Description
Round 1 poster judging: 2pm - 4pm
Round 2 poster judging: 4pm - 6pm
Particle tracking serves as a computational technique for determining the mean field of dynamically tracked charged macroparticles of a particle beam within an accelerator. Conventional solver tend to neglect collisionality, resulting in loss of relevant information (particle and momentum redistribution). In this study, macro-particle collisions are incorporated into a 3D Poisson solver. In...
With the development of the steady state micro bunching (SSMB) storage ring, its parameters reveal that the ultra relativistic assumption which is wildly used is not valid for the electron beam bunch train, which has length in the 100 nm range, spacing of 1 μm and energy in hundreds MeV range. The strength of the interaction between such bunches and the potential instability may need careful...
As one of the state-of-the-art radiotherapy approaches, proton therapy possesses conformal dose profiles yet expensive cost. Designing a facility with a small footprint and a high treatment efficiency is the main goal for researchers to fulfill the potential of proton therapy and make it more affordable both for vendors and patients. In this contribution, the design of a light-weight proton...
Permanent quadrupole magnet (PQM) has good physical properties and extremely high economic performance, which can be used in proper physical design to adjust the central magnetic field gradient and at the same time greatly reduce the operating cost of modern gas pedals, but the design and optimization of the PQM's pole is still a difficult problem that needs to be solved at present. We hope to...
The International Linear collider (ILC) is an electron-positron linear collider with a center-of-mass energy up to 1 TeV. At the interaction point, the beam shape must be flat in the transverse space to maximize the luminosity and minimize the energy spread by Beamstrahlung. The flat beam is obtained by asymmetric emittance in x and y made up by radiation damping with a 3 km damping ring. We...
The Beam Coupling Impedance (BCI) is a crucial aspect in the realm of accelerator physics, as it describes the electromagnetic interactions between charged particle beams and the accelerator structure. The measurement and quantification of BCI is an essential requirement to assess and mitigate its impact, particularly when introducing new components or addressing problems within existing...
This study introduces a convolutional encoder-decoder architecture inspired by the skip connections used in ResNets, designed for predicting the transversal E-field. It has demonstrated impressive initial results, achieving a mean squared error (MSE) of $0.0054$, which further improves to $10^{-7}$ within just a few minutes of training. These results establish a strong foundation for advancing...
An accurate physics simulation model is key to accelerator operation because all beam control and optimization algorithms require good understanding of the accelerator and its elements. For the AGS Booster, major discrepancy between the real physical system and online simulation model mainly comes from magnet misalignments, which also lead to beam degradation and prevent the beam from reaching...
Steady-state microbunching (SSMB) represents an innovative scheme for generating high-power coherent radiation. This approach is expected to generate kilowatt-scale extreme ultraviolet (EUV) radiation for lithography in the semiconductor industry. During the second phase of the SSMB proof-of-principle experiment (SSMB PoP II), the creation of quasi-steady-state microbunches requires specific...
Strong field Terahertz (THz) light source has been in-creasingly important for many scientific frontiers, while it is still a challenge to obtain THz radiation with high pulse energy at wide-tunable frequency. In this paper, we introduce an accelerator-based strong filed THz light source to obtain coherent THz radiation with high pulse energy and tunable frequency and X-ray pulse at the same...
The development and standardization of in-situ plasma cleaning for superconducting radio frequency (SRF) cavities have a well-established history. This technique has demonstrated efficacy in reducing dark current and electron multiplication, thereby enhancing the acceleration gradient and stability of SRF devices. However, applying in-situ plasma cleaning to normal-temperature copper (NTC)...
An ion cloud confined in a Paul trap eventually reaches a Coulomb crystalline state when strongly cooled toward absolute zero. The normalized emittance of the Coulomb crystal can be in the sub-femtometer range. The trap is thus usable as a unique ion source for nano-beam production, though the available beam intensity is limited. This new concept was first discussed nearly 20 years ago* and...
This study examines Laser Engineered Surface Structures (LESS) in the context of their potential application within particle accelerators. These structures are investigated due to their efficient reduction of secondary electron yield to counteract the formation of electron clouds, a phenomenon detrimental to accelerator performance. A critical aspect of their evaluation involves understanding...
In the SuperKEKB/Belle-II experiment, a multitude of elementary particle reactions is initiated through the collision of 4 GeV positrons with 7 GeV electrons, paving the way for the exploration of new physics. The experiment includes plans for the substantial enhancement of luminosity in the future, aiming to achieve an integrated luminosity approximately 100 times the current level. However,...
This paper primarily explores the application and comparative analysis of the Accelerator Physics Emulation System Cavity-Beam Interaction (APES_CBI) module in the BEPC-II (Beijing Electron-Positron Collider) experiments. The APES_CBI module is an advanced time-domain solver, designed for analyzing RLC circuits driven by beam and generator currents and simulating the dynamic responses and...
The alignment installation work of Hefei Advanced Light Facility (HALF) is usually carried out in tunnels. We convert the coordinates of the landmark points to the global coordinate system through coordinate transformation, and accurately adjust them to the corresponding coordinate values for alignment and installation. However, tunnels are often long and narrow, which can easily lead to...
A novel tuning approach, Model Coupled Accelerator Tuning (MCAT), has been applied to the separated function DTL at TRIUMF's Isotope Separator and Accelerator (ISAC). A digital twin of the rare-isotope postaccelerator is used for transverse and longitudinal tune optimizations, which are then loaded directly into the control system. Beam-based testing produced accelerated beam with a 0.26%...
The automation upgrade of the photoinjector for the Compact X-Ray Light Source (CXLS) at Arizona State University is described. As the accelerator vault of the CXLS is only 10 meters long, the photoinjector drive laser is located in an enclosure inside the vault. Since ionizing radiation is present in this room during operations, it necessitates remote control of all devices used to optimize...
Super-NaNu is a proposed neutrino experiment as part of the SHADOWS proposal for the high intensity facility ECN3 in CERN's North Area. It aims to detect neutrino interactions downstream of a beam-dump that is penetrated with a 400 GeV high intensity proton beam from the SPS. The experiment would run in parallel to the HIKE and SHADOWS experiments, taking data with an emulsion detector....
We present a novel method for minimizing the effects of radiative depolarization in electron storage rings by use of vertical orbit bumps in the arcs. Electron polarization is directly characterized by the RMS of the so-called spin orbit coupling function in the bends. In the Electron Storage Ring (ESR) of the Electron-Ion Collider (EIC), as was the case in HERA, this function is excited by...
Tuning of radioactive beams in a post-accelerator facility such as TRIUMF’s ISAC involves a considerable amount of overhead and often leads to tunes which diverge from the theoretical optimum for the system, introducing undesirable effects such as aberrations or chromatic couplings. We hereby present the development and application of a Bayesian Optimization algorithm for corrective transverse...
High Power Targetry (HPT) R&D is critical in the context of increasing beam intensity and energy for next generation accelerators. Many target concepts and novel materials are being developed and tested for their ability to withstand extreme beam environments; the HPT R&D Group at Fermilab is developing an electrospun nanofiber material for this purpose.
The performance of these nanofiber...
This work examines the multi-pass steering of six electron beams in an FFA arc ranging from approximately 10.5 GeV to 22 GeV. Shown here is an algorithm based on singular value decomposition (SVD) to successfully steer all six beams through the arc given precise knowledge of all beam positions at each of one hundred and one diagnostic locations with one hundred individual corrector magnets:...
We are developing a compact synchrotron light source using laser electron acceleration, focusing on creating a tabletop accelerator-based radiation system. Our approach involves a small ring-type dipole with block-shaped permanent magnets, prioritizing cost and weight reduction. Simple beam dynamic calculations revealed that a smaller electron beam divergence angle results in a more stable...
Compared to conventional free-electron lasers (FELs), high-repetition-rate FEL has the ability to generate laser pulses at a higher frequency, thereby significantly enhancing the laser's mean power. The high-repetition-rate infrared FEL (IR-FEL) device aims to incorporate optical resonator-based FEL technology, powered by a photocathode RF gun and a superconducting RF accelerator. This paper...
Beam lengthening is significant for improving the beamlife of storage rings. Based on the previously proposed design of a room temperature conducting bimodal RF cavity, we conducted relevant dynamic simulations. The results showed that in a simulated storage ring lattice with the beam energy of 2 GeV and the synchronous radiation energy of 0.0356 MeV, the bimodal cavity realizes a same...
A beam position monitor based on Cherenkov diffraction radiation (ChDR) is being investigated as a way to disentangle the signals generated by the electromagnetic fields of a short-pulse electron bunch from a long proton bunch co-propagating in the AWAKE plasma acceleration experiment at CERN. These ChDR BPMs have undergone renewed testing under a variety of beam conditions with proton and...
Beam tomography is a method to reconstruct the higher dimensional beam from its lower dimensional projections. Previous methods to reconstruct the beam required large computer memory for high resolution; others needed differential simulations, and others did not consider beam elements' coupling. This work develops a 4D reconstruction using Markov Chain Monte Carlo.
The linear acceleration part of the SHINE project consists of two 3rd harmonic cryogenic modules which are operating at 3.9 GHz. Each of the cryomodules consists of eight 3.9 GHz 9-cell superconducting cavities. The SHINE specifications of the 3.9 GHz cavities are Qo >2.0e+9@13.1 MV/m and maximum accelerating gradient >15 MV/m. The 3.9 GHz cavities were treated with buffered chemical polishing...
Recent experimental measurements in the Large Hadron Collider (LHC) have shown a clear correlation between beam-beam resonance driving terms and beam losses, with a characteristic bunch-by-bunch signature. Due to the encounter schedule of the different bunches as they cross the interaction points, it is known that different bunches experience different long-range interactions with bunches of...
We performed an optimisation study of a C-band photoinjector for high-charge electron beams. Such a device is capable of producing high brightness electron beams, with low energy spread and small transverse emittance, which are properties required by Inverse Compton Scattering radiation sources and compact light sources in general. This work aimed to carry out, via numerical simulations,...
FEL oscillators typically employ a two-mirror cavity with spherical mirrors. For storage ring FELs, a long, nearly concentric FEL cavity is utilized to achieve a reasonably small Rayleigh range, optimizing the FEL gain. A challenge for the Duke storage ring, with a 53.73 m long cavity, is the characterization of FEL mirrors with a long radius of curvature (ROC). The Duke FEL serves as the...
A large challenge with plasma wakefield acceleration (PWFA) lies in creation of a uniform-density plasma with profile and length that properly match the electron beam. Using a laser-ionized plasma source provides control in creating an appropriate plasma density ramp. Additionally, using a laser ionized plasma instead of ionization from the electron beam, allows for the accelerator to run at a...
Niobium thin films play a crucial role in both macroscopic SRF cavities for particle accelerators and microscopic superconducting qubits used in quantum computing applications. This study aimed to investigate the RF performance of a 1.3 GHz single-cell elliptical Nb thin film cavity deposited using the DC bias High-Power Impulse Magnetron Sputtering (HiPIMS) technique. Experimental testing of...
Photocathodes at Negative Electron Affinity (NEA), like GaAs and GaN, allow for efficient production of spin-polarized electrons. When activated to NEA with cesium and an oxidant, they are characterized by an extreme sensitivity to chemical poisoning, resulting in a short operational lifetime. In this work, we demonstrate that deposition of a cesium iodide (CsI) layer can be used to enhance...
A Compact Transverse Deflecting System (Compact-TDS) designed for longitudinal electron bunch diagnostics in the femtosecond regime is presently undergoing commissioning at the Karlsruhe Institute of Technology (KIT). This technique, based on THz streaking with a Split-Ring Resonator (SRR), demands a high level of electron beam controllability and stability at the micrometer scale. To meet...
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator [1]. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch...
This work unveils the design of a compact high-power terahertz source, a collaborative effort between UCLA and RadiaBeam Technologies. The system, driven by a thermionic RF gun, features an alpha-magnet beamline that effectively compresses the beam, resulting in short bunch lengths and an additional S-band linac that elevates the beam energy to 10 MeV. The key to achieving high-efficiency...
This paper explores the phenomenon of asymmetric blowout in plasma wakefield acceleration (PWFA), where the transversely asymmetric beam creates a transversely asymmetric blowout cavity in plasma. This deviation from the traditional axisymmetric models leads to unique focusing effects in the transverse plane and accelerating gradient depending on the transverse coordinates. We extend our...
As part of the Snowmass'21 planning exercise, the Advanced Accelerator Concepts community proposed developing multi-TeV linear colliders and considered beam-beam effects for these machines [1]. Such colliders operate under a high disruption regime with an enormous number of electron-positron pairs produced from QED effects. Thus, it requires a self-consistent treatment of the fields produced...
Computational Fluid Dynamics (CFD) has been used to design a very high-power rotating tungsten target to produce a positron beam. The positrons will be produced by a primary 1 mA electron beam with energy 120 MeV impinging on a rotating tungsten wheel through bremsstrahlung. The W target will be instrumented with water cooling to remove the estimated 17 kW of heat deposited by the primary...
An electron beam degrader is under development with the objective of measuring the transverse and longitudinal acceptance of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. This project is in support of the CE+BAF positron capability. Computational simulations of beam-target interactions and particle tracking were performed integrating the GEANT4 and Elegant...
This paper details the implementation and benchmarking of crystal collimation within MERLIN++ accelerator physics library and demonstrates its application in simulating crystal collimation process for the High Luminosity upgrade of LHC at CERN. Crystal collimation is one of the key technologies suggested to enhance the current collimation system according to the requirements of HL-LHC upgrade...
In vivo studies support that the combination of protons and spatial fractionation, the so-called proton minibeam radiotherapy (pMBT), enhances the protection of normal tissue for a given tumor dose. A preclinical pMBT facility for small animal irradiation at the 68 MeV cyclotron of Helmholtz-Zentrum Berlin (HZB) will improve the understanding of this method. A two-step energy-degrading system...
The Compact X-ray Light Source (CXLS) requires the acceleration of electron bunches to relativistic energies, which collide with focused IR laser pulses to produce X-rays which are then transported to the experiment hutch. A class 4 UV laser is used at the photocathode to liberate the electrons that are generated via the photoelectric effect. During electron acceleration bremsstrahlung...
In addition to the desired electron beam, RF photoinjectors such as the one in LCLS-II produce dark current via field emission. Left unchecked, the dark current can cause various operational issues in the accelerator, such as increased radiation, damage to accelerator components and diagnostics, and desorption of gases from vacuum chamber surfaces. In this contribution, we present measurements...
NSRRC THz facility provides MW-level superradiant radiation with wavelengths ranging from 100–500 μm from a U100 planar undulator. An S-band laser-driven photocathode radio-frequency (RF) gun has been used in its 25 MeV linac system to generate a sub-picosecond high brightness relativistic electron beam for coherent emission of undulator radiation. However, the high accelerating field in the...
The attainable acceleration gradient in normal conducting RF accelerating structure is limited by RF breakdown, a major challenge in high gradient operation. Some of the recent experiments at the Argonne Wakefield Accelerator (AWA) facility suggest the possibility of breakdown mitigation by using short RF pulses (on the order of a few nanoseconds) to drive the accelerating structures. To...
To generate the very high brightness beams in light sources, injectors based on radiofrequency photo-guns with very high peak electric fields on the cathode are used. However, this very high surface electric field on the surface of a radio frequency cavity leads to the generation of dark current due to the field emission effect which can damage the instrumentation and radio-activate...
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...
Linear accelerators with multiple ray sources are widely used in detection imaging technology. In this paper, an S-band multipoint source traveling wave accelerator tube is designed and developed. The accelerator tube consists of 8 parallel-arranged accelerator cavity units and uses a power source to output 8 X-ray beams alternating from different positions. The acceleration tube operates at...
In this paper, we present the design of a multipurpose 3-cell deflecting RF cavity for a compact terahertz (THz) free electron laser (FEL) facility. The 3-cell deflecting RF cavity is mainly used for longitudinal bunch length measurement and a chopper system to cut off the bunch tail caused by the thermionic gun. Single-cell cavities suffer from orbit offset, while a 3-cell cavity is possible...
As compared to conventional travelling-wave (TW) structures, parallel-coupled accelerating structures eliminate the requirement for the coupling between cells, providing greater flexibility in optimizing the shape of cells. Each cell is independently fed by a periodic feeding network for this structure. In this case, it has a significantly short filling time which allows for ultrashort pulse...
Capable of achieving a high repetition rate with strong focusing, Fixed Field Alternating gradient (FFA) accelerators have the potential to be used for pulsed high intensity operations. With no pulsed high intensity FFA ever built so far, a prototype machine called FETS-FFA has been proposed to study the FFA option for the next generation spallation neutron source (ISIS-II). One of the...
In the field of structure wakefield acceleration there is considerable interest in radiofrequency (RF) structures capable of producing high gradients. Structures in the sub-terahertz (sub-THz) regime are of note due to their high gradient and high efficiency, allowing for a low physical footprint. In the pursuit of this goal we have designed a metallic corrugated W-band structure using the CST...
Coherent synchrotron radiation (CSR) effects in linear accelerators, such as projected emittance growth and microbunching, have been well studied. However, traditional measurement techniques lack the precision to fully comprehend the intricate multi-dimensional aspects of CSR, particularly the varying rotation of transverse phase space slices along the longitudinal coordinate of the bunch....
Minimizing the energy spread within the electron bunch is essential for an optimal performance of free electron lasers. Wakefields from corrugated and dielectric structures have been demonstrated to be effective in bunch dechirping. However, the repercussions in beam quality are not yet well understood. Here, a dielectric wakefield structure, manufactured to be included at the CLARA facility,...
Negative Electron Affinity (NEA) activated GaAs photocathodes are the only one capable of generating spin-polarized electron beam larger than 90%. However, the NEA layer currently made from mainstream cesium (Cs) and oxygen (O) is chemically unstable, the NEA-GaAs photocathode has a rapid QE degradation over time or electron beam. As a result, it requires an operating vacuum pressure of 1e-9...
Radiotherapy is an effective, non-invasive, widely used treatment for cancerous tumors that uses x-ray photon, electron and ion beam sources. The Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is a proposed novel laser-driven accelerator system under development that aims to deliver a multi-ion Particle Beam Therapy (PBT) technique. This study aims to develop a novel...
A surface treatment device has been established at the Wuxi Platform, enabling chemical polishing treatment on coupon samples. Currently, several samples treated with buffered chemical polishing (BCP) have been utilized in the investigation of nitrogen doping and medium-temperature baking mechanisms. This paper presents the development process of this device along with the experimental...
Meaningful prediction and enhancement of spin-polarization in the RHIC and EIC accelerators relies on accurate modeling of each sub-component. While nonlinear beam propagation and symplectic tracking is well established for common accelerator components, it has hitherto not been established for Siberian Snakes, which are essential for the acceleration of polarized protons in storage rings....
The thermal diffusion and acoustic properties of Nb impacts the thermal management of devices incorporating Nb thin films such as superconducting radiofrequency (SRF) cavities and superconducting high-speed electronic devices. The diffusion and acoustic properties of 200-800 nm thick Nb films deposited on Cu substrates were investigated using time-domain thermoreflectance (TDTR). The films...
Many mature methods to study the betatron function of a lattice rely on beam position monitor (BPM) data and the model of the whole machine. In this study, we focused on analyzing specific parts of the lattice of the Relativistic Heavy Ion Collider (RHIC), taking advantage of BPMs separated by drift space near interaction points (IPs) of RHIC. This (local) approach would provide a alternative...
One of the Grand Challenges in beam physics is development of virtual particle accelerators for beam prediction. Virtual accelerators rely on efficient and effective methodologies grounded in theory, simulation, and experiment. We will address one sample methodology, extending the understanding and the control of deleterious effects, for example, emittance growth. We employ the application of...
The Rapid Cycling Synchrotron (RCS) of the Electron Ion Collider (EIC) will be used to accelerate polarized electrons from 400 MeV to a top energy of 5, 10, or 18 GeV before injecting into the Electron Storage Ring. At 1 GeV, the RCS will perform a merge of two bunches into one, adding longitudinal dynamics that effects the dynamic aperture, depending on the merge parameters. In this paper,...
Crab crossings are designed to increase the luminosity of accelerators by ensuring beam interactions are closer to a head on collision. One will be implemented at the Electron Ion Collider (EIC) at Brookhaven National Laboratory. It is then important to examine how the crab cavity will affect beam dynamics at the EIC. Methods such as Frequency Map Analysis (FMA) have been shown to be helpful...
The use of glassy carbon (GC) as a future nuclear waste storage material depends on its capability to retain all radioactive fission products found in spent nuclear fuels. Ruthenium (Ru) is one of the most important fission products in nuclear reactors. This work investigates the effects of implantation temperature and annealing on the structural evolution and migration of Ru implanted in GC....
DAΦNE is a a medium energy electron-positron collider operating in the National Laboratory of INFN at Frascati, Italy. The accelerator complex consists of two rings with an approximate circumference of 97 m. High-intensity electron and positron beams circulate and collide with the center of mass energy of around 1.02 GeV. The FCCee is an ongoing lepton collider project and its current injector...
ELISA (Experimental LInac for Surface Analysis) is a linear proton accelerator installed in the Science Gateway exhibition at CERN since October 2023. Its development is built upon the experience gained at CERN from the R&D for LINAC4, with an innovative design of the Radio Frequency Quadrupole (RFQ). With a footprint of only 2x1 square meters, ELISA has the potential of full portability and...
In the context of the HL-LHC upgrade, RF Crab Cavities (CCs) are one of the key components. Due to the increased intensity, the collider will operate with a large crossing angle scheme and these CCs will be used to counteract the geometrical reduction factor coming from the crossing angle. Amplitude and phase noise injected from the Low-Level RF, are known to induce transverse bunch emittance...
CERN Proton Synchrotron (PS) is featured with 100 C-shaped combined-function Main Units (MUs) magnets with a complicated pole shape. The operation and the modelling of the PS-MUs has been historically carried out with empirical beam-based studies. However, it would be interesting to understand whether, starting from a proper magnetic model and using the predicted harmonics as input to optics...
The Future Circular Collider (FCC) study foresees the construction of a 90.6 km underground ring where, as a first stage, a high-luminosity electron-positron collider (FCC-ee) is envisaged, operating at beam energies from 45.6 GeV (Z pole) to 182.5 GeV (ttbar). In the FCC-ee experimental interaction regions, various physical processes give rise to particle showers that can be detrimental to...
As the China Spallation Neutron Source (CSNS) Phase II project upgrades beam power to 500 kW, maintaining horizontal beam orbit stability necessitates more precise output current from the main magnet power supplies. The existing control strategy, suited for 100 kW extraction power, falls short of the higher precision requirements for the output current, characterized by a quasi-sinusoidal...
Three L-Band cavity BPMs were tested at the Accelerator Test Facility (ATF) for raising beam position resolution. In the previous study, we found each BPM has a different resonant frequency due to manufacturing tolerance. From the earlier experiment, the position resolution was around 324 nm, while data incoherence problems occurred. Recently, we developed a Local oscillator (LO) to compensate...
THz-frequency accelerating structures could provide the accelerating gradients needed for compact next generation particle accelerators. One of the most promising THz generation techniques for accelerator applications is optical rectification in lithium niobate using the tilted pulse front method. However, accelerator applications are limited by losses during transport and coupling of THz...
The present ion physics program in the CERN accelerator complex is mainly based on Pb ion beams. The ALICE3 detector upgrade proposal at the Large Hadron Collider (LHC) requests significantly higher integrated nucleon-nucleon luminosity compared to the present Pb beams, which can potentially be achieved with lighter ion species. These lighter ion species have also been requested by the...
Plasma wakefield acceleration is nowadays very attractive in terms of accelerating gradient, able to overcome conventional accelerators by orders of magnitude. However, this poses very demanding requirements on the accelerator stability to avoid large instabilities on the final beam energy. In this study we analyze the correlation between the driver-witness distance jitter (due to the RF...
Dielectric-lined waveguides have been extensively studied for high-gradient acceleration in beam-driven dielectric wakefield acceleration (DWFA) and for beam manipulations, including the application of zero transverse force modes in the waveguides. In this paper, we investigate the zero transverse force modes excited by a relativistic electron bunch passing through a dielectric waveguide with...
A non-invasive gas jet in-vivo dosimeter for medical treatment facilities is being developed at the Cockcroft Institute, (UK) to provide full online (real time) monitoring with less frequent calibration. The monitor functions via a thin, low-density, gas jet curtain, intersecting with the beam. Online monitoring is crucial for hadron beams where acceptable dose tolerances are narrow, hence the...
We present measurements of quantum efficiency (QE) modulations in CsSb and Cs3Sb photocathodes that arise from optical interference of reflections from the underlying substrate that has multiple semi-transparent layers. The photocathode films are grown on a cubic silicon carbide layer (3C-SiC) which itself is grown epitaxially on Si(100) during fabrication. We find that the QE modulates by up...
Field emission (FE) and vacuum arcs limit the maximum achievable accelerating field of both normal and superconducting cavities. The performance of accelerating cavities can be improved after a long conditioning process. Understanding this process and the formation of vacuum arcs is important for all technologies where vacuum arcs cause device failure. The understanding could be more complete...
In order to miniaturize ion injectors for particle therapy, a design of ion injectors based on a 325 MHz operating frequency was completed. The LINAC was consist of a 2.0 m length RFQ and a 3.8 m length IH-DTL, which was designed to accelerate 12C4+, 3H+, 3He+ and 18O6+ beams to 7 MeV/u. The RFQ cavity and the first DTL tank was been manufactured using aluminum. This paper gives an overview of...
The knowledge of the longitudinal bunch shape is of high interest to accelerator performance optimization and advanced beam application. Attracted by the ability to continuously monitor the beam in real time, there is always a demand for bunch-by-bunch and non-invasive diagnosis. However, such diagnosis is difficult to achieve for proton beam with high intensity and high repetition. Using the...
The occurrence of breakdown events are a primary limiting factor for future accelerator applications aiming to operate under high field-gradient environments. Experimental evidence often leads to a hypothesis that breakdown events are associated with temperature and dark current spikes on the surface of RF devices. In the past decade, there has been increased interest in unveiling the...
Fourth-generation synchrotron radiation sources, which are currently being planned in several accelerator laboratories, require fast orbit feedback systems to correct distortions in the particle orbit in order to meet stringent stability requirements. Such feedback systems feature corrector magnets powered at frequencies up to the kilohertz range, giving rise to strong eddy currents. To...
The Future Circular Electron-Positron Collider (FCC-ee) represents a cutting-edge particle physics facility designed to further investigate the Z0, W± and Higgs boson in addition to the top quark. The implementation of Combined Function Magnets (CFMs) in the FCC-ee arc cells would maintain high luminosity and reduce its energy consumption. The use of these special magnets induces changes in...
Radio Frequency Knock Out (RF-KO) resonant slow extraction is commissioned at the Cooler Synchrotron (COSY) Jülich for the first time to extract the stored beam and deliver spills with constant particle rates to the experiments. Therefore, transverse RF excitation generated with a software-defined radio is applied to control the extraction rate. A built-in feedback system adjusts the...
Particle beams with asymmetric transverse emittances and profiles have been utilized in facilities for driving wakefields in dielectric waveguides and to drive plasma wakefields in plasma. The asymmetric plasma structures created by the beam produce focusing forces that are transversely asymmetric. We utilize the ellipticity of the plasma ion cavity to model the beam evolution of the flat beam driver.
By using a high-energy electron beam (beam energy of several hundred MeV) strongly focused on the tumor lesion area, radiotherapy can be performed with a relatively simple beam generation and handling system while resulting in a suitable shape of the deposition energy curve in a tissue-like material. Quadrupole magnets are typically used for beam focusing, which makes the beam delivery system...
A non-invasive bidirectional beam profile monitor using beam-induced fluorescence upon a thin sheet of gas has been developed at the Cockcroft Institute in collaboration with CERN and GSI. This device is particularly suited to the Electron Beam Test Stand, and as such, a bespoke gas injection has been optimized for this specific use-case to provide diagnostics unavailable to conventional...
As an important experimental tool, the Optical Frequency Combs (OFCs) has had a profound impact on research in various fields, whereas, generating high power high repetition frequency OFCs at tunable frequencies is still a limitation for most of the existing methods. In this study, free-electron laser (FEL) is proposed to generate coherent X-ray OFC with a tunable repetition frequency and...
Obtaining ultrashort electron bunches is the key to the studies of ultrafast science, yet second and higher order nonlinearities limits the bunch length to a few femtoseconds after compression. Traditional regulation methods using rf higher order harmonics have already optimized the bunch length to sub-fs scale, yet the energy loss and rf jitter are not negligible. In this paper we demonstrate...
Generating layers of symmetrical optical caustic beams using a specific configuration of cylindrical lenses is an innovative idea with potential application in precision alignment and other fields. The technique allows the generation of layers of non-diffracting beams with opposite accelerating directions. This approach can be extended in two dimensions or to create rotationally symmetric...
The CERN Accelerator Beam Transfer group has recently launched a study to investigate the life cycles of pulsed septum magnets. The development is aiming to enhance the prediction of anomalies, leading to reduced life cycles of these beam transfer equipment. For this reason, the standard vacuum operated, direct drive septa magnet has been chosen to investigate critical design features. In the...
Future electron accelerator applications such as x-ray free electron lasers and ultrafast electron diffraction are dependent on significantly increasing beam brightness. We have designed and produced a new CrYogenic Brightness-Optimized Radiofrequency Gun (CYBORG) for use in a new beamline at UCLA to study the brightness improvements achievable in this novel low temperature high gradient...
A Dielectric Disk Accelerator (DDA) is a metallic accelerating structure loaded with dielectric disks to increase its shunt impedance. These structures use short RF pulses of 9 ns to achieve accelerating gradients of more than 100 MV/m. Single cell and multicell clamped structures have been designed and high power tested at the Argonne Wakefield Accelerator. During testing, the single cell...
LCLS-II-HE is an energy upgrade of the LCLS-II linac from 4 GeV to 8 GeV. The X-ray FEL photon energy (Self-Amplified Spontaneous Emission mode) will extend towards 12 keV (from the present 5 keV) based on the current beam emittance. To reach higher photon energy range towards 20 keV, a new injector with a much brighter electron beam will be required. Here we study an X-ray regenerative...
Schottky monitors serve as non-invasive tools for beam diagnostics, providing insights into crucial bunch characteristics such as tune, chromaticity, bunch profile, or synchrotron frequency distribution. However, octupole magnets commonly used in circular storage rings to mitigate instabilities through the Landau damping mechanism, can significantly affect the Schottky spectrum. Due to the...
In the upcoming compact STorage ring for Accelerator Research and Technology (cSTART), LPA-like electron bunches are only stored for about 100 ms, in which the equilibrium emittance will not be reached. Therefore, to measure parameters such as bunch profiles, arrival times and bunch current losses, bunch-resolved diagnostics are needed.
The booster synchrotron of the KARA accelerator accepts...
SIRIUS is a 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). Recently, investigations of noise sources and the storage ring RF plant identification enabled a fine-tuning of the Digital Low-Level Radio Frequency (DLLRF) parameters. This paper presents the main improvements implemented, which include the mitigation of 60Hz noise...
The institute of applied physics (IAP), university of Frankfurt, has been working for years on the development of increasingly powerful 4-Rod RFQ accelerators for hadron acceleration. The need for such accelerators has increased significantly in the recent past, as accelerator-driven neutron sources are becoming increasingly important following the closure of various test reactors. High beam...
Using hollow plasma channels is one approach to compact positron acceleration, potentially reducing the cost and footprint of future linear colliders. However, it is prone to transverse instabilities since beams misaligned from the channel axis tend to get deflected into the channel boundary. In contrast, asymmetric electron drive beams can tolerate misalignment and propagate stably after the...
The deflection of charged particles in matter can be characterized by multiple-Coulomb scattering. Simulating the interaction of each particle with the Coulomb forces of the material is prohibitively time-consuming from a computational perspective. To address this, scientists have developed a scattering probability models, such as the Moliere model, which have seen refinements and...
Digital Tomosynthesis (DT) is a 3D mode of x-ray imaging. Adaptix Ltd have developed a novel mobile DT device enabled by implementing an array of R-ray emission points and a flat-panel detector. This device gives access to human and animal 3D imaging, as well as to non-destructive material evaluation. DT is not as clinically popular as Computed Tomography (CT) or radiography, and flat-panel...
One of the significant sources of residual losses in superconducting radio-frequency cavities is magnetic flux trapped during the cool-down due to the incomplete Messier effect. If the trapped vortices are non-uniformly distributed on the cavity surface, the temperature mapping revealed the “hot-spots” at the location of high density of pinned vortices. In this contribution, we present the...
A muon collider allows one to have a high energy reach for physics studies while having a relatively compact footprint. Ideally such a machine would accelerate muon beams to about 5 TeV. We present a preliminary lattice design for a pulsed synchrotron that will accelerate muon beams to their maximum collision energy and having a circumference of 16.5 km, which would allow it to fit just within...
In 2023, about 2 months of the LHC operation were devoted to the Heavy Ions physics, after more than 5 years since the last ion run. In this paper, the results of the 2023 Ion optics commissioning are reported. Local corrections in Interaction Point (IP) 1 and 5 were reused from the regular proton commissioning, but the optics measurement showed the need for new local corrections in IP2. We...
SLAC's LCLS-II is rapidly advancing towards MHz repetition rate attosecond X-ray pulses, opening new opportunities to leverage the abundance of data in combination with advances in machine learning (ML) to better align the x-ray source with specific experimental goals. We approach the challenge from both ends of the facility. Starting at the X-ray output, we showcase our low latency, high...
The luminosity of particle colliders depends, among other parameters, on the transverse profiles of the colliding beams. At the LHC at CERN, heavy-tailed transverse beam distributions are often observed, and the luminosity is modeled with the assumption that the x-y planes are independent in each beam. Analytical calculations show that the solution of inverting 1D heavy-tailed beam profiles to...
Compact synchrotrons, such as those proposed for cancer therapy, use short and highly bent dipoles. Large curvature drives non-linear effects in both body and fringe fields, which may be critical to control to obtain the desired dynamic aperture. Similarly to current practice, for straight magnet, our long-term goal is to aim at finding a parametrization of the field map that requires few...
Skeleton cyclotron is a compact size air-cored cyclotron with a high temperature superconducting (HTS) coil system. HTS coils’ high critical current density and high heat stability allow magnetic field induction without using any iron core. With this advantage, the magnetic field configuration can be adjusted quickly without consideration for the hysteresis from iron. The purpose of skeleton...
In the framework of the acceleration techniques, the Plasma Wake Field Acceleration (PWFA) is one of the most promising in terms of high machine compactness. For this purpose, a crucial role is played by the particle beam focusing upward and downward the plasma-beam interaction, performed by high gradient Permanent Magnet Quadrupoles (PMQs). In the framework of the INFN-LNF SPARC_LAB (Sources...
Development of an optical fiber-based beam loss monitor (OBLM) is in progress at the Cockcroft Institute (CI), UK. The novel sensor utilizes the Cherenkov radiation (CR) emitted in optical fibers by relativistic particle showers generated in beam loss or RF breakdown events.
RF breakdowns are a problem for high-power magnetrons, such as those in medical accelerator facilities, as damage to...
SLAC’s LCLS-II-HE upgrade will expand the energy regime of their XFEL at high repetition rates. Due to the low emittance requirement, a superconducting QWR based electron gun was proposed by SLAC and is being developed by FRIB in collaboration with ANL and HZDR. The emittance compensation solenoid consists of two main coils, along with horizontal and vertical dipoles as well as normal and skew...
Ongoing studies at the Spallation Neutron Source (SNS) Beam Test Facility (BTF) seek to understand and model bunch dynamics in a high-power LINAC front-end. The BTF has recently been upgraded with a reconfiguration from a U-shaped line to a Straight line. We report the current state of model benchmarking, with a focus on RMS beam sizes within the FODO line. The beam measurement is obtained...
Nonlinear focusing elements can enhance the stability of particle beams in high-energy colliders through Landau Damping, by means of the tune spread which is introduced. Here we discuss an experiment at Fermilab's Integrable Optics Test Accelerator (IOTA) which investigates the influence of nonlinear focusing elements, such as octupoles, on the beam’s transverse stability. In this experiment,...
SSRF/SXFEL has develop the advanced transverse deflecting structure TTDS (two-mode transverse deflecting structure) to perform variable polarization based on the design of a dual-mode structure. The 15-cell prototype of the TTDS was designed and fabricated at SSRF/SXFEL. The non-resonant perturbation was chosen as the measurement for HEM modes and improved for the two modes in TTDS...
The brightness of the beam in any linear accelerator can be no greater than at its source. Thus characterization of source initial conditions, including spatial and momentum distributions, is then critical to understand brightness evolution in a linac. Often measurement of the initial momentum distribution and closely related quantities such as the mean transverse energy (MTE) is hampered by...
We report updates on design work* and ongoing development of a fluorescence-based molecular gas curtain which will be used to observe the 2D transverse profile of multi-charge state heavy ion beams at the Facility for Rare Isotope Beams (FRIB). The device will produce an ultra-thin, rarefied nitrogen gas sheet and requires that the gas curtain be uniform and thin to prevent distortion of the...
This paper describes the mechanical design of the Future Circular Collider e+e- interaction region. The Future Circular Collider, as a forefront particle accelerator project, demands meticulous attention to the mechanical integrity and performance of its components, to the integration of the different systems and to the respect of the spatial constraint. The vacuum chamber design, the support...
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...
Space charge has been a limiting effect for low energy accelerators inducing emittance growth and tune spread. Tune shift and tune spread parameters are important for avoiding resonances, which limits intensity of the beam. Circular modes are round beams with intrinsic flatness that are generated through strong coupling, where intrinsic flatness can be transformed to real plane flatness...
Linear particle accelerators are elaborate machines that demand a thorough comprehension of their beam physics interactions to enhance performance. Traditionally, physics simulations model the physics interactions inside a machine but they are computationally intensive. A novel solution to the long runtimes of physics simulations is replacing the intensive computations with a machine learning...
GaAs-based photocathodes activated to negative electron affinity (NEA) is the only existing technology that can deliver intense and highly spin-polarized electron beams for the forthcoming Electron-Ion Collider as well as enable spin-polarized scanning tunneling microscopy, ultrafast spin-polarized low-energy electron diffraction, and other cutting-edge experiments. The degree of...
We present the design and initial characterization of a multi-mode cavity, a novel electromagnetic structure with potential benefits such as compactness, efficiency, and cost reduction. The 2nd Harmonic mode was chosen to linearize the fundamental mode for use as an accelerating and bunching cavity. The reduction in the number of cavities required to bunch and accelerate promises cost and...
Requirements for the noise in electron beams (NEB) have recently approached the Shot-noise level in some new applications. The density fluctuations of intense beams in the near-infrared (NIR) region are being measured at the Fermilab Accelerator Science and Technology (FAST) facility. The main goal of the experiment is to accurately compare the Shot-noise model with the observations of optical...
Numerical optimizations on couplers of the traveling wave accelerating structures usually require lots of calculation resources. This paper proposes a new technique for matching couplers to an accelerating structure in a more efficient way. It combines conventional Kroll method with improved Kyhl method, thereby simplifying the tuning and simulation process. We will present the detailed design...
The research is focused on finding new ways to generate high-intensity, monochromatic X and gamma-rays, surpassing the capabilities of existing methods. While Free-Electron Lasers (FEL) have limitations on photon energy, and Inverse Compton Scattering relies on powerful lasers, the search for alternatives continues. TECHNO-CLS, a PATHFINDER project funded by the European Innovation Council, is...
Bulk niobium is currently the standard material for constructing superconducting radio frequency (SRF) cavities for acceleration in particle accelerators. However, bulk niobium is limited, and new materials and surface treatments may allow greater performance to be reached. We present progress on novel materials and treatments for SRF cavity fabrication.
The Shanghai Light Source has been operated since 2009 to provide synchrotron radiation to 40 beamlines of the electron storage ring at a fixed electron energy of 3.5 GeV. The Shanghai Laser Electron Gamma Source (SLEGS) is approved to produce energy-tunable gamma rays in the inverse Compton slant-scattering of 100 W CO2 laser on the 3.5 GeV electrons as well as in the back-scattering. SLEGS...
The beam transverse emittances play a critical role in high-energy colliders. Various measurement techniques are employed to measure them. In particular, the so-called luminosity emittance scans (or Van der Meer scans) are used in order to evaluate the convoluted beam emittances. This method assumes different emittances in the two planes but identical emittances in the two beams. In this...
Low energy electron bunches experience emittance growth due to space charge. This effect can lead to large emittances which are unacceptable for a facility like PERLE at IJCLab. PERLE will be an ERL test facility circulating a high current electron beam. The traditional method to reduce emittance due to this effect is already planned for the PERLE injector, this has a limit of how small the...
The Electron-Ion Collider (EIC) Hadron Storage Ring (HSR) will use strong hadron cooling to maintain the beam brightness and high luminosity during long collision experiments. An Energy Recovery Linac is used to deliver the high-current high-brightness electron beam for cooling. For the best cooling effect, the electron beam requires low emittance, small energy spread, and uniform longitudinal...
ELSA LINCS (ELSA Linac INverse Compton Source) at CEA DAM DIF is an Inverse Compton Scattering X-ray source in the 5-40 keV range, through interaction between 10-30 MeV electrons with a Nd:YAG laser. The source was upgraded to increase the X-ray flux produced in the 5-40 keV range. The new experimental setup and imaging systems have been modified for compatibility with fundamental emission at...
Laser-plasma accelerators (LPAs) can have high acceleration gradients on the order of 100 GeV/m. The high acceleration gradients of LPAs offer the possibility of powering future colliders at the TeV range and reducing the size of particle accelerators at present energy levels. LPAs need tightly focused, high intensity laser pulses and require guiding structures to maintain the laser focus over...
Nanostructures are currently attracting attention as a medium for obtaining ultra-high-density plasmas for beam-driven or laser-driven acceleration. This study investigates Bayesian optimization in Laser Wakefield Acceleration (LWFA) to enhance solid-state plasma parameters towards achieving extremely high gradients on the order of TV/m or beyond, specifically focusing on nanostructured...
The Future Circular electron-positron Collider, FCC-ee, is a design study for a 90 km circumference luminosity-frontier and highest-energy e+e- collider. It foresees four operation modes optimized for producing different particles by colliding high-brightness lepton beams. Operating such a machine presents unique challenges, including stored beam energies up to 17.5 MJ, a value about two...
Ultrafast electron diffraction (UED) is a growing accelerator application that enables the study of transient material processes at sub-picosecond timescales with nanometer spatial resolution. In this proceeding, we present simulations of the Cryogenic Brightness-Optimized Radiofrequency Gun (CYBORG) beamline using the General Particle Tracer (GPT) code that are optimized for the application...
The cathode test stand at LANL is utilized to test velvet emitters over pulse durations of up to 2.5 µs. Diode voltages range from 120 kV to 275 kV and extracted currents exceed 25 A and depend on cathode size and pulse duration. Current density measurements taken with scintillators or Cherenkov emitters produce inconsistent patterns that disagree with the anticipated beam profile. Several...
Ionization cooling is only cooling technique capable of efficiently reducing the phase space of a muon beam within a short timeframe. The ultimate cooling phase of a muon collider aims to minimize transverse emittance while simultaneously curbing longitudinal emittance growth, to achieve optimal luminosities within the collider ring. This study shows that achieving efficient cooling...
At the FACET-II accelerator, a pair of 10 GeV high-current electron beams can be used to study a method called Plasma Wakefield Acceleration (PWFA) in a few-cm short laser-ionized gas jet. While PWFAs allow for astonishingly high accelerating gradients of 10s of GeV/m, matching the electron beam into the plasma wake with micrometer precision to maintain beam quality requires precise tuning of...
For the Recycler Ring at Fermilab, space charge tune shifts of almost 0.1 will have to be dealt with under the Proton Improvement Plan (PIP-II) framework. This will lead to the excitation of third order resonances. The minimization of Resonance Driving Terms (RDTs) allows to mitigate the harmful effect of these betatron resonances. Past work has shown that previously-installed sextupoles can...
This study primarily investigates the parameters and processes involved in depositing Nb thin films on copper cavities under DC and HIPIMS modes. For this purpose, a high-power magnetron sputtering system was designed, conducting a total of 36 experiments. Improvement and optimization of parameters such as duty cycle (under HIPIMS mode), peak current, and bias voltage were undertaken to...
The study investigates the radiation attenuation performance of five ternary glass systems with varying chemical compositions: 50P$_2$O$_5$-(50-x)BaO-xEu$_2$O$_3$, where x = 0, 1, 2, 4, and 6 mol%. It utilizes theoretical and Monte Carlo methods to determine shielding parameters such as attenuation coefficients, mean free path, value layers, electron densities, conductivity and neutron...
Generating beam with nC-level charge is of great significance for particle colliders. In order to achieve lower emittance and length of bunch, based on the photocathode injector, we designed a L-band gun and L-band accelerating tube. However, with many coupled parameters, it is difficult to optimize its performance to the limit when optimizing them separately. Therefore, we employed a...
In this work we demonstrate the generation of a record low root mean square normalized transverse electron emittance of less than 30 pm-rad from a flat metal photocathode – more than an order of magnitude lower than the best the emittance that has been achieved from a flat photocathode. This was achieved by using plasmonic focusing of light to a sub-diffraction regime using plasmonic...
Fermilab is currently engaged in the development of an 800 MeV superconducting RF linac, aiming to replace its existing 400 MeV normal conducting linac. PIP-II is a warm front-end producing 2 mA of 2.1 MeV H-, followed by a sequence of superconducting RF cryomodules leading to 800 MeV. To mitigate potential damage to the superconducting RF cavities, PIP-II uses laser-based monitors for beam...
With very small beam sizes at IP (several tens of nanometers in the vertical direction) and the presence of strong FFS quadrupoles in the CEPC, the luminosity is very sensitive to the mechanical vibrations, requiring excellent control over the two colliding beams to ensure an optimum geometrical overlap between them and thereby maximize the luminosity. Fast luminosity measurements and an IP...
Ultrafast high-energy pulsed electron beams can provide deep penetration and variable linear energy transfers by controlling the characteristics of the electron bunch, both of which currently oversubscribed heavy ion facilities cannot provide. Early experiments at the UCLA PEGASUS beamline (~3 MeV) with ~1 ps electron bunches and a 50 μm spot size yielded charge collection transients that were...
The longitudinal compression of intense proton bunches with strong space-charge force is an essential component of a proton-based muon source for a muon collider. This paper discusses a proton-bunch compression experiment at the Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab to explore optimal radio frequency (RF) cavity and lattice configurations. IOTA is a compact...
For certain photonuclear experiments utilizing Compton gamma-ray beams, beam-uncorrelated background poses a significant challenge. At the High Intensity Gamma-ray Source (HIGS), we have developed methods to generate pulsed free-electron laser (FEL) beams by transversely or longitudinally modulating the storage ring FEL. Both methods enable periods of FEL interaction: one by transversely...
Superlattice GaAs photocathodes play a crucial role as the primary source of polarized electrons in various accelerator facilities, including CEBAF at Jefferson National Laboratory and the Electron Ion Collider (EIC) at Brookhaven National Laboratory. To increase the quantum efficiency (QE) of GaAs/GaAsP superlattice photocathodes, a Distributed Bragg Reflector (DBR) is grown underneath using...
At the CERN Large Hadron Collider (LHC), bent crystals play a crucial role in efficiently redirecting beam halo particles toward secondary collimators used for absorption. This innovative crystal collimation method leverages millimeter-sized crystals to achieve deflection equivalent to a magnetic field of hundreds of Tesla, significantly enhancing the machine’s cleaning performance...
Ultra-low-charge operation of free-electron lasers down to 1 pC or even lower, requires adequate diagnostics for both, the users and the operators. For the electro-optical bunch-arrival time monitor a fundamental design update is necessary to yield single-digit fs precision with such low charges. In 2023 a vacuum sealed demonstrator for a novel pickup structure with integrated combination...
The utilization of laser modulation techniques shows potential in producing sub-femtosecond electron beams within photoinjector electron guns. The precise spatial alignment between the modulated laser and electron beam is crucial for the stable emission of sub-femtosecond electron beams. In practical applications, inevitable lateral positional fluctuations are present in both the modulated...
The design of the electron-positron Future Circular Collider (FCC-ee) challenges the requirements on optics codes (like MAD-X) in terms of accuracy, consistency, and performance. Traditionally, MAD-X uses a transport formalism by expanding the transfer map about the origin up to second order to compute optics functions and synchrotron radiation integrals in the TWISS and EMIT modules....
Pulse compressors have been widely used to generate very high peak RF power in exchange for the reduction in the RF pulse length for linear accelerators. As compared to a traditional SLAC Energy Doubler(SLED), a spherical pulse compressor is more compact while maintaining a high energy gain. A C-band spherical pulse compressor is studied in this paper, which consists of a dual-mode polarized...
Diamond Light Source (DLS) is a 3 GeV synchrotron facility in the UK, which has been a part of the Cherenkov diffraction radiation (ChDR) collaboration since 2017 and is now in its second phase of experiments. The current experiment aims to produce and test a one-dimensional beam position monitor (BPM) that utilizes ChDR at visible and near-infrared (NIR) wavelengths. This paper will cover the...
Muon colliders hold promise for high luminosity multi-TeV collisions, without synchrotron radiation challenges. However, this involves investigation into novel methods of muon production, acceleration, cooling, storage, and detection. Thus, a cooling demonstrator has been proposed to investigate 6D muon ionization cooling. The MICE experiment validated ionization cooling to reduce transverse...
Laser wakefield accelerators (LWFAs) are capable of supporting accelerating and focusing forces on the order of 10–100 GeV/m, about three orders of magnitude greater than conventional RF accelerators. While theoretical solutions for the electromagnetic (EM) focusing fields have been developed, the field structures have yet to be verified experimentally. In this poster, we present simulation...
In the injector section of electron linacs, both internal space charge forces and wakefield effects influence the beam dynamics. So far, existing simulation approaches can not account for both effects simultaneously. To fill this gap, we have developed a computational method to account for both effects self-consistently*. It couples a space charge solver in the rest frame of the bunch with a...
Moving towards beam energies around 2-6 MeV in ultrafast electron diffraction (UED) experiments allows achievement of larger coherence length for better k-space resolution, while the temporal resolution is improved when shorter electron bunches are generated and the velocity mismatch between the optical pump and UED probe is reduced.
At Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a series...
The proof-of-principle (PoP) experiment at the Super Proton Synchrotron (SPS) at CERN aims at demonstrating laser cooling of high energy Li-like Pb79+ in a synchrotron. First laser cooling simulations with realistic laser and beam parameters of the Gamma Factory proof-of-principle experiment (PoP) in the Super Proton Synchrotron (SPS) at CERN are presented. Furthermore, we investigate the...
On-axis injection mode is planned to use in the Southern Advanced Photon Source (SAPS), which requires high quality to injection pulsed power supply. Gyromagnetic nonlinear transmission line (GNLTL) is introduced as a pulse compressor to meet the needs for pulse width. In this paper, 3-D finite element model is established based on Landau-Lifshitz-Gilbert equation and Maxwell’s equations. The...
The Karlsruhe Research Accelerator (KARA) is an electron storage ring and synchrotron light source for accelerator research at the Karlsruhe Institute of Technology (KIT). It features an electro-optical (EO) in-vacuum bunch profile monitor to measure the longitudinal bunch profile in single shot on a turn-by-turn basis using electro-optical spectral decoding (EOSD). A simulation procedure has...
The beam loading effect results in a gradient reduction of the accelerating structures due to the excitation of the fundamental mode when the beam travels through the cavity. A recent implementation of this process in the tracking code RF-Track allows the simulation of realistic scenarios, thus revealing the impact of this phenomenon in start-to-end accelerator designs. In this paper, we...
The CXFEL project at ASU will produce coherent soft x-ray radiation at a university-scale facility. Unlike conventional XFELs, the CXFEL will use an optical undulator in addition to nanobunching the electron beam instead of a static magnetic undulator. This reduces the undulator period from cm-scale to micron scale and lowers the requirements on the electron beam energy. CXFEL’s overtaking...
High quality electron bunch trains enable investigations in scientific frontiers with high resolution and efficiency and are earnestly desired by various accelerator facilities, including inverse Compton scattering (ICS), high energy computed tomography, and free electron lasers. An average beam flux can be greatly increased by using the bunch train mode. A bunch train with an average current...
A cavity-based x-ray free-electron laser (CBXFEL) is a possible future direction in the development of fully coherent hard x-ray sources of high spectral brilliance, a narrow spectral bandwidth of ~1-100 meV, and a high repetition rate of ~1 MHz. A diagnostic tool is required to measure CBXFEL spectra with a meV resolution on the shot-to-shot bases. Here we present test results of a single...
A pair spectrometer, designed to capture single-shot gamma spectra over a range extending from 10 MeV through 10 GeV, is being developed at UCLA for installation at SLAC’s FACET-II facility. Gammas are converted to electrons and positions via pair production in a beryllium target and are then subsequently magnetically analyzed. These charged particles are then recorded in an array of quartz...
Recent studies have revealed an intriguing longitudinal instability that may develop in electron storage rings featuring higher-harmonic cavities. The instability, also referred to as periodic transient beam loading, manifests as a slow oscillation of bunch longitudinal profiles following a coupled-bunch mode-1 pattern. In this contribution, we applied the well-established theory of...
In this study, we present a deep learning-based pipeline for predicting superconducting radio-frequency (SRF) cavity faults in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. We leverage pre-fault RF signals from C100-type cavities and employ deep learning to predict faults in advance of their onset. We train a binary classifier model to distinguish between stable...
During the operation of the Continuous Electron Beam Accelerator Facility (CEBAF), one or more unstable superconducting radio-frequency (SRF) cavities often cause beam loss trips while the unstable cavities themselves do not necessarily trip off. The present RF controls for the legacy cavities report at only 1 Hz, which is too slow to detect fast transient instabilities during these trip...
Iron-dominated superconducting magnets are one of the most popular and used design choices for superconducting magnetic quadrupoles for accelerator systems. While the iron yoke and pole tips are economic and effective in shaping the field, the large amount of iron also leads to certain drawbacks, namely, unwanted harmonics from the sextupole correctors nested inside of quadrupole iron pole...
Beam profile measurements in the LHC injector complex show heavy tails in both transverse planes. From these profile measurements, it is not possible to determine if the underlying 4D phase space distribution is statistically independent. A measurement campaign in the CERN PSB was carried out to introduce cross plane dependence in bunched beams in controlled conditions, in view of...
The space-charge neutralization of an ion beam by created electrons when the beam ionizes the gas is investigated using a three-dimensional electrostatic particle-in-cell code. Different kinds of injected gases are considered, and their space-charge compensation transient times are compared. The created secondary electrons by the beam collision with neutral gas along the beam trajectories are...
In order to further improve the accelerating gradient of accelerators, the cryogenic acceleration structure is stud-ied. Based on material characteristics and technical con-ditions, the basic design is completed. Photonic band-gap (PBG) structures use a lattice of rods to prevent prop-agation of RF field through the lattice at certain frequen-cies while the higher order modes are damped. The...
To achieve very high luminosity, the next generation circular colliders adopt the crab waist collision scheme with a large Piwinski angle. In this scheme, beams collide with high current, low emittances, and small beta functions at the interaction point (IP). However, several effects arising from these extreme parameters, especially the coherent X-Z instability, will significantly impact the...
A new infrared Free-Electron Laser (FEL) facility FELiChEM has been established as an experimental facility at the University of Science and Technology of China.It consists of two free electron laser oscillators which produce mid-infrared and far-infrared lasers covering the spectral range of 2-200 μm at the present stage. Both oscillators are driven by a normal conducting S-band linac and...
Manipulation electron beam phase space technology by laser-electron interaction has been widely used in accelerator-based light sources. The energy of the electron beam can be modulated effectively under resonant conditions by using an intense external laser beam incident into the undulator together with the electron beam.
Enhancing the modulation efficiency is crucial for the performance of...
The Mainz Energy-Recovering Superconducting Accelerator (MESA), an energy-recovering (ER) LINAC, is currently under construction at the Institute for Nuclear physics at the Johannes Gutenberg-Universität Mainz, Germany. In the ER mode continues wave (CW) beam is accelerated from 5 MeV up to 105 MeV. The energy gain of the beam is provided through 2 enhanced ELBE-type cryomodules containing two...
Accelerator-based light source can produce extremely high brightness radiation and has been an indispensable tool in various fields. By exploiting the collective dynamics of electrons in external fields, high-gain free electron lasers can generate radiation with powers several orders of magnitude higher than typical synchrotron radiation. This collective enhancement, could also be realized in...
Our research focuses on the design of a beamline. Due to the numerous beamline components involved, without strict optimization of each component's parameters, the transmitted temporal profile of beam may distort, failing to meet the expected requirements. Additionally, different initial temporal profile of the beam will undergo longitudinal shaping during transmission through the beamline....
Metamaterial accelerators driven by nanosecond-long RF pulses show promise to mitigate RF breakdown. Recent high-power tests at the Argonne Wakefield Accelerator (AWA) with an X-band metamaterial structure have demonstrated to achieve a gradient of 190 MV/m, while we also observed a new acceleration regime, the breakdown-insensitive acceleration regime (BIAR), where the RF breakdown may not...
Recent advancements in electron beam compression methods have enabled the production of ultrashort electron beams at the sub-femtosecond scale, significantly expanding their applications. However, the temporal resolution of these beams is primarily limited by the flight time jitter, especially during their generation in photocathode RF electron guns. This paper explores the dynamics of...
Beam Plasma Interactions Experiment (Beam-PIE) is a NASA sounding rocket experiment that successfully ran in November 2023. Beam-PIE used space as a laboratory to explore wave generation from a modulated electron beam in the ionosphere. Beam-PIE electron accelerator used a 10keV electron gun and a 5-GHz RF cavity, enabling the acceleration of the electron beam to a total energy of ~25–60 keV....
The proton Electric Dipole Moment (pEDM) storage ring to measure the electric dipole moment of the proton [1] is proposed to be built in the tunnel of the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) by storage ring EDM (srEDM) Collaboration. We proposed that the AGS Booster to pEDM ring transfer and injection line (BtP) would use the partial portions of the...
High-brightness photoinjectors generate low emittance, ultrashort electron beams that are capable of tracking dynamical states of matter with atomic-scale spatio-temporal resolutions via ultrafast electron scattering, as well as providing precisely-shaped electron beams for advanced acceleration research and large-scale facilities such as free-electron laser and inverse Compton scattering. In...
SLEGS is a Laser Compton Scattering gamma source. The gamma energy is 0.66 to 21.7 MeV, and the gamma flux is approximately 4.8e+5 to 1.5e+7 phs/s. Gamma activation method is used in beam flux monitor, medical isotpoe production and nuclear astrophysics in SLEGS*. Gamma beam flux under different collimated apertures has been checked by gamma activation method by using various half-life nuclide...
The thermal emission of photoelectric cathodes significantly influences the emittance of electron beams. Employing cesium telluride as the cathode material, the hard X-ray free-electron laser device utilizes thermal evaporation deposition for fabrication. The typical thermal emission value for cesium telluride cathode materials is ~0.7 mm-mrad/mm. Poor processes and formulations lead to...
Laser-field emission is a process that can produce electron beams with high charge density and high brightness with ultrafast response times. Using an extended nanostructure, such as a nanoblade, permits plasmonic field enhancement up to 80 V/nm with an incident ultrafast laser wavelength of 800 nm. Stronger ionizing fields lead to higher current densities, so understanding how this field is...
The precision of the proton therapy beam depends on maintaining high field quality in the magnet’s good field region. Iron yoke is employed in magnets to increase the magnetic field and reduce the fringe field. However, when providing a high magnetic field for transporting relatively high-energy particles, the saturation effect of the yoke can distort the field quality. To mitigate this...
Worldwide Isotope Separation On-Line (ISOL) facilities face growing demand for producing and extracting high-purity exotic radioactive ion beams to serve nuclear physics, astrophysics and medical applications. In this technique, a particle beam interacts with a suitable target material to produce the desired isotopes through a combination of mechanisms like spallation, fragmentation and...
The performance and scientific reach of advanced electron accelerator applications, such as particle colliders, x-ray free electron lasers, and ultrafast electron diffraction, are determined by beam brightness. The beam brightness is constrained by the quality of photocathodes and is associated with low Mean Transverse Energy (MTE) of photoemitted electrons. To meet the requirements for...
The Continuous Electron Beam Accelerator Facility (CEBAF) operates hundreds of superconducting radio frequency (SRF) cavities in its two linear accelerators (linacs). Field emission (FE) is an ongoing operational challenge in higher gradient SRF cavities. FE generates high levels of neutron and gamma radiation leading to damaged accelerator hardware and a radiation hazard environment. During...
Laser-driven ion accelerators (LDIAs) are well-suited for radiobiological research on ultra-high dose rate effects due to their high intensity. For this application, a transport system is required to deliver the desired beam intensity and dose distribution while online dosimetry is required due to the inherent shot-to-shot variability of LDIAs. At the BELLA Center's iP2 beamline, we...
This study focuses on the beam source for the LCLS-II-HE Low Emittance Injector (LEI) design: a state-of-the-art superconducting radiofrequency (SRF) gun. The LEI is intended to enable extending the LCLS-II-HE’s useful photon energy to 20 keV without additional cryomodules. We consider a robust two-slit emittance measurement optimized for the LEI SRF gun, compatible with the current LEI...
The spontaneous emission of radiation from relativistic electrons within a plasma channel is called betatron radiation and has great potential to become a compact x-ray source in the future. We present an analysis of the performance of a broad secondary radiation source based on a high-gradient laser-plasma wakefield electron accelerator. The purpose of this study is to assess the possibility...
The strength of a first-order spin-orbit resonance is defined as the amplitude of the corresponding Fourier component of the spin-precession vector. However, it is possible to obtain the resonance strength without computing the Fourier integral directly. If a resonance is sufficiently strong, then to a good approximation, one can neglect all other depolarizing effects when near the resonance....
A superconducting radio frequency (SRF) cryomodule (CM) for the International Linear Collider (ILC) Technology Network (ITN) is being developed at KEK. In the scope of this, a waveguide system is being designed. Its main features are a low center of gravity, a reduced number of corners and waveguide elements, and a compact bellow for connecting it to the input power coupler. Furthermore, the...
