Microbunching - or short-wavelength – instabilities are well-known for drastic reduction of the beam quality, its filamentation and strong amplification of the noise in a beam. Space charge and coherent synchrotron radiation (CSR) are the leading causes for such instability. In this paper we present rigorous 3D theory of such instabilities driven by the space-charge forces. We define the...
Muon is a unique particle. The muon is the elementary particle same as the electron, but the mass is much heavier than the electron. The muon collider can reach much higher energy than the electron-positron circular collider. Muon is useful for imaging. Recently, the anomalous magnetic moment of Muon is one of the hottest topics. In this article, a compact electron linac for muon production...
In this contribution, we investigate electrostatic traps as a novel source of positron beams for accelerator physics applications. Penning-Malmberg (PM) traps are commonly employed in low-energy antimatter experiments. Positrons contained in the trap are cooled to room temperature or below. We calculate the thermal emittance of the positrons in the trap and show that it is comparable to or...
X-rays in the water window (2.33 nm to 4.40 nm wavelength) can be used to provide high quality images of wet biological samples. Given the limited availability of current generation light sources in this energy range, table-top water window X-ray sources have been proposed as alternatives. We present start-to-end simulations in RF-Track of a water window X-ray source based on inverse Compton...
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...
C-band technology holds the potential to generate a high-energy, high-brightness electron beam by elevating the peak field of both the cathode and cavity within the machine. This proposed injector offers a promising avenue for achieving a high repetition rate, facilitating kHz operation. The conceptualization of this injector draws inspiration from the EuPRAXIA@SPARC_LAB S-band injector,...
The Future Circular Collider (FCC) study includes two accelerators, a high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh). Both machines share the same tunnel infrastructure. We present the current design status of FCC-hh, highlighting the most recent changes, including a new layout following updated tunnel dimensions, a change from 12 to 16 dipoles per cell...
The mitigation of collective beam effects, in particular Coherent Synchrotron Radiation (CSR), is crucial for the development of particle accelerators with higher beam brightness. Among the strategies proposed in the literature, the use of appropriate shielding walls to curb CSR is an attractive strategy with many associated open problems. In particular, simulation methods that account for...
THz (1e+12 Hz) radiation is very attractive for its non-ionizing penetrative nature and unique absorption in water, metals, and other chemicals. While THz has great potential for imaging and for diagnosing chemical traces, it has not been utilized extensively due to scarcity of high-power THz sources. Currently, compact THz sources deliver power in the range of 50 μW — 0.5 W, insufficient for...
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...
A particle accelerator is a time-varying complex system whose various components are regularly perturbed by external disturbances. The tuning of the accelerator can be a time-consuming process involving manual adjustment of multiple components, such as RF cavities, to minimize beam loss due to time-varying drifts. The high dimensionality of the system (~100 amplitude and phase RF settings in...
Owing to strong 10-100 GV/m accelerator gradients, Laser Plasma Accelerators (LPAs) have the capability to generate high-brightness and high-energy electron beams in compact facilities. The (sub)PW laser systems that drive LPAs are currently operating at 1-10 Hz repetition rates, while the next generation of multi-kHz technologies are being aggressively pursued at various R&D facilities...
A new, rapidly converging cavity optimization tool is presented that uses adjoint methods. The tool is able to work with any cavity solver that can output and input the results of cut-cell meshing of a cavity. Because it is an adjoint method, one needs only a single forward solve for each iteration in the process of convergence. One also needs a backward solve for each optimization target or...
Dielectric laser acceleration (DLA) is a promising approach to accelerator single electrons at a high repetition rate to GeV energies, for indirect dark matter searches. Relevant concepts include the integration of the dielectric structure inside the laser oscillator, deflecting DLAs combined with a segmented detector, high-rate source of single electrons, DLA structure alignment, and...
The Electron-Ion Collider (EIC) will use swap-out injection scheme for the Electron Storage Ring (ESR) to overcome limitations in polarization lifetime. However, the pursuit of highest luminosity with the required 28 nC electron bunches encounters stability challenges in the Rapid Cycling Synchrotron (RCS). Consequently, multiple RCS bunches will be accumulated in the ESR.
A pivotal aspect...
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...
A new growth chamber at the High ElectRon Average Current for Lifetime ExperimentS (HERACLES) beamline at Cornell has been installed enabling Negative Electron Affinity (NEA) activations of GaAs using Cs-Sb-O and Cs-Te-O recipes. These activation recipes have been shown to be more robust against vacuum poisoning when measured at low voltages and currents. In this proceeding we present charge...
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...
A beam physics design has been carried out for a 200 MeV-LWFA injector to the AWAKE Run 2 experiment as an alternative to the reference RF injector. It is composed of a laser-plasma acceleration stage and a transport line. In addition to specific environment constraints that impose a dogleg configuration, the electron beam must feature unprecedented performances for a plasma-based accelerator:...
Multipacting is a phenomenon arising from the emission and subsequent multiplication of charged particles in accelerating radiofrequency (RF) cavities, which can limit the achievable RF power. Predicting field levels at which multipacting occurs is crucial for optimizing cavity geometries. This paper presents a new open-source Python code for analyzing multipacting in 2D axisymmetric cavity...
The development of a robust spin-polarized electron source capable of sustaining mA scale average beam currents in a photoinjector is critical for many future accelerator facilities such as the International Linear Collider (ILC). In this proceeding we overview the several efforts being carried out at Cornell towards this end, including: high current (>1 mA) gun tests of robust activation...
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...
The Electron-Ion Collider (EIC) requires continuous replacement of the stored electron bunches to facilitate arbitrary spin patterns in the Electron Storage Ring (ESR). This is accomplished by a dedicated, spin transparent Rapid Cycling Synchrotron (RCS). The dynamic range of the accelerator is from 400 MeV to 18 GeV. To maintain stability throughout the acceleration ramp, the linear and...
The Electron-Ion Collider (EIC) plans to utilize the local crabbing crossing scheme. This paper explores the feasibility of adopting a single crab cavity with adjusted voltage, inspired by the successful global crabbing scheme in KEKB, to restore effective head-on collisions. Using weak-strong simulations, the study assesses the potential of this global crabbing scheme for the EIC while...
Attosecond X-ray free-electron lasers can deliver isolated sub-fs pulses with a peak power that surpasses conventional table-top sources by more than six orders of magnitude in the soft X-ray region [1]. The intensity at the focus is sufficient for non-linear X-ray spectroscopy methods, and two-color configurations enable applications such as attosecond pump/attosecond probe experiments.
I...
The complexity of the GSI/FAIR accelerator facility demands a high level of automation in order to maximize time for physics experiments. Accelerator laboratories world-wide are exploring a large variety of techniques to achieve this, from classical optimization to reinforcement learning. This paper reports on the first results of using Geoff at GSI for automatic optimization of various beam...
In this work, we investigate the transverse dynamics of a single particle in a model integrable accelerator lattice, based on a McMillan axially symmetric electron lens. Although the McMillan e-lens has been considered as a device potentially capable of mitigating collective space charge forces, some of its fundamental properties have not been described yet. The main goal of our work is to...
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...
The high-luminosity, 10e+33 — 10e+34 cm-2s-1 (e-p), Electron-Ion Collider is presently being developed at Brookhaven National Laboratory in partnership with the Jefferson Laboratory. Beam commissioning is planned right after the installation is complete and after passing all necessary reviews, including the Accelerator Readiness Reviews. Initially, the detector performance testing and...
Beam diagnostic technology is one of the foundations of large particle accelerator facilities. A challenge with operating these systems is the measurement of beam dynamics. Many methods such as beam position monitors have an inherent destructive quality to the beam and produce perturbations after the measurement. The ability to measure the beam conditions with non-destructive edge radiation...
The LCLS-II is a high repetition rate upgrade to the Linac Coherent Light Source (LCLS) and will offer photon science users an unprecedented million pulses per second. However, the accelerating gradient on the cathode of the Very-High-Frequency photoinjector is relatively lower compared to traditional electron guns, the longitudinal beam dynamics become more complicated as required to achieve...
The paper introduces the design and optimization of a high-repetition-rate infrared terahertz free-electron laser (IR-THz FEL) device, which leverages optical resonator-based FEL technology to achieve a higher mean power output through increased pulse frequency. This IR-THz FEL is designed around a photocathode RF gun and is further accelerated by a superconducting RF accelerator. The research...
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...
One of the challenges in designing the Electron-Ion Collider (EIC) is mitigating beam-induced heating caused by the intense electron and hadron beams. Heating of the ESR vacuum chamber components is primarily due to beam-induced resistive wall (RW) losses and synchrotron radiation. For the HSR, heating results mainly from large radial offsets and heat conduction from room temperature to...
Charge-exchange injection is a key to overcome the Liouville's theorem and to get over the intensity barrier. Specifically negative hydrogen linac injector for a ring is mostly used to obtain high intensity pulsed proton beam for high-energy physics or neutron application. However, different from proton linac, beam loss due to stripping can be a significant issue. For instance, the intra-beam...
The CERN Linear Electron Accelerator for Research (CLEAR) has been operating since 2017 as a user facility providing beams for a large variety of experiments. Its photocathode-based linear accelerator can accelerate electrons up to 220 MeV with a bunch charge of 0.1-1.5 nC, from single bunches up to 150 bunches per train. Its wide range of applications require different beam parameters,...
The MITHRA facility being commissioned at UCLA, will be capable of producing low emittance beams with 100s pC of charge with bunch lengths in the 100s of fs range having an energy of 60 MeV. This can be used to drive plasma wakefields and the long bunch length compared to the plasma skin depth allows us to create a beam with a broadband energy spectrum. The energy spectrum resembles the...
Beam-based alignment (BBA) studies are done for the FCC-ee baseline lattice, using two parallel BBA methods. The results will be presented.
Recently exact Hamiltonian integrators have been added for drift, multipoles and dipoles in Accelerator Toolbox. This paper reports the tracking simulations benchmarks performed to compare with the results provided by MADX-PTC for four lattices: FODO, DBA, H7BA and FCC-HFD@Z. Tracking times are also reported for completeness. The agreement in 4D is complete while small discrepancies persist...
The bunch-to-bunch energy control of the electron beam is crucial in the continuous wave XFEL facility. Recently, a delay system based on Double Bend Achromat (DBA) was proposed for the SHINE linear accelerator to achieve this goal. On this basis, we further optimize this structure to realize the bunch compression/decompression while maintaining the electron beam qualities. Here, we will...
One of the main methods to generate X-rays is to bombard metal targets with electron beams. However, this process introduces uncertainty in the electron transport, which leads to uncertainty in the position and momentum of the secondary X-rays. As a result, the focal spot of the X-rays is larger than the electron beam. In this paper, we use the Monte Carlo software Geant4 to investigate the...
The initial design of the capture cavities for a continuous wave (CW) polarized positron beam for the Continuous Electron Beam Accelerator Facility (CEBAF) upgrade at Jefferson Lab is presented. A chain of standing wave multi-cell copper cavities inside a solenoid tunnel are selected to bunch/capture positrons in CW mode. The capture efficiency is studied with varying cavity gradients and...
In a high-energy circular electron-positron collider like the Future Circular Collider (FCC-ee) at CERN, synchrotron radiation (SR) presents a significant challenge due to the radiation load on collider magnets and equipment in the tunnel like cables, optical fibers, and electronics. The efficiency of the anticipated photon absorbers in the vacuum chambers depends on the operational beam...
Near-adiabatic capture into an RF bucket with rising voltage has been used since 1946 or earlier. But until the present work, there is no analytic and deterministic description of the process capable of predicting the final phase space distribution (for arbitrary voltage ramps). Recently, we have developed formulae for trajectories that cross the instantaneous separatrix, and the corresponding...
A single-pass THz free-electron laser (FEL) at the Photo Injector Test facility at DESY in Zeuthen (PITZ) was designed and implemented for a proof-of-principle experiment on a tunable high-power THz source for pump-probe experiments at the European XFEL. THz pulses are generated at a radiation wavelength of 100 μm within a 3.5 m long, strongly focusing planar LCLS-I undulator. High gain is...
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...
An ultrafast laser system for driving the photocathode RF gun at the European XFEL has been recently put into operation. The new laser system, NExt generation PhotocAthode Laser (NEPAL) is capable of providing drive laser pulses of variable pulse lengths and shapes, supporting the facility to extend its capabilities to operate in multiple user-desirable FEL modes. In this paper, we present a...
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 general theory of symplectic tracking under the influence of space charge force is not yet available, even if some specific solution was proposed [1, 2]. In this paper we will first review how the pull-back of the Lie transform can be used to self-transport the beam distribution and its associated electromagnetic potential under the effect of the space-charge. We will then classify the...
X-ray free-electron lasers (XFELs) have emerged as a promising counterpart to high harmonic generation sources for scientific applications requiring high power attosecond X-ray pulses. To date, attosecond XFELs have specialized in producing isolated pulses enabling the study of nonlinear ultrafast science in the impulse regime. We present a method to coherently shape the spectrotemporal...
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...
The program to upgrade CEBAF cryomodules has been implemented to enhance the energy gain of refurbished cryomodules up to 75 MeV. This strategy involves reusing the waveguide end-groups from original CEBAF cavities produced in the 1990s, and existing five elliptical cell cavities are replaced with a new optimized cell shape cavity constructed from large-grain, ingot Nb material. Following...
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...
We discuss a compact, laser-plasma-based scheme for the generation of positron beams suitable to be implemented in an all-optical setup. A laser-plasma-accelerated electron beam hits a solid target producing electron-positron pairs via bremsstrahlung. The back of the target serves as a plasma mirror to in-couple a laser pulse into a plasma stage located right after the mirror where the laser...
Ion beams from laser-driven plasma sources can provide ultra-short (10s of fs for 10s of MeV), ultra-low slice emittance (10s of nm), and high-charge (100s of pC) properties. Demonstrated maximum energies for laser-ion sources are just short of those needed for pivotal applications, such as proton tumor therapy. Here, a robust and energy-scalable concept is presented that could boost the...
The question of the mitigation of the Transverse Mode Coupling Instability (TMCI) by space charge has been discussed for more than two decades. Since few years, it has become clear that the ABS model, which has been often used in the past and which assumes an air-bag bunch in a square well, is not sufficient to properly describe the complexity of the interaction between impedance and space...
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...
HZB is currently designing the lattice for BESSY III, the successor of the 1.7 GeV electron storage ring running in Berlin since 1998. HZB follows a deterministic lattice design strategy, where the natural substructures of a non-hybrid MBA lattice are optimized separately. The substructures consist of only a few parameters, that can be derived from the strategic goals of the project. In the...
The linac-based single-pass FEL has been successfully operated
in the EUV and x-ray regions for about two decades. However, the oscillator FEL has been limited to operating in the longer wavelength region. This limitation arises from the challenge of obtaining short-wavelength FEL mirrors with high reflectivity, thermal stability, and radiation resistance. With the Duke storage ring FEL, we...
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...
The conceptual design of the laser-plasma-based soft X-ray Free Electron Laser at ELI-Beamlines involves the integration of a novel high-power, high-repetition-rate laser, plasma source, compact LPA-based electron beam accelerator, dedicated electron beam line with relevant diagnostics, undulator beam line, photon beam line with required diagnostics, as well as a photon beam distribution...
The ELBE radiation source at HZDR has a long success story of delivering bright and powerful infrared and THz beams to a broad user community. Following the science driven user requests we have written a conceptual design report for the Dresden Advanced Light Infrastructure (DALI) as a successor to ELBE.
The proposed DALI facility aims to increase the spectral brightness and pulse energy by...
Superconductors, multiferroic materials, and giant magnetoresistance are the key to the information, energy, and optoelectronic industries. In the terahertz band, their common characteristics are related to the terahertz complex optical constant, and they also strongly interact with ultrafast terahertz waves, resulting in many fascinating physical phenomena. This paper will introduce an...
The muon collider has great potential to facilitate multi-TeV lepton-antilepton collisions. Reaching a suitably high luminosity requires low-emittance high-intensity muon beams. Ionization cooling is the technique proposed to reduce the emittance of muon beams. The Muon Ionization Cooling Experiment (MICE) has demonstrated transverse emittance reduction through ionization cooling by passing...
The Electron Ion Collider design strategy for reaching unprecedented luminosities and detection capabilities involves collision of flat bunches at a relatively large crossing angle. The collision geometry is further complicated by a tilt of the Electron Storage Ring plane with respect to that of the Hadron Storage ring. In addition, the interaction point is placed inside the field of a...
The Relativistic Heavy Ion Collider (RHIC) was designed for head-on collisions in the Interaction Regions. However, RHIC operation in recent years necessitated crossing angles to limit collisions to a narrow longitudinal vertex region, which created operating conditions with a large Piwinski angle (LPA). The angles were implemented by adjusting the shunt currents of four dipoles, the D0 and DX...
Increasing accelerating gradients in normal conducting cavities is a major focus in the development of future lepton linacs in applications like light sources and medical devices. To this end, improved understanding of material and surface physics of cavities is of paramount importance especially in the context of reducing breakdown rates. We are here interesting in considering the use of CuAg...
An upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (JLAB) to extend its energy reach from 12 GeV to 22 GeV is being explored. The upgrade pushes the boundaries of the current CEBAF facilities and will require several state-of-the-art beamline components. The first of which is nonscaling Fixed Field Alternating (FFA)...
Phase space reconstruction using Neural-Networks and differentiable simulation* is a robust beam diagnostic method to obtain complete 4D phase space including the coupling terms such as (x-y’) and (y-x’). In the first experimental demonstration, it was verified that the RMS beam envelope and normalized emittance from the reconstructed phase space are quantitatively similar to those from the...
This poster will discuss the design of the photocathode vacuum suitcase that we currently design and construct for the Cathodes And Radiofrequency Interactions in Extremes (CARIE) test stand. The CARIE test stand is built to test behavior of the high quantum efficiency photocathodes at strong fields. The semiconductor photocathodes must be grown and delivered to the photoinjector under...
Linear accelerators with multiple ray sources are widely used in detection imaging technology. An S-band multi-point light source standing wave Linac is designed and developed in this paper. The tube consists of 7 parallel-arranged acceleration cavity units, and adopts a power source to output 7 X-ray beams alternating from different positions. The accelerating tube operates at S-band 2998...
Structured plasma channels are an essential technology for driving high-gradient, plasma-based acceleration and control of electron and positron beams for advanced concepts accelerators. Laser and gas technologies can permit the generation of long plasma columns known as hydrodynamic, optically-field-ionized (HOFI) channels, which feature low on-axis densities and steep walls. By carefully...
An energy-recovery-linac (ERL)-based X-ray free-electron laser (FEL) is proposed considering its three main advantages: i) shortening the linac by recirculating the electron beam by high-gradient SRF cavities, ii) saving the klystron power and reducing the beam dump power through the energy recovery in the SRFs, iii) producing a high average photon brightness with high average beam current....
Laser Wakefield Acceleration (LWFA) can generate a high-energetic electron beam in a short accelerating distance of several cm, which is advantageous for the development of an compact accelerator. The LWFA using metal targets is highly influenced by the field ionization process of metal atoms (or ions) due to the high intensity of main laser. Titanium produces a large amount of ionized...
Shanghai HIgh repetitioN rate XFEL and Extreme light facility (SHINE) is an x-ray FEL facility, consisting of an 8 GeV CW superconducting linac and 3 FEL undulator lines, covering the spectral ranges 0.4-25 keV. Photoinjector using VHF gun is one of the key part of the facility. The installation of the electron gun section of the SHINE injector has been completed in August 2023. RF...
The bunching system of injector Linac in High Energy Photon Source (HEPS) includes two sub-harmonic bunchers, a prebuncher and a traveling wave S band buncher. In this paper, the design and test of the traveling wave buncher are presented The buncher is a 6-cell constant impedance traveling wave structure operating in 2π/3 mode at 2998.8 MHz. The phase velocity is 0.75 times the velocity of...
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...
Distributed-coupling structures has been proposed as an advanced type of high-gradient accelerators, RF power flow independently into each cavity.This method has few advantages such as high shunt impedance, superior power efficiency, and low costs. And the most distributed-coupling structures typically set 0° or 180° as the phase advance which can simplify the design.In this study we...
The Electron-Ion Collider (EIC) at Brookhaven National Laboratory will feature a 3.8-kilometer electron storage ring (ESR) that will circulate polarized beams with energies ranging from 5 to 18 GeV for collision with hadrons from a separate ring at luminosities up to 10^34 cm^{-2} s^{-1}. This contribution focuses on several recent changes to the lattice design of the ESR. Super-bend dipole...
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...
Space charge lenses are ion-optical devices that focus an ion beam by the intrinsic electric field of confined non-neutral plasmas, for example electron clouds. This was first proposed by Dennis Gabor in the year 1947 and is therefore also known as Gabor-lenses. Previous studies have shown the strong linear focusing forces of a confined electron plasma. In this paper, the first confinement of...
Scaling the RF-accelerator concept to terahertz (THz) frequencies possesses several compelling advantages, including compactness, intrinsic timing between the photoemission and driving field sources, and high field gradients associated with the short THz wavelength and high breakdown threshold promises vastly smaller and cost-efficient accelerators. These benefits, however, come at the cost of...
A single wide-momentum-acceptance FFA beam line allows for recirculating a beam several times through a linac. Such a scheme provides an efficient path towards high-energy, high-power continuous beams. This paper describes the development of a conceptual design of an FFA RLA focusing on but not limited to a high-power hadron beam case. We present a complete optics design including arc, linac,...
Many of ion beams generated by the Electron Cyclotron Resonance Ion Source (ECRIS) originate from solid-state materials and undergo a conversion process to transition from a solid to a gaseous state before being introduced into the plasma. Established techniques for thermal evaporation encompass ovens and others. The primary objective is to advance oven technology targeting increased...
A liquid lithium target system is being developed for laser ion sources. Existing laser ion sources are operated at the repetition rate of the order of 1 Hz. The limitation stems from the use of solid laser targets because of the craters created and the need to provide a fresh surface by either repositioning the laser beam or the target. In addition, an enormously large surface area is needed...
Research on heavy ion linac was began more than ten years ago to improve the HIRFL operation. In China, the first continuous wave (CW) heavy ion linac, SSC Linac, working at 53.667 MHz was designed and constructed as the SSC injector. The ion particle can be accelerated to 1.48 MeV/u with the designed A/q=5.17. At present stage, this CW linac has been put into operation and the Uranium has...
Intra-beam Scattering (IBS) is one of the main mechanisms of emittance blowup and performance deterioration in the Large Hadron Collider (LHC) accelerator complex. It is particularly relevant since the recent upgrades across the injector complex to reach the high brightness beams of the High Luminosity LHC (HL-LHC) era have been implemented. Several studies have focused on developing an...
The X-ray Laser Oscillator (XLO) uses LCLS pulses to pump population inversion in solid copper and lase on the K alpha line, producing fully coherent, transform limit X-ray pulses, opening new avenues for experiments in fields such as inelastic X-ray scattering, parametric down-conversion, quantum science, X-ray interferometry, and coherent imaging. An important component of XLO is a bow-tie...
Terahertz radiation sources have significant applications in non-invasive detection fields, including medical imaging, drug design, and the quantification of specific biochemical substances. Currently, accelerator-based terahertz sources play a crucial role in producing high-power terahertz radiation. To achieve high-power Terahertz output, beam manipulation is necessary. This paper presents...
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....
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...
Electron storage rings in synchrotron light sources are typically composed of 𝑁 identical sectors that repeat over the ring. Transverse plane betatron frequencies are not an integer harmonic of the beam revolution frequency to avoid that accelerator imperfection effects are turn-by-turn amplified causing beam losses. Consequently, orbit variations induced by ring parameters not affecting beam...
Since the start of the Large Hadron Collider (LHC), dust-induced beam loss events resulted in more than hundred premature beam aborts and more than ten dipole quenches during proton physics operation. The events are presumably caused by micrometer-sized dust grains, which are attracted by the proton beams and consequently give rise to beam losses due to inelastic proton-nucleus collisions....
Design of the electron-ion collider (EIC) at Brookhaven National Laboratory continues to be developed. Particularly, the collider storage ring lattices have been optimized. Dynamic aperture of the evolving lattices must be kept sufficiently large, as required. In this paper, we discuss the collider Electron Storage Ring, where the lattice updates include various modifications of the...
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 E-320 collaboration is colliding an electron beam generated at FACET-II with a 10 TW laser pulse [1,2]. In the rest frame of the electron beam, the laser field intensity is comparable to the Schwinger limit, allowing for the study of Strong-Field QED (SFQED). In this regime, quantum corrections to classical synchrotron radiation become important and the probability for electron positron...
Cavity-based XFEL, or CBXFEL, is a future photon source concept under intense development at SLAC. It is considered a path towards full 3D coherence at angstrom wavelength, delivering another 2-3 orders of magnitude leap in source brightness compared to current XFELs configurations. In a first phase of the project, one of the goals is to demonstrate the regenerative amplification by returning...
The EIC electron storage ring has very tight tolerances for the amplitude of electron beam position and size oscillations at the interaction point. The oscillations at the proton betatron frequency and its harmonics are the most dangerous because they could lead to unacceptable proton emittance growth from the oscillating beam-beam kick from the electrons. To estimate the amplitude of these...
ALBA, the Spanish third generation synchrotron light source, is studying the future construction in the same location of a fourth generation light source called ALBA-II. Since the construction of ALBA in 2008, its critical slab has moved significantly, changing with it the accelerator elements positions. In this study, the effects on closed orbit and beam optics errors are simulated from data...
The front end of the 800-MeV proton linac at the Los Alamos Neutron Science Center (LANSCE) is still based on Cockcroft-Walton voltage generators that bring proton and H- beams of various flavors to 750 keV. We have developed 3D CST models of the LANSCE front-end elements including low-frequency and main bunchers. The fields in these elements are calculated with MicroWave and ElectroMagnetic...
In present paper, the coupled effect of spatio-temporal variation of the laser pulse propagating inside magnetoplasma on electron acceleration have been investigated theoretically. The variation in the dielectric properties under the combined effect of relativistic and ponderomotive non-linearity have been taken into account. Two coupled second order non-linear differential equations...
We experimentally and numerically demonstrate that electron beam energy spread produced by laser heating can be used for shaping electron beam current profile. In particular, we introduce this method for generating attosecond pulse duration X-ray free electron laser. Electron beam scattering material (slotted foil) is additionally used for final selection of the effective current profile. This...
High current electron bunches with lower emittance and slice energy spread are required to generate the intense XFEL. However, it is difficult to maintain the emittance and slice energy spread during the bunch compression at magnetic bunch compressors (BC). The higher current peaks in the head and tail of compressed bunches spoil the core slices by the wakefield and coherent synchrotron...
Laser wakefield accelerators (LWFAs) have been experimentally shown to produce sustained gradients of tens of GeV/m over tens of centimeters. While the strength of these fields has been demonstrated, a direct measurement of the field configurations inside an LWFA represents an emerging research topic. Here, we report on the results of transverse probing of the fields inside an LWFA at...
The FERMI free-electron laser makes use of electron bunches in the 50 fs to 1 ps range. After the FEL process, the spent electron bunches are sent through a thin metallic foil placed in the main beam dump, where coherent transition radiation with THz frequencies is generated and transported to the TeraFERMI beamline. Intensity and spectral properties of those THz pulses strongly depends upon...
GaAs-based photocathodes can provide electron beams with high spin-polarization. In order to be used in a photo-gun for high-current applications such as energy-recovery linacs and colliders, the quantum efficiency as well as the lifetime of the photocathode needs to be as high as possible. Both parameters depend on the quality of the thin layer that is applied to the photocathode surface...
Brookhaven National Laboratory is presently implementing dedicated accelerator research space to support development of accelerator technology for industrial, security, and medical applications. The need for such research capacity was identified through interactions with non-DOE organizations needing support in the development of accelerator technology as part of outreach events supported by...
RadiaBeam is building an Inverse Compton Scattering (ICS) source with a complex Interaction Region to increase interaction efficiency. By colliding an infrared laser head-on with a tunable 60-100 MeV electron beam, up to 200 KeV photons are produced. This is done with a setup consisting of the final focus and re-capture system, an interaction chamber, an infrared (IR) laser beam delivery...
The utilization of machine learning techniques in accelerator research has yielded remarkable advancements in optimization strategies. This paper presents a pioneering study employing a machine learning algorithm, GPTune, to optimize beam intensity by adjusting parameters within the EBIS injection and extraction beam lines. Demonstrating significant enhancements, our research showcases a...
The Super Proton Synchrotron at CERN serves the fixed-target experiments of the North Area, providing protons and ions via slow extraction, and employs the crystal shadowing technique to significantly minimize losses. Over the past three operational years, the use of a crystal, positioned upstream of the electrostatic septum to shadow its blade, has allowed to achieve a 25% reduction in...
Accelerator-driven high brilliance neutron sources are an attractive alternative to the classical neutron sources of fission reactors and spallation sources to provide scientists with neutrons. A new class of such neutron facilities has been established referred to as High-Current Accelerator-driven Neutron Sources (HiCANS). The basic features of HiCANS are a medium-energy proton accelerator...
We report on a week-long study of a conceptual design of EUV FEL light source based on an energy recovery linac with on-orbit laser plasma accelerator injection scheme. We carried out this study during USPAS Summer 2023 session of Unifying Physics of Accelerators, Lasers and Plasma applying the art of inventiveness TRIZ. An ultrashort Ti-sapphire laser accelerates electron beams from a gas...
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 Large Hadron Collider (LHC) employs special optics and configurations, alongside low-beta* collision optics, to address specific experimental requirements. These include calibrating luminosity monitors (vdM) and facilitating forward physics measurements in TOTEM and ALFA experiments (high-beta). The special optics have been in use since Run 1, and for Run 3, they have been updated for...
The present ion physics program in the CERN accelerator complex is mainly based on lead (Pb82+) ion beams. Lighter ions have been considered both by the ALICE3 detector upgrade proposal at the Large Hadron Collider (LHC) --- as a potential way to achieve higher integrated nucleon-nucleon luminosity compared to the present Pb beams --- and also by the Super Proton Synchrotron (SPS) fixed-target...
The physical realization of integrable Hamiltonian dynamics provides promising avenues for investigations of new particle accelerators, best demonstrated by the Integrable Optics Test Accelerator (IOTA) at Fermilab. The core concept of IOTA centers around the results of the Danilov-Nagaitsev paper, where taking the paraxial approximation of the Hamiltonian for a charged particle can lead to a...
Echo-enabled harmonic generation (EEHG), a free-electron laser (FEL) scheme relying on two modulating sections, each consisting of an optical seed laser, an undulator and a magnetic chicane, has recently been implemented on the FEL-1 radiator line at the FERMI FEL user facility in Trieste, Italy. This setup imprints a density modulation onto a relativistic electron beam at a high harmonic of...
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...
In non-linear optics, achieving integrability can enhance the dynamic aperture in storage rings. We analyze turn-by-turn phase-space data from our Danilov-Nagaitsev lattice implementation at Fermilab's Integrable Optics Test Accelerator using machine learning. AI Poincare estimates conserved quantities from experimental data without prior knowledge of the invariant structure, showing...
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...
Transverse resonance island buckets (TRIBs) near a third-order resonance are observed at the Cornell Electron Storage Ring with a newly-designed lattice. Hamiltonian perturbation theory and map-based PTC method have been successfully implemented to design the TRIBs lattice and find the fixed points near the third-order resonance. For higher order resonances (fourth order and higher) which are...
Laser Doppler cooled ion traps can produce stationary bunches of ions with extremely low velocity spread (0.6 m/s RMS) and emittance (10e-13 m normalized). This corresponds to temperatures of a few milli-Kelvin and allows the ions to settle into a fixed lattice analogous to a solid crystal, but with the Coulomb repulsion balanced by the trapping force, rather than a chemical bond. Extraction...
We show how a chicane with anomalous dispersion can be used to compress an electron beam into a narrow, high-current, spike by exploiting the intrinsic chirp created by collective effects. We explore the limits of compression in a linearized model and then apply these beams to impulsively pump valence electrons. In the limit of an ultrashort electron beam, the valence electron wave-packet is...
A new X-band phase shifter for the Very Compact Inverse Compton Scattering Gamma-ray Source (VIGAS) program in Tsinghua University has been fabricated and conducted high-gradient testing. After 10 h of conditioning in the Tsinghua X-band high-power test stand (TPOT), the phase shifter reached a peak power of 72 MW at 230 ns pulse width, and peak power of 82 MW at 130 ns pulse width.
A new X-band mode converter for the Very Compact Inverse Compton Scattering Gamma-ray Source (VIGAS) program in Tsinghua University has been fabricated and conducted low-power testing. S11 is under -30 dB with -0.05 dB of S21 at the operating frequency of 11.424GHz according to the low-power test using the vector network analyzer, which is consistent with simulation results.
A corrugated waveguide based collinear wakefield accelerator is under development at Argonne National Laboratory. The accelerating mode is operating at 180 GHz with a high average power level up to 600 W compounding at the end of the 0.5 m long accelerator module. It is extracted by a dedicated coupler to prevent excessive heating of the corrugated structure of the next accelerator module...
In a preceding study, the wakefield accelerator, which is being actively researched worldwide, was successfully developed by the die stamping method. In order to realize smaller and more precise structure for future wakefield accelerators, X-ray based lithography is successfully implemented to fabricate micro-meter scale wakefield structure. The fabricated structure is half mm radius and 400...
We have fabricated corrugated structures for sub-THz regime by stacking disks. By sending electron beams into the structure, the wakefield of 200 GHz was successfully measured. The frequency and power levels of wakefield were very similar to our design. For the our next target of gigawatts power, we have newly designed a structure of 400 GHz. More precise fabrication is required compared to...
RadiaBeam is designing and manufacturing a fast-ramping alpha magnet is developed for interleaved operation at the Argonne APS. This interleaving operation requires the alpha magnet to stably complete a 5 s long cycle with a 100 ms ramp-up, 1000 ms nominal field output and a 100 ms ramp-down. A laminated yoke is used to minimize eddy currents, ensure fast field response times and reduce...
The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is the world's largest and most powerful particle accelerator, colliding beams of protons and lead ions at energies up to 7 ZTeV. ALICE is one of the detector experiments optimized for heavy-ion collisions.
A fixed-target experiment in ALICE is considered to collide a portion of the beam halo, split using...
Most FELs employ the mechanism of self-amplified spontaneous emission (SASE) from a relativistic electron beam to generate intense femtosecond pulses in the x-ray spectral region. Such SASE FELs are characterized by a broad bandwidth and relatively poor longitudinal coherence, and offer a rather limited control over the spectro-temporal properties. The limitations of a SASE FEL can be overcome...
The Continuous Electron Beam Accelerator Facility (CEBAF) is a 12 GeV recirculating electron accelerator at the Thomas Jefferson National Accelerator Facility (JLAB). Major upgrades to the accelerator are being investigated which include a new 650 MeV injection beamline and state-of-the-art fixed-field alternating (FFA) gradient recirculation arcs. The upgrade will extend the energy of the...
Nowadays, DC gun field emission currents have become common applications as electron sources for electron microscopy, while we focus on the research of field emission of sharp tips in microwave fields, which promises low emittance currents for high energy electron imaging. The tungsten rods are fabricated into tips by electrochemical etching with the radius of curvature of apex within one...
This paper presents the final physics design of the Proton Improvement Plan-II (PIP-II) at Fermilab, focusing on the linear accelerator (Linac) and its beam transfer line. We address the challenges in longitudinal and transverse lattice design, specifically targeting collective effects, parametric resonances, and space charge nonlinearities that impact beam stability and emittance control. The...
FLASH, the superconducting XUV and soft X-ray FEL is undergoing a substantial upgrade (FLASH2020+) with two long shutdowns 2021/22 and 2024/25. In the 1st shutdown, FLASH's 2nd bunch compression chicane (BC2) has been completely redesigned for the FLASH2020+ upgrade project. The redesign allowed the installation of two quad/skew-quad packs in each of the arms of the 4-dipole (C-type) chicane....
Light with polarization structure is called Fully Structured Light (FSL). We present an experimental demonstration of coherent FSL EUV light with spatially varying states of polarization generated at the FERMI free electron laser (FEL) in Trieste, Italy. Control of the polarization is obtained through the overlap of radiation emitted in orthogonally polarized helical undulators with different...
Magnetic hysteresis, eddy currents, and manufacturing imperfections pose significant challenges for beam operation in multi-cycling synchrotrons. Addressing the dynamic dependency of magnetic fields on cycling history is a current limitation for control room tools using existing models. This paper outlines recent advancements to address this, presenting the outcome of operational tests...
This contribution presents the initial findings from the 3.2 Million Euro EuPRAXIA Doctoral Network. European Plasma Research Accelerator with eXcellence In Applications (EuPRAXIA) is at the forefront of advanced particle accelerator research, focusing on the development of plasma-based accelerator technologies.
The EuPRAXIA Doctoral Network, a collaborative effort among leading research...
High brightness electron beams with high peak current are critical to reducing the size of XFEL. A promising approach consists in combining low emittance beam generated high-frequency photoinjector with a laser-assisted bunch compression scheme. Such a compression consists in using an infrared laser to modulate the electron beam energy in a planar undulator and a low R56 chicane to compress...
We present a novel concept of the Fixed-Field-Alternating (FFA) permanent magnet small racetrack proton accelerator with kinetic energy range between 10-250 MeV. The horizontal and vertical tunes are fixed within the energy range providing very fast cycling with a frequency of 400 Hz to 1.3 KHz. The injector is commercially available cyclotron with RF frequency of 65 MHz. The permanent magnet...
FLASH, the XUV and soft X-ray free-electron laser user facility at DESY, is in the transitional period between two substantial upgrade shutdowns within the FLASH2020+ upgrade project. FLASH consists of a common part FLASH0 (injector & superconducting linac), two FEL beamlines (FLASH1/2) and an experimental beamline FLASH3, accommodating the plasma wakefield experiment FLASHForward. The first...
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.
Almost all linac-based free-electron laser (FEL) facilities have employed a symmetric three- or four-dipole chicane to compress the electron beam in order to achieve a kA-level bunch current. The achromatic C-type chicane has been widely used in present linac-FEL facilities. Coherent synchrotron radiation (CSR) induced microbunching instability (MBI) can be an issue in the chicane design....
We present second-order fringe maps for gradient dipoles whose poles are curved to follow the reference orbit. While some of the results have been previously found, we find new contributions including soft-edge linear terms that can be significant for gradient dipoles. In addition, we depart from previous works by writing all soft-edge corrections in terms of integrals along the particle...
Strong Hadron Cooling (SHC), utilizing the coherent electron cooling scheme, has been extensively investigated for the Electron Ion Collider (EIC). Throughout our cooling optimization studies, we realized that a Super-Gaussian electron bunch offers enhanced performance in comparison to a Gaussian bunch. Our approach involves initiating the electron beam distribution in a double peak form,...
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...
Bunch trains have been considered as a promising means of generating intense, coherent radiation in compact accelerator facilities. However, conventional methods, which impart a sinusoidal modulation on the beam’s longitudinal phase space, are inefficient for generating a high bunching factor density modulation. Only a small fraction of a sinusoidal modulation, which has linearity, primarily...
The Electron Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities up to 1e+34 cm^−2 s^−1 in the center-mass energy range of 20-140 GeV. The Hadron Storage Ring (HSR) of the EIC will utilize the arcs of the Relativistic Heavy Ion Collider (RHIC) and construct new straight sections...
The longitudinal distribution of the electron beam in the electron storage ring of the Electron-Ion Collider will be modified by the machine impedance. The modified distribution, combined with crab cavities may have an impact on the quality of the hadron beam during the collision. In this paper, we will explore the possible impact on the hadron beam quality with strong-strong and...
Hard X-ray self-seeded (HXRSS) free-electron lasers (FEL) provide high intensity radiation pulses with both transverse and longitudinal coherence in the hard X-ray regime. These sources are important for experiments requiring high spectral density and high photon energies like nuclear resonance scattering. However, as the photon energy increases, HXRSS efficiency may decrease in a typical...
The International Linear Collider (ILC) is a next-generation electron-positron collider designed to operate at center-of-mass energies ranging from 250 GeV to 1 TeV, opening up a wide range of possibilities for exploring physics beyond the Standard Model. Being the first of its kind, the ILC requires sophisticated technology to produce large quantities of positrons. The ILC electron-driven...
The international e-e FCC study group aims to design an accelerator complex capable of injecting tunable and high charge electron-positron bunches into a collider with center-of-mass energy between 90 and 365 GeV. The injector complex will boost the initial energy of the electron-positron bunches using multiple linacs accelerating only electrons, only positrons, and both species up to the...
C-band accelerators have been of particular interest in recent years due to their ability to provide high gradients and transport high charge beams for applications such as colliders and medical technologies. New Advancements in high gradient technologies that can suppress the breakdown rate in a particular structure by using distributed coupling, cryogenic cooling, and copper alloys. Previous...
We report simulation results showing the use of sacrificial bunch charge to achieve high brightness in photoinjector beamlines designed for Ultrafast Electron Diffraction (UED) and Inverse Compton Scattering (ICS). The beam undergoes nonlaminar focusing during which the tails dynamically linearize the core’s transverse phase space. An aperture then removes the resulting diffuse tails, leaving...
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...
High field radio frequency (RF) accelerating structures are an essential component of modern linear accelerators (linacs) with applications in photon production and ultrafast electron diffraction. Most advanced designs favor compact, high shunt impedance structures in order to minimize the size and cost of the machines as well as the power consumption. However, breakdown phenomena constitute...
Reliable operation of a seeded Free Electron Laser requires the simultaneous control of several electron-beam, laser and accelerator parameters. With EEHG the complexity increases due to the second seed laser and the strong dependence of EEHG bunching to seeding parameters. With the recent upgrade of the FEL-1 line, FERMI is the first FEL facility to be operated in EEHG mode for users. This...
In a radiofrequency accelerating structure with ceramic insertion, high shunt impedance (162 megaohm/m) and high group velocity (3.1% of the speed of light) are achieved simultaneously. The ceramic insertion is in the form of a cylinder, sandwiched between copper endplates with the beam aperture opened at the center. We report our theoretical study on this novel type of traveling wave...
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...
Due to their compactness, laser-plasma accelerators are a promising approach to future energy frontier electron accelerators. To reach multi-GeV energies in a single accelerator stage, the high-intensity drive laser pulse must be kept focused over several tens of centimeters through a sufficiently low density plasma. Without an external guiding mechanism, the laser will diffract reducing the...
We present a high-performance solver for the magnetostatic equations. The solver can simulate nonlinear and anisotropic magnetic materials on a highly variable grid, enabling efficient resolution of fine features even in very large systems. It is built on the Tpetra parallel sparse linear algebra package, allowing it to handle problems with billions of degrees of freedom and employ hardware...
In this paper, the results of high-resolution X-ray topography characterization of monocrystal diamond plate with (100) crystal surface orientation used as high-quality monochromator of high-heat-load self-seeding free electron lasers are reported. The plate was fabricated by laser-cutting of the (100) facet of monocrystal diamond grown using high-pressure high-temperature method. The...
We are researching the development of an ultra-high intensity heavy ion source based on laser ablation ion source (LIS) technology coupled with a unique beam injection technique called Direct Plasma Injection Scheme (DPIS). A metallic target is ablated using a Q-switched Nd:YAG laser to generate a pulsed high-density plasma, which is then injected and accelerated by a radio-frequency...
Imparting designed nonlinear correlation on the longitudinal phase space is nontrivial task. While RF cavities operating at different frequencies can generate arbitrary correlation in principle, it is hard to realize such system due to the lack of RF power sources and their costs. We present a new method that may overcome such practical limitation by adopting transverse wigglers and transverse...
Betatron radiation is a form of synchrotron radiation emitted by moving or accelerated electron or positron-like charged particles. As a valuable tool it can provide useful information about their trajectories, momentum and acceleration. It has good potential as a novel non-destructive diagnostic for laser-driven plasma wakefield acceleration (LWFA) and beam-driven plasma wakefield...
Elettra 2.0, will be a 4th generation synchrotron radiation source that will replace Elettra, the 3rd generation light source that has been in operation since 1993 at Trieste. In this paper, the effects of the quadrupolar wake fields are investigated, and the transverse mode coupling threshold is presented. Also, the incoherent tune shift for multi-bunch operation is examined considering the...
Use of uncertainties is key to improving the efficiency and interpretability of ML algorithms. One interesting uncertainty-aware technique is Bayesian parameter inference, whereby posterior distributions are determined from experimental data though gradient-enabled methods like Hamiltonian Monte Carlo. Key to this idea is implementation of standard linear optics and tracking in a...
The Los Alamos Neutron Science Center (LASNCE) is over 50 years old. Currently, Cockroft-Waltons are being used to accelerate H+ and H- beams to 750 keV. The LANSCE Modernization Project (LAMP) is proposing to replace the font-end of LANSCE with a Radio-Frequency Quadrupole (RFQ). A RFQ Test Stand is being commissioned at LANL for technical demonstration of simultaneous dual-beam species...
The plasma accelerator community has made significant progress in advancing particle beams, bringing us closer to realizing the dream of replacing the radio frequency (RF) cavities' MV/m fields with the plasma-sustained GV/m fields for collider applications. The beam requirements for realizing this vision emphasize a collider-quality beam featuring hundreds of pC of charge, energy spread less...
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 operation of light source accelerators is a complex process that involves a combination of empirical and theoretical physics, simulations, and data-intensive methodologies. For example, the FLASH1 beamline at DESY is upgrading to an external seeding FEL light source*. We utilize special diagnostics, machine learning algorithms, and comprehensive simulations to achieve this. To optimize...
The intrabunch motion for independent longitudinal or transverse beam oscillation modes has been explained analytically for impedance driven bunched-beam coherent instabilities already several decades ago by Laclare and they have been observed in many measurements and simulations. These oscillation patterns do not depend on the bunch intensity, they are head/tail symmetric and they exhibit a...
This study focuses on beam generation in the laser back-illumination mode using metal cathodes of varying thicknesses in a 200-kV photocathode DC electron gun. The aim is to investigate the quality and characteristics of beam production in this mode and provide valuable insights for the application of the electron gun in electron microscopy and related fields. Experimental preparations...
The quest for novel technologies in the ever-evolving landscape of scientific exploration has led to the investigation of plasma lensing as a potential solution for optical matching devices at the International Linear Collider (ILC) positron source. This research becomes increasingly significant as the need for higher data output demands innovative concepts to increase positron yield and...
Transfer maps of different ion optical elements are usually obtained via ray tracing methods without taking into account the imperfections and misalignments of the optics. Normally beam profile monitors do not measure the full 6D phase-space, but only a portion of it. To verify the beam phase-space, we have constructed an Ion Optics Test Stand (IOTS) that is located at the Low Energy Branch...
The plasma wakefield accelerator, with acceleration gradients ranging from GeV/m to TeV/m, holds promise for propelling particles to high energies in linear colliders. This results in exceptionally bright beams characterized by intense ion-derived focusing, leading to the collapse of plasma ions. The non-uniform ion density triggers robust nonlinear focusing, potentially resulting in...
Data driven methods have proved to be a useful tool for analyzing Hamiltonian systems. The symplectic condition is a strong constraint on Hamiltonian systems and it is therefore useful to implement this constraint into neural networks to ensure the accuracy of long term predictions about the system. One such method is the use of SympNets*, linear, activation, and gradient layers that guarantee...
Laser-plasma accelerators (LPAs) are compact accelerators with field gradients that are approximately 3 orders of magnitude higher than RF-based machines, which allows for very compact accelerators. LPAs have matured from proof-of principle experiments to accelerators that can reproducibly generate ultrashort high-brightness electron bunches. Here we will discuss a first combination of LPAs...
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...
Linac Coherent Light Source (LCLS) copper linac typically functions in a single bunch mode, having a repetition rate of 120 Hertz. Numerous internal projects and external user experiments at the LCLS necessitate X-ray pulse trains consisting of two or multiple pulses. Previously we have reported on implementing a system of two ultra-fast stripline kickers, aimed at correcting pulse train...
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...
The LHC machine configuration was changed in 2023 compared to previous years, requiring a new set of optics configurations to be measured and corrected. A telescopic optics was deployed in energy the ramp for the first time, which gave rise to a beta-beating of up to 25%. This was corrected using a global correction approach which reduced the beta-beat down to 10%. A change in the phase...
EuPRAXIA@SPARC_LAB is a multi-disciplinary user facility currently under construction at the Laboratori Nazionali di Frascati of the INFN as part of the EuPRAXIA collaboration. This facility features a multi-GeV plasma-based accelerator with high-quality electron beams, intended for piloting two Free Electron Laser (FEL) beamlines for experiments — one in the VUV and the other in the XUV-soft...
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...
Local coupling correction in Interaction Regions (IRs) and global coupling correction based on Base-Band Tune (BBQ) measurement have been performed routinely for RHIC operation. However, one still observes significant residual local coupling measured by beam position data. For the Electron-Ion Collider (EIC) project, betatron decoupling for the hadron beam needs to be improved to maintain a...
Operation with ultra-low momentum-compaction factor (alpha) is a desirable capability for many storage rings and synchrotron radiation sources. For example, low-alpha lattices are commonly used to produce picosecond bunches for the generation of coherent THz radiation and are the basis of a number of conceptual designs for EUV generation via steady-state microbunching (SSMB). Achieving...
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...
For the 2024 100 GeV proton run at RHIC, the new sPHENIX detector will require a maximum amount of collisions within ±10 cm of its central Interaction Point (IP), and preferably few or no collisions outside this range. To maximize the collisions within the vertex, a large crossing angle of up to 2 mrad will be used, operating the Large Piwinski Angle (LPA) scheme. To compensate for the...
Laser, MPS, Modulator, Vacuum, LLRF, etc. are installed at the Pohang Accelerator Laboratory-XFEL linac section. Each device must be protected against emergency situations. When an interlock signal occurs in the XFEL linac section of Pohang Accelerator Research Institute, the beam shutter is closed using the PLC and the operation of each device is blocked. We used an Emerson PLC and connected...
The isolated resonances model of spin depolarization hinges on a closed-form solution of energy ramping through the Single Resonance Model by Froissart and Stora. However, depolarization by single-resonance crossing is impossible in the SRM with pairs of Siberian Snakes for appropriately chosen orbital tunes, since the amplitude-dependent spin tune is fixed to one-half. This demonstrates that...
The peak detected Schottky system is a powerful diagnostic tool for determining longitudinal beam parameters. According to the theoretical model, the peak value of the signal from a wideband pick-up contains information on particle distribution as a function of the synchrotron frequency. Due to intrinsic assumptions for modelling the acquisition set-up and uncertainties of beam parameters, a...
We present a beam-focusing architecture using electro- and permanent magnets for a novel compact electron beam buncher under development for space-borne electron accelerators. Developing compact and efficient accelerator components has become desirable with renewed interest in using space-borne electron beams for ionospheric aurora research and very low frequency wave generation for particle...
Power limitations are expected at injection for the main Radio Frequency (RF) system due to the doubled bunch intensity in the High Luminosity (HL-) Large Hadron Collider (LHC). One way to overcome these power limitations is to reduce the capture voltage. The smaller RF bucket, however, increases both capture and flat-bottom beam losses. In practice, the start of the ramp losses, which is the...
Compact free electron laser (FEL) technology enabled by plasma-based accelerators is rapidly maturing with several milestone demonstrations in the last 2-3 years. Still, critical work is needed to bridge the gap from proof of concept experiments to reliable operation of plasma-based FELs. At the BELLA Center, we have a laser plasma accelerator (LPA) beamline equipped with an electron beam...
Understanding and optimizing the electron cooling performance is essential to ensure high-brightness antiproton beams at the Extra Low Energy Antiproton (ELENA) ring at CERN. This paper presents measurements and simulations of the electron cooling performance in ELENA. The simulations are obtained using the Parkhomchuk model for electron cooling recently implemented in the Xsuite simulation...
As a part of the High Energy upgrade to the Linac Coherent Light Source II at SLAC, LBNL is responsible for the update of the undulators of the Soft X-Ray (SXR) line. In order to span the required photon energy range, the SXR undulators require longer magnetic period. This increased magnetic period leads to higher magnetic force, requiring updates to certain elements of the design. In...
Two distinct crab cavities are planned to compensate the luminosity loss of the 25 mrad crossing angle at the Electron Ion Collider (EIC) interaction point. The crab cavity systems being developed will operate at either 197 MHz or 394 MHz and the 197 MHz system will provide up to 11.5 MV of transverse voltage with up to 60 kW of fundamental mode power with a coaxial coupler. The 197 MHz crab...
The Electron-Ion Collider (EIC) is currently under development to be built at Brookhaven National Lab and requires cooling during collisions in order to preserve the quality of the hadron beam; an Energy Recovery Linac (ERL) operated at either 150 or 55 MeV is being designed to provide cooling through the mechanism of Coherent electron Cooling (CeC). This requires that the electron beam...
Microbunching instability (MBI) has been an important issue in the design of advanced x-ray free-electron lasers. We have performed theoretical and simulation analyses of MBI for the transport in the beam switchyard system, including the effects of different initial beam parameters. In addition, a comparison is given for different beam switchyard section designs.
Previous start-to-end simulations of an emittance exchange (EEX)-based photoinjector have demonstrated highly attractive beam properties. The EEX-based photoinjector can provide another interesting opportunity that potentially eliminate the microbunching instability issue. The space-charge and/or CSR-induced amplification occurs during density-to-energy and energy-to-density modulation...
Two parallel corrugated plates will be installed at the KIT storage ring KARA (KArlsruhe Research Accelerator). This impedance manipulation structure will be used to study and eventually control the electron beam dynamics and the emitted coherent synchrotron radiation (CSR). In this contribution, we present the impedance that is most effective to manipulate the threshold of the microbunching...
High Harmonic Generation (HHG) has been a brilliant and successful technique for the generation of natural mode-locked attosecond laser pulses in the VUV regime. It’s promising to employ the HHG laser as an external seed in a harmonic-generation FEL facility for the generation of high power short wavelength mode-locked FEL pulses. In this paper we propose a method to try to make this happen....
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...
The TopGun photoinjector is a 1.6-cell C-band gun developed by the University of California, Los Angeles team. Originally optimized for 100 pC operation, its low emittance design has been our starting point. However, the Los Alamos National Laboratory (LANL) needs to operate with a 250 pC bunch charge while maintaining an emittance below 100 nm. The initial optimization of the High Charge...
This work aims to improve the ability of particle accelerator researchers to develop high-performance accelerator cavity designs by creating an overall multiphysics framework that integrates and couples existing application codes. This framework will allow accelerator researchers to build multiphysics models that will optimize cavity design, improve understanding of whole-device performance,...
Many reactor-based neutron sources are planned to shut down in the near future, and this is despite the increasing demand for neutron beamlines for a wide range of scientific and industrial applications. Consequently, compact accelerator-based neutron sources arise as a competitive alternative that could meet the need for medium-flux fission or spallation sources. In this work, we explore the...
At Varex Imaging Corporation, we have started a transition to our in-house supply of Accelerator Beam Centerlines (ABC), replacing Varian as a supplier. As part of this program we are considering changing design of our K-15, the only standard production unit capable of delivering Bremsstrahlung at 12000 R/min@1m by striking a copper target with high energy electron beam at 15 MeV. We plan on...
The FLASH facility is currently undergoing a transformation to generate FEL radiation suitable for next generation user experiments. Here, the transition of FLASH1 from a SASE to an externally seeded FEL beamline is in main focus and will significantly expand the facilities capabilities. Near transform limited pulses at superior spectral and energy stability at full FLASH repetition rate of 1...
Steady-state microbunching (SSMB) storage rings are promising candidates for coherent-EUV-radiation light sources. In a generalized longitudinal strong focusing (GLSF) approach, the concept is to achieve perfect cancellation of modulations by ensuring that a particle's coordinate remains identical after passing through both modulators. This requires effective control over the deviation in the...
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...
In high-gain free-electron lasers (FELs) with planar undulators it is possible (in the linear regime) to independently amplify at the fundamental and at odd harmonics, a process referred to as Harmonic Lasing (HL). For the HL process preservation of the quality of the incoming high-brightness electron beam is essential. This requires suppression of the lasing at the fundamental, which can be...
Following the decommissioning of the Main Injector Neutrino Oscillation Search (MINOS) experiment, muon and hadron monitors have emerged as essential diagnostic tools for the NuMI Off-axis nu_mu Appearance (NOvA) experiment at Fermilab. For this study, we use a combination of muon monitor simulation and measurement data to study the monitor responses to variations in proton beam and lattice...
Charged-particle beams with intense longitudinal fields in accelerating structures inevitably couple to transverse modes, potentially causing beam break-up instability. To maintain beam quality in applications like linear colliders, addressing this coupling is crucial. Flat-beams, featuring highly asymmetric transverse sizes, can delay the initial instability in slab-symmetric structures....
In 2023 the LHC restarted after the yearly winter shutdown with a new machine configuration optimized for intensities of up to 1.8e+11 protons per bunch. In the first two months of the 2023 run the bunch intensities were pushed up to 1.6e+11 protons per bunch until a severe vacuum degradation, caused by a damaged RF bridge, occurred close to the ATLAS experiment. Following repair, the decision...
The favorable wavelength scaling of ponderomotive interactions indicates that long-wave infrared (LWIR) lasers are well suited for applications such as laser wakefield acceleration and high harmonic generation. CO2 amplifiers are the primary source of such wavelengths, able to generate TW peak powers with sub-ps pulse lengths. However, a limiting factor for these amplifiers is the necessity of...
To maintain beam emittance and quality, particle beams in plasma wakefield accelerators (PWFAs) need to be focused to extremely small sizes upon entering the accelerator. Conventional methods that achieve this involve large quadrupole electromagnets, which can occupy a considerable amount of space, often spanning several meters. The plasma lens, however, represents a compact, strong...
Measuring the composition and content of dissolved substances in aqueous solutions is in demand in fields such as biomedicine, and industrial production. The material analysis technique based on thermal neutron capture reaction is one of the commonly used methods for analyzing the composition and content of dissolved substances in aqueous solutions. The material analysis technology based on...
The injector section of the SHINE device is currently in the debugging phase. The electron beam energy in the injector section is low and is significantly affected by the geomagnetic field, with an intensity of approximately 250 milligauss. Through theoretical optimization, adjustments to the positions and intensity parameters of helical coils and corrector magnets are being made to...
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...
Plasma-based particle accelerators maintain accelerating fields that are several orders of magnitude higher than conventional accelerators. This allows for more compact accelerator footprints that can deliver particle beams of very high charge (> 100 pC) and large current (> kA) for various applications. Plasma-wakefield accelerators are promising candidates for next-generation TeV-class...
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...
Scientific opportunities with very hard XFEL radiation demands dedicated facility development towards FEL operation in the sub-ångström regime. Very hard X-rays provide capabilities of high Q-range coverage and high penetration, and also allow access to the K-edge spectroscopy of high-z materials. Production of such X-rays using FELs takes advantage of general FEL characteristics such as large...
The interactions of charged particles with carbon nanotubes (CNTs) may excite electromagnetic modes in the electron gas that makes up the nanotube surface. This novel effect has recently been proposed as an alternative method to achieve ultra-high gradients for particle acceleration. In this contribution, the excitations produced by a localized point-like charge propagating in a single wall...
An analytical form is derived using the Faddeeva function to represent terahertz-frequency pulses generated by optical rectification of ultrashort laser pulses. Spectra of these pulses can be described by a Gaussian fall-off at high frequencies and a power-law as DC is approached. A set of pulsed beams based on this form is also derived for the special case of propagation-invariant...
Coherent synchrotron radiation (CSR) induced microbunching instability (MBI) has been an issue in the multi-bend design for a single-pass high-brightness electron beam transport. Recently a novel design of a non-symmetric four-dipole bunch compressor chicane has been proposed to effectively mitigate the CSR-induced emittance growth, compared with the symmetric C-type chicane widely used in...
Numerical modeling of low-temperature plasma (LTP) ion sources provides cost-effective techniques for developing and optimizing beam characteristics for ion implantation and other applications, including plasma processing and etching. Particle-in-cell (PIC) models are a powerful tool for simulating plasma formation and dynamics in LTP sources. Beam formation and transport of the beam through...
Single-spoke resonators (SSRs) have been developed and tested for the RAON SCL2 project. The design pa-rameters for the SSRs are provided, and the performance of the superconducting cavities is assessed. The single-spoke resonator cavities, cryogenic systems, cryostats, and human machine interface (HMI) are depicted for a vertical test. Calibration and cavity preparations are demonstrated to...
We are presenting a design of a 2-18 GeV electron synchrotron accelerator made of permanent non-linear combined function magnets with fixed betatron tunes. It is based on the successfully commissioned CBETA Energy Recovery Linac where we used a single return beam line based on Fixed Field Alternating gradient (FFA) principle. The 2 GeV injection energy electrons come from the Recirculating...
High-efficiency alkali antimonide photocathodes degrade with little oxidation, making them hard to characterize and test outside their growth chamber. In this proceeding, we report on the design and performance of the PHOtocathode Epitaxy and BeamExperiments (PHOEBE) laboratory at Cornell University, where the growth, characterization, and testing of photocathodes in vacuum has been...
The plasma accelerator-based Free Electron Laser research program at ELI-ERIC (ELI-Beamlines, Czech Republic) intends to utilize the unique qualities of plasma accelerators to build FELs with remarkable brightness, coherence, and pulse length. The program is based on the novel high-power, high-repetition-rate laser system, which is under preparation at ELI-Beamlines. The program entails...
We study the design and spin performance of a polarized electron Booster. This booster will accelerate polarized electrons from 200 MeV to 3 GeV. We examine the polarization transmission of the existing NSLS-II Booster design as well as a modified AGS-Booster lattice using an 8-fold symmetric design and increasing the betatron tune to 7.85 to avoid all intrinsic spin resonances.
The Electron Storage Ring (ESR) of the Electron-Ion Collider (EIC) to be built at Brookhaven National Laboratory will provide spin-polarized electron beams at 5, 10, and 18 GeV for collisions with polarized hadrons. Electron bunches with polarization parallel and anti-parallel to the arc dipole fields will co-circulate in the ring at the same time, and each bunch must be replaced once it is...
PolFEL, the Polish Free Electron Laser facility, after recent configuration adjustments, will feature a dual superconducting electron linac fed in the first stage by pulse-operating, made of copper photoinjectors. In the second stage, both Cu injectors will be replaced by superconducting injectors enabling the cw operation. The first linac line equipped with two Rossendorf-RI type cryomodules...
The Advanced Wakefield Experiment (AWAKE) aims
to accelerate electrons to particle physics relevant energies
using self-modulated proton bunches as drivers in a single
plasma. AWAKE is now in its Run 2b (2023-2024), where
the goal is to stabilise wakefields by using a plasma density step. Experimental demonstrations require probing of the longitudinal wakefields by externally injected...
SLAC has developed the parallel finite element electromagnetics simulation suite ACE3P which employs the parallel high-order finite element (FE) method to solve Maxwell's equations at the macroscopic level. Under the support of an SLAC LDRD, optical nonlinearities in the transient regime have been incorporated into the ACE3P time-domain solver for the investigation of nonlinear physical...
Previously we had developed a new method to fabricate corrugated waveguides (CW) operating in sub-THz frequency regime. As the next step, collaborative effort is underway to demonstrate GW-level high-power sub-THz pulse generation using a CW. We plan to fabricate a CW operating at around 400 GHz. This waveguide will be driven by a bunch train including 16 bunches with nanocoulomb-level charges...
At UCLA, a plasma source using capillary discharge has been developed and studied for its potential use in plasma wakefield experiments at MITHRA and AWA facilities. This compact, 8-cm long source, has the ability to create plasmas covering a wide range of densities, making it suitable for various experiments involving plasma wakefield acceleration (PWFA). With a 3-mm aperture, it can transmit...
We present an update on the design of the Interaction Region (IR) for the the Electron Ion Collider (EIC) being built at Brookhaven National Laboratory (BNL). The EIC will collide high energy and highly polarized hadron and electron beams with a center of mass energy up to 140 GeV with luminosities of up to 10^34 /cm^2/s. The IR, located at RHIC's IR6, is designed to meet the requirements of...
Plasma-wakefield acceleration represents an exciting route towards reducing the footprint of future high-energy electron accelerators by accelerating bunches in fields exceeding 1 GV/m. One such technique employs a double-bunch structure where the trailing bunch is accelerated in the fields of a high-amplitude plasma-density wake driven by the leading bunch. A future particle collider or...
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...
In December 2021, damage to RHIC helical magnets forced one of two Siberian Snakes in the Blue ring to operate as a partial Siberian Snake and with a different snake axis of rotation. Quite surprisingly, the time-averaged polarization for that run actually ended higher than in the Yellow ring, after casting the undamaged snake as a partial snake as well to optimize polarization parameters. In...
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...
Studying the energy deposition in accelerator components, mechanical supports, services, ancillary equipment and shielding requires a detailed computer readable description of the component geometry. The creation of geometries is a significant bottleneck in producing complete simulation models and reducing the effort required will allow non-experts to simulate the effects of beam losses on...
FLUKA simulations of beamlines are important for understanding numerous different aspects of accelerators, including beam losses, particle backgrounds, activation and shielding. Creating a beamline simulation using FLUKA is a time consuming and potentially error prone process. This paper describes a set of python tools called pyflubl (Python FLUKA beamline) which can create a FLUKA simulation...
Dielectric Wakefield Acceleration is a technology under active research, providing the potential to accelerate charged particle bunches with gradients much greater than conventional RF-based metallic cavities. The stability of driving bunches needs to be solved before practical applications are seen. Strong transverse fields are known to be excited in DWAs, with previous research focusing on...
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...
For the development of X-band deflecting structure at Shanghai Synchrotron Radiation Facility (SSRF), two units of X-band deflecting structures totally including six RF structures have been used on SXFEL successfully for ultra-fast beam diagnostics. The construction of another new FEL facility has started from 2018, which is named Shanghai high repetition rate XFEL and extreme light facility...
The Accelerator Test Facility (ATF) at Brookhaven National Laboratory is a DOE Office of Science User Facility supported by the DOE Office of Accelerator R&D and Production. It provides its users with 3 major beam capabilities: 75 MeV high brightness electron beams, multi-terawatt long-wave infrared (LWIR) laser beams, and near infrared (NIR) laser beams. These capabilities can be used...
The Electron Storage Ring (ESR) of the Electron-Ion Collider requires some 400 quadrupoles and 200 sextupoles, plus dipole magnets and correctors. In an effort to reduce cost and relax the demand on the magnet vendor pool, used quadrupoles and sextupoles of the Advanced Photon Source at Argonne National Laboratory will be refurbished and installed in the ESR.
Semi-deterministic optimization problems are common in operating complex lasers and accelerator facilities. In these problems, a few optimal solutions exist that can achieve satisfactory system performance for a specific system state. Typically, online optimizations are performed to find these optimal solutions, which can be time-consuming and must be repeated when the system state changes. In...
CLAPA-II, a novel proton therapy accelerator under development at Peking University and supported by the Ministry of Science and Technology of China, utilizes chromatic aberration and dispersion effects for energy selection of the laser proton beam driven by the radiation pressure acceleration (RPA). Through comprehensive research of the energy selection system using TraceWin, CLAPA-II can...
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 Electron-Ion Collider (EIC) utilizes the existing Relativistic Heavy Ion Collider (RHIC) rings as a Hadron Storage Ring (HSR) with some modifications. However, this presents significant challenges, primarily due to beam-induced Resistive Wall (RW) heating resulting from a larger radial offset and shorter EIC bunches (up to 10 times shorter than RHIC). Additionally, the formation of an...
The CERN Proton Synchrotron Booster (PSB) operation involves the crossing of multiple resonance lines in the tune diagram. Loss maps from dynamic tune scans are a helpful way to visualize and quantify the strength of such resonances. Sextupole and octupole correctors can be used in order to partially or fully compensate multiple resonance lines, i.e., third and fourth order lines. The...
This talk summarizes the plans, challenges and key components of the four phases in the AWAKE roadmap. In addition, an overview of the rich measurement program of the second phase, AWAKE Run 2b, during 2023 and 2024 is given. Results from a unique 3-week measurement opportunity with a 10m discharge plasma source prototype are shown, including the effects of different gases, plasma densities,...
The Relativistic Heavy Ion Collider (RHIC) Run 23 program consisted of collisions of 100 GeV gold beams at two collision points for the first time since 2016; the sPHENIX collaboration used the beam to commission their new detector systems while STAR took physics data. Completion of sPHENIX construction pushed the start of the run to May, forcing the collider complex to operate over the summer...
The RPI LINAC refurbishment control system engineering plan outlines Cosylab's and RPI's approach to initiating and managing the control system architecture for an accelerator refurbishment project at RPI. One of the goals was to achieve a low total cost of ownership, which encompasses the direct price, the cost of maintenance, the upgrade potential, and the quality and cost of support...
The objective of the EuPRAXIA@SPARC_LAB European user facility is to operate a stable, reliable, and reproducible machine. This study delves into a comprehensive analysis of injector jitter to assess the machine's stability concerning RF and laser jitters. The stability and reproducibility of the beam are significantly influenced by RF generation. As such, a portion of the work concentrates on...
During 2023, examination of the action dependence of sextupolar resonance driving terms (RDT) in the LHC at injection, as measured with an AC-dipole, demonstrated that a robust measurement of the RDTs could still be achieved even with very small amplitude kicks, typically used for linear optics studies. Consequently, analysis of optics measurements from 2022 and 2023 during the LHC energy ramp...
In the High Luminosity Large Hadron Collider (HL-LHC) era, the intensity of the circulating bunches will increase to 2.2e+11 protons per bunch, almost twice the nominal LHC value. Besides detailed studies of known and new failure cases for HL-LHC*, it is also required to investigate failures beyond nominal design. The consequence of such failures can be the impact of a large number of...
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...
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...
Laser wakefield acceleration (LWFA) has been highlighted in the development of table-top accelerators and compact light sources. However, the stability issues on beam quality and pointing remain unsolved problems. Many groups apply the technique of ionization injection for higher charge with the narrower energy spread into a supersonic gas jet target or a capillary discharge system. The LWFA...
Generating nanometer-scale density modulation has been pursued due to its potential for compact X-ray source applications. Realization of this nanometer modulation involves two key challenges: development of sub-micron-scale momentum modulation method and conversion method to density modulation without quality degradation. Addressing the first challenge, emittance exchange (EEX) beamline is a...
Dynamic Aperture (DA) studies, based on single-particle tracking simulations including important non-linear fields such as beam-beam effects, have played a crucial role in guiding the operation of the Large Hadron Collider (LHC) in proton-proton collisions. The correspondence between DA computed through simulations and the actual beam lifetime during operation has been established for proton...
The Variable Energy Gamma (VEGA) System is under implementation in Bucharest-Magurele Romania as one of the major components in the project of Extreme Light Infrastructure Nuclear Physics. The VEGA System is designed as an advanced Laser Compton Scattering gamma-ray source with unique parameters in terms of high spectral density, monochromaticity, high polarizability, and energy tunability. It...
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...
The first operational high peak and average power THz SASE FEL at the Photo Injector Test facility at DESY in Zeuthen (PITZ) has demonstrated up to 100 uj single pulse energy at a center frequency of 3 THz from electron bunches of 2-3 nC. The measured shot-to-shot radiation pulse energy has a fluctuation of ~10\%. Shot-to-shot stability and temporal coherence in FELs can be greatly enhanced by...
We present an initial capture concept for the continuous wave (CW) polarized positron beam at the Continuous Electron Beam Accelerator Facility (CEBAF) upgrade at Jefferson Lab. This two-step concept is based on (1) the generation of bremsstrahlung radiation by a longitudinally polarized electron beam (1 mA, 120 MeV, >90% polarization), passing through a tungsten target, and (2) the production...
We present a Fixed-Field-Alternating (FFA) permanent magnet racetrack electron accelerator with energy range between 10-60 GeV for the future LHeC. Electron beam is brought back to the linac by the single beam line without requiring electric power REDUCING estimated wall power of 100 MW in the present LHeC design to a negligible power for arcs as the permanent magnets are used. The design is...
Diamond-II is a future 4-th generation synchrotron light source with a significantly narrower vacuum chamber compared to the existing Diamond storage ring. The strength of wake fields will increase, and, consequently, the risk of single-bunch instabilities also rises. We consider chromaticity adjustment and a passive harmonic cavity as mitigation measures, including for cases with impedance...
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...
The 2D Orszag-Tang vortex magnetohydrodynamics (MHD) problem is studied through the use of physics-constrained convolutional neural networks (PCNNs). The density and the magnetic field are forecasted, and we also predict magnetic field given the velocity field of the fluid. We examined the incorporation of various physics constraints into the PCNNs: absence of magnetic monopoles,...
In free-electron lasers seeded by a coherent pulse, the term superradiance refers to a regime in which the seed pulse is consistently shortened by a slippage-dominated interaction with the electron beam. This regime is extremely promising for attosecond X-ray free-electron lasers in particular, as it offers a potential path towards shorter, higher power pulses. We study the practical limits of...
In collinear wakefield acceleration, two figures of merits, gradient and transformer ratio, play pivotal roles. A high-gradient acceleration requires a high-charge beam. However, shaping current profile of such high-charge beam is challenging, due to the degradation by CSR. Recently proposed method, utilizing transverse deflecting cavities (TDC) for shaping, has shown promising simulation...
A second hard X-ray beamline (HX2) at the PAL-XFEL (Pohang Accelerator Laboratory, X-ray Free Electron Laser) has been proposed to meet the increased demands of XFEL science. A photon energy ranging between 1.5 to 10 keV was determined to cover low photon energy with enhanced FEL pulse energy of about 3.0 mJ, and to cover mostly used range between 8 to 10 keV simultaneously. Accordingly,...
The microbunching instability (MBI) driven by beam collective effects can cause significant electron beam quality degradation in advanced X-ray free electron lasers. Typically, multiple stage magnetic bunch compressors used to generate high peak current electron beam will dramatically amplify the microbunching instability. In this paper, by redesigning the solenoid elaborately and adopting a...
Cavity-based X-ray free electron laser (CBXFEL) is the proposed scheme to dramatically improve stability and coherence of the existing XFELs. A project to demonstrate proof-or-principle CBXFEL is underway at SLAC National Accelerator Laboratory, in collaboration with Argonne National Lab (ANL, USA) and RIKEN Research Institute (Japan). CBXFEL is expected to operate at 9.831 keV photon energy,...
Laser-plasma accelerators (LPAs) have potential to enable compact light sources and high-energy linear colliders. At the BErkeley Lab Laser Accelerator (BELLA) PW facility, electron bunches with energy up to 8 GeV have been generated using laser pulses with peak power of 0.85 PW (energy 31 J) and an acceleration length of 20 cm. In order to accelerate over this distance of 15 diffraction...
The status of commissioning of the electron injector intended for the next phase of the proton driven wakefield experiment (AWAKE) is presented, showing first experimental results from operating the brazing-free electron gun. To provide a high-quality electron beam, the UV laser was centered on the copper cathode, and a novel simplex and beam-based alignment of the focusing solenoid was...
Provisions are being made in the Electron Ion Collider (EIC) design for future installation of a second Interaction Region (IR), in addition to the day-one primary IR. The envisioned location for the second IR is the existing experimental hall at RHIC IP8. It is designed to work with the same beam energy combinations as the first IR, covering a full range of the center-of-mass energy of ~20...
In the framework of the FLASH2020+ project, the FLASH1 beamline will be upgraded to deliver seeded FEL pulses for users. This upgrade will be achieved by combining high gain harmonic generation and echo-enabled harmonic generation with a wide-range wavelength-tunable seed laser, to efficiently cover the 60-4 nm wavelength range. The undulator chain will also be refurbished entirely using new...
The SASE3 Variable Polarization project is intended to offer the polarization control of the soft X-ray FEL pulses. The project was completed in early 2022. During the winter shutdown 2021-2022, all four APPLE-X helical undulators were placed in the tunnel and the first lasing was achieved in April 2022. Unfortunately, further use of the helical afterburner proved impossible, as the encoders...
A program is underway at the Argonne Wakefield Accelerator (AWA) facility, in collaboration with Euclid Techlabs and Northern Illinois University (NIU), to develop a GV/m-scale photocathode gun, to produce bright electron bunches. The novel X-band (11.7 GHz) photoemission gun (Xgun) is powered by high-power, short RF pulses (9 ns) generated by the AWA drive beam in a wakefield structure. In...
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...
Using a simplified multi spin resonances model we study the how the interference of spin resonances near a strong intrinsic spin resonance crossing effect the polarization transmission as a function of emittance for a lattice with more than two snakes.
Machine learning has been applied in many fields in recent decades. Many research articles also presented remarkable achievements in either operation or designing of the particle accelerator. This paper present orbit correction by neural networks, a subset of machine learning, in Taiwan Photon Source.
Synchrotron radiation could contribute to detector background significantly, especially when the electron beam deviates from the design orbit. Without effective control, synchrotron radiation could impede physics data taking or even damage detector components. One of the key contributors to suppress synchrotron radiation in the Electron-Ion Collider IR is to control the electron orbit upstream...
A new layout for the energy-frontier hadron collider (FCC-hh) under study at CERN has been designed, following the constraints imposed by the outcome of recent tunnel placement studies. The new lattice and the need to maximize the dipole filling factor triggered a deep revision of the corrector systems located in the regular arcs, such as orbit, tune, linear coupling, and chromaticity...
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 soliton-like superradiant regime in a free-electron laser is a fully non-linear phenomenon in which the bandwidth of a short pulse can be coherently broadened as the pulse is amplified. As such, superradiance has long been considered a promising route towards high-power ultrashort pulses exceeding the natural bandwidth of high-gain FELs. This regime has now been observed in several...
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...
The Advanced Light Source Upgrade (ALS-U) is a 2 GeV high-brightness, nine-bend achromat storage ring, designed to reduce the natural emittance relative to the existing ALS by a factor of 20 for improved x-ray coherent flux and brightness. The upgrade includes the installation of an accumulator ring of the same energy as, and slightly smaller circumference than, the storage ring. The bending...
High-power attosecond X-ray pulses are ideal probes of ultrafast nonlinear interactions in quantum systems. We demonstrate the production of soft X-ray pulses with terawatt-scale peak powers and few hundred attosecond pulse durations in a two-stage cascaded X-ray free-electron laser. We diagnose the pulse properties in the time domain with angular streaking. Our results exceed the peak power...
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...
The Fritz-Haber-Institut (FHI) der Max-Planck-Gesellschaft Free Electron Laser (FEL) achieved first light from its Mid-IR beamline at 18 microns on February 14, 2012. In the subsequent years, the 3 to 60 micron light has been supplied to users resulting in 96 refereed publications in Chemical Physics. In 2019, the FEL Group initiated an upgrade to add a Far-IR beamline to the system. On June...
The CXFEL is designed to produce attosecond-femtosecond pulses of soft X-rays in the range 300-2500 eV using nanobunched electron beams and a very high power laser undulator. The project includes 5 X-ray endstations with applications in biology, quantum materials, and AMO science. The CXFEL Project overall includes both the CXFEL and the nonlasing hard X-ray CXLS that is described elsewhere in...
The polarized pre-injector for the Electron-Ion Collider is intended to produce four bunches every second, each containing 7 nC, with 85% polarization along the longitudinal axis, for injection into the Rapid Cycling Synchrotron. The pre-injector consists of a polarized electron source, bunching section, longitudinal phase space manipulation, and SLC-Type LINAC. To reduce energy spread and...
The design of the electron-ion collider (EIC) at Brookhaven National Laboratory is well underway, aiming at a peak electron-proton luminosity of 10e+34 cm^-1·sec^-1. This high luminosity, the wide center-of-mass energy range from 29 to 141 GeV (e-p) and the high level of polarization require innovative solutions to maximize the performance of the machine, which makes the EIC one of the most...
The hadron storage ring (HSR) of the Electron-Ion Collider (EIC) is a modification of the RHIC for acceleration and collision of protons and ions. The 6 straights in RHIC will be modified, and the 6 arcs will be left in place. There are four geometric configurations, switching one arc depending upon the energy of the hadrons or ions, and with two different configurations for one straight,...
Wigglers are periodic arrays of magnets with myriad applications in accelerator physics. Generally though, they are only tunable by adjusting the gap between jaws. Here, we present a wiggler based on diametrically magnetized cylindrical magnets with independently adjustable angle. This allows the realization of arbitrary (bandwidth constrained) magnetic configurations. We illustrate its...
The UK XFEL project is now mid-way through its three-year Conceptual Design and Options Analysis (CDOA) phase. The purpose of this phase is to develop concepts to meet the required ‘next-generation’ XFEL capabilities identified in the project’s comprehensive, peer-reviewed, Science Case, which was developed by UK academia. The envisaged next-generation features are a step-change in both the...
An x-ray free-electron laser oscillator (XFELO) is a promising candidate for producing fully coherent x-rays beyond the fourth-generation light sources. An R&D XFELO experiment (ANL-SLAC-Spring-8 collaboration) to demonstrate the basic principles and measure the two-pass FEL gain is expected to be accomplished by 2024. Beyond this R&D experiment, an XFELO user facility will be eventually...
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 addition of spin-polarized, continuous-wave (c.w.) positron beams to the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) would provide a significant capability to the experimental nuclear physics program at Jefferson Lab. Based on bremsstrahlung and pair-production in a high-Z target, a 120 MeV spin-polarized c.w. electron beam of several milliamperes is required. While the...
We have launched a research program on attosecond X-ray sources utilizing high-harmonic generation (HHG) driven by an infrared free-electron laser (FEL) oscillator. As the results of the first six years of the program, we have improved the FEL performance at KU-FEL and LEBRA-FEL to achieve FEL intensity high enough for HHG. We observed HHG from a solid target and tunnel-ionizing electrons in...
We report on the status of a degrader device to generate large phase space beams for machine acceptance studies in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. The degrader device consists of thin, low-Z targets to degrade the electron beam phase space through multiple scattering, two apertures to define the maximum transverse emittance, and a solenoid to aid in...
Addressing the charged particle beam diagnostics in accelerators poses a formidable challenge, demanding high-fidelity simulations in limited computational time. Machine learning (ML) based surrogate models have emerged as a promising tool for non-invasive charged particle beam diagnostics. Trained ML models can make predictions much faster than computationally expensive physics simulations....
The FLARE project aims to investigate special operation modes of the laser heater at the free-electron laser FLASH in Hamburg that enable the generation of few- or possibly sub-femtosecond soft X-ray pulses. To this end, laser pulses of the laser heater are split and then recombined after one pulse has been delayed. By controlling the interference of both pulses via their temporal overlap, a...
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...
SOLEIL II is an upgrade project of the existing Synchrotron SOLEIL facility. It aims to reach fourth-generation light source parameters. This includes reductions of the transverse beam emittance, vacuum chamber dimensions and momentum compaction factor. A new impedance model of the SOLEIL II storage ring was developed. This paper demonstrates the evaluation of transverse single- and...
We study coherent transverse beam oscillations in the EIC electron storage ring (ESR), to specify the tolerance for high-frequency ripple of the magnet power supplies. To avoid unacceptable proton emittance growth from the oscillating beam-beam kick from the electrons, the amplitude of these oscillations at the proton betatron frequency needs to be limited to about 1e-4 fraction of the beam...
Plasma temperature dynamics provide significant insight when evaluating ion source performance. Quantities such as beam emittance, or mean transverse energy, are strongly correlated with the source plasma temperature. At LANSCE there is currently no method implemented for measuring initial source emittance or implementing tunability of mean transverse energy through ion source control...
Ultrafast Electron Diffraction (UED) is a pioneering method for real-time observation of atomic-level structures. Recent advancements leverage relativistic electrons from radiofrequency (RF) guns to overcome space charge limitations, enhancing resolution. While perspectives may differ, an ongoing debate surrounds the optimal energy for a UED instrument. Our study contributes to this discussion...
As one of the most important frontiers of international science and technology, the development of ultrafast science has provided important research tools for many disciplines. Free-electron laser (FEL) has the unique advantages of high power and short wavelength in generating ultrafast pulses. In this paper, the theoretical simulations were performed to produce the ultrafast pulses, utilizing...
In this study, we reassess the dynamics within a simple accelerator lattice featuring a single degree of freedom and incorporating a sextupole magnet. In the initial segment, we revisit the Henon quadratic map, a representation of a general transformation with quadratic nonlinearity. Through a stability diagram, we offer a precise description of dynamic aperture, tune spreads, and nonlinear...
The aims of the CLARA experiment at the Fermilab Integrable Optics Test Accelerator (IOTA) were to directly measure the coherence length of undulator radiation emitted by a single electron and to test whether the radiation is in a pure classical Glauber coherent state or in a quantum mixture of coherent and Fock states. We used a Mach-Zehnder interferometer (MZI) to study visible radiation...
Thermionic electron guns that use borides of lanthanum or cerium as the electron emission surface are widely adopted for electron microscopes due to their high brightness. CeB6 cathodes are known for their high environmental durability and can be used up to a vacuum pressure of 1e-6 Pa. At MHI-MS, our company, we also adopt CeB6 cathodes in the C-band compact accelerating structure units we...
Interaction between the beam and residual gas ions can lead to a variety of undesirable effects, such as instability and emittance growth. This ion instability is a serious concern for high-brightness electron storage rings, such as the APS-Upgrade. To study ion instability in detail, an IONEFFECTS element was added to the particle tracking code ELEGANT. Recently the IONEFFECTS code was...
Coherent synchrotron radiation has a significant impact on electron storage rings and bunch compressors, inducing energy spread and emittance growth in a bunch. While the physics of the phenomenon is well-understood, numerical calculations are computationally expensive, severally limiting their usage. Here, we explore utilizing neural networks (NNs) to model the 3D wakefields of electrons in...
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...
Powered by a storage ring with energies ranging from 240 MeV to 1.2 GeV, the Duke Free-Electron Laser (FEL) has demonstrated operation across a broad wavelength spectrum from infrared (IR) to vacuum ultraviolet (VUV): 1100 nm to 170 nm. This FEL serves as a photon source for the High Intensity Gamma-ray Source (HIGS), producing polarized, near-monochromatic, and high-flux Compton gamma-ray...
High flux, coherent hard X-rays constitute an efficient tool for applications in high resolution (sub nm) chip metrology which offers notable advantages to the modern semiconductor industry. A candidate source for such photons is represented by a recently proposed compact X-rays free electron laser (XFEL) based on high gradient cryogenic accelerating structures and short period cryogenic...
The Electron Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities of up to 1e+34 cm^−2 s^−1 in the center-mass energy range of 20-140 GeV. Crab cavities are employed to compensate for the geometric luminosity loss caused by a large crossing angle of 25 mrad in the interaction region....
The Electron Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities up to 1e+34 cm^−2 s^−1 in the center-mass energy range of 20-140 GeV. The current fractional design tunes for the Hadron Storage Ring (HSR) are (0.228, 0.210) to mitigate the effects of synchro-betatron resonances. In...
The cavity-based x-ray free-electron laser (CBXFEL) R&D project utilizes a low-loss x-ray cavity (65.5 m long) to provide circulating monochromatized x-ray seeding for electrons from the Cu-linac at SLAC. The project aims to demonstrate the two-pass gain in x-ray regenerative amplifier and XFELO modes by 2024. Here, we report on the design, manufacture, and characterization of x-ray optical...
The 2016 RHIC Au-Au run took place from February 8 to June 27, 2016. Four so-called vernier scans were performed at 100 GeV per beam, with γ=107.396 at flattop at one of the interaction points, IP6. During this type of procedure, one beam is swept across the other, first horizontally and then vertically, recording the interaction rate as a function of the beam to beam distance. From that...
