing through its preliminary research phase, aiming to meet the demand for a tunable, high-power light source within the long wavelength spectrum. This initiative aligns with the broader objectives of the Hefei Advanced Light Facility (HALF) project. This paper presents simulation outcomes for...
In the field of accelerator physics, the quality of a particle beam is a multifaceted concept, encompassing characteristics like energy, current, profile, and pulse duration. Among these, the emittance and Twiss parameters—defining the size, shape, and orientation of the beam in phase space—serve as important indicators of beam quality. Prior studies have shown that carefully calibrated...
Though transverse matching was performed, the measured beam emittances at the end of the CSNS linac were bigger than the simulated ones. We find that the longitudinal mismatch is responsible for the emittance growth because of lacking longitudinal diagnostics. A matching technique based on the emittance measurement at the end of the linac was performed on CSNS linac. By modifying the...
The Los Alamos Neutron Science Center (LANSCE) accelerator celebrated fifty years of operation in 2023. The LANSCE Modernization Project (LAMP) aims to ensure the future, by upgrading the aging hardware with a new replacement front end. This includes plans to replace the Cockcroft-Walton generators with a Radio-Frequency Quadrupole (RFQ), the low and medium energy transport (LEBT and MEBT...
High intensity linacs based on RF structures suffer from beam loading effects, which result into a bunch-to-bunch energy loss as a consequence of the beam-induced excitation of the fundamental accelerating mode. Since its latest version, 2.3.0, the code RF-Track implements an update of its beam loading module that allows for charge-varying scenarios. In this work, we present the latest update...
Superconducting technology has significantly advanced the capabilities of particle accelerators, facilitating higher beam-power operations for fundamental research at a comparatively lower cost. However, the conventional implementation of superconducting technology introduces complexities in the form of cryogenic plants, cryogenic distribution systems and substantial construction and...
BPMs have been used for decades since their easy-to-use absolute transverse position capability. Left signal minus right signal divided by the sum times the radius gives the beam position. The charge is “just” a relative measurement and has to be calibrated (or ironed) against a toroid signal. Even when the incoming charge variation is high (like 3% rms for the superconducting LCLS2), the...
The Japan Atomic Energy Agency (JAEA) is designing a 30-MW CW proton linear accelerator (linac) for nuclear waste transmutation. Space-charge is the primary challenge in achieving low losses and high beam quality for high-power accelerators, especially at low energy levels where space-charge forces are greater. To counteract the space-charge effects, the low-energy beam transport (LEBT) uses a...
This work describes the latest updates on the conceptual design of the proposed multidisciplinary ICS X-ray source BoCXS and its feasibility study. In particular a full C-band RF accelerating structure, recently designed at the LNF, is adopted to take advantage of higher gradient RF fields, allowing the production of high-brightness electron beams and large radiated energy in a compact...
FLASH Therapy, a novel cancer treatment technique, aims to control the tumor-grown sparing the healthy tissue from radiation damage increasing the therapeutic index. The translation of FLASH therapy into clinical practice, especially for treating deep-seated tumors, necessitates achieving Very High Electron Energy (VHEE) levels within the 50-150 MeV range.
In collaboration with INFN, Sapienza...
This paper describes a C-Band RF system for the SAPS (Southern Advanced Photon Source of China) linear accelerator. The linear accelerator section of SAPS consists of one photocathode electron gun and two 2-m-long equal gradient acceleration structures.Photocathode electron gun contains a 4-cell standing wave accelerator.The RF system powered by a 50 MW klystron based power plant.The power...
A programmable signal processor-based credited safety control that calculates pulsed beam power based on beam kinetic energy and charge was designed as part of the Proton Power Upgrade (PPU) project at the Spallation Neutron Source (SNS). The system must reliably shut off the beam if the average power exceeds 2.145 MW averaging over 60 seconds. System calibration requires pedigree in...
A high-current proton source has undergone rigorous development and testing for the FRANZ-Project at the University of Frankfurt. The latest version of the filament-driven arc discharge ion source has a design with filter magnets that ensure a high purity of the proton beam (up to 90%). Experimental efforts have yielded results showing the extraction of a proton beam of 85 mA at a beam energy...
Linear accelerators with dispersive elements experience projected emittance growth due to coherent synchrotron radiation (CSR) effects which become relevant for highly compressed beams. Even though this is a widely known effect, conventional measurement techniques are not precise enough to resolve the multi-dimensional effects in detail, namely the different rotations of transverse phase space...
As part of the PIP-II project at Fermilab, a pre-production cryomodule featuring 325 MHz Single Spoke Resonator type 2 (SSR2) superconducting RF cavities is under construction. These SSR2 cavities are fabricated by industry partners and undergo initial cold testing at our collaborating institution, IJCLab in France, utilizing low-power coupler. Subsequently, the cavities are subjected to final...
At the Los Alamos Neutron Science Center (LANSCE), an upgrade of the Proton Storage Ring (PSR) is potentially possible under the LANSCE Modernization Project (LAMP). For the PSR, reducing or at least controlling the beam losses could maximize the beam current delivered to the users and extend the run cycle via shortening the maintenance period. One of the approaches would be to install...
RadiaBeam and RadiaSoft have been developing a LLRF system for a 100MeV C-band LINAC. The system is based on a Keysight PXIE arbitrary waveform generator and ADCs. We are in the process of commissioning our system and validating its performance. In this presentation, we will provide details on amplitude and phase calibration, improvements to signal conditioning, comparisons between...
Muons, Inc is developing Compact Electron Linacs to meet the increasing demand for modern solutions to address diverse applications including Co60 replacement, isotope production, industrial uses, and sterilization of medical devices, food and water. The designs employ the Muons, Inc. – Richardson Electronics Limited 1497 MHz magnetrons that were designed, built, and being tested to replace...
Accelerator-based light sources require high brightness electron bunches to improve performance in exploring structure of matter. Higher acceleration gradient is the key to generate high brightness electron bunches and is more feasible with higher frequency and shorter pulse length electromagnetic wave according to previous empirical formulas. A tapered rectangle waveguide structure driven by...
In the framework of the medical application research at CERN, a very compact (~ 2 cm) system of electrodes has been designed to facilitate high-current proton beam extraction and matching to an RFQ. Tailored to the already existing LINAC4 ion source, known for its capability of delivering high current proton beams, this system benefits from the capabilities of a fully operational test stand...
High-intensity Superconducting Radio Frequency (SRF) ion/proton linear accelerators (linacs) typically utilize Half Wave Resonators (HWR) and Single Spoke Resonators (SSR) for beam acceleration in the low-energy section of the linac. Because of lack of azimuthal symmetry, HWR and SSR geometries result in a quadrupole field component of operating mode accelerating field. This, in turn, results...
The Engineering Validation and Engineering Design Activities for the International Fusion Materials Irradiation Facility (IFMIF/EVEDA) are being pursued under the Broader Approach agreement between EURATOM and the Japanese government. The Linear IFMIF Prototype Accelerator (LIPAc) is under commissioning in Rokkasho, Japan to demonstrate the feasibility of the high duty (CW) and high current...
The Proton Power Upgrade (PPU) project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory has completed the installation and testing of all project scope, supported beam commissioning in June 2024, and transitioned to operations in July 2024. Increasing the beam energy from 1.0 to 1.3 GeV required the installation of seven additional cryomodules in the SNS Linac along with...
Abstract: Inductive Output Tube (IOT) is a vacuum electronic device used for generation of radio frequency power.. IOT based RF amplifiers are used in accelerator systems, industrial heating systems among other applications. It is compact in size and provides linear operation over its entire operating range with efficiency varying from60 to 70 percent. This paper proposes the conceptual...
Rotation of beams is usually quantified through its angular momentum rather than through its vorticity. However, the difference of the two transverse eigen-emittance is linked more strongly to vorticity as to angular momentum. It has been found that the dynamics of vorticity has remarkable similarity to the dynamics of the beam envelope along channels of solenoids and quadrupole triplets....
This work is part of the development study of a linac injector for hadron therapy with carbon ion beams. The initial cavities of the future injector consist of two 750 MHz Radio Frequency Quadrupoles (RFQ), which are based on the compact CERN High-Frequency RFQ. These RFQs are designed by CERN to accelerate the ions from 15 KeV/u to 5 MeV/u. Each RFQ, with a length of 2 meters, comprises four...
The superconducting (SC) driver linac for the Facility for Rare Isotope Beams (FRIB) includes 46 cryomodules for acceleration of heavy ions to 200 MeV per nucleon. FRIB cryomodules have been supporting sustainable and reliable delivery of high-power heavy ion beams, including 10 kW uranium beam, to the target for production of rare isotope beams to nuclear physics user experiments. The linac...
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. Follwoing successful beam commissioning of the 700 keV proton RFQ, further beam experiments including emittance measurements have been performed. Preparations for conditioning and commissioning of the IH-DTL are running in parallel to the current...
Compact SRF industrial linacs can provide unique parameters of the beam (>1 MW and >1-10 MeV) hardly achievable by normal conducting linacs within limited space. SRF technology was prohibitively expensive until the development of conduction cooling which opened the way for compact stand alone SRF systems suitable for industrial and research applications. Limited cooling capacity puts strict...
The performance of superconducting radiofrequency (SRF) cavities is critical to enabling the next generation of efficient high-energy particle accelerators. Recent developments have focused on altering the surface impurity profile through in-situ baking, furnace baking, and doping to introduce and diffuse beneficial impurities such as nitrogen, oxygen, and carbon. However, the precise role and...
In recent years significant progress in increase intensity of H- beam in RF surface plasma sources. H- beam intensity in RF SPS of J-Parc was increased up to 145 mA.Intensity of H- in RF SPS of SNS was increased up to 110 mA, which is enough for European spallation source storage ring. Reduction of beamlet divergence in RF negative ion source for NBI is one of high-priority targets to be...
HEPS injector is consist of a 500-MeV Linac and a full energy booster ring. A beam charge diagnostic system is designed to provide the bunch charge and the transmission efficiency. The system with commercial sensors and open-source hardware is applied for both normal charge mode and high bunch charge mode. This paper presents the details of the design and the recent commissioning results.
Abstract: Nowadays, radiation therapy is considered a critical method of cancer treatment. The most common devices for this purpose are linear accelerators that produce electrons, protons, and X-rays. This paper uses electron linear accelerators to produce both high-energetic electrons and x-ray beams, which are obtained through the bremsstrahlung process, which occurs when electrons strike...
The 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 developed as the SSC injector. The ion particle 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 the Uranium...
In this paper, the design of a compact C-band SLED RF Pulse Compressor for a Very High Electron Energy (VHEE) FLASH machine is presented. A spherical cavity RF pulse compressor - selected because of its compactness and relative ease of fabrication - is adopted to compress the 3 µs RF pulse, down to 1 µs obtaining a peak power gain greater than 3. Both the RF and thermo-mechanical design have...
This work presents the design and optimization of a compact electron linear accelerator capable of achieving an energy less than 5 MeV, specifically tailored for industrial applications. The innovative design incorporates a Superconducting RF photoinjector. A significant focus has been placed on optimizing the geometry of the SRF photoinjector cavity to accelerate high-charge and...
In the development of the linac for fourth generation storage ring, we conducted a comprehensive beam dynamics simulation to optimize the design of the injector system. To achieve this, we employed the Multi-Objective Genetic Algorithm (MOGA) to improve the linac operation parameters. The primary objectives of this optimization study were to minimize energy spread and transverse emittance at...
The Virtual Pepper Pot (VPP) is a 4D transverse phase space measurement technique based on pepper-pot-like patterns that are generated by crossing each measured horizontal slit-based beamlet with all measured vertical slit-based beamlets. The VPP beam phase space distribution reconstruction and simulation are performed using the Beam Delivery Simulation (BDSIM) code, which is a Geant4 toolkit....
A new type tuner is designed for the double spoke superconducting cavity of the Spallation neutron Source Phase II project in China. The tuner is mounted on the side of the cavity, and each module contains two tuner systems. In this paper, the structure and working principle of the tuner are designed and analyzed, also the testing results of the tuner with the superconducting cavity system as...
Electron accelerators utilized for radiation processing demand high beam currents and power outputs to maximize processing rate. Compared to conventional room-temperature accelerators, superconducting linear accelerators offer the capability to accelerate high-intensity continuous-wave (CW) electron beams. Therefore, the Design of a compact, 200mA, 2-5MeV CW superconducting linear accelerator...
Superconducting Radio Frequency (SRF) technology is a proven solution for generating high-power electron beams (EB), suitable for tasks like purifying wastewater from challenging impurities such as Per- and polyfluoroalkyl substances (PFAS). This paper elaborates on effectiveness of EB treatment and outlines design considerations for a 1.3 GHz SRF linac operating at 5 MeV with an average beam...
Laser wakefield accelerator (LWFA) and plasma wakefield acceleration (PWFA) have attracted a wealth of research interests since they can provide an accelerating gradient of ~100 GV/m. Recently, a series of LWFA/PWFA external injection experiments are foreseen to be carried out based on the linear accelerator (LINAC) of Beijing Electron-Positron Collider II (BEPCII). We hereby present a design...
We have designed a proton LEBT, aiming at transporting 100 mA proton beam to RFQ. In this paper, we present the design of the key paraneters including drift spaces and solenoid magnetic feilds. Simulations showed the final design can meet our requirements.
The Los Alamos Neutron Science center (LANSCE) facility at LANL is considering an upgrade of its front end, from the source to the end of a 100 MeV DTL. One of the main features of LANSCE is that it delivers several types of bunching systems to 5 users (Lujan Neutron Scattering Center, Proton Radiography Facility, Ultra Cold Neutron Center, Isotope Production Facility and the Weapons Neutron...
This works presents the design of Beam Position Monitors for a 750 MHz linac for hadrontherapy studies.
BPMs will be installed in different sections of the Linac, operating at different energies, from the RFQ exit at 5 MeV/u to the end of the line after IH cavities at 10 MeV/u. The BPMs will allow measurement of the beam position, phase and time of flight (tof) studies. Therefore, being...
Interest in helium ions for cancer therapy is growing, motivated by their superior conformability as compared to protons or carbon. Clinical trials are starting, using beams produced by large carbon synchrotrons. To exploit the potential of this new ion, a compact synchrotron is being designed to accelerate helium and protons at treatment energies, for about half the size of a carbon machine....
This study presents a preliminary design analysis of the low energy beamline for the UK XFEL, employing an inbuilt multi-objective optimiser within OPAL. The conceptual design study of the beamline explores various electron gun options such as VHF and SRF L-Band. This paper concentrates on the design based on an SRF L-band gun optimising to achieve minimum beam emittance and energy spread. The...
The PAL-XFEL accelerator is operating simultaneous operation of HX (10 GeV) and SX (3 GeV). To facilitate simultaneous operation, kicker MPS is necessary, requiring both AC mode and DC operation mode. AC mode operates with a square waveform at a repetition rate of 60 Hz. It operates as a bipolar type with an output voltage of 200 V and an output current of 45 A. The MPS is implemented using...
The RIKEN Linear Accelerator (RILAC), one of the injectors at RIBF was upgraded by installing a superconducting RILAC (SRILAC) to search for superheavy elements with element number 119 and above. Before the SRILAC upgrade, the machine protection system in the RILAC was constructed using simple relay circuits. On the other hand, most of the accelerators at RIBF other than RILAC have been...
The development of a few MeV/n carbon ion injector using laser-driven ion acceleration by Target-Normal Sheath Acceleration (TNSA) is carrying out. And the prototype injector has been completed at QST-Kansai in Japan. The beam commissioning is underway and first data on beam characteristics obtained from them will be presented.
A compact 10 MeV S-band irradiation electron linear accelerator has been developed to simulate electronic radiation in outer space and carry out electron irradiation effect tests on spacecraft materials and devices. According to the requirements of space environment simulation, the electron beam energy is adjustable in the range of 3.5 MeV to 10 MeV, and the average current is adjustable in...
In a linear accelerator, phase drift in upstream cavities can adversely affect downstream cavity synchronization, leading to beam degradation and potential loss. J-PARC LINAC employs different phase reference signals for beam monitoring and RF systems, hindering direct comparison. Recent observations revealed susceptibility of reference signals to environmental effects in the Klystron Gallery....
The China Spallation Neutron Source Upgrade Project (CSNS-Ⅱ) will use two debuncher cavities to supplement the beam energy at the end of the linear accelerator. The PI mode structure operating at room temperature is chosen, and each debuncher cavity is equipped with an online adjustable waveguide coupler. The main body of the coupler is the WR1500 waveguide, and a hole on the narrow wall of...
EuPRAXIA stands for “European Plasma Research Accelerator with eXcellence In Applications". It's a next generation free-electron laser (FEL) aimed at developing a compact, cost-effective particle accelerator based on novel wake-field accelerator technology. Traditionally, high-energy physics requires higher acceleration voltages, so developing an X-band acceleration technology, enables the...
Electron beams with low emittance are vital for a wide range of accelerator-based applications, including free-electron lasers, Thomson scattering sources, and ultrafast electron diffraction. Superconducting Radio Frequency (SRF) photo-injectors can produce low-emittance electron beams, particularly in continuous wave (CW) operation. Among the various photo-emissive layers, bi-alkali...
Various types of radioisotopes (RIs) are used in the field of nuclear medicine for diagnosis, such as PET and SPECT. In recent years, RIs are applied to therapy of cancer and the Ac-225 has been confirmed to be effective in the treatment of advanced cancer. One of the promising RI production methods for medical application is the use of high-intensity beam in accelerators. In the case of an...
The KEK injector linac injects high-charge electron and positron beams into the high-energy-ring and low-energy-ring of SuperKEKB respectively.
The linac also injects electron beams to the two light source rings, PF ring and PF-AR. We operate simultaneous top-up injections into the four rings by using many pulsed magnets. We have been upgrading the linac to attain the higher-quality beam...
The mid-Infrared region (2-5 um) is currently a frontier of laser science with short durations, where many molecular absorbing spectrums exist. The oscillator free electron lasers have advantages against solid-state laser systems, that include the fundamental generations of high-intensity mid-IR pulses with femto-seconds scale short duration, continuous variations of the central wavelength,...
Superconducting RadioFrequency (SRF) technology is a key component in many particle accelerators operating in a continuous wave, or high duty cycle, mode. The on-line performance of SRF cavities can be negatively impacted by the gradual reduction in the accelerating gradient that can be attained within a reasonable field emission level. Conventional cleaning procedures are both time- and...
The power coupler is one of the most important components for superconducting cavities. Different from the normal conducting cavity, the superconducting cavity has to keep an ultra-high cleanliness environment for operation. As the vacuum barrier, power couplers are welded by many different materials and maybe the gas source since they are installed to the cavities after vertical test,...
Nuclotron-based Ion Collider fAcility (NICA) is an accelerator complex under construction in JINR, in which superconducting linac-injector can accelerate protons up to 20 MeV and light ions to 7.5 MeV/u. To achieve this design target, a 325 MHz, beta=0.21 niobium half-wave superconducting structure called NICA cavity was developed jointly by IMP and JINR. This paper optimizes the...
FRIB is developing a new N-doping method with a simplified recipe. This recipe is called wet nitrogen doping, by adding nitric acid to the conventional EP acid. Nitrogen doping introduces impurities to the SRF surface, and reduces the BCS resistance by shortening the mean free path, which leads to a higher Qo. Conventional nitrogen doping, developed at FNAL and Jlab, requires a...
This paper describes the development status of solid-state switches for thyratron replacement. A 50 kV, 10 kA solid-state switch has been developed based on IGBT series stacking technologies, including voltage balancing and synchronous driving. The proposed stacking structure minimizes internal inductance and provides a fast current rising time of up to 7 kA/us. Additionally, the developed...
For high-intensity linear accelerators, space-charge halo mechanisms are largely classified into two families: particle resonances and parametric instabilities. The dominance between the fourth-order particle resonance and the envelope instability has been argued and studied. Our studies and previous literature indicate the dominance of particle resonances over parametric instabilities in...
The SNS Drift Tube Linac (DTL) operates at 402.5 MHz and consists of 6 RF tanks, DTL1 to DTL6, which can accelerate the H- beam from 2.5 MeV to 87 MeV before entering the Coupled Cavity Linac (CCL). Each DTL tank assembly has 2 sets of horizontal and vertical electromagnetic steering magnets (24 in total) required for transverse beam steering. The coils of these steering magnets were routed...
LANSCE accelerator complex was successfully supporting nuclear science research at LANL for more then 50 years. However, the need of the upgrade of the linear accelerator becomes immanent due to development of the modern accelerator technology, and due to inevitable aging of the existing equipment. The first stage of the planned upgrade of the linear accelerator at LANSCE includes the...
Dust particulates are always present to some degree inside the vacuum space of particle accelerators, causing a variety of issues. At the LHC, beam loss events have been linked to the interaction of charged dust with the proton beams. In superconducting rf cavities, dust contamination leads to field emission, limiting the accelerating gradient and causing damage to external beamline...
Fundamental power couplers are utilized in SRF accelerators to transfer RF power from a source to the accelerating cavities. However, the issue of thermal heat load during high-power transmission in continuous wave (CW) mode operation poses a significant challenge for power couplers. To address this concern critical modifications have been implemented within the warm sections of the cERL...
Next-generation accelerator concepts, which hinge on the precise shaping of beam distributions, demand equally precise diagnostic methods capable of reconstructing beam distributions within 6-dimensional position-momentum spaces. However, the characterization of intricate features within 6-dimensional beam distributions using current diagnostic techniques necessitates a substantial number of...
Electropolishing is an important and widely used technique for smoothing the surface of superconducting radiofrequency (SRF) cavities and to remove the so-called damaged layer created during the fabrication process. However, electropolishing is still not well understood on a fundamental level. In this study, we analyze the chemistry of electropolishing using electrochemical impedance...
In this paper, we present the development and performance evaluation of embedded single-board cameras utilizing the Raspberry Pi Camera v3 and the new picamera2 library based on libcamera. These compact camera systems (dimensions: 25 × 24 × 11.5mm) offer a versatile and cost-effective solution for real-time monitoring of beam induced residual gas fluorescence phenomena in accelerator...
An energy upgrade of the existing 100 MeV proton linear accelerator is considered at Korea Multi-purpose Accelerator Complex (KOMAC). 1 GeV proton linac for spallation neutron source is planned through 200 MeV linac upgrade as a near term project. Two options are considered for 200 MeV linac structure, one is a superconducting linac based on the half-wave resonator (HWR) and the other is a...
The Drift Tube Linac (DTL) for the European Spallation Source (ESS ERIC) will accelerate proton beam up to 62.5mA peak current from 3.62 to 90 MeV. The 5 cavities are now fully installed and tested in the linac tunnel. Moreover, in 2023 DTL1 to DTL4 have been RF conditioned to full power and beam commissioned with max peak current at short pulses. Relevant results of these activities are...
We are developing a laser-driven ion accelerator aimed at downsizing heavy ion therapy devices. The ion beam produced by this accelerator exhibits a broad energy spectrum (from keV to MeV) and a large divergence angle (up to approximately 10 degrees), with a very short pulse width (about picoseconds). As a result, the peak current reaches the kA level. However, explosive beam divergence is...
The KEK-ATF (Accelerator Test Facility) is an R&D facility for the final focus system to develop the nanometer beam technology required for the International Linear Collider. ATF is the best research environment for the study of wakefield effects on the nanometer small beam. The vertical beam size growth as a function of the bunch intensity was observed at the virtual interaction point (IP),...
The electropolishing process and cathodes have undergone modification and optimization for both low- and high-beta 650 MHz five-cell niobium cavities. Cavities treated with these novel electropolishing conditions exhibited superb surface quality and performance in baseline tests. Nonetheless, due to administrative constraints on project cavities, maximum gradient performance testing was not...
Plasma processing has been demonstrated to be an effective in-situ method to mitigate field emission and multipacting in superconducting radio frequency (SRF) cavities. In this work, we present the development of a new plasma processing method aimed at mitigating such performance-limiting phenomena in PIP-II spoke resonators of type II (SSR2) equipped with cryomodule style high power coupler.
We investigated the versatility of manipulating the nonlinear longitudinal phase space for an electron injector including a VHF gun, bunch compressor cavities and a booster section. The research focuses on minimising the bunch length through RF compression while preserving the emittance produced after the gun. We will present the best results obtained from the OPAL simulations. The findings of...
RF long-term stability (drift) is as important as RF short-term stability for the stable operation of particle accelerators including PAL-XFEL. Increasing the performance of LLRF itself becomes an important factor in maintaining the long and short-term stability of the RF field. The reference tracking method applied to LLRF is effectively used as a method of reducing the drift of the RF phase....
Successful implementation of AI/ML models for online tuning of accelerators highlights the need for accurate simulation of beamline elements. Deployment of such models requires the inclusion of realistic element misalignments during the simulation process. This paper presents an original method to determine misalignments across entire beamlines and apply them to the previously developed TRACK...
Jefferson lab is considering an energy increase from current 12 GeV to 22 GeV for its CEBAF accelerator. This will be accomplished by recirculating 5-6 additional turns through two parallel CEBAF LINACs using an FFA arc at each end of the racetrack. The total recirculation turns would be 10 times, the first four turns use present conventional arcs to make the 180-degree bends from one LINAC to...
The operation of hard X-ray FEL in a self-seeded mode requires much more precise control of electron phase space distribution compared to a SASE mode. In PAL-XFEL, we developed a unique RF feedback control based on high precision e-beam characterization (combined with ~1 fs RF timing distribution) to maintain the optimized self-seeded FEL without drift during the user run.
This paper provides an overview of the current fabrication status of superconducting SSR1 spoke cavities intended for integration into the PIP-II SRF linac at Fermilab. It explores the ongoing development and fabrication processes of the jacketed SSR1 cavity, highlighting key modifications made in the mechanical design to enhance structural integrity.
The International Fusion Materials Irradiation Facility – DEMO-Oriented Neutron Early Source (IFMIF-DONES) will provide a deuteron beam of unprecedented intensity for irradiation and characterization of materials to be used in fusion reactors. In recent years, the possibility to use a small fraction of this beam for other applications in parasitic mode was discussed. This not only has the...
In-situ plasma processing is a promising technique to reduce field emission in superconducting radio-frequency cavities and thus maintain maximum accelerator performance for long-term operation. Continuous-wave accelerators such as FRIB are more challenging than pulsed accelerators due to relatively weak coupling (Qext = 2E6 to 1E7 for FRIB) via the fundamental power coupler (FPC). This...
The China Initiative Accelerator Driven System (CiADS), a multi-purpose facility driven by a 500 MeV superconducting RF linac, is currently under construction in Huizhou, Guangdong. In order to ensure the stable operation of the superconducting linac, we conducted optimization research on the beam quality in the front-end section of CiADS. By using the point scraping method, part of the beam...
Two 1.5 GHz CEBAF C75-shape 5-cell accelerator cavities were coated with Nb3Sn film using the vapor diffusion technique at Fermilab and Jefferson Lab coating facilities. Both cavities were measured at 4 K and 2 K in the vertical dewar test in each lab, then assembled into a CEBAF quarter cryomodule at Jefferson Lab. The cryomodule was tested in 4 K and 2 K in the CryoModule Test Facility at...
The China Spallation Neutron Source (CSNS) project is now operating stably at the CSNS campus and the upgrade work (CSNS-Ⅱ) has already started in 2023, meanwhile, the preliminary research work on the south advance photon source (SAPS) project is in progress. More than six types of accelerator cavities: radio frequency quadrupole (RFQ), drift tube linac (DTL), double spoke superconducting...
Using 2D and 3D particle-core models, we thoroughly studied potential resonance interactions between particles and core in matched beams within complete periodic and double periodic channels. By keeping consistent geometrical structures and phase advances, we compared the Poincaré sections obtained from both models. The findings show that the differences between the models are negligible. This...
The development of Nb3Sn thin film cavities is ongoing with several projects to implement Nb3Sn cavities into a cryomodule. One of the challenges with this task is the brittleness of the Nb3Sn film, which can easily be damaged during the assembly and tuning of Nb3Sn cavities. Nb3Sn cavities frequently show degraded performance during transportation, assembly, and tuning. In this study we will...
After dedicated machine upgrade measures at the GSI UNILAC, a high current beam campaign has been performed recently. The presented results were accomplished - among other things - with newly installed electrodes for the superlens (short RFQ-type matching section), working completely fault free.
Beam experiments have been conducted with high intensity proton beam (1.2 mA), carbon (1 mA 12C6+)...
The 50 years old GSI-UNILAC (Universal Linear Accelerator) as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the FAIR (Facility for Antiproton and Ion Research) synchrotron SIS100. The UNILAC together will provide for short and intense pulses. This contribution presents the results of the full performance high current uranium beam machine experiment...
Additive manufacturing (AM) has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for direct additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel, as well as pure copper using AM. We present the most...
The implementation of High Pressure Rinse (HPR) not only ensures thorough cleaning of the inner high purity niobium surface of Superconducting Radio Frequency (SRF) cavities but also unlocks their full potential for achieving peak performance. By effectively removing contaminants and impurities, HPR sets the stage for enhanced superconducting properties, improved energy efficiency, and...
The Cornell High Pulsed Power Sample Host Cavity (CHPPSHC) is a new system designed to measure the superheating field of candidate superconducting RF (SRF) materials, giving insight into their operational limits. This system is designed to reach peak magnetic fields of up to 0.5 T in only a few microseconds, allowing us to achieve a pure magnetic field quench on the sample. We present an...
The world’s first 1.3 GHz cryomodule containing eight 9-cell superconducting radio-frequency (RF) cavities treated by medium-temperature furnace baking (mid-T bake) was developed, assembled and tested at the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences for the Dalian Advanced Light Source (DALS). The 9-cell cavities in the cryomodule achieved an unprecedented high...
High-efficiency sub-GHz elliptical superconducting RF cavity are a critical enabling technology for multiple upcoming accelerator development projects such as for the Powerful Energy Recovery Linac for Experiments (PEARLE), the Future Circular Collider (FCC) FCC Booster, and for a certain realization of the FCC Collider ring. The ambitious quality factor and gradient requirements of these...
Space-borne accelerator technologies suffer from significant electron beam loss during beam acceleration and excessive energy spread of the output beam. LANL is proposing a deployable and compact solution using electrostatic potential depression (EPD) to achieve higher bunching, lower beam loss, and smaller energy spread. This buncher system involves the use of three EPD sections, each...
We have tested the acceleration of highly charged aluminum beams at high currents using a 4-rod test RFQ. A bulk pure aluminum target was irradiated with a YAG laser pulse of 6 nanoseconds at about 1 J to generate a high-temperature plasma. Since this plasma has an expansion velocity, Direct Plasma Injection Scheme (DPIS) can be used to carry the ion flux up to the RFQ without space-charge...
After the discovery of Higgs boson at LHC, Chinese scientists have planned to build a “Great Collider”, that is a next-generation multinational particle accelerator research facility proposed as a circular electron positron collider (CEPC) and a super proton–proton collider (SPPC). The main component of the CEPC accelerator complex is the Collider ring, which has a circumference of 100...
Steady-state microbunching (SSMB) storage ring is a promising high-power coherent light source for the future. The generalized longitudinal strong focusing (GLSF) scheme exploits the low vertical beam emittance in a planar ring to achieve steady-state ultra-short bunch through vertical-longitudinal coupling. When the bunch length is extremely short, the coherent synchrotron radiation (CSR)...
Precisely calibrating RF superconducting radio-frequency linear accelerators is crucial for accurately assessing cavity bandwidth and detuning, which provides valuable insights into cavity performance, facilitates optimal accelerator operation, and enables effective fault detection and diagnosis. In practice, however, calibration of RF signals can present several challenges, with calibration...
INFN Milano - LASA recently concluded its in-kind contribution to European Spallation Source Eric, providing the 36 Superconducting Medium Beta cavities that will allow boosting the proton beam energy from 216 Mev to 571 Mev. The performances of the last four cavities, treated with Electro-Polishing as main removal step, are presented and compared with the results obtained on the remaining...
Nuclotron based Ion Collider fAcility (NICA) project is being realized in JINR, Dubna.The main goal of new collider facility is investigations of the heavy ions collisions with center-of-mass energy up to 11 GeV/u.Two injectors will provide the beams as for colliding and for extracted beam experiments.One of them is Heavy Ions Linear Accelerator (HILAC) intended to inject heavy ions produced...
The European Spallation Source (ESS) is a state-of-the-art research facility currently under construction in Lund, Sweden. Upon project delivery, ESS will host the most powerful linear proton accelerator and a spallation target capable of producing the brightest neutron source in the world. In order to enable safe commissioning and operation of these potent systems, each system has a dedicated...
PIP-II cryomodules use a computer vision system (H-BCAMs system) to monitor the alignment of SRF cavities and focusing lenses during assembly, testing, and operation. This contribution details the integration of the H-BCAMs into the Spoke Test Cryostat (STC) at Fermilab, which is utilized for cold testing SRF cavities prior to their integration into the string assembly. Thermal and structural...
Recent studies have identified intrabeam scattering (IBS) as one of the processes that can have a greater impact on the beam dynamics of linacs with high density and low energy beams. This work presents the implementation of IBS in RF-Track, a tracking code developed for linear accelerators. The numerical simulation follows a novel methodology based on a hybrid-kinetic Monte Carlo approach....
Accurate beam emittance measurement and characterizing beam parameters are essential steps in the performance improvement and better physics studies of high-intensity proton beam accelerators. While various procedures exist for measuring beam parameters, they often come with limitations and provide only a linear space charge approximation of the phase space ellipse. To achieve better...
The 805MHz RF power plant at Los Alamos Neutron Science Center (LANSCE) is powered by 44 86kV 1.25MW klystrons which generate the required RF to produce 800MeV proton beam. These 805MHz klystrons are of the modulated-anode type and are specially engineered for a long pulse duration of 1.475 ms pulse and 120Hz repetition rate with a 15% duty factor. In this paper we will talk about the original...
The advent of c-band and x-band technology has made it possible to reduce the footprint of linear accelerators. Additionally, for industrial systems a more compact linac is enabling technology for burgeoning applications in security and defense. A key aspect to operating these machines in an industrial environments is stabilization of the amplitude and phase signals for the cavities. In this...
The proposed novel 100 MeV injector for the LANSCE Accelerator Facility* is designed to replace the existing 750-keV Cockcroft-Walton-columns-based injector. The new Front End includes two independent low-energy transports for H+ and H- beams merging at the entrance of a single RFQ, with the subsequent acceleration of particles in the new Drift Tube Linac. The challenge of the design is...
Ultra-fast science, at free electron laser (FEL) facilities driven by linear accelerators, is pushing accelerator and FEL technology towards shorter laser pump and FEL probe pulses to resolve fast dynamics. Ideally, the short pulses should be backed by a synchronization system that provide a pump-probe jitter that is similar to the pulse duration.
Recent developments at MAX IV are focused on...
RadiaSoft and RadiaBeam are partnering on the development of a low level RF control system to support a 100MeV C-Band LINAC. Our system utilizes a Keysight data acquisition system and arbitrary waveform generator to drive the LINAC. The controllers are fully integrated with EPICS and are actively being commissioned. In this presentation we will provide an overview of the design architecture,...
A machine learning-based virtual diagnostic method for measuring the longitudinal phase space is proposed. Utilizing multiple measurements of bunch length from the Facility for Rare Isotope Beams (FRIB) accelerator, beam parameters are fitted with a concrete simulation model. A neural network model is trained to learn the correlations between the signals from beam position monitors (BPMs) and...
Obtaining the complete distribution of a beam in high-dimensional phase space is crucial for predicting and controlling beam evolution. Previous studies on tomographic phase space reconstruction often required linear beam optics in the relevant transport section. In this paper, we show that the method of maximum entropy tomography can be generalized to incorporate nonlinear transformations,...
Beam tomography offers a distinctive approach for indirectly reconstructing a beam's phase space using downstream measurements. Our study introduces a novel algorithm utilizing Markov Chain Monte Carlo techniques to reconstruct a four-dimensional phase space upstream. Notably, this method can be easily parallelized, leading to enhanced efficiency compared to existing beam tomography methods....
Given the present availability of high-gradient accelerator technology for compact and cost-effective electron linacs in the 100-200 MeV energy range, the interest for Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment recently reached an all-time high. Particular significance is assumed by the Ultra-High Dose Rate (UHDR) regime where the so-called FLASH biological effect...
The SRF community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurities of niobium coupons with a low residual resistance ratio (RRR) and correlate these impurities with the RF...
During qualification testing of 650MHz cavities for PIP-II, field emission became a performance limiting factor, delaying cavity qualification efforts. A comprehensive plan to investigate sources of particulate contamination and develop mitigations was developed and pursued. This plan considered such factors as water quality, cleanroom performance, high-pressure rinse effectiveness, cavity...
The linear accelerator at the Facility for Rare Isotope Beams (FRIB) at Michigan State University uses a thin liquid Lithium film for charge stripping of high-intensity heavy ion beams. Energy straggling of the beam in the non-uniform Lithium film affects the energy distribution in the beam. This can lead to non-linear “tails” in the longitudinal phase-space beam distribution after bunching at...
A crucial milestone towards the final expansion stage of the HELIAC (Helmholtz linear accelerator at HIM & GSI) is the commissioning of the first fully equipped cryomodule, the so-called Advanced Demonstrator. The cryomodule comprises three accelerating superconducting crossbar H-mode cavities, a buncher and two superconducting solenoids. For modelling the beam dynamics of the Advanced...
In this paper, we investigate Ka-Band (35-36 GHz) metallic accelerating structures made of multiple sectors in order to operate at ever higher useful accelerating gradients (well above 100 MV/m) and minimum RF breakdown probability. We illustrate the results of the initial samples that were TIG welded. We discuss the performance of the mechanical process, welding procedure and visual...
The phenomenon of multipacting happens when in an RF cavity or wave guide electrons, randomly generated on the surfaces mainly by secondary emission and accelerated by the RF field, find e periodic and stable condition able to sustain the discharge. It is particularly detrimental for long pulse operation as in high intensity hadron linacs. An original view point for the associated dynamical...
Since the second half of 2013, Korea Multi-purpose Accelerator Complex (KOMAC) has been supporting user beam service by using a 100-MeV proton linac. As the operation period of the proton accelerator exceeds 10 years and the cumulative operating time surpasses 33,000 hours, we judge that it is an opportune time to establish a long-term plan to prepare for the aging of the accelerator. To...
Los Alamos Neutron Science Center uses a coupled-cavity linac (CCL) to accelerate H- beam from 100 to 800 MeV. This was the first CCL put into operation (1972) and is powered by forty-four 1.25 MW 805 MHz klystrons developed in the same era. A new initiative is underway to develop a replacement RF amplifier that fits in place of one klystron with HV modulator tank, and is functionally...
Niobium-tin has been identified as the most promising next-generation superconducting material for accelerator cavities. This is due to the higher critical temperature (Tc = 18 K) of Nb3Sn compared to niobium (Tc = 9.2 K), which leads to greatly reduced RF losses in the cavity during 4.5 K operation. This allows two important chang-es during cavity and cryomodule design. First, the higher Tc...
The Fermilab Side-Coupled Linac accelerates H- beam from 116 MeV to 400 MeV through seven 805 MHz modules. Twelve wire scanners are present in the Side Coupled Linac and four are present in the transfer line between the Linac and the Booster synchrotron ring. These wire scanners act as important diagnostic instruments to directly collect information on the beam’s transverse distribution. The...
Synchrotrons form the basis of many accelerator complexes in the US and around the world, supporting high-energy and nuclear physics research, including the Fermilab (FNAL) Main Injector (MI) as well as Brookhaven's Alternating Gradient Synchrotron (AGS), and Hadron Storage Ring for the Electron-Ion Collider (EIC). Currently, normal-conducting cavities are used in these applications, but...
CW magnetrons, initially developed for industrial RF heaters, were suggested to power RF cavities of superconducting accelerators due to their higher efficiency and lower cost than traditionally used klystrons, IOTs or solid-state amplifiers. RF amplifiers driven by a master oscillator serve as coherent RF sources. CW magnetrons are regenerative RF generators with a huge regenerative gain....
Modern CW or pulsed Superconducting RF (SRF) accelerators require efficient RF sources controllable in phase and power with a reduced cost. Therefore, utilization of the high-power CW magnetrons as RF sources in SRF accelerator projects was proposed in a number of works. But typically, the CW magnetrons are designed as RF sources for industrial heating, and the lifetime of the tubes is not the...
In 2019, the annual number of cancer cases exceeded 100 million, resulting in 10 million deaths worldwide. Radiation therapy stands out as one of the most effective methods for cancer treatment. Electron beams in the 100-MeV range can reach even deep-seated tumors without the need for surgical intervention. Thanks to novel high-gradient acceleration technologies, clinical facilities for...
At the Los Alamos Neutron Science Center (LANSCE), the accelerator operation is loss-dominated, and the losses are primarily minimized via operators’ intuition. The physics tune-up procedures for the linac, including the Drift Tube Linac (DTL) and the Side-Coupled Cavity Linac (CCL), does not take the bunch distribution into consideration. For the DTL, only statistical quantities like the full...
The CERN Linear Accelerator for Research (CLEAR) at CERN is a user facility providing a 200 MeV electron beam for accelerator R&D and irradiation studies, including medical applications. In this paper we will outline the most recent improvements in CLEAR operation and beam control and delivery, and describe the upgrades under way, giving an update of their current status. These upgrades...
During the first cool down of the prototype HB650 cryomodule (pHB650 CM), high static heat loads have been measured compared to the estimation. Several analysis and calculations have been performed to explain this difference which led to cool down this cryomodule two additional times. Before each cool down, repairs and upgrades have been done, and instrumentations were added to identify the...
In electron linear accelerators, the improvement of the acceleration gradient of the acceleration structure has been a continuous research topic for scientists, which can reduce the construction cost of the entire accelerator by increasing the acceleration gradient. For the CEPC and HEPS projects at IHEP, S-band 3 meters long accelerating structure has been developed. The operating frequencies...
We generalize a native Nb2O5 dissolution model [G. Ciovati, Appl. Phys. Lett. 89, 022507 (2006)] to sequential overlayer dissolutions, multilayer dissolution, and realistic temperature profiles, which may be applicable to other materials. The model is applied to secondary ion mass spectrometry depth profile measurements for varying temperature profiles and two-step oxide dissolution in Nb and...
The Viton gate valves installed in the CEBAF beamline have significantly degraded after long-term operation in a radiation environment, generating numerous particles that cause heavy contamination and strong field emission. As a replacement, all-metal gate valves have been proposed for installation in the CEBAF beamline. In this paper, we present thorough comparison tests between the Viton...
The Bhabha Atomic Research Centre (BARC) of Department of Atomic Energy (DAE) has indigenously designed, developed and tested high efficiency compact 7 kW and 20 kW solid state amplifier (SSA) systems at 325 MHz. These SSAs will be used for both Indian accelerators and Proton Improvement Plan II (PIP-II) project of Fermilab, USA. The PIP-II accelerator requires two levels of RF power at 325...
After shipment to the Daresbury Lab and return to Fermilab, the prototype HB650 cryomodule underwent another phase of 2K RF testing to ascertain any performance issues that may have arisen from the transport of the cryomodule. While measurements taken at room temperature after the conclusion of shipment indicated that there were no negative impacts on cavity alignment, beamline vacuum, or...
The Fermilab linac injection line consists of a 35 keV magnetron-type H- ion source, two-solenoid Low Energy Beam Transport (LEBT), 201 MHz 4-rod 750 keV Radio Frequency Quadrupole (RFQ), and a Medium Energy Transport (MEBT) containing 4 quadrupoles and a bunching cavity. The injector delivers 25 mA, 48 µs pulses to drift-tube linac at a repetition rate of 15Hz. The transmission efficiency has...
The 800 MeV side coupled cavity linac (CCL) at LANSCE is physically tuned with a single particle model. A model of the CCL was created using the High-Performance Simulator (HPSim) code to expedite beam recovery by comparing measurements to a 6D phase space model. The current status of the phase scan simulation for the 805 MHz CCL modules is presented.
The SPIRAL2 superconducting LINAC accelerates beams of different species, in a large energy range. During operation, the beam requested by the physics can change quite often and it is mandatory that beams that have been already tuned can be obtained again by simple application of the machine parameters already used. This reduces the accelerator retuning time and increases the machine...
Xi’an 200 MeV proton application facility (XiPAF) dedicated to proton single particle effect studies is undergoing heavy-ion upgrading and renovation. A heavy-ion injector will be constructed for XiPAF to provide the heavy-ion beam. The single particle effect studies will be expanded to cover proton and heavy-ions. In this paper, physical design of the heavy-ion injector for XiPAF-upgrading is...
Physics applications have been developed and applied to the linac commissioning of the RAON injector and superconducting linac. Beam parameters obtained from the physics applications have been checked and validated during the beam commissioning using various ion beams.
The importance of shaping temporal profiles in accelerator physics is highlighted by a wide range of applications, such as optimal plasma acceleration and improved performance in free electron laser applications. In our study, we focus on controlling the parameters in a beamline and Initial beam to achieve diverse temporal profiles. The transmission of electron beams through dispersive...
The PIP-II linac cryogenic distribution system (CDS) is characterized by extremally small heat inflows and robust mechanical design. It consists of a distribution valve box (DVB), intermediate transfer line, tunnel transfer line comprising 25 bayonet cans, and ends with a turnaround can. Multiple helium streams, each characterized by distinct helium parameters, flow through each of these...
We have studied high-power terahertz-wave sources using a normal-conducting S-band linac at the Laboratory for Electron Beam Research and Application (LEBRA) at Nihon University [1, 2]. The developed coherent transition radiation (CTR) had a high energy of 1 mJ per macropulse [3]. However, the peak power of the CTR was approximately 100 kW and did not reach 1 MW, i.e., the level at which...
Under the Broader Approach (BA) agreement the Accelerator Facility validation activities aim at demonstrating the acceleration of 125 mA D+ beam up to 9 MeV. This is the main goal of the Linear IFMIF Prototype Accelerator (LIPAc) under installation, commissioning and operation in Rokkasho.
LIPAc is currently operating in its Phase B+ configuration, which consists of all the beamline except...
Conventional beam diagnostics only measure 2D projections of the phase space in x-x', y-y' and z-z'. To estimate a 6D beam phase space distribution for simulations, these 2D projections are multiplied without any correlations between them. It is true only if their degrees of freedom are independent. Recent studies show that there exists correlation across conjugate pairs. This correlation can...
A high beam brightness is a crucial requirement for an electron linear accelerator, with the electron source setting the lower limit for the achievable brightness. A superconducting radio-frequency photoelectron injector (SRF gun) ) stands out as an advanced electron source capable of delivering beams with superior properties compared to other continuous-wave injectors. Currently, SRF guns are...
Field emission and multipacting are phenomena that can limit the performance of superconducting radio frequency (SRF) cavities, decreasing the gradient that cavities can be operated at. Plasma processing has been proven successful in addressing hydrocarbon-related field emission and multipacting in several cavity geometries. The Commissariat Energie Atomique Saclay (CEA-Saclay), Fermi National...
The RIKEN Superconducting Heavy-Ion Linear accelerator (SRILAC) has been steadily supplying beams for superheavy element synthesis experiments since the commissioning in January 2020. The overall availability of the accelerator during beam supply periods, excluding regular maintenance and downtime due to major malfunctions, is approximately 90%, with availability exceeding 99% for the...
Traveling-wave (TW) technology can push the accelerator field gradient of niobium SRF cavity to 70MV/m or higher beyond the limit of 50~60MV/m in Standing-wave (SW) technology. The early stages of TW SRF cavity developments had been funded by several SBIR grants to Euclid Techlabs and completed in collaboration with Fermilab through a 1-cell prototype and a proof-of-principle 3-cell TW cavity....
The progress and status of the high intensity short pulse 325 MHz proton linac driver for the FAIR facility in Darmstadt is described. The proton linac is designed to deliver a beam current of 70 mA at an energy of 68 MeV. The design of the normal conductiong CCH cavities was carried out in collaboration with our partners at the IAP Frankfurt and industrial partners. First bead pull...
The China Spallation Neutron Source (CSNS) is designed and constructed by physicists at the Institute of High Energy Physics (IHEP). It is the first pulsed neutron source facility in developing countries, which locates at Dalang Town of Dongguan city, the heart of the Guangdong-Hong Kong- Macao greater bay area. CSNS beam power reached design goal of 100 kW in 2020. The pre-research of CSNS...
The Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven nuclear transmutation system (ADS) as a future nuclear system. In preparation for the actual design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. The cavity fabrication started in 2020. Most of the cavity parts were shaped in fiscal year 2020 by...
The SNS beam test facility is a model of the SNS front end (source through medium-energy transport). On-going work at the BTF focuses on accurate modeling of the beam distribution to enable the prediction of halo losses (>100 parts per million). This presentation will discuss the latest progress towards this goal, including recent results after a reconfiguration of the test beamline and...
A new storage ring based on a multi-bend achromat (MBA) lattice has been built at the Advanced Photon Source. Currently, the commissioning process is underway to bring beamlines back into operation. The APS linac consists of two S-band thermoionic cathode guns at the front end and thirteen S-band traveling-wave RF structures, all powered by five klystrons. A major upgrade is in progress to...
Sustainability and cost reduction are key factors for the development of future large particle accelerators. This motivated INFN LASA to initiate an INFN-funded R&D program dedicated to improve the performance of SRF Nb cavities in terms of quality factor (High-Q) and accelerating gradient (High-G). The R&D program will start by exploiting state-of-the-art surface treatments on 1.3 GHz...
The FLASH 2020+ project at DESY includes, among other modernizations, an upgrade of the electron beam energy. Two accelerator modules were replaced and the RF distribution of the other modules was optimized. The limiting factors such as cavity quenching and field emissions are identified and measured at acceleration modules. At a later stage, based on those measurements, a high-power...
Nb3Sn is one of the most promising materials for the next generation of superconducting RF (SRF) cavities. One reason is that Nb3Sn cavities can achieve high Q-values at 4 K, whereas conventional Nb cavities need to be cooled down to 2 K. This allows for the operation of SRF cavities with conduction cooling, eliminating the need for liquid helium, unlike conventional SRF cavities which require...
The bipolar pulsed electropolishing (BPEP), due to its HF-free feature, can offer much safer, more environmentally friendly, and lower-cost operation compared to the conventional electropolishing, using concentrated HF and H2SO4 as electrolyte. Jefferson Lab has developed the BPEP system using diluted H2SO4 only for implementing final surface processing of niobium SRF cavities, including...
FERMI is the seeded free electron laser (FEL) user facility at Elettra laboratory in Trieste, operating in the VUV - soft X-ray spectral range. In order to extend the FEL radiation to shorter wavelengths, an energy increase from 1.5 GeV to 2.0 GeV is required in the linear accelerator (linac). This result is achievable by replacing the present old sections with the newly designed accelerating...
Achieving high-quality proton beams for accelerators hinges on effective beam tuning. However, the conventional "Monkey Jump" method, widely used for tuning, proves labor-intensive and inefficient. Through harnessing Reinforcement Learning (RL), a novel beam tuning strategy can swiftly emerge, making informed decisions based on the prevailing system status and control demands, offering a...
The Laboratory for Electron Beam Research and Application (LEBRA) at Nihon University has been developing free electron laser (FEL), parametric X-ray radiation (PXR), and terahertz (THz) wave sources in collaboration with KEK and the National Institute of Advanced Industrial Science and Technology (AIST) using a 100 MeV electron linac. Each of these light sources is used for both internal and...
The performances and failure cases of the power couplers of the IFMIF/EVEDA RFQ and ESS DTLs have been analyzed with dedicated high-power test campaigns and multipacting simulation methods. The paper presents test and simulation methodology, results, and inputs for the next activities.
Field emission (FE) is a major contributor to degradation in the high-field performance of Superconducting Radio Frequency (SRF) cavities. The driver linac for the Facility for Rare Isotope Beams (FRIB) has been operating for user experiments since May 2022, using 104 quarter-wave resonators and 220 half-wave resonators in 46 cryomodules. We have used pulsed RF conditioning to mitigate the FE...
The RF reference phase in the SuperKEKB injector LINAC has been specially controlled for the stable beam injection to the main rings (HER/LER). The phase control system consists of three parts: MOFB, MOPS and SECT35PS. MOFB is the phase feedback system for drift compensation between the LINAC master oscillator (LMO) of 571.2 MHz and ring MO (RMO) of 508.9 MHz which has frequency ratio of 49/55...
A series of detailed Linac4 end-to-end simulations were conducted using RF-Track and benchmarked against PATH for validation. The simulations were performed from the RFQ entrance to the Linac4 end. In RF-Track, all the accelerating structures are described with calculated 3d field maps while the calculation time remains within minutes for half a million particles. Despite the inherent...
The CSNS consists of an H- linac as injector, and inside the LEBT, the interaction of the residual gas with H- particles will strip the electrons to produce companion protons, which follow the H- into the subsequent accelerating structure. In order to avoid the adverse effects of proton loss on the device, in this paper, the feasibility of employing a bump for companion proton separation at...
The accurate measurement of longitudinal beam parameters is paramount for controlling beam losses in high-power superconducting linac accelerators, particularly for low-energy beams which are significantly affected by the compensative challenges of nonlinear effects and pronounced space charge effects. In this context, systematic simulation and experimental studies of longitudinal acceptance...
It has been found in benchmark tests that some Single Spoke Resonator Type-2 (SSR2) cavities have early field emission onset as well as strong multipacting barriers. A longstanding hypothesis is that field-emitted electrons in the high electric field accelerating gap can migrate and ignite multipacting bands in the low electric field regions of the cavity periphery. In this study, we use...
The Los Alamos Neutron Science Center (LANSCE) accelerator complex delivers both protons (p) and negative hydrogen ions (H-) and provides various beam patterns simultaneously to multiple users. The LANSCE linac front end is still based on Cockcroft-Walton voltage generators that bring proton and H- beams to 750 keV. An upgrade of the front end to a modern, RFQ-based version is now under...
The Linac for Diamond Light Source has been running with two 3 GHz klystrons, powering two 5.2m-long accelerating structures to deliver 100 MeV electron beam since the start of operation. By introducing a SLED pulse compressor system to generate a pulse capable to power both structures from one klystron, redundancy and reliability will be improved. With a 5 µs total pulse, it is possible to...
This presentation details the design and fabrication process of a prototype of a normal-conducting X-band accelerator structure, which we denominate Smartcell. These structures, achieved through brazing/bonding techniques, are crucial components for future linear colliders.
We will cover the brazing/bonding geometry, materials selection and their implications, variations in heat cycles, and...
A new longitudinal diagnostic has been proposed, the SPACEChip (Smith-Purcell ACcElerator Chip-based) diagnostic, which can infer information about the temporal profile of a particle bunch from the Smith-Purcell radiation spectrum generated when the bunch passes close to a dielectric grating. This is done using the bunch form factor after retrieving the phase. A simulated dielectric grating...
GANIL (Grand Accélérateur National d'Ions Lourds) started the operation of the SPIRAL2 superconducting linac in 2022. Experiments in the Neutron For Science (NFS) room, specific beam dynamics studies and different technical improvements are carried out during its operation in the second half of each year. Up to now, accelerated particles are mainly D+ and 4He2+ beams with energies between 7...
For assemblies of cavities in cleanrooms, single-use tooling systems are made for the alignment and installation of ancillary components such as couplers and bellows. To try and minimize the amount of tooling sets used, a design has been created to standardize alignment features to allow for assembly of different components with one set of tooling. A prototype set of tooling has been developed...
A Dielectric Disk Accelerator (DDA) is a metallic accelerating structure loaded with dielectric disks to increase coupling between cells, thus high group velocity, while still maintaining a high shunt impedance. This is crucial for achieving high efficiency high gradient acceleration in the short rf pulse acceleration regime. Research of these structures has produced traveling wave structures...
The Proton Improvement Plan II (PIP-II) project at Fermilab is the first U.S. accelerator project that will have significant in-kind contributions (IKC) from international partners. CEA joined the international collaboration in 2018 and will deliver 10 low-beta cryomodules as IKC to the PIP-II project, with cavities supplied by INFN-LASA (Italy) and DAE-VECC (India), and power couplers and...
One of the crucial control systems of any synchrotron is the Low-Level Radio Frequency (LLRF). The main purpose of an LLRF is to generate and maintain a stable electric field within the accelerator cavities by controlling its amplitude and phase.
SAFRAN Electronic & Defense Spain S.L.U. is currently developing the new digital LLRF to update the system in the ALBA Synchrotron Light facility...
The status of INFN LASA in-kind contribution to the PIP-II project at Fermilab is reported in this paper. The effort for the series production of the 38 INFN LASA designed, 5-cell cavities with beta 0.61 for the LB650 section of the linac commenced and the status of ongoing activities and major procurements is here conveyed. At the same time, preliminary tests on INFN LB650 cavity prototypes...
Gun5, the new generation of high-gradient normal conducting 1.3 GHz RF guns for linac driven free-electron lasers like FLASH and European XFEL is under development at the Photo Injector Test facility at DESY in Zeuthen (PITZ). Its improved cell geometry and cooling concept allow for RF pulse durations of up to 1 ms at 10 Hz repetition rate, at gradients of ~60 MV/m at the cathode. Gun5 is also...
The Proton Improvement Plan II (PIP-II) project at Fermilab is the first U.S. accelerator project that will have significant in-kind contributions (IKC) from international partners. As a part of the French IKC to this project, CEA will provide ten 650 MHz low-beta cryomodules (LB650) equipped with cavities from INFN-LASA (Italy), Fermilab (USA), and DAE-VECC (India), and power couplers and RF...
The ongoing multi-user upgrade of the superconducting ion linac, ATLAS at Argonne, will enable simultaneous acceleration and delivery of two different ion beams to different experimental areas. In the initial phase, one stable, nearly continuous wave, beam from the ECR ion source and one pulsed radioactive beam from the EBIS charge breeder of the Californium Rare Isotope Beam Upgrade...
This paper outlines the strategy aimed at mitigating the adverse effects of residual magnetic fields on the performance of pre-production SSR2 superconducting cavities within the context of the PIP-II project at Fermilab. Residual magnetic fields can significantly impact cavity performance, leading to reduced quality factor. To address this challenge, our strategy integrates various approaches...
In high-intensity linacs, bunch-to-bunch effects due to the excitation of short and long-range wakefields can lead to beam instabilities and beam breakup. Wakefields can be due to resistive or geometric effects excited in the RF structures or in the beam pipe. From version 2.3.0 onwards, the particle tracking code RF-Track has been modified to implement a multi-bunch beam model that simplifies...
The X-ray free-electron laser facility SACLA generates X-ray SASE up to 20 keV in a compact 700 m long machine using a low-emittance thermal cathode electron gun, a high-field C-band normal-conducting 8 GeV linac and short-period in-vacuum undulators. The next upgrade plan for SACLA is to increase the repetition rate of the accelerator, which is currently 60 Hz, by one order of magnitude to 1...
As an initial part of a future linac for hadron therapy, two 750 MHz Radio Frequency Quadrupoles (RFQs) have been preliminarly designed by CERN, based on the compact HF-RFQ model. These RFQs aim to accelerate carbon ions from 15 KeV/u to 5 MeV/u. Each RFQ is composed of four individual modules.
Manufacturing imperfections and misalignments can result in local variations in the frequency and...
Mechanical grinding is commonly employed to eliminate surface defects such as scratches and pits from niobium cavity surfaces or sheets before cavity formation. Subsequently, chemically buffered polishing or electropolishing is often utilized to completely remove residues of the polishing media and any defects induced by mechanical grinding, ensuring a pristine surface. In this study, we...
To minimize the contamination of SRF cavities, remote installation techniques are needed during the installation of components. Recent work at Fermilab has been performed to begin the process of developing techniques for assembling cavities using robotics. Multiple alignment methods were prototyped including alignment and computer vision methods. Using a remotely controlled robotic arm, the...
The PIP-II Project will receive fully assembled cryomodules from CEA and STFC-UKRI as in-kind contributions. Damage to these cryomodules during transport is understood to be a significant risk to the project, so an extensive testing and validation program has been executed to mitigate this risk. The centerpiece of this effort was the successful shipment, from FNAL to STFC-UKRI and back, of a...
A 325 MHz, optimal beta=0.40 niobium half-wave resonator called HWR040 for the superconducting driver linac of the China Initiative Accelerator Driven System (CiADS) has been designed and analysed at IMP. The linac requires 60 HWR040s to accelerate protons from 45 MeV to 175 MeV. This paper mainly presents the multi-physics studies of the HWR040, include electromagnetic design, mechanical...
Significant progress towards the suitability of Additive Manufacturing (AM) metal parts for the production of linear accelerator components has been made in recent years. One significant factor for the suitability of AM parts to produce linac rf structures is the surface quality of the parts. Due to the inherently higher surface roughness of AM metal parts, post-processing is necessary to...
The CSNS-II superconducting Linac accelerator includes 20 sets of 324 MHz superconducting spoke cavities and 24 sets of 648 MHz superconducting Ellipsoidal cavities. The beam energy at the end of the superconducting Linac accelerator reaches 300 MeV. The 324 MHz solid-state power source supplies RF power to superconducting Spoke cavity, while the 648 MHz klystron power source supplies RF power...
The production of low energy high intensity heavy ion beams is challenging for the community. Several high intensity heavy ion beam accelerators for versatile purposes have been developed at IMP, such as LEAF, which is a low energy high intensity heavy ion accelerator complex for multidiscipline researches that features a superconducting ECR source, and a heavy ion beam linac. The major...
We have successfully accelerated charge state 11+ beam of aluminum above 50 mA. This beam current is limited by the fact that the RFQ was optimized for 40 mA of lithium beam. We therefore designed a new RFQ with a varying aperture along the beam axis to accelerate even higher currents. This means that the focusing force B is not constant. When this electrodes are attached to an existing 4-rod...
The commissioning of the Normal Conducting Linac (NCL) of the European Spallation Source (ESS) in Lund (Sweden), started in September 2018 and was completed in July 2023.
The four NCL commissioning phases required the design, procurement, test, installation and operation of four distinct beam destinations in order to safely dump the proton beam and measure the current of protons with energy...
LINACs is a simulation framework for designing optics and beam dynamics of charged particles in particle accelerators. LINACs is an open-source software that enables the user complete control over all design and simulation parameters of RFQs. This includes beam-driven design, fully 3D simulation using precise quadrupolar symmetry, and rigorous Poisson solution for external and space charge...
A continuous-wave (CW) superconducting electron Linac (e-Linac) is being installed at TRIUMF as a driver for radioactive beam production as part of the ARIEL project. The currently installed configuration with one single cavity injector cryomodule (ICM) and one double cavity accelerating cryomodule (ACM1) to accelerate in CW up to 30MeV. This paper is focused on the recent advances towards...
The UK is conducting a multi-stage project to analyse the case for major investment into XFELs, through either developing its own facility or by investing at existing machines. The project’s 2020 Science Case identified a clear need for ‘next-generation’ XFEL capabilities including near-transform limited x-ray pulses across a wide range of photon energies and pulse durations; evenly spaced...
New materials beyond the standard bulk niobium have the potential to greatly improve the performance of Superconducting Radio Frequency (SRF) cavities. Specifically, thin coatings of normal conductors such as gold have the potential to improve the key RF performance metric of quality factor. We present progress on depositing thin gold layers onto 2.6 GHz SRF cavities and testing their RF performance.
Fermilab has optimized the surface processing conditions for PIP-II high beta 650 MHz cavities. This encompasses conditions for bulk electropolishing, heat treatment, nitrogen doping, post-doping light electropolishing, and surface rinsing. The technology has been effectively transitioned to industry. This paper details efforts made to accomplish this milestone.
A multi-harmonic buncher cavity, MHB, is being designed by ESS Bilbao for HIE-ISOLDE Superconducting Recoil Separator at CERN, ISRS project. The MHB will bunch particle beams at 10% of HIE-ISOLDE RF frequency. Beams before ISOLDE RFQ have a relativistic beta of 0.00328. To test the MHB cavity with ESS Bilbao light-ion injector, extraction voltages of 5 kV and 10 kV must be respectively used...
The normal conducting part of ESS LINAC in Lund (Sweden) uses 5 DTL cavities, provided by INFN LNL as in-kind partner, to accelerate 60 mA proton beam from 3.9 MeV to 90 MeV. DTL1 have been tuned, installed in the accelerator tunnel and RF conditioned in 2021, DTL2, 3 and 4 in 2022, while DTL5 has been tuned and installed in summer 2023, but not yet conditoned. All the DTLs were equiped with...
The ESS-Bilbao RFQ fabrication is completed. The RFQ will operate at 352.2 MHz and will accelerate a 45 mA proton beam from 45 keV up to 3.0 MeV. The RFQ is build up of 4 copper segments, for a total length of 3.2 m. Each segment is composed of 4 subparts, 2 major and 2 minor vanes, that are assembled together by using bolts, vacuum and RF gaskets, with no brazing used in the procedure. This...
The Alvarez-type post-stripper DTL at GSI accelerates intense ion beams with A/q <= 8.5 from 1.4 to 11.4 MeV/u. After more than 45 years of operation it suffers from aging and its design does not meet the requirements of the upcoming FAIR project. Prototyping of a new 108 MHz Alvarez-type DTL has been completed and series components for the 55 m DTL are under production and have been delivered...
The Los Alamos Neutron Science Center (LANSCE) accelerator is MW-class H-/H+ 800 MeV linear accelerator that serves five distinct user facilities that support Los Alamos National Laboratory (LANL) national security missions, commercial applications, and the Department of Energy’s Office of Science medical isotope production program. Now into it’s sixth decade of continuous operation, major...
The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. These algorithms have been implemented in the python package Xopt, which has been used to solve online and offline accelerator optimization problems at a wide number of facilities, including at SLAC, Argonne, BNL,...
The delivery of high RF power---from hundreds of kW to MW---by klystrons, is linked with a high overall energy consumption. A research programme led by CERN in collaboration with the industry is being conducted to understand what limits klystron efficiency and how to develop high-efficiency klystrons. As a result of this program, two first prototypes of X-band (11.994 GHz) high-efficiency...
Corrugated structures have recently been utilized for the time-resolved diagnostics of electron bunches and free-electron-laser (FEL) pulses across several FEL facilities: SwissFEL at PSI and European XFEL at DESY. This approach is simple and cost-effective, based on the self-streaking of electrons with a transverse wakefield enhanced in such structures.
In this work, we optimize the design...
The Fermilab Linac delivers a 400 MeV H- beam to the Booster rapid cycling synchrotron. The drift in centroid energy (momentum) and significant longitudinal emittance in the Linac contribute to beam losses during Booster injection. Various factors, such as fluctuations in ambient temperature and humidity, impact cavity resonant frequencies, leading to fluctuations in beam energy and phase.
To...
The timing system is a critical element in scientific facilities such as particle accelerator or laser ignition installations.
The different subsystems that integrate these scientific facilities need to have a common notion of time. This common time reference is provided by the timing system. Thank to that, it is possible to operate the machine in a time coherent manner and to properly track...
