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 fabrication, each cavity undergoes centrifugal barrel polishing and electropolishing and then is tested at 2.07 K. Eight cavities are then assembled into "cavity pairs" and tested at 2.07 K before integration into the cryomodule. This paper presents the outcomes of the cavity qualification for the third C75 module, providing a detailed account of the assessment in both a vertical cryostat and the commissioning results of the cryomodule. Furthermore, efforts have been made to address performance limitations arising from field emission and multipacting.

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 expanding the LUIS experimental setup to test and validate the performance of the laser-plasma accelerator-based extreme ultra-violet (EUV) FEL, integrating a high-power laser, plasma source, and electron beam transport line with relevant diagnostics to create a comprehensive test bed for the development of the EuPRAXIA LPA-based FEL. The plasma accelerator-based FEL development program at ELI-Beamlines represents an innovative effort to expand the capabilities of FEL technology and open new possibilities for scientific research and industrial applications. In the frame of this report, we provide an overview of the relevant developments at ELI-ERIC (ELI-Beamlines) as well as the main challenges of this program.

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 target with mean energy of 20 MeV, which are then ramped up to 1 GeV in a five-turn scheme with a series of fixed field alternating magnets and two superconducting RF cavities (100 MeV per cavity per turn). The electron beam is then bypassed to an undulator line optimized to generate EUV light of 13.5 nm at kW level in a single pass.

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 a pure proton plasma in a Gabor-lens will be discussed. The confinement of a positive space charge column provides either a linear de-focusing force for positively charged ion beams or a linear focusing force for negatively charged heavy ion beams. Very first results of proton confinements and their diagnostics will be presented. A special focus lies on the diagnosis of the proton density distribution, as well as the comparison between the behavior of the proton and electron clouds.

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 nanotube are described by means of the linearized hydrodynamic model. In this model, the electron gas is treated as a plasma with specific solid-state properties. The governing set of differential equations consists of the continuity and momentum equations for the electron fluid, in conjunction with Poisson's equation. Through numerical simulations, we investigate the influence of key factors, including the driving velocity, CNT radius, surface density and the friction (between the electron fluid and the ionic lattice) parameter, on the excited wakefields, comparing the results with Particle-in-Cell (PIC) simulations. A comprehensive discussion is presented to analyze similarities, differences and limitations of both methods. This research provides a valuable perspective on the potential use of CNTs to enhance particle acceleration techniques, paving the way for further advancements in high-energy physics and related fields.

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: 100 pC charge, a few mm·mrad emittance, and a few % energy spread. Thanks to an integrated beam physics study assigning specific roles to each section of the accelerator, all the requirements are successfully met in numerical simulations, paving the way for plasma-based accelerators to be competitive with conventional accelerators.

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 for all kinds of positron sources. This research becomes increasingly significant as the need for higher data output demands innovative concepts to increase positron yield and therefore luminosity. Instabilities were observed during the first test trials. This poster presents the results of high-temporal resolution imaging to analyse the discharge instabilities. Furthermore, the results show not expected but interesting insights and challenges. Overcoming these challenges is pivotal for a future application of plasma lenses as an integral part of high-performance positron sources.

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 field of a high-amplitude plasma-density wake driven by the leading bunch. A future particle collider or photon science facility incorporating plasma accelerators will be required to accelerate up to millions of bunches per second with high energy efficiency while preserving the brightness of the accelerating bunch. This contribution presents the latest progress towards these goals at FLASHForward (DESY).

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, bunch charges and plasma lengths on the proton bunch self-modulation, ion-motion, current filamentation instabilities and plasma light. A new 10 m long rubidium vapor source was installed in the summer of 2023 with the possibility to generate a density step (0-10%) every 50 cm along the first 4 m. First measurement results with this plasma cell are also presented, showing the positive effect of the density step on the plasma light as well as an increased energy gain for externally injected electrons.

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 electron bunches. To optimise charge capture in the wakefields, the electron beam density should be maximised at the site of injection ze. This is achieved by setting the beam waist at ze. Since no diagnostics are currently available at these locations, waist beam sizes are extrapolated from measurements upstream. The qualitative and quantitative agreement obtained between measured and simulated transverse electron beam sizes, at locations where these can be measured, demonstrates good understanding of the beam line optics and provides confidence in the extrapolated beam sizes at waist locations, where these cannot be measured. This information can then be used in the experiment to maximise the beam density at the site of injection.

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 timing jitter) and the witness energy gain in a plasma wakefield accelerator stage. Experimental measurements are reported by using an electro-optical sampling diagnostics with which we correlate the distance between the driver and witness beams prior to the plasma accelerator stage. The results show a clear correlation due to such a distance jitter highlighting the contribution coming from the RF compression.

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 with an electron storage ring, namely an LPA-based injector for the cSTART ring at the Karlsruher Institute of Technology (KIT). The cSTART ring is currently in the final design phase. It will accept electron bunches with an energy of 50 MeV and will have a large energy acceptance to accommodate the comparably large energy spread of LPA-generated electron beams. The LPA will be required to reproducibly and reliably generate 50 MeV electron bunches with few percent energy spread. To that end, different controlled electron injection methods into the plasma accelerating structure, tailored plasma densities are explored and beam transfer lines to tailor the beam properties are designed.

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 initial evolution, but this has only been reported for short distances. In this work, we use quasi-static particle-in-cell simulations to demonstrate the instability of asymmetric drivers even after splitting into two beamlets and reaching equilibrium. As the driver decelerates, its particles gradually return into the channel, making the driver susceptible to deflection by the transverse dipole mode. To understand this behavior, the transverse motion of an individual beam particle is modeled. Strategies to mitigate this instability are also proposed.

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 selecting the background gas and laser properties, one can generate narrow, tunable plasma channels for guiding high intensity laser pulses. We present on the development of 1D and 2D simulations of HOFI channels using the FLASH code, a publicly available radiation hydrodynamics code with specific improvements to model plasma channels. We explore sensitivities of the channel evolution to laser profile, intensity, and background gas conditions. We examine efforts to benchmark these simulations against experimental measurements of plasma channels. Lastly, we discuss ongoing work to couple these tools to community PIC models to capture variations in initial conditions and subsequent coupling for laser wakefield accelerator applications.

At the Facility for Advanced Accelerator Experimental Tests (FACET-II) accelerator, a pair of 10 GeV high-current electron beams is used to investigate Plasma Wakefield Acceleration (PWFA) in plasmas of different lengths. While PWFA has achieved astonishingly high accelerating gradients of tens of GeV/m, matching the electron beam into the plasma wake is necessary to achieve a beam quality required for precise tuning of future high energy linear accelerators. The purpose of this study was to explore how start-to-end simulations could be used to optimize two important measures of beam quality, namely maximizing energy gain and minimizing transverse emittance growth in a 2 cm long plasma. These two beam parameters were investigated with an in-depth model of the FACET-II accelerator using numerical optimization. The results presented in the paper demonstrate the importance of utilizing beam-transport simulations in tandem with particle-in-cell simulations and provide insight into optimizing these two important beam parameters without the need to devote significant accelerator physics time tuning the FACET-II accelerator.

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 of having a new source for a non-destructive X-ray phase contrast imaging and tomography of heterogeneous materials. We report studies of compact and UV-soft X ray generation via betatron oscillations in plasma channel and in particular measurement of the radiation spectrum emitted from electron beam is analyzed from a grazing incident monochromator at Centro de Laseres Pulsados Ultraintensos (CLPU).

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 institutions, is dedicated to exploring and advancing the frontiers of plasma-based particle acceleration. The network’s research involves a wide range of topics, from beam diagnostics and optimization techniques to new applications. Here, we present the innovative approaches and methodologies employed to achieve very high acceleration gradients, improve the energy sharpness and overall beam quality. Some of the early results of this new network are discussed, showcasing the progress made across the network’s three scientific work packages. The contribution also gives an overview of the initial training provided to the network’s Fellows.

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.

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 series of studies on plasma wakefield acceleration (PWFA) by comparing our recently developed analytic model on the blowout cavity shape created by transversely asymmetric long beams, with Particle-in-Cell (PIC) simulations. The analysis focuses on validating the model's ability to predict the behaviors of different beam profiles in this regime.

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 high-aspect ratio beams, and its adjustable density feature allows for a detailed exploration of the shift from linear to nonlinear PWFA stages. In this paper, we will delve into the construction and evaluation of this capillary discharge plasma source, as well as the utilization of an interferometric diagnostic system for measuring plasma density.

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 undesirable beam emittance growth. Our study extends prior research focused on electron acceleration by investigating ion-ion collisions, studying different collision models emphasizing the near-equilibrium state post-ion collapse utilizing the OSIRIS PIC code. Notably, our findings reveal that parametric excitations arising from plasma non-uniformity have an insignificant impact on phase space diffusion, a crucial insight for optimizing linear colliders.

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 for long-term operation. This limits the total yield of lithium ions and the application of laser ion sources. To dramatically increase the repetition rate, we propose the use of a liquid lithium target in a crucible because a liquid surface shape is recovered by itself after laser irradiation. The establishment of a liquid target system is an important objective for the development of the intense lithium beam driver for a clean compact source of a directional neutron beam. In the conference, the concept and design of experimental apparatus for the development will be presented.

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 quadrupole (RFQ) linear accelerator. The ion source enables the production of rare isotopes, the use of particle beams in cancer treatment, and nuclear physics experiments. The exploration of multiple charge states for Mg production is currently underway. The measurement of beam current is conducted using a Faraday cup positioned at the end of the beam line. Following the RFQ acceleration, the beam is transported by multiple quadrupole magnets and a steerer, and a dipole magnet then directs the beamline into the Faraday cup. Notably, we have accomplished an ion beam current of about 20 mA for Mg10+ ions and a current exceeding 10 mA for fully stripped Mg12+ ions. In this presentation, I will discuss the operation of the LIS at Brookhaven National Laboratory (BNL) and the outcomes of Mg ion production.

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 extraction optics can benefit from reduced physical models. One can couple a PIC model for plasma chambers with a different transport model in the extraction region. However, this coupling is ad hoc, and it is often not clear that the models are physically consistent with each other. We present an integrated modeling capability that couples plasma chamber modeling with beam formation using the VSim computational framework. We leverage advanced modeling techniques such as energy-conserving PIC and variable meshing to improve simulation performance. We present results for modeling and optimization of beams for ion implantation. Our results show that our integrated models can improve optimization of beam currents, beam uniformity, and emittance for LTP ion sources.

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 acceleration (PWFA). Since information about the properties of the beam is encoded in the betatron radiation, measurements using the Maximum Likelihood Estimation (MLE) method, rich information about the beam parameters (beam spot size, emittance, charge, energy etc.) can be extracted. Machine learning (ML) techniques can then be applied to improve the accuracy of these measurements. It has already been observed that betatron radiation can give an insight into the change in plasma density. The QUASAR Group, based at the Cockcroft Institute on Daresbury Sci-Tech campus, is planning to build on and expand an existing collaboration with UCLA and also to apply the technique for the AWAKE experiment at CERN. In this work, a hybrid ML-MLE approach is attempted to optimize the use of these diagnostics and obtain a deep insight into the beam’s parameters e.g. beam spot sizes where ML and MLE individually have their limitations.

Coherent electron cooling (CeC) is a novel technique for rapidly cooling high-energy, high-intensity hadron beam. Plasma cascade amplifier (PCA) has been proposed for the CeC experiment in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Cooling performance of PCA based CeC has been predicted in 3D start-to-end CeC simulations using code SPACE. The dependence of the cooling rate on the electron beam parameters has been explored in the simulation studies.

Nanostructures are currently attracting attention as a medium for obtaining ultra-high-density plasmas for beam-driven or laser-driven acceleration. This study investigates Bayesian optimization in Laser Wakefield Acceleration (LWFA) to enhance solid-state plasma parameters towards achieving extremely high gradients on the order of TV/m or beyond, specifically focusing on nanostructured plasmas based on arrays of carbon nanotubes. Through Particle-In-Cell (PIC) simulations via EPOCH and custom Python scripts, we conducted a parameter analysis for various configurations of carbon nanotube arrays. Utilizing the open-source machine learning library BoTorch for optimization, our work resulted in a detailed database of simulation results. This enabled us to pinpoint optimal parameters for generating effective wakefields in these specialized plasmas. Ultimately, the results demonstrate that Bayesian optimization is an excellent tool for significantly refining parameter selection for nanostructures like carbon nanotube arrays, thus enabling the design of promising nanostructures for LWFA.

Laser plasma acceleration (LPA) technology is advancing day by day, getting ready for user facility applications. LPA might be applicable to a generation of electron beams directly within the light-source storage-ring vacuum chamber. Typical injector of the light source facility consists of linac and synchrotron booster (or simply a full energy linac). It can be replaced by a laser plasma cell and a driving laser system that can generate multi-GeV electron beams through so-called self injection. The electron beam out of plasma cell has typically a large energy spread. In this application, however, we do not require small energy spread since the storage ring can accept off-energy electrons of up to ±5% or so. It can also have a transverse angular acceptance of a few hundred micro radian. Therefore, a large fraction of generated electrons can be eventually accepted by the storage ring. LPA system, which replaces the conventional injector, may contribute to significant energy saving.

GL2000 Gabor-lens (GL)[1, 2] is a 2-m long device constructed and successfully operated at Goethe University. The confined electron column is much longer compared to previous constructed lenses and offers unique opportunity for investigation of electron cloud dynamics. Especially, kind of fingertip stopband structures were precisely measured in production diagram (operation function) in the year 2023 [2]. This fully reproducible behavior and dependence on a rest gas pressure left unexplained. For this purpose, a large scale multi-particles simulation PIC(particle-in-cell)-code was written in C++ and implemented on FUCHS-Cluster of the Goethe University. The main objective is to find an optimal operation parameter set for a stable operation of GLs, which is crucial for high energy hadron beam transport and focusing. Further topic will be investigation of possible longitudinal handling of bunched ion beams. The first simulation result will be presented and discussed.

In this groundbreaking study, an advanced particle-in-cell (PIC) simulation code,QuickPIC, is used to explore beam physics within Plasma Wakefield Accelerators (PWFA). The primary aim is to comprehensively analyze beam distributions, particularly those exhibiting perturbations with significant instabilities. To connect simulated beam distributions to physical observables, the study uses cutting-edge neural networks. This research underscores the transformative potential of machine learning (ML) in unraveling PWFA complexities and enhancing our capabilities in the development of advanced accelerators.

A large challenge with Plasma Wakefield Acceleration lies in creating a plasma with a profile and length that properly match the electron beam. Using a laser-ionized plasma source provides control in creating an appropriate plasma density ramp. Additionally, using a laser-ionized plasma allows for an accelerator to run at a higher repetition rate. At the Facility for Advanced Accelerator Experimental Tests, at SLAC National Accelerator Laboratory, we ionize hydrogen gas with a 225 mJ, 50 fs, 800 nm laser pulse that passes through an axicon lens, imparting a conical phase on the pulse that produces a focal spot with an intensity distribution described radially by a Bessel function. This paper overviews the diagnostic tests used to characterize and optimize the focal spot along the meter-long focus. In particular, we observe how wavefront aberrations in the laser pulse impact the peak intensity of the focal spot. Furthermore, we discuss the impact of nonlinear effects caused by a 6 mm, CaF2 vacuum window in the laser beam line.

In the context of research on simultaneous heavy ion radiotherapy and radiography, a mixed carbon/helium ion beam has been successfully established and investigated at GSI for the first time to serve fundamental experiments on this new mode of image guidance. A beam with an adjustable ratio of 12C3+/4He+ was provided by the 14.5 GHz Caprice ECR ion source for subsequent acceleration in the linear accelerator UNILAC and the synchrotron SIS18. Despite the mass difference between the 4He+ and 12C3+ ions, both could be slowly extracted simultaneously at 225 MeV/u using the transverse knock-out extraction scheme. The ion beam has been finally characterized in the biophysics cave in terms of beam composition (particularly inter- and intra-spill He fraction), depth-dose-profiles, beam size, position and other parameters, all related to combined ion beam treatment and online monitoring. Utilizing high-speed particle radiography techniques, a fast extracted mixed ion beam has also been characterized in the plasma physics cave under conditions favorable to FLASH therapy.

In Mithra Laboratory at UCLA, we are commissioning an S-band Hybrid gun which has a photocathode RF gun and a traveling-wave velocity buncher section contained in one integrated structure. To analyze its performance, we have measured the beam energy at various launch phases and the cavity temperatures. The beam charge was observed up to 200 pC, and emittance and bunch length measurements are now underway. We will report the detailed results of this experimental campaign, and plans for the near future.

A beam position monitor based on Cherenkov diffraction radiation (ChDR) is being investigated as a way to disentangle the signals generated by the electromagnetic fields of a short-pulse electron bunch from a long proton bunch co-propagating in the AWAKE plasma acceleration experiment at CERN. These ChDR BPMs have undergone renewed testing under a variety of beam conditions with proton and electron bunches in the AWAKE common beamline, at 3 different frequency ranges between 20-110 GHz to quantify the effectiveness of discriminating the electron beam position with and without proton bunches present. These results indicate an increased sensitivity to the electron beam position in the highest frequency bands. Furthermore, high frequency studies investigating the proton bunch spectrum show that a much higher frequency regime is needed to exclude the proton signal than previously expected.

Ultrafast high repetition-rate laser systems are essential to modern scientific and industrial applications. Variations in critical figures of merit, such as focal position, can significantly impact efficacy for applications involving laser plasma interactions, such as electron beam acceleration and radiation generation. We present a diagnostic and correction scheme for controlling and determining laser focal position by utilizing fast wavefront sensor measurements from multiple positions to train a focal position predictor. We present the deployment and testing of this scheme at the BELLA Center at Lawrence Berkeley National Laboratory. Online optical adjustments are made to a telescopic lens to provide the desired correction on millisecond timescales. A framework for generating a low-level hardware description of ML-based correction algorithms on FPGA hardware is coupled directly to the beamline using the AMD Xilinx Vitis AI toolchain in conjunction with deployment scripts.

Particle tracking serves as a computational technique for determining the mean field of dynamically tracked charged macroparticles of a particle beam within an accelerator. Conventional solver tend to neglect collisionality, resulting in loss of relevant information (particle and momentum redistribution). In this study, macro-particle collisions are incorporated into a 3D Poisson solver. In the previous studies, identifying close particles have been performed in a static condition (IPAC23-Macroparticle collisionality in PIC solver). The requirement to uphold energy momentum within a dynamic tracking is initiated in simple lattices and the results are presented. A comparison with analytic model of the Bjorken-Mtingwa or Conte-Martini is included to verify.

Beam Delivery Simulation (BDSIM), is a C++ program that seamlessly models particle beam transport within an accelerator model that can encompass the beam line, the accelerator's environment, and any accompanying detectors. Based on a suite of high-energy physics software including Geant4, CLHEP, and ROOT, BDSIM transforms the optical design of an accelerator into a detailed 3D model. This facilitates the simulation of particle interactions with matter and the subsequent production of secondary particles. Widely utilized across diverse accelerators worldwide, BDSIM is ideal for simulating energy deposition and assessing charged particle backgrounds. Here, the latest BDSIM developments are shown, including python bindings & interfacing with external tracking tools such as Xsuite.

The AEgIS (Antimatter Experiment on Gravity, Interferometry and Spectroscopy) project, based at CERN's Antiproton Decelerator (AD) facility, has undergone significant enhancements, capitalizing on the increased quantity of colder antiprotons made available by the new Extra Low Energy Antiproton Ring (ELENA) decelerator. These improvements aim to create a horizontal beam and enable a direct investigation into the impact of gravity on antihydrogen atoms. This exploration seeks to probe the Weak Equivalence Principle for antimatter. In AEgIS a series of circular ring electrodes and an axial magnetic field of 1T are utilized for the trapping of antiprotons. This contribution describes the design and optimization of the electrodes to generate a parabolic potential well to effectively trap the antiprotons. The behavior of the trapped antiprotons is reproduced by simulating a spherical source under different bias voltage settings applied to the electrodes. The general layout of the AEgIS trap is shown, alongside suitable electrode configurations, and results from electrostatic particle-in-cell code simulations carried out to optimize the confinement time of the antiprotons.

The main challenge in the development of high intensity ion sources is, besides the space charge limited extraction, the available plasma density. Conventional plasma generators use e.g. arc discharge plasmas or RF generated plasmas. Preliminary tests are carried out on both types of plasma generators and plasma parameters are determined to create a basis for evaluation. A concept is being developed that combines the advantages of both types. This hybrid plasma generator will also be investigated in terms of plasma parameters in order to test a possible application for high intensity ion sources. Further the proposed plasma generator has the property that due to a permanently available low-density RF plasma a faster build-up of the highly dense arc discharge plasma may be achieved. The properties of the concept with regard to a fast plasma build-up time are being investigated in order to test a possible application for the fast pulsing of high intensity ion sources.

The LANSCE H- Ion Source utilizes a cesium coated converter to induce H- surface conversion. To achieve an optimal cesium coating, a heated cesium reservoir and transfer tube vaporizes cesium onto the converter surface. An initial coating of cesium is done via an initial cesium transfer. During this process, the cesium heater is brought to a high initial temperature (250°C) and is slowly lowered to the operational temperature (~190°C) over six hours, followed by a static conditioning for another 18 hours to get the cesium converter coating optimal for H- surface conversion. Any reduction in the 24-hour cesium transfer process would allow more for experimental time for LANSCE experiments. Thus, there is high value in seeking to reduce the initial Cs transfer time. The LANSCE H- Ion Source Laser Diagnostic Stand was recently utilized to take cesium density measurements inside the H- Ion Source as a function of cesium reservoir temperature. A comparison of the measured cesium densities to the theoretical cesium vapor pressure values will be presented. Also, results using the measured cesium densities to calculate and run a faster cesium transfer process will be discussed.

Goethe University (GU), Gesellschaft für Schwerionenforschung (GSI) and Helmholtz Institut Mainz (HIM) work in collaboration on the Helmholtz Linear Accelerator (HELIAC). A new superconducting (SC) continuous wave (CW) high-intensity heavy ion linear accelerator (Linac) will provide ion beams with a maximum duty factor up to beam energies of 7.3 MeV/u. The acceleration voltage will be provided by SC Crossbar H-mode (CH) cavities, developed by the Institute for Applied Physics (IAP) at GU. Preparation methods were investigated to increase their performance. High-pressure rinsing (HPR) with ultra-pure water was performed at HIM and recovered the maximum electric field of a 360 MHz 19-cell CH cavity from Ea = 1.6 MV/m to Ea = 8.4 MV/m. This result exceeds the prior highest electric field observed of Ea = 7 MV/m by 20%. The effect of helium processing has been subsequently investigated. The cavity has been processed for a total of 2 hours at a cavity pressure of 5e-5 mBar. The performance measurement showed promising results, with an increase in maximum gradient and a change in Q-slope behavior. Further tests of helium processing concerning the reproducibility, longevity, and optimization of the observed effects are scheduled at IAP.

Most superconducting thin films found on SRF cavity are generally produced through magnetron sputtering using niobium (Nb) as target. Yet, this technique can still be improved as the resulting film lack in efficiency. Alternative materials such as NbTiN could potentially be used with significant improvement compared to pure Nb films. Here, we report the use of both high-power impulse magnetron (HiPIMS) and bipolar HiPIMS to produce superconducting thin films, with a particular attention on the optimal conditions to enhance the film growth highly dependent on the pressure and power conditions. We used both mass spectroscopy and optical emission spectroscopy to analyze the plasma chemistry providing information on the mass/energy of the ions formed.

SRF cavities are commonly coated with superconducting materials (e.g., niobium) using magnetron sputtering. In this process, various power supplies are employed such as DC, pulsed DC or HiPIMS. The sputtered ions are ejected from the target to the cavity or sample surface with an energy dependent on the power conditions and pressure range. In this study, we investigated the efficiency of such deposition by tracking the mass and energy of the main ions produced (e.g., Kr+, Kr2+, Nb+, Nb2+) using mass spectroscopy. We report the optimal conditions suitable to enhance both ions energy and film growth by comparing to power supplies (DC and HiPIMS), for different pressure conditions ranging from 1e-3 mbar to 1e-1 mbar. To support the gas phase analysis, niobium films were produced on copper substrate and the film structured was analysed by SEM.

Jefferson Lab has an ongoing R&D program in plasma processing. The experimental program investigated processing using argon/oxygen and helium/oxygen gas mixtures. Plasma processing is a common technique where the free oxygen produced by the plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient. The initial focus of the effort was processing C100 cavities by injecting RF power into the HOM coupler ports. We also developed the methods for establishing a plasma in C75 cryomodules where the RF power is injected via the fundamental power-coupler. Four C100 cryomodules were in-situ processed in the CEBAF accelerator in May 2023 with the cryomodules returning to an operational status in Sept. 2023. The overall operational energy gain for the four cryomodules was 49 MeV. Methods, systems and results from processing cryomodules in the CEBAF accelerator and vertical test results will be presented. Current status and future plans will also be presented.

Plasma processing of superconducting radio frequency (SRF) cavities has shown an improvement in accelerating gradient by reducing the radiation due to field emission and multipacting. Plasma processing is a common technique where the free oxygen produced by the plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient. The hydrocarbon fragments of H2, CO, CO2, and H2O are removed from the system with the process gas which is flowing through the system. Here, we present COMSOL for the first time to simulate the plasma processing of an SRF cavity. In this work, we use Jefferson Lab's C75 SRF cavities design as our case study. Using simulation, we predict the condition of plasma ignition inside the SRF cavity. The simulation provides information about the optimal rf coupling to the cavity, mode for plasma ignition, choice of gas concentration, power, and pressure.

Laser plasma accelerators have a great potential to accelerate a charged particle beam to high energy within a short distance due to their extraordinarily high accelerating gradient. However, in order to effectively use the laser plasma accelerator, the input beam has to be moving at relativistic velocities, with a duration 100 femtoseconds or less. In this study, we propose a scheme to generate a femtosecond proton beam for the laser plasma acceleration. The self-consistent simulation including the three-dimensional space-charge effects was used to verify this concept in a simplified version.

This study focuses on developing beam-matching optics for the transport of the MITHRA beam into plasma to study long range plasma effects. To ensure successful injection into the plasma chamber, matching conditions are crucial at the entrance. A dedicated focusing system, comprising beam-matching optics, is designed to transport the beam from the 1.5-meter linear accelerator (linac) and align the necessary parameters at the plasma entrance. Optimization simulations employing Elegant and General Particle Tracer (GPT) codes, based on MITHRA gun data, have been conducted with promising results that align with our expectations. Further investigations involve simulating the PWFA interaction using advanced, fully relativistic, three-dimensional Particle-in-Cell (PIC) codes, namely OSIRIS and QuickPIC.

The design and manufacturing of the Nonlinear Injection Kicker is one of the upgrade project for the Taiwan Photon Source (TPS). In accordance with the requirements of the developed ceramic vacuum chamber, it is necessary to apply a uniform titanium coating on the inner surface of the ceramic substrate to reduce the impedance and image current observed by the stored electron beam. Therefore, titanium films must be sputtered onto a 30 cm × 6 cm ceramic substrate, and these films must exhibit excellent uniformity. Based on our tests of sputtering titanium films on ceramic substrate, the uniformity of the titanium film can be controlled within 5%. The adhesion between the ceramic substrate and the titanium films meets the highest level of ASTM-D3359 5B standard, with an adhesive strength reaching 40 MPa. This paper describes the detailed manufacturing processes and testing results.

In the framework of the acceleration techniques, the Plasma Wake Field Acceleration (PWFA) is one of the most promising in terms of high machine compactness. For this purpose, a crucial role is played by the particle beam focusing upward and downward the plasma-beam interaction, performed by high gradient Permanent Magnet Quadrupoles (PMQs). In the framework of the INFN-LNF SPARC_LAB (Sources for Plasma Accelerators and Radiation Compton with Laser And Beam) six Halbach-type PMQs have been tested before installing them into the machine. This paper presents the outcomes of magnetic measurements conducted using a Single-Stretched Wire (SSW) system. The results include comprehensive details on integrated gradients, magnetic multipole components, and roll angles of the magnets. By considering the operational parameters of the machine, the results show that the tested magnets can be feasibly installed only within limited triplets configurations.

To reduce the dark current and secondary electron multiplication in conventional conducting accelerator cavities, and to improve the quantum efficiency of copper photocathodes, thereby achieving higher beam quality and enhancing the acceleration gradient and operational stability of accelerators, Tsinghua University designed a 13.56 MHz internal coil-type capacitive discharge plasma experimental platform to validate the feasibility of in-situ plasma cleaning of conventional superconducting copper cavities. This paper mainly introduces the architecture of this experimental platform, including the structure of the experimental cavity and its accompanying gas system, microwave system, and monitoring system. This experiment also validates the oxidation and reduction capabilities of the active components in the plasma, particularly comparing the oxidation ability of excited oxygen atoms and oxygen ions and the reduction ability of excited hydrogen atoms and hydrogen ions. This experimental platform can be used for cleaning and reduction of small and simple copper structures and verifies the feasibility of In-situ plasma cleaning of conventional conducting copper cavities.