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...
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 an analytical approach to RF design for the traveling-wave (TW) structures including a pulse compression system to meet the rigorous specifications of the FCC-ee...
Neutron scattering is an indispensable technique in material science research for providing solutions to important 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...
Nb$_3$Sn 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, Nb$_3$Sn offers the potential for developing smaller, more powerful, and more efficient accelerators. We have designed a comprehensive study to synthesize and characterize...
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 China Spallation Neutron Source (CSNS) has been operating at a stable beam power of 160 kW since March 2024, marking a significant 60% increase from its original design capacity. The ongoing CSNS upgrading project, known as CSNS-II. As part of this upgrade, a versatile Medium Energy Beam Transport (MEBT) system has been meticulously studied and redesigned to meet the stringent requirements...
Superconducting RF (SRF) structures are susceptible to frequency detuning from external vibrations and modal mechanical resonances in the structure. These small disturbances, known as microphonics, require additional RF power in CW accelerating structures since the frequency is constantly shifting. In the Jefferson Lab CEBAF accelerator, time and frequency data of this frequency shift have...
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...
In this paper, we derive the multipolar form of the change in transverse and longitudinal momenta of an ultra-relativistic charged particle that traverses a harmonic TM$_{mn0}$ mode in a pillbox cavity with a beam pipe. The relevant equations are first formalised before presenting results from the numerical integration of RF cavity field maps. In particular, we show that the radial dependence...
The installation and alignment of new beamlines and beamline components is necessary at any accelerator facility. The equipment and methods used to perform these precision driven tasks must be accurate, reliable and above all, easily repeatable. Using coordinate measuring machines (CMM), laser trackers, combined with Spatial Analyzer, Autodesk Inventor and other custom tools, it is possible...
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...
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 compact accelerating 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. To track charged particles under this effect, the code RF-Track implemented a beam loading module in version 2.2.2. For ultrarelativistic scenarios in...
Beam loss in high-intensity H- linacs, such as the PIP-II linac at Fermilab, is a critical challenge that requires comprehensive study and understanding to ensure efficient and safe operation. This study explores the various beam loss mechanisms encountered in the PIP-II linac and its beam transfer line, drawing parallels from other high-intensity H- linacs. Key loss mechanisms include...
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...
This work describes a C-band RF system for the SAPS (Southern Advanced Photon Source of China) test bench linear accelerator.SAPS' RF testing system comprises of a photocathode electron gun and a 2-metre-long equal gradient acceleration device.The klystron power source delivers energy to the photocathode electron gun and the travelling wave acceleration structure,respectively.Test the...
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...
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...
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...
IFMIF-DONES (International Fusion Materials Irradiation Facility - DEMO-Oriented NEutron Source) is a facility under construction as part of the European fusion roadmap. The facility, located in Granada (Spain), is a powerful neutron irradiation facility for validation and qualification of materials to be used in fusion reactors. The construction of the facility under the framework of the...
In accelerator physics, radio-frequency (rf) systems play a pivotal role in particle beam acceleration and diagnostics. This work presents a graphical interface designed with Python for interaction with rf instruments, enabling efficient data acquisition, processing, and visualization. Leveraging advanced software tools, the system enables efficient management and analysis of rf data. This...
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...
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...
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....
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...
Wakefield structures are broadly employed in free electron laser (FEL) facilities for beam manipulation. Compared with cylindrical geometries, planar structures are typically preferred due to their increased flexibility, allowing for tunable wakefield strength through gap adjustment. However, these planar configurations can induce time-dependent quadrupole wakefields, which require careful...
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...
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...
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,...
As part of CERN's medical application research, a compact electrode system (< 30 cm) has been designed to facilitate low-current, multiparticle beam extraction and matching to a high-frequency RFQ. This study explores the innovative extraction system design and evaluates its simulation performance. Superfish (SF) and CST Studio Suite were employed to export the 2D and 3D electric field maps of...
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...
The wakefield of a charged particle moving along an elliptical spiral-shaped trajectory in an infinite elliptical waveguide with resistive walls is calculated. A limiting transition to a flat trajectory located in one of the symmetry planes of the elliptic cylinder is carried out.
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...
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...
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...
Coherent synchrotron radiation has a significant impact on electron storage rings and bunch compressors, inducing energy spread and emittance growth in a bunch. Calculating the effects are computationally expensive, severally limiting the use of simulations. Here, we explore utilizing neural networks (NNs) to model the 3D wakefields of electrons in circular orbit in the steady state condition....
The patterns of occurrence of geometric resonances of the wakefield in a two-layer metal-dielectric cylindrical waveguide are determined. It is shown that the sequences of their resonant frequencies are determined by the thickness of the dielectric layer and the dielectric constant of the material filling it, and do not depend on the radius of the waveguide and on the serial number of the term...
The concept of a compact linear accelerator for industrial application suggested in reference* is based on the use of SRF cavities. The design of a thermionic electron source which can either be directly connected to a superconducting cavity or be part of a normal conducted injector cavity is described. The direct connection option is applied in a prototype 1½ cell 650 MHz SRF cavity capable...
With the development of radiotherapy,the need for high doses became strong.However, existing ion chambers are either more absorbent of X-rays in terms of material or are non-sealed, that subject to environmental influences and have a short lifecycle. Now we designed a new ion chamber, which have high dose pass-rate, sealed and long lifecycle under radiation environments. The dose pass-rate...
Fermilab recently completed production and testing of 1.3 GHz cryomodules for the LCLS-II project. Each cryomodule consists of eight TESLA-shaped superconducting elliptical cavities equipped with two High Order Mode (HOM) coupler ports. Measurement of the HOM spectrum is part of the incoming quality control of cavities at room temperature and the final qualification cold test of cryomodules at...
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...
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...
The 805 MHz RF power plant at Los Alamos Neutron Science Center (LANSCE) is powered by 44 86kV 1.25 MW klystrons which generate the required RF to produce 800MeV proton beam. These 805 MHz klystrons are of the modulated-anode type and are specially engineered for a long pulse duration of 1.475 ms pulse and 120 Hz repetition rate with a 15% duty factor. In this paper we will talk about the...
From being the first computer-controlled accelerator, through its 52-year long operational history, today the LANSCE Instrumentation and Control System (LICS) shows little resemblance of its early days. Over the past 5 decades, generations of control system engineers were faced with the challenge of maintaining the LICS. However, its maintainability depends on the ability that a failed...
Charged particle dynamics under the influence of electromagnetic fields is a challenging spatiotemporal problem. Current physics-based simulators for beam diagnostics are computationally expensive, limiting their utility for solving inverse problems in real time. The problem of estimating upstream six-dimensional phase space given downstream measurements of charged particles is an inverse...
The side-coupled cavity linac (CCL) at the Los Alamos Neutron Science Center (LANSCE) is tuned by matching a single-particle model to the RF phase signature of the modules. In the future, the High-Performance Simulator (HPSim), a GPU-powered, 6-D particle tracking code, will be used to reveal additional information that will assist with tuning. In this proceeding, the status of the HPSim-based...
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...
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,...
At a heavy ion linac facility, such as ATLAS at Argonne National Laboratory, a new ion beam is tuned once or twice a week. The use of machine learning can be leveraged to streamline the tuning process, reducing the time needed to tune a given beam and allowing more beam time for the experimental program. After establishing automatic data collection and two-way communication with the control...
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...
The Los Alamos Neutron Science Center (LANSCE) provides an 800-MeV H- ion beam to four of its five user facilities. Two new methods for studying the beam profile are being installed in the south transport lines to the Lujan Spallation Neutron Center and the Weapons Neutron Science (WNR) Facility. The Laser Profile Monitor (LPM) studies the longitudinal beam profile by neutralizing the H-...
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...
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...
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 accelerating gradient. For the CEPC and HEPS projects at IHEP, S-band 3 meters long and C-band 1.8 meters long accelerating structure has been...
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...
A Ytterbium-based photocathode gun drive laser is proposed for the Advanced Photon Source linac to replace the existing antiquated Nd:Glass laser. The proposed laser will readily operate at 30 Hz providing 0.3 mJ of 257-nm UV radiation per pulse yielding 1 nC from our copper cathode, s-band gun in support of user operations. In addition, the laser allows generation of lower-charge,...
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...
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...
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...
The U4 single pass rf driver (SPRFD) concept as developed overwhelms heavy ion beam requirements for pellet ignition to meet the need to be investment grade, commercial IFE, to justify building the first-of-a-kind, HIF IFE regional energy and water supply facility, with co-located heavy energy-use industries, from a coordinated set of computer models supported by empirical data including...
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 to accelerate the ions from 15 KeV/u to 5 MeV/u. Each RFQ, with a length of more of 2 meters, comprises four...
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, the interaction of the residual gas with H- particles will strip the electrons to produce associated protons within the LEBT, which follow the H- into the subsequent accelerating structure. In order to avoid the adverse effects of proton loss on the device, the feasibility of employing a bump for associated proton separation at the MEBT was...
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...
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 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 transverse emittance at the exit of the China Spallation Neutron Source（CSNS）DTL is measured regularly every year. However, recently, the measured transverse emittance growth became larger than the his-torical data. It is also bigger than the simulated emittance. The process of measurement, data analysis and matching methods used are almost the same. Several factors con-tributed to the...
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...
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...
The PIP-II linac will include thirty-five 325 MHz Single Spoke Resonators Type 2 (SSR2) cavities. Each cavity will be equipped with a tuner for resonance control. The tuner consists of mechanical frame with a motor for coarse frequency tuning and a piezoelectric actuator for fine frequency tuning. The tuner was tested for the first time at Fermilab on an SSR2 cavity. This dressed cavity-tuner...
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...
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.
A multi-harmonic buncher cavity, MHB, is being designed by ESS Bilbao for HIE-ISOLDE ISRS project at CERN, to bunch beam pulses with 5 keV/u input energy. The MHB will be tested with ESS Bilbao light-ion injector. Transverse beam dynamics simulations were carried out to analyse preliminary measurements from hydrogen beams produced at 5 and 10 kV. Results have demonstrated that ESS Bilbao...
Resonant cavities used in accelerating structures have been studied and used in excited modes other than the fundamental frequency TM accelerating mode. These cavities can also be overmoded to accomplish specific beam quality or bunch structures. A TE mode properly phased can be used to induce a transverse kick to an 800 MeV proton beam, such as the beam produced by the Los Alamos Neutron...
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 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...
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...
