acceleration
MOCD1
X-band high gradient accelerating structure for VIGAS project at Tsinghua university
14
A light source project named Very Compact Inverse Compton Gamma-ray Source (VIGAS) is under development at Tsinghua University. VIGAS aims to generate monochromatic high-energy gamma rays by colliding a 350 MeV electron beam with a 400-nm laser. To produce a high-energy electron beam in a compact accelerator with a length shorter than 12 meters, the system consists of an S-band high-brightness injector and six X-band high-gradient accelerating structures. The X-band structure’s frequency is 11.424 GHz, and it adopts a constant gradient traveling wave approach; thus, the iris from the first cell to the end cell is tapered. The total cell number is 72, so we named it XT72. In the last two years, we conducted the design, fabrication, and tuning of the first prototype of XT72. Recently, we finished the high-power test, and the result demonstrates that it has the ability to work at an 80 MV/m gradient. In this paper, we present the latest update on this structure.
Paper: MOCD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOCD1
About: Received: 05 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOCD2
Multi-mode cavity design and characterization
18
We present the design and initial characterization of a multi-mode cavity, a novel electromagnetic structure with potential benefits such as compactness, efficiency, and cost reduction. The 2nd Harmonic mode was chosen to linearize the fundamental mode for use as an accelerating and bunching cavity. The reduction in the number of cavities required to bunch and accelerate promises cost and space savings over conventional approaches. Superfish and COMSOL simulations were used to optimize the cavity's geometry with the goal of balancing various design parameters, such as quality factor (Q-factor), harmonic modes, and mode coupling. A 3D-printed copper-plated cavity was used to validate code predictions. The cavity's multi-mode nature positions it for use with other harmonic modes with small deviations in design. For example, a 3rd Harmonic can be used to decrease energy spread by widening the peak of the fundamental. This research lays the foundation for further exploration of the cavity's applications and optimization for specific use cases, with potential implications for a wide range of accelerator fields.
Paper: MOCD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOCD2
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOCN2
Direct RF sampling based LLRF control system for C-band linear accelerator
25
Low Level RF (LLRF) control systems of linear accelerators (LINACs) are typically implemented with heterodyne based architectures, which have complex analog RF mixers for up and down conversion. The Gen 3 RF System-on-Chip (RFSoC) device from AMD Xilinx integrates data converters with maximum RF frequency of 6 GHz. That enables direct RF sampling of C-band LLRF signal typically operated at 5.712 GHz without RF mixers, which can significantly simplify the system architecture. The data converters sample RF signals in higher order Nyquist zones and then up or down converted digitally by the integrated data path. The closed-loop feedback control firmware implemented in FPGA integrated in RFSoC can process the baseband signal from the ADC data path and calculate the updated phase and amplitude to be up-mixed by the DAC data path. We have developed an LLRF control RFSoC platform, which targets Cool Copper Collider (C3) and other C or S band LINAC research and development projects. In this paper, the architecture of the platform and the test results for some of the key performance parameters, such as phase and amplitude stability with our custom solid-state amplifier, will be described.
Paper: MOCN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOCN2
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC01
Study of interfering spin resonances in multi-snake lattice
29
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.
Paper: MOPC01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC01
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPC02
ZDC effective cross section for Gold-Gold Collisions During RHIC'S Run 16
32
The 2016 Relativistic Heavy Ion Collider (RHIC) Au-Au run took place from January 25 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 separation. From that data, the effective cross section of the Zero Degree Calorimeter (ZDC) can be derived. This paper discusses the results of the scans, as well as the systematic uncertainties of the derived effective cross section.
Paper: MOPC02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC02
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPC09
Luminosity effects due to dependent heavy-tailed beams
55
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 typically observed in routine operation. The luminosity is usually modelled with the assumption that the 𝑥-𝑦 planes are independent (i.e. statistically uncorrelated particle distributions between the planes) in each beam. Analytical calculations show that the solution of inverting 1D heavy-tailed beam profiles to transverse 4D phase-space distributions is not unique. For a given transverse beam profile, the distributions can be dependent (i.e. statistically correlated) or independent in the transverse planes, even in the absence of machine coupling. In this work, the effect of transverse 𝑥-𝑦 dependence of the 4D phase space distribution on the luminosity of a particle collider is evaluated for heavy-tailed beams.
Paper: MOPC09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC09
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPC22
Lattice optimization of RF electron linac designed for VEGA LCS gamma-ray source
107
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 (ELI-NP). 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 brings new opportunities and is dedicated for photonuclear research in both applied and fundamental physics, and will be open for worldwide users. Optimization of spectral density and guaranty of monochromaticity of the gamma-rays impose the necessity to control both, transverse emittance and energy spread, putting strong requirements on electron beam dynamics. The paper presents results from computer simulations carried out for the injector of the LCS gamma-ray source based on a normal-conducting RF LINAC, and investigation of a lattice configuration to optimize the electron beam parameters at the transfer line and storage ring entrance.
Paper: MOPC22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC22
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPC24
The design progress of a high charge low energy spread polarized pre injector for Electron Ion Collider
114
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 increase bunch length, a compact zig-zag chicane and dechirp cavity rotate the bunch in longitudinal phase space. In this paper, we will discuss the progress of recent pre-injection design and RF frequency selection. Additionally, we will examine the effects of wakefield, as well as coherent and incoherent synchrotron radiation on beam quality.
Paper: MOPC24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC24
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPC31
Establishing a new class of high-current accelerator-driven neutron sources with the HBS Project
129
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 with of tens of MeV and up to 100 mA beam current, a compact neutron production and moderator unit and an optimized neutron transport system to provide a full suite of high performance, fast, epithermal, thermal and cold neutron instruments. The Jülich Centre for Neutron Science (JCNS) has established a project to develop, design and demonstrate such a novel accelerator-driven facility termed High Brilliance neutron Source (HBS). The aim of the project is to build a versatile neutron source as a user facility. Embedded in an international collaboration, the HBS project offers the best flexible solutions for scientific and industrial users. The overall conceptual and technical design of the HBS as a blueprint for the HiCANS facility has been published in a series of recent reports. The status and next steps of the project will be presented, focusing on the high-current linear accelerator and the proton beamline, including a novel multiplexer to distribute the proton beam to three different neutron target stations while adapting a flexible pulse structure.
Paper: MOPC31
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC31
About: Received: 08 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC34
Performance test for single-spoke resonator superconducting cavities in RAON
136
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 evaluate the performance of the super-conducting cavities. Testing of the single-spoke resonator type 1 (SSR1) performance is conducted via a vertical test. Q slopes are presented as a function of accelerating field, and Lorentz force detuning (LFD) as well as pres-sure sensitivity are conducted for the superconducting cavities.
Paper: MOPC34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC34
About: Received: 09 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC38
Electromagnetic and beam dynamics modeling of LANSCE front-end elements with CST studio
146
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 Studio. Beam dynamics is modeled with Particle Studio for beams with realistic charge distributions using the CST calculated fields. The modeling results provide insight into linac operations and a guidance for designing a modern, RFQ-based front end for the LANSCE linac.
Paper: MOPC38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC38
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC39
Initial results from 35 keV H+ beam at the LANL RFQ test stand
149
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 acceleration through a RFQ under the timing constraints required by the LANSCE users facilities. We will describe the status and present initial results of the 35keV H+ line on the RFQ Test Stand.
Paper: MOPC39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC39
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPC41
Magnetic focusing architecture for a compact electron buncher
153
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 removal from the magnetosphere. An electron gun injects a direct current electron beam, and the buncher modulates the DC beam into periodic bunches at a frequency of 5.7 GHz. A 5.7 GHz linear accelerator in the downstream will capture the bunched beam with minimal acceptance mismatch. The beam modulation is done by three radiofrequency pillbox cavities. The buncher uses the electrostatic potential depression (EPD) method to shorten the structure length remarkably. The electron gun and a tunable solenoid provide the initial focusing of the beam. We then use a series of permanent magnets surrounding the buncher cavities clamped together by ferromagnetic steel plates to focus the beam through the buncher. Permanent magnets do not consume any power and weigh less than solenoid magnets, which provide equivalent focusing, making them ideal for use on a satellite or sounding rocket. We use the three-dimensional (3D) particle tracking solver from CST Studio Suite to simulate the beam-focusing.
Paper: MOPC41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC41
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC44
Transfer learning for field emission mitigation in CEBAF SRF cavities
160
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 machine development periods, we performed invasive gradient scans to record data capturing the relationship between cavity gradients and radiation levels measured throughout the linacs. However, the field emission environment at CEBAF varies considerably over time as the configuration of the radio-frequency (RF) gradients changes or due to the strengthening of existing field emitters or the abrupt appearance of new field emitters. To mitigate FE and lower the radiation levels, an artificial intelligence/machine learning (AI/ML) approach with transfer learning is needed. In this work, we mainly focus on leveraging the RF trip data gathered during CEBAF normal operation. We develop a transfer learning based surrogate model for radiation detector readings given RF cavity gradients to track the CEBAF’s changing configuration and environment. Then, we could use the developed model as an optimization process for redistributing the RF gradients within a linac to mitigate field emission.
Paper: MOPC44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC44
About: Received: 14 May 2024 — Revised: 11 Jun 2024 — Accepted: 11 Jun 2024 — Issue date: 01 Jul 2024
MOPC51
Capture cavities for the CW polarized positron source Ce⁺BAF
173
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 phases. The heating load from the incoming particle radiation shower and RF field will limit the achievable gradients, especially the first cavity. The cooling method and results are shown. The beam loading cancellation from positrons and electrons are investigated.
Paper: MOPC51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC51
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC53
Towards large phase space beams at the CEBAF injector
180
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 matching to the rest of the injector beamline. The engineering design of the degrader device and projected degraded beam phase space parameters obtained from simulation are presented.
Paper: MOPC53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC53
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC56
Design of X-band distributed-coupling accelerating structure
192
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 introduces a new-designed distributed-coupling structures with phase advance greater than 180°. This choice of angle will significantly reduce costs without affecting the shunt impedance.
Paper: MOPC56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC56
About: Received: 11 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC57
Development of an S-band multi-beam accelerator for stationary CT application
195
Stationary CT is a novel CT technology to significantly improve scanning speed, by using distributed multiple ray sources instead of conventional helical rotation with single source. This work presents an S-band multi-beam accelerator as a multiple MV-level X-ray source for industrial stationary CT application. This accelerator consists of 7 parallel-distributed acceleration cavity and 6 coupling cavity, operating in pi/2 standing-wave mode with a centre frequency of 2998MHz. This structure can generate 0.7 MeV electrons with 100 mA peak current at each beamline according to the imaging requirement. The novel multiple high-energy X-ray source will fill in the blank of source requirements in industrial stationary CT application.
Paper: MOPC57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC57
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC58
Fabrication and low-power testing of an X-band mode converter for VIGAS
198
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.
Paper: MOPC58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC58
About: Received: 03 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC63
New high power linear accelerator ABC and platform
208
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 changing the RF source from frequency of 2856 MHz, used by Varian to 2998 MHz, establishing one common frequency for all our S-Band linear accelerator supply. We may be using a two-section design of the new 15 MeV ABC and yet various designs are being investigated, including, but not limited to two collinear standing wave (SW) sections and a patented combination of SW and Traveling Wave (TW) Sections with reverse feed. We have analyzed both concepts and present the preliminary analysis results. The platform can be used for running guides at various energy levels from 2 to 20 MeV, continuously changing energy or doing that selectively, various combinations of energy levels will be possible, also, upgrading the platform to higher average beam power levels. Indeed, operating at high average beam power above 1-2 kW level may require new advanced target development, and in case of e-beam applications, a scan horn will be required for extracting e-beam from vacuum to air.
Paper: MOPC63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC63
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC69
Permanent magnet electron energy synchrotron 2.5–18 GeV with fixed betatron tunes
222
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 Llnear Accelerator (RLA) with 500 MeV linac and a single FFA linear combined function magnet beam line to return electrons to the linac. The electron collision energy uses the same single beam line avoiding the RF accelerating cavities during selected number of turns.
Paper: MOPC69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC69
About: Received: 16 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPG01
Effects of the ALBA slab movement on ALBA-II
281
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 of the survey campaigns on the ALBA storage ring and compared to measurements in terms of orbit, linear optics, and orbit correctors budget. The results of this study on ALBA are used to infer the effect of the slab movement on the future machine through simulations, predicting yearly and seasonal changes. Plausible correction methods are discussed.
Paper: MOPG01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG01
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPG09
A faster algorithm to compute lowest order longitudinal and transverse resistive wall wake for non-ultrarelativistic case
312
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 evaluation. At the same time, the effect of the space charge inside a single bunch due to space charge effect also needs to be considered. In this article, we reorganized the lowest-order longitudinal wakefield under non-ultra relativistic conditions, and the lowest-order transverse wakefield. We present the modified theoretical results and analysis. Then based on the result we have derived, we give a algorithm which is thousands time faster than direct calculation. It lays foundation in future research.
Paper: MOPG09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG09
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPG14
The CXFEL project at Arizona State University
331
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 these proceedings. The CXFEL has recently completed a 3-year design phase and received NSF funding in March 2023 for construction over the next 5 years. Both CXFEL and CXLS instruments use recently developed X-band distributed-coupling, room-temperature, standing-wave linacs and photoinjectors operating at 1 kHz repetition rates and 9300 MHz RF frequency. They rely on recently developed Yb-based lasers operating at high peak and average power to produce fs pulses of 1030 nm light at 1 kHz repetition rate with pulse energy up to 400 mJ. We present the design and initial construction activities of the large collaborative effort to develop the fully coherent CXFEL.
Paper: MOPG14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG14
About: Received: 23 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPG16
FLASH status – FEL user facility between two upgrade shutdowns
335
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 (2021/22) shutdown was aimed at upgrading FLASH0 and install an APPLE-III undulator in the otherwise unchanged beamline FLASH2, enhancing the third harmonic at flexible output polarization. The next (2024/25) shutdown will focus on the complete exchange of the FLASH1 beamline to allow for externally seeded operation in the range from 60 nm down to 4 nm at 1 MHz bunch repetition rate (600 μs trains at 10 Hz train repetition rate). We report on the operation between the two shutdowns which was, to a large extend, dedicated to FEL operation for users and on the commissioning of the new features implemented in the last shutdown.
Paper: MOPG16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG16
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPG32
Plasma accelerator based free electron laser program at ELI-ERIC (ELI-Beamlines)
372
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.
Paper: MOPG32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG32
About: Received: 18 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPG53
Extreme pulse compression for impulsive ionization of valence wavepackets
396
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 accelerated so rapidly that the excited state forms an image of the bound state, allowing for unique insight into the structure of the electronic states of a molecule.
Paper: MOPG53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG53
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPG66
EUV FEL light source based on energy recovery linac with on-orbit laser plasma injection
408
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.
Paper: MOPG66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG66
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPG71
Beam dynamics study for a high-repetition-rate infrared terahertz FEL facility
428
The paper introduces design and optimization of a high-repetition-rate infrared terahertz free-electron laser (IR-THz FEL) facility, which leverages optical resonator-based FEL technology to achieve a higher mean power output by increasing pulse frequency. Electron beam of the facility will be generated from a photocathode RF gun injector and further accelerated with a superconducting linear accelerator. Taking into account the collective effects, such as space charge, coherent synchrotron radiation (CSR), and longitudinal cavity wake field impacts, beam dynamics simulation for the injector, the accelerator, as well as the bunch compressor, has been done with codes of ASTRA and CSRTrack. With optimized microwave parameters of the linac, current profile with good symmetry has been obtained and the peak current can reach 100 A.
Paper: MOPG71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG71
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPG74
Development progress of a tunable terahertz free electron laser based on a pre-bunched linear accelerator
438
To explore and detect novel effects and mechanisms inherent in materials, a tenable wavelength terahertz free electron laser (THz-FEL) is integrated into the terahertz near-field high-throughput material property testing system (NFTHZ). Employing a compact linear accelerator capable of adjusting electron energy within the range of 10 to 18 MeV as the injector, pre-bunching of electron bunches is implemented to create longitudinal spacing structures by manipulating the driving laser. By appropriately correlating the forming factor of electron bunches, electron beam energy at the undulator entrance, and the undulator K value, a terahertz free electron laser with peak power in the megawatt range and a central wavelength spanning from 0.5 to 5 THz can be achieved. This article provides an overview of the development progress of THz-FEL within the NFTHZ framework.
Paper: MOPG74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG74
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPR01
Lattice design of a pulsed synchrotron for a muon collider fitting within the Fermilab site boundary
448
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 the Fermilab site boundary. We wish to estimate the maximum energy that muons can be accelerated to on the Fermilab site based on a realistic lattice layout. To achieve a high average bend field, superconducting fixed field dipoles are interleaved with iron-dominated dipoles whose field is rapidly ramped from negative to positive field. Multiple RF stations are required to ensure that the beam energy and the dipole fields are reasonably well synchronized and to avoid longitudinal losses due to the large synchrotron tune. We use FODO arc cells with dispersion suppressed into the RF straights. We will discuss tradeoffs between maximum energy, energy range, and muon decays. We will consider whether to mix superconducting and iron quadrupoles like the dipoles.
Paper: MOPR01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR01
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPR02
A compact electron accelerator for muon production
452
The muon is a unique particle. It is an elementary particle similar to the electron, but with a mass approximately 200 times greater. Because of their high penetrating power, muons can also be used for imaging such as non-destructive inspection and muon tomography for interior surveys of large structures. Muons derived exclusively from cosmic rays have heretofore been used for these applications, but the low rate and restricted angular range of cosmic rays restricts their usefulness.In this article, a compact and portable muon source based on super-conducting electron accelerator technology is considered. The addition of a muon accelerator provides a variable energy, portable muon source.
Paper: MOPR02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR02
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR03
Cooling demonstrator target and pion capture study
456
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 beams with relatively large emittance through a single absorber, without acceleration. The international Muon Collider Collaboration aims to demonstrate 6-D ionization cooling at low emittance using beam acceleration. Two siting options are currently considered for a Cooling Demonstrator facility at CERN, with proton-driven pion production facilitated by the Proton Synchrotron or the Super Proton Synchrotron. In this work, we use FLUKA-based Monte Carlo simulations to optimize the number of pions produced in the proton-target interactions and subsequently captured by a magnetic horn-based system. We explore the feasibility of different target and capture system designs for 14, 26 and 100 GeV proton beam energies.
Paper: MOPR03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR03
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR04
Extraction of Coulomb crystals with limited emittance growth
460
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 of such a bunch into a beamline could provide a new regime of ultra-low emittance beams if the emittance is preserved through the extraction operation. This paper shows that extraction from the ion trap and initial acceleration does not cause drastic growth, thus preserving the ultra-low emittance nature of the bunch. Techniques for compensating coherent 'emittance growth' effects such as nonlinear bunch distortion are also investigated.
Paper: MOPR04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR04
About: Received: 02 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPR05
Design of prototype magnet for FETS-FFA
464
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 essential components of this machine will be the main magnets which must satisfy the following conditions: zero chromaticity during acceleration, flexibility in operating tune point to test dynamics for high beam intensity and a large dynamic aperture to avoid uncontrolled loss. The chosen lattice design utilizes spiral magnets to provide edge focusing to focus in the vertical direction while also introducing a reverse bending magnet to better control the vertical tune. A three-dimensional study is being carried out in OPERA 3D software to investigate the parameters of the magnets to achieve the required field. The details on the design will be presented in this paper.
Paper: MOPR05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR05
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPR06
Fixed tunes fast cycling permanent magnet proton FFA synchrotron
467
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 synchrotron has a shape of a racetrack where the two arcs are made of combined function permanent non-linear fields magnets to provide fixed betatron tunes for the extraordinary kinetic energy range between 10 and 250 MeV.
Paper: MOPR06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR06
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPR07
FFA@CEBAF beam transport error and tolerance simulation studies
471
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 electron beam to over 20 GeV. In this paper, we provide an error and tolerance simulation study of the amended beam optics transport of the existing accelerator tuned for 22 GeV operation. The study is conducted with the particle tracking codes elegant and Bmad in two parts. In the first part, we treat each section of the accelerator (electromagnetic arcs and linacs) modularly with ideal conditions at the beginning. The second part is a pseudo start-to-end (S2E) simulation with accumulated errors propagating from one beamline to the next.
Paper: MOPR07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR07
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR08
Current status of the FFA@CEBAF energy upgrade
474
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) Gradient recirculation arcs, using novel Halbach-style permanent magnets. These new arcs would replace the current highest-energy recirculating arcs and allow up to six new beam passes spanning approximately a factor of two in energy. Matching into these arcs will require the design of splitter bend systems proceeding the north and south linac sections. Matching from these arcs into the proceeding linac section will be achieved using a novel transition section. Additionally, several major changes to the existing CEBAF accelerator will be implemented including a 650 MeV recirculating injector, a new multi-pass linac optics design based on a triplet focusing lattice, and a newly designed spreader/recombiner bend systems to accommodate the higher energy requirement.
Paper: MOPR08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR08
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR10
Quadrupole field instability in cylindrical dielectric wakefield accelerators
478
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 mitigating single-beam breakup instability (BBU) induced when a beam propagates off-center due to orbit-jitter or misalignment. It is also known that quadrupole-like fields are excited in planar/slab DWA structures and research has been conducted on mitigating this effect. We present simulation results that demonstrate quadrupole-like fields are also excited in circular DLWs, induced by beam astigmatism. We have shown that this in an extra source of instability within circular DWA structures and calculate the size of the fields excited as a function of beam astigmatism.
Paper: MOPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR10
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPR13
High-efficiency traveling-wave accelerating structure with ceramic insertion
482
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 accelerating structure that operates with a 2pi/3-mode at 5.7 GHz. The high shunt impedance is realized by the low-loss, highly reflective ceramic insertion confining the accelerating mode at the center. The high group velocity, or fast filling time of the radiofrequency wave, is made possible by the side coupling slots designed with large dimensions. As a result, this novel traveling wave accelerating structure enhances the power efficiency significantly, by two means. The high shunt impedance allows providing a greater accelerating gradient with a given amount of radiofrequency power. The fast filling time allows an earlier start of the beam acceleration within each radiofrequency power pulse, thus leading to a higher duty factor of the accelerator beam production. This type of the structure design allows using metallic iris features, which minimizes the electric field magnitude witnessed by the ceramic component. We also discuss the scheme of using periodic permanent magnets to focus an electron beam in the accelerating structure. The unique radiofrequency coupler design is also addressed.
Paper: MOPR13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR13
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
MOPR15
Fabrication and testing of mode couplers for a 180 GHz colinear wakefield accelerator
485
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 downstream. Also, it is necessary to monitor beam offsets from the center of the corrugated structure. It is done by utilizing the offset beam’s induced wakefield dipole mode at 190 GHz and extracting it to diagnostic electronics via the second dedicated coupler. Both are contained in the transition section between the accelerator modules*. This paper presents the mechanical design, fabrication, and performance testing of the transition section. Testing included mmWave measurements at ANL and electron beam measurements at Brookhaven National Lab’s Accelerator Test Facility. Both tests involved characterizations of the wakefield modes and coupler’s performances.
Paper: MOPR15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR15
About: Received: 08 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR17
Advanced accelerator concepts for dark sector searches and fast muon acceleration
489
Dielectric laser acceleration (DLA) is a promising approach to accelerate 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. To efficiently use muons for high energy physics applications, they need to be accelerated rapidly, before they decay. Plasma acceleration achieves GV/m accelerating fields and could be ideal for accelerating to muon-collider energies. Single muons could also be accelerated in DLAs for dark matter searches. They could be injected from existing low-intensity muon sources, such as the one at PSI. A workshop organized in the frame of the EU project “Innovation Fostering in Accelerator Science and Technology” (I.FAST) focused on GHz Rate & Rapid Muon Acceleration for Particle Physics to address these topics. We report highlights and future research directions.
Paper: MOPR17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR17
About: Received: 13 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR23
Start-to-end simulation of high-gradient, high-transformer ratio structure wakefield acceleration with TDC-based shaping
504
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 results for accurate shaping of high-charge beams. This is attributed to its dispersion-less feature. We plan to experimentally demonstrate high-gradient (>100 MV/m) and high-transformer ratio (>5) collinear structure wakefield acceleration. The experiment is planned at Argonne Wakefield Accelerator Facility. We present results from start-to-end simulations for the experiment.
Paper: MOPR23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR23
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR24
Progress on high-power generation using sub-THz corrugated waveguide
507
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 per bunch. We present an overview of project’s current status.
Paper: MOPR24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR24
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR25
Design, fabrication, and testing of a W-band corrugated waveguide for Wakefield acceleration
511
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 Studio Suite. After optimizing for the maximum achievable gradient from a nominal Argonne Wakefield Accelerator (AWA) electron bunch at 65 MeV with a Gaussian distribution we attempted to achieve a higher transformer ratio using a shaped bunch. Shaped bunches such as these are achievable at the AWA emittance exchange (EEX) beamline. Preliminary results from the structure testing at AWA using shaped electron bunches will be presented. Further tests are planned, involving a comprehensive optimization of the beamline at AWA.
Paper: MOPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR25
About: Received: 24 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR26
Test of a metamaterial structure for structure-based wakefield acceleration
515
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 interrupt acceleration of a main beam. Statistical analysis between different breakdown types reveals that the characteristics of the BIAR breakdown are beneficial to high-gradient acceleration at short pulse lengths.
Paper: MOPR26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR26
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR29
High gradient C-band cryogenic copper silver structures
519
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 work has shown each of these separately to significantly improve the maximum gradient. In this work, for the first time, we will combine all three methods in an ultra-high gradient structure and benchmark the difference between Cu and CuAg. The exact same structures were previously tested at room temperature and showed gradients in excess of 200 MeV/m and a 20% improvement in the CuAg version over its pure Cu counterpart [1]. These structures are now tested at 77K simultaneously. They were found to perform similarly due to the presence of significant beam loading. Taking beam loading into account, a maximum achievable gradient of 200 MeV/m achieved for a 1 µs pulse at an input power of 5 MW into each cavity with a breakdown rate of 1e-1 breakdown/pulse/m.
Paper: MOPR29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR29
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR33
Preliminary tests for the diffusion bonding of high gradient cryogenic radio-frequency cavities
531
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 an intrinsic limitation to high field operation which ultimately affects the performance of a given structure requiring dedicated tests. The introduction of a recent design based on cryogenic distributed coupling structures working at C-band (~6 GHz) allows to increase the shunt impedance by use of alternative distribution schemes for the RF power while mitigating the breakdowns thanks to the low temperature. In this paper we introduce the plan for high field and breakdown tests envisioned for a simple two-cell version of the aforementioned structure. Moreover, we discuss the joining procedure utilized to unify the two fabricated halves of such a structure and relying on the diffusion bonding technique which constitutes an attractive alternative to the brazing approach.
Paper: MOPR33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR33
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR38
An LWFA injector for AWAKE Run 2 experiment
535
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.
Paper: MOPR38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR38
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR40
Progress towards high-quality, high-repetition-rate plasma acceleration at FLASHForward
541
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).
Paper: MOPR40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR40
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR43
Experimental characterization of the timing-jitter effects on a beam-driven plasma wakefield accelerator
553
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.
Paper: MOPR43
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR43
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR44
Laser-plasma injector for an electron storage ring
557
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.
Paper: MOPR44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR44
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPR53
Instability of asymmetric electron drive beams in hollow plasma channels
561
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.
Paper: MOPR53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR53
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPR57
Automated emittance and energy gain optimization for plasma wakefield acceleration
569
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.
Paper: MOPR57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR57
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPR62
First results from the EuPRAXIA doctoral network: paving the way for next-generation particle accelerators
576
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.
Paper: MOPR62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR62
About: Received: 09 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR64
Flat beam transport for a PWFA experiment at AWA
580
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.
Paper: MOPR64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR64
About: Received: 17 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR67
Ion-ion collisions in plasma wakefield accelerators
591
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.
Paper: MOPR67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR67
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR69
Highly charged Mg ion production using laser ablation ion source at Brookhaven National Laboratory
598
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.
Paper: MOPR69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR69
About: Received: 16 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR72
Transport and dosimetry of laser-driven proton beams for radiobiology at the BELLA center
610
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 implemented two compact, permanent magnet-based beam transport configurations for delivering 10 or 30 MeV protons to a biological sample, along with a suite of diagnostics used for dosimetry. These diagnostics include multiple integrating current transformers (ICTs) for indirect online dose measurements and calibrated radiochromic films (RCFs) to measure the dose profile and calibrate the ICT dosimetry. Benchmarked Monte-Carlo (MC) simulations of the beamline allow us to predict the dose received by the sample and correct the linear energy transfer (LET)-dependent response of the RCFs. This work not only further establishes the practicality of utilizing LDIAs for radiobiological research but also highlights the BELLA Center's capacity to accommodate further experiments in this domain.
Paper: MOPR72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR72
About: Received: 17 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPR79
Demonstration of enhanced quantum efficiency from optical interference in alkali antimonide photocathodes
634
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 to a factor of two over a laser wavelength range of 30 nm, and that a modulation peak can be tuned to coincide with a desired laser wavelength by changing the thicknesses of both the photocathode and the silicon carbide layer in the substrate. A model for the QE modulations is derived and fitted to QE measurements of CsSb and Cs3Sb films, which have different indices of refraction, in addition to QE measurements of Cs3Sb films grown on 3C-SiC substrates with two different silicon carbide layer thicknesses. Good agreement is found between the model and measurements, confirming the optical interference effect can be exploited to enhance quantum efficiency at desired visible wavelengths.
Paper: MOPR79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR79
About: Received: 17 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR82
Chemical robustness enhancement of negative electron affinity photocathodes through cesium-iodide deposition
646
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 the dark lifetime of both GaN and GaAs photocathodes activated with cesium. The mechanism behind this improvement is investigated using X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM) techniques.
Paper: MOPR82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR82
About: Received: 17 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR91
Particle motion in spatio-spectrally iso-diffracting ultrabroadband pulsed beams
672
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 spatio-temporal coupling (iso-diffracting). Motion of charged particles in these pulsed beams is considered analytically and numerically and energy gain is computed and compared with ponderomotive force laws. Particle motion in more complex pulsed-beam fields is also considered.
Paper: MOPR91
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR91
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR92
Evaluation of ultrafast THz near-fields for electron streaking
675
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 radiation to the acceleration structure. Applying the near-field of the lithium niobate source directly to the electron bunch removes losses due to transport and coupling, yielding a simplified and efficient system. Using electro-optic sampling we have reconstructed the full temporal 3D THz near-field close to the lithium niobate emission face and shown that it can be controlled by manipulating the generation setup. Analysis of the results of this measurement shows an estimated peak field strength of 86 MV/m. A future THz near-field electron streaking experiment is currently planned as a first test of manipulating an electron bunch with the THz near field. Analysis for this planned experiment has yielded an estimated THz near-field kick strength of 23 keV.
Paper: MOPR92
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR92
About: Received: 15 May 2024 — Revised: 28 May 2024 — Accepted: 28 May 2024 — Issue date: 01 Jul 2024
MOPR93
Neutron production using compact linear electron accelerators
678
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 performance of compact electron accelerators as neutron drivers and propose a preliminary target design for an X-band electron-linac-based neutron source.
Paper: MOPR93
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR93
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS02
Modeling interference of two first-order resonances with two Siberian snakes using machine learning
682
The model of spin depolarization invoking isolated resonances hinges on a closed-form solution of energy ramping with the Single Resonance Model by Froissart and Stora. However, for non-resonant orbital tunes, resonant depolarization by single resonance crossing is impossible in the SRM while using a pair of Siberian Snakes since the amplitude-dependent spin tune is then fixed to one-half. Polarization loss in RHIC demonstrates that the isolated resonances model is not a good approximation of polarization dynamics with two Siberian Snakes. We therefore extend the model in which a pair of resonances in close proximity push the amplitude-dependent spin tune away from one-half in the presence of Siberian Snakes, allowing the crossing of higher-order spin resonances associated with depolarization. We present results from applying Machine Learning methods that establish spin transport models with two overlapping resonances from tracking data.
Paper: MOPS02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS02
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPS03
Comprehensive modeling of Siberian Snakes in BNL’s AGS: symplectic tracking and optical compensation
686
Meaningful prediction and enhancement of spin-polarization in the RHIC/EIC accelerator complex relies on accurate modeling of each sub-component. Here we describe a symplectic field approximations of both Siberian Snakes in the AGS, enabling practical long-term tracking calculations. Without such symplectic representations, particle motion destabilizes very quickly close to injection energy. This optical instability manifests in $O(10^3)$ turns, and makes dynamic aperture smaller than realistic emittances. Combined with optimization using the Bmad toolkit, we implement steering and optical corrections of the snake effects at 80 distinct energies from injection to extraction, mimicking the measured lattice conditions at each energy. This process unveils unforeseen snake distortions of the vertical dispersion near injection energy, which are addressed. By interpolating between such optimized lattice configurations, Bmad's tracking capabilities allow advanced simulation of polarization transmission through the full AGS cycle.
Paper: MOPS03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS03
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPS07
Classification of potentials for self consistent symplectic space charge
702
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 functions suitable for an iterative algorithm with the Lie transform. Those functions will be used to describe the electromagnetic potential of the space charge.
Paper: MOPS07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS07
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPS09
Benchmark of AT vs MADX-PTC with exact integrators
709
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 for 6D tracking. Fringe fields models were not included in the comparison and are known to be different for the two codes.
Paper: MOPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS09
About: Received: 10 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS10
Koopman operator method for nonlinear dynamics analysis using symplectic neural networks
713
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 the symplectic condition is met without the use of symplectic integration or extra gradient calculations. Data driven methods are also useful for calculating Koopman operators which aim to simplify nonlinear dynamical systems into linear ones. By using SympNets, one can ensure that the transformation described by the Koopman operator is symplectic, reversible, and more easily trained.
Paper: MOPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS10
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS12
Axially symmetric e-lens based on McMillan map
721
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 close this gap and understand the limitations and potential of this device. We classify possible regimes with stable trajectories and provide set of canonical action-angle variables, along with an evaluation of the dynamical aperture, Poincar\'e rotation numbers as functions of amplitudes, and spread in nonlinear tunes.
Paper: MOPS12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS12
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPS13
Understanding sextupole
725
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 H\'enon quadratic map, a representation of a general transformation with quadratic nonlinearity. In the subsequent section, we unveil that a conventional sextupole is essentially a composite structure, comprising an integrable McMillan sextupole and octupole, along with non-integrable corrections of higher orders. This fresh perspective sheds light on the fundamental nature of the sextupole magnet, providing a more nuanced understanding of its far-from-trivial chaotic dynamics. Importantly, it enables the description of driving terms of the second and third orders and introduces associated nonlinear Courant-Snyder invariant.
Paper: MOPS13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS13
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPS14
Comparison of Bayesian optimization and the reduction of resonance driving terms in the optimization of the dynamic aperture of the BESSY III MBA lattice
729
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 next step, the focusing and de-focusing sextupole families are split up, to optimize the longitudinal and the transverse apertures. The paper compares two approaches to select the optimal sextupole strengths. The first one is multi-objective Bayesian optimization, where the dynamic aperture volume from tracking simulations is used as an objective to be maximized. The second approach does not involve tracking and minimizes the geometric and chromatic resonance driving terms. The comparison of the two results includes their quality in terms of the size of the achievable 3D dynamic aperture and the computational effort involved.
Paper: MOPS14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS14
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS18
Expansions of the integrability program for novel accelerators
744
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 completely integrable system for a charged particle in the transverse plane. However, certain generalizations of that paper fail to provide similar results. We provide insights into some reasons for failure, as well as discuss a set-up for establishing a 6D integrable Hamiltonian system, in order to include the possibility of acceleration.
Paper: MOPS18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS18
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPS24
PYG4OMETRY update: a tool to create geometries for Geant4, BDSIM, G4Beamline and FLUKA
763
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 realistic accelerators. This paper describes a flexible and easy to use Python package to create geometries usable by either Geant4 (and so BDSIM or G4Beamline) or FLUKA either from scratch or by conversion from common engineering formats, such as STEP or IGES created by industry standard CAD/CAM packages. This paper describes the updates to pyg4ometry since IPAC19. These updates include ROOT geometry loading, refactored geometry processing using CGAL, direct CAD file loading using OpenCASCADE, geometrical feature extraction and geometry comparison algorithms. The paper includes small examples of the new features with explanations.
Paper: MOPS24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS24
About: Received: 23 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS29
Multiphysics modeling of accelerators through code integration
775
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, and reduce the development and fabrication costs of accelerator research. We utilize the open-source VizSchema data standard as an intermediate data structure interface layer to standardize interfaces between individual application codes. VizScema is extensively documented online, and plugins for VizSchema are available for popular visualization packages, including VisIt and ParaView. Currently, the work focuses on coupling the EM field solver COMSOL and the electron gun code MICHELLE to allow COMSOL field-solve results to be seamlessly used by MICHELLE for particle-solve. Later work will extend this integration to include other fields, particles, and thermodynamics simulation codes.
Paper: MOPS29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS29
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPS30
High-performance magnet simulation software
778
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 acceleration with Nvidia graphics processing units. Integration into the VSim electromagnetics software allows users to design magnetic systems using existing graphical interface features. Example simulations of nonlinear magnets, with application to particle accelerator magnet design, will be shown.
Paper: MOPS30
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS30
About: Received: 22 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS37
Development of numerical tools for intra-beam scattering modelling
802
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 accurate formalism to describe IBS, and the integration of IBS in codes such as, e.g. MAD-X, is widely used in the accelerator physics community. This study presents the latest developments of a Python package for IBS simulations, recently developed at CERN, meant for integration with the Xsuite ecosystem. The new capabilities of the Python code are detailed and a thorough benchmark against existing codes is presented, for various machines of the CERN accelerator complex in different configurations.
Paper: MOPS37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS37
About: Received: 08 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPS42
Start-to-end simulations of microbunching instability based on optimized velocity bunching in linac-driven FELs
817
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 dual-mode buncher cavity with the third harmonic mode used to correct the RF curvature, in combination with the evolutionary many-objective beam dynamics optimization, it is potential for the electron beam to be further compressed in velocity bunching (VB) process. Therefore, a VB plus one bunch compressor could be a promising alternative scheme to achieve moderate peak current beam for X-ray FELs. Start-to-end simulations based on the Shanghai high-repetition-rate XFEL and extreme light facility proves the feasibility of the scheme in suppressing the additional MBI gain due to multi-stage magnetic bunch compressors.
Paper: MOPS42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS42
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPS56
Imparting arbitrary correlation on longitudinal phase space using transverse wigglers and deflecting cavities
844
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 deflecting cavities. Deflecting cavities introduce and eliminate linear correlation between longitudinal and transverse coordinates. We located transverse wigglers, which impart arbitrary correlation on the transverse phase space, where the longitudinal-to-transverse correlation is maximized. In principle, this system only requires deflecting cavities operating in the same frequency and several magnets such as transverse wigglers and quadrupoles.
Paper: MOPS56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS56
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPS57
Proposal for a proton-bunch compression experiment at IOTA in the strong space-charge regime
848
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 fixed-energy storage ring that can circulate a 2.5-MeV proton beam with varying beam parameters and lattice configurations. The study will aim to demonstrate a bunch-compression factor of at least 2 in the IOTA ring while examining the impact of intense space-charge effects on the compression process.
Paper: MOPS57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS57
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS61
Change of Hamiltonian during longitudinal separatrix crossing
860
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 change of Hamiltonian. Previous attempts at this calculation were unsatisfactory: either plagued by singularities, or limited to probabilistic results for linear variation of the confining potential. Previously*, we presented formulae for the changes in Hamiltonian (due to modulation and bunching) before and after separatrix crossing; and those contributions to emittance growth are equally or more important. Together, the three results provide a complete, analytic description of near-adiabatic capture into an RF bucket.
Paper: MOPS61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS61
About: Received: 03 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPS67
Experimental verification of integrability in a Danilov-Nagaitsev lattice using machine learning
878
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 Poincaré estimates conserved quantities from experimental data without prior knowledge of the invariant structure, showing qualitative agreement with theoretical predictions. Additionally, one of the two learned invariants exhibits comparable or better conservation compared to known theoretical expressions.
Paper: MOPS67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS67
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS68
Automated optimization of accelerator settings at GSI
882
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 manipulations. Geoff (Generic Optimization Framework & Frontend) is an open-source framework that harmonizes access to the above automation techniques and simplifies the transition towards and between them. It is maintained as part of the EURO-LABS project in cooperation between CERN and GSI. In dedicated beam experiments, the beam loss of the multi-turn injection into the SIS18 synchrotron has been reduced from 40% to 10% in about 15 minutes, where manual adjustment can take up to 2 hours. Geoff has also been used successfully at the GSI Fragment Separator (FRS) for beam steering. Further experimental activities include closed orbit correction for specific broken-symmetry high-transition-energy SIS18 optics with Bayesian optimization in comparison to traditional SVD-based correction.
Paper: MOPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS68
About: Received: 06 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS69
Harnessing machine learning for the optimal design of ILC e-driven positron source
886
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, providing opportunities for exploring physics beyond the Standard Model. A critical component of the ILC is the E-driven positron source, which requires sophisticated technology to produce large quantities of positrons. Traditional accelerator design methods involve sequential optimization, which is inefficient and challenging for achieving global optimization. This study introduced the use of the Tree-structured Parzen Estimator (TPE) algorithm, a black-box optimization method, to improve the design efficiency of the ILC E-driven positron source. By implementing the TPE algorithm using Optuna, we optimized up to 8 parameters, achieving a positron capture efficiency of 1.42, significantly higher than the 1.20 efficiency obtained through manual optimization. This substantial improvement is expected to meet the safety standards for target destruction. The optimization process was also expedited, reducing the time from about a week to approximately half a day. These results demonstrate the potential of machine learning techniques in accelerator design, offering a more comprehensive global optimization by exploring a broader parameter space and avoiding local minima.
Paper: MOPS69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS69
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS72
Solving the Orszag-Tang vortex magnetohydrodynamics problem with physics-constrained convolutional neural networks
897
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, non-negativity of density and use of only relevant variables. Translation equivariance was present from the convolutional architecture. The use of a residual architecture and data augmentation was found to increase performance greatly. The most accurate models were incorporated into the simulation, with reasonably accurate results. For the prediction task, the PCNNs were evaluated against a physics-informed neural network (PINN), which had the ideal MHD induction equation as a soft constraint. The use of PCNNs for MHD has the potential to produce physically consistent real-time simulations to serve as virtual diagnostics in cases where inferences must be made with limited observables.
Paper: MOPS72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS72
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS74
Accelerator system parameter estimation using variational autoencoded latent regression
905
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 the LANSCE accelerator) makes it difficult to achieve optimal operation. The time-varying drifts and the dimensionality make system parameter estimation a challenging optimization problem. In this work, we propose a variational autoencoded latent regression (VAELR) model for robust estimation of system parameters using 2D unique projections of a charged particle beam's 6D phase space. In VAELR, VAE projects the phase space projections into a lower-dimensional latent space, and a dense neural network maps the latent space onto the space of system parameters. The trained network can predict system parameters for unseen phase space projections. Furthermore, VAELR can generate new projections by randomly sampling the latent space of VAE and also estimate the corresponding system parameters.
Paper: MOPS74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS74
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS75
Towards latent space evolution of spatiotemporal dynamics of six-dimensional phase space of charged particle beams
909
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. In this work, we have proposed a temporally structured variational autoencoder model to autoregressively forecast the spatiotemporal dynamics of the 15 unique 2D projections of 6D phase space of charged particle beam as it travels through the LANSCE linear accelerator. In the model, VAE embeds the phase space projections into a lower dimensional latent space. A long-short-term memory network then learns the temporal correlations in the latent space. The trained network can evolve the phase space projections across further modules provided the first few modules as inputs. The model predicts all the projections across different modules with low mean squared error and high structural similarity index.
Paper: MOPS75
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS75
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPS79
Modeling and optimization of the FACET-II injector with machine learning algorithms
913
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 model that predicts the results instead of simulating them. Simple neural networks take milliseconds to compute the results. The ability to make physics predictions in almost real time opens a world of online models that can predict diagnostics which typically are destructive to the beam when measured. This research entailed the incorporation of an innovative simulation infrastructure for the SLAC FACET-II group, aimed at optimizing existing physics simulations through advanced algorithms. The new infrastructure saves the simulation data at each step in optimization and then improves the input parameters to achieve a more desired result. The data generated by the simulation was then used to create a machine learning model to predict the parameters generated in the simulation. The machine learning model was a simple feedforward neural network and showed success in accurately predicting parameters such as beam emittance and bunch length from varied inputs.
Paper: MOPS79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS79
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS81
Implementing betatron radiation for beam diagnostics studies
917
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.
Paper: MOPS81
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS81
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPS82
Discovering transient models of emittance growth via mode interaction of phase space nonuniformities
921
One of the Grand Challenges in beam physics is development of virtual particle accelerators for beam prediction. Virtual accelerators rely on efficient and effective methodologies grounded in theory, simulation, and experiment. We will address one sample methodology, extending the understanding and the control of deleterious effects, for example, emittance growth. We employ the application of the Sparse Identification of Nonlinear Dynamical systems algorithm–previously presented at NAPAC’22 and IPAC’23–to identify emittance growth dynamics caused by nonuniform, empirical distributions in phase space in a linear, hard-edge, periodic FODO lattice. To gain further understanding of the evolution of emittance growth as the beam’s distribution approaches steady state, we compare our results to theoretical predictions describing the final state emittance growth due to collective and N-body mode interaction of space charge nonuniformities as a function of free-energy and space-charge intensity. Finally, we extend our methodology to a broader range of virtual and real experiments to identify the growth(decay) of (un)desired beam parameters.
Paper: MOPS82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS82
About: Received: 22 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUAD2
Correcting asymmetry of closed-orbit distortion in J-PARC main ring by reducing current ripples of main magnet power supplies
931
The main ring (MR) of the Japan proton accelerator research complex (J-PARC) delivers the high-intensity proton beams to the T2K long-baseline neutrino experiment. To observe charge-conjugation and parity-transformation violation in the lepton sector with high accuracy, the upgrade of the MR toward the beam power of 1.3 MW is mandatory. The magnet power supply system of MR was upgraded for this purpose during the long-term shutdown period in FY2021. However, the asymmetry of the closed-orbit distortion (COD) was observed after the upgrade. The cause of the asymmetry was attributed to the large ripples of the excitation currents for the bending magnets. The measures to reduce the ripples were applied to six identical power supplies for the bending magnets, and then the asymmetry was successfully corrected. This result suggests the tune region of the stable beam operation is expected to be improved since the effect of the non-structure resonance should be suppressed. This presentation reports the scheme of the ripple reduction for the excitation currents of the bending magnets and the measurement results of the COD in the MR.
Paper: TUAD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUAD2
About: Received: 14 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUAN1
Beam loss and beam emittance minimization at J-PARC RCS for simultaneous operation to the MLF and MR
939
The 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC (Japan Proton Accelerator Research Complex) simultaneously delivers high-intensity proton beam to the muon and neutron production targets at the MLF (Material and Life Science Experimental Facility) as well as to the MR (Main Ring). Beam loss mitigation is highly essential not only to keep the machine activation lower for maintaining a stable operation with high availability, but also to ensure a high-quality beam having a lower beam emittance and minimum beam halos. We have performed systematic numerical simulations and beam studies and implemented several measures, such as resonance corrections, optimization of the longitudinal and transverse paintings and also optimization of the betatron tune. We have obtained significant beam loss mitigation as well as beam emittance improvement for the beam delivered to both MLF and the MR. Recently, a transverse painting area of 50π mm·mrad has been increased to 100π mm·mrad implemented for the MR beam. This gives a half reduction of the average foil hitting of the circulating beam. As a result, not only the uncontrolled foil scattering beam losses but also the beam loss at the collimator have been reduced to half. Such improvements in the RCS have also been well recognized at both MLF and the MR by reducing the beam losses at the beam transport as well as each facility. The RCS has been continued a sustainable operation with record high of nearly 99% availability.
Paper: TUAN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUAN1
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUAN3
Understanding of the LHC warm vacuum module heating
947
During the third run of the Large Hadron Collider in 2023, which had the highest intensity bunch population compared to previous runs, increased losses attributed to pressure spikes within a warm vacuum sector triggered a beam dump. Subsequent inspections revealed localised annealing and plasticisation of the tension spring in the sliding contact radio-frequency finger module, alongside traces of vapour deposition on the various module components with the stainless-steel spring material. A comprehensive analysis involving vacuum and beam impedance studies was conducted to investigate the triggering mechanisms behind the radio-frequency finger module failure. The findings indicate localised beam-induced heating, which could lead to the annealing of the spring with a consequent cascade of effects. Additionally, investigations of potential mitigation measures were performed.
Paper: TUAN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUAN3
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUBD3
Analyzing sudden beam loss in the SuperKEKB/Belle-II experiment with RFSoC technology
959
In the SuperKEKB/Belle-II experiment, a multitude of elementary particle reactions is initiated through the collision of 4 GeV positrons with 7 GeV electrons, paving the way for the exploration of new physics. The experiment includes plans for the substantial enhancement of luminosity in the future, aiming to achieve an integrated luminosity approximately 100 times the current level. However, the realization of this goal is impeded by a recurrent occurrence of a phenomenon known as "Sudden Beam Loss," which entails the abrupt disappearance of the beam within tens of microseconds. The cause and location of these occurrences have not yet been identified. To provide the tools to diagnose and debug these sudden beam loss events, a new Bunch Oscillation Recorder (BOR) has been developed to analyze this phenomenon, utilizing the Radio Frequency System on Chip (RFSoC) from AMD/Xilinx. The beam position of each individual bunch is measured and recorded by the BOR just prior to the onset of sudden beam loss. We will present how the signal from the button beam position monitor of the beam pipe is processed by RFSoC, along with the results obtained from observing the actual SuperKEKB beam using RFSoC.
Paper: TUBD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUBD3
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUBN1
Multicell dielectric disk accelerating structure high power experiment results
963
A Dielectric Disk Accelerator (DDA) is a metallic accelerating structure loaded with dielectric disks to increase its shunt impedance. These structures use short RF pulses of 9 ns to achieve accelerating gradients of more than 100 MV/m. Single cell and multicell clamped structures have been designed and high power tested at the Argonne Wakefield Accelerator. During testing, the single cell clamped DDA structure achieved an accelerating gradient of 102 MV/m with no visible damage in the RF volume region. The minimal damage that was seen outside the RF volume was likely due to RF leakage from uneven clamping during assembly. Based on the success of that experiment, a clamped multicell DDA structure has been designed and tested at high power. Simulation results for this new structure show a 108 MV/m accelerating gradient with 400 MW of input power with high shunt impedance and group velocity. Engineering designs were improved from the single cell structure for a more consistent clamping over the entire structure. Up to this point in the high power experiments, the results show a peak input power of 222 MW correlating to an accelerating gradient of 80 MV/m. Testing of this structure will continue January 2024.
Paper: TUBN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUBN1
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUCN2
Machine learning for orbit steering in synchrotrons
977
In the latest years Machine Learning (ML) has seen an unprecedented diffusion in the most different fields in simulations and real life as well. Probably two of the first and most used ML applications in accelerators are the optimization of the final performance of the machines, and the so called virtual diagnostics. In the latest years ML was successfully applied to improve the machine safety performing fault detection or to prevent interlocks. In this work we explored the possibility to use a ML approach to efficiently steer the beam in case the lattice contains high order magnets (sextupolar order and higher). We applied this scheme to SLS 2.0, the synchrotron upgrading at the Paul Scherrer Institut.
Paper: TUCN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUCN2
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPC02
Design of a two-cell C-band accelerator cavity with higher-order mode damping
989
Higher-order mode (HOM) damping is essential for building large-scale facility linear accelerators, such as a linear collider, because of the need to reduce the wakefield strength inside the accelerating structure. We designed a C-band accelerator cavity with distributed coupling and thin HOM-damping waveguides oriented in the radial direction. It was proposed that nickel-chrome (NiCr) coating deposited on the surface of the thin waveguides will be used to increase the surface resistivity and to damp the HOMs. Recently, we designed a two-cell cavity to conduct a concise high power test that will help us understand the fabrication challenges for the cavity with NiCr HOM absorbers, and examine the performance of the NiCr coating under high-power conditioning. This presentation will report the detailed electromagnetic and engineering design of the cavity, the theoretical prediction of the cavity high-gradient performance, the status of fabrication, and plans for high-gradient testing.
Paper: TUPC02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC02
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC03
Multi-bunch beam dynamics studies for the C3 main linac
992
The Cool Copper Collider (C3) is a novel accelerator concept for a linear collider utilizing a cryogenically-cooled copper linear accelerator (linac) with a distributed coupling architecture. The C3 main linac is designed to accelerate electron/positron from 10 GeV to 125 GeV while preserving the beam emittance. Here we present the analysis of the multi-bunch beam dynamics for the C3 main linac. We show the beam dynamics simulation results of the C3 main linac to identify the frequency bands that cause emittance growth and the amount of frequency detuning required to suppress it. Results presented will be used to guide the future design of the accelerating structure.
Paper: TUPC03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC03
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC05
Correction of horizontal partial snake resonances with pulsed skew quadrupoles at the Brookhaven AGS
1000
Proton polarization is preserved in the AGS by using helical dipoles partial snakes to avoid depolarizing vertical resonances. These same helical dipoles also drive numerous (82) weak horizontal resonances that result in polarization loss. These horizontal resonances occur at the same energy (and therefore frequency) as depolarizing resonances driven by linear betatron coupling. A new scheme has therefore been implemented to correct the snake-driven resonances with the placement of skew quadrupoles in the AGS ring powered to cancel the resonance driving term at each horizontal resonance crossing. The skew quadrupoles are required to pulse independently for each resonance to account for the variation of drive term phasing with energy. Fifteen thin skew quadrupoles have been installed in the AGS ring to implement this correction. We describe the correction principle, the magnet design and commissioning results from RHIC Run 24.
Paper: TUPC05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC05
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPC10
RF system upgrade for 1.3 MW operation of J-PARC main ring
1017
The J-PARC Main Ring accelerates proton beam from 3 GeV to 30 GeV and delivers it to T2K neutrino experiment with fast extraction and hadron experiments with slow extraction. In the last two years the beam power to the neutrino experiment was increased from 500 kW to 750 kW. The T2K detector is scheduled to be replaced by the new Hyper-K detector; the latter will be able to accept a 1.3 MW proton beam by 2028. To achieve 1.3 MW beam power, J-PARC plans to upgrade the Main Ring by increasing intensity and repetition rate. The Main Ring uses low frequency, high bandwidth RF cavities with Magnetic Alloy cores, powered by two 600 kW tetrode tubes. Under the upgrade plan, the number of RF cavities will be increased to secure the RF voltage and longitudinal acceptance. The anode power supply will be upgraded to provide enough current for both gap voltage and beam loading compensation. The upgraded LLRF system will be optimized to control fundamental and 2nd harmonic RF voltages, suppress coupled bunch instabilities and compensate beam loading effects. Current operational status as well as details of the upgrade plan and related simulation results will be discussed in this paper.
Paper: TUPC10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC10
About: Received: 20 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPC11
Advancements in the development of beam dynamics software APES for CEPC
1021
The design and study of the Circular Electron Positron Collider (CEPC) present a significant challenge, requiring the proper modeling of various physical phenomena such as the crab-waist collision scheme with a large Piwinski angle, strong nonlinear effects, energy sawtooth, beam-beam interactions, and machine impedances. In response to this challenge, the APES software project was proposed in 2021 and received support from the IHEP Innovative Fund in 2022. This paper provides an overview of the progress made in the APES project, encompassing modeling for special cases, orbital and spin tracking with synchrotron radiation, optics and emittance calculation, particle tracking, and more. Additionally, the paper discusses future developments.
Paper: TUPC11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC11
About: Received: 11 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC14
Application and comparative analysis of the APES_CBI module in BEPC-II experimental results
1033
In this paper, we delve into the application and comparative analysis of the Accelerator Physics Emulation System Cavity-Beam Interaction (APES_CBI) module within the BEPC-II (Beijing Electron-Positron Collider) experiments. We developed the APES_CBI module as an advanced time-domain solver, specifically designed to analyze RLC circuits driven by beam and generator currents and to simulate the dynamic responses and synchrotron oscillations of charged particles within the cavity. We begin by discussing our method for solving RLC parallel circuits, followed by an explanation of the logical architecture of our program. In the second part, we detailed our simulation results, starting with the BEPC-II electron ring. By comparing these results with experimental data, we validate the reliability of our simulations, showcasing our module's ability. Additionally, we extend our simulations to the CEPC Higgs mode on-axis injection conditions and studied the transient phase response to the sudden change of beam pattern.
Paper: TUPC14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC14
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC20
Simulating a 6D cooling channel in BDSIM
1050
Muon colliders hold promise for high luminosity multi-TeV collisions, without synchrotron radiation challenges. However, this involves investigation into novel methods of muon production, acceleration, cooling, storage, and detection. Thus, a cooling demonstrator has been proposed to investigate 6D muon ionization cooling. The MICE experiment validated ionization cooling to reduce transverse emittance. The demonstrator will extend this to also cool longitudinal emittance. It would also use bunched beams instead of single particles from a muon source. The 6D cooling lattice comprises successive cells which consist of: solenoids for tight focusing, dipoles to introduce dispersion in the beam, wedge-shaped absorbers for differential beam absorption, and RF cavities for reacceleration. In this paper, the simulation and further optimization of the rectilinear cooling channel is discussed. This analysis extends existing theoretical and numerical work using BDSIM, a Geant4-based accelerator framework built to simulate the transport and interaction of particles. The study also incorporates beams from existing proton drivers, using output from targetry and capture designs for the same.
Paper: TUPC20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC20
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPC22
Optimisation of a permanent magnet multi-energy FFA arc for the CEBAF energy upgrade
1053
It is currently planned to increase the energy of the CEBAF recirculating linear accelerator to 20 GeV or more by adding two new recirculating arcs that contain multiple new energy passes. The beam is continuous (CW), so no field ramping is desired, making this a fixed-field accelerator (FFA). The wide energy range requires a low dispersion lattice that can be created with high-gradient permanent magnets. One constraint is the existing tunnel radius in relation to the fields achievable by practically-sized permanent magnets. Thus, searching for the most efficient implementation in terms of magnet material volume is important. In this paper, a lattice cell search and optimization is conducted that evaluates cells by the magnet volume per unit length, with the permanent magnet designs also produced via an automated code. The new lattice cells are compared to the previous manually designed cell.
Paper: TUPC22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC22
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPC23
Beam correction for multi-pass arcs in FFA@CEBAF: status update
1057
This work examines the multi-pass steering of six electron beams in an FFA arc ranging from approximately 10.5 GeV to 22 GeV. Shown here is an algorithm based on singular value decomposition (SVD) to successfully steer all six beams through the arc given precise knowledge of all beam positions at each of one hundred and one diagnostic locations with one hundred individual corrector magnets: that is successive application of SVD to different 100 × 101 response matrices—one for each beam energy. Further, a machine learning scheme is developed which only requires knowledge of the energy-averaged beam position at each location to provide equivalent steering. Extension of this scheme to other beam optics quantities as well as transverse and longitudinal coupling is explored.
Paper: TUPC23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC23
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPC29
Optimization of nanostructured plasmas for laser wakefield acceleration using a Bayesian algorithm
1064
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.
Paper: TUPC29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC29
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPC30
Active control of the energy chirp of a relativistic electron beam at the Argonne Wakefield Accelerator
1068
A very high electron peak current is needed in many applications of modern electron accelerators. To achieve this high current, a large energy chirp must be imposed on the bunch so that the electrons will compress when they pass through a chicane. In existing linear accelerators (LINACs), this energy chirp is imposed by accelerating the beam off-crest from the peak fields of the RF cavities, which increases the total length and power requirements of the LINAC. A novel concept known as the Transverse Deflecting Cavity Based Chirper (TCBC) [1] can be used to actively impose a large energy chirp onto an electron beam in an accelerator, without the need for off-crest acceleration. The TCBC consists of 3 transverse deflecting cavities, which together impose an energy chirp while cancelling out the transverse deflection. An experiment is being developed to demonstrate this concept at the Argonne Wakefield Accelerator (AWA) facility. Here we explain the concept, show preliminary simulations of the experiment, and report on progress related to implementation of the experiment at AWA.
Paper: TUPC30
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC30
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPC32
High-current deuteron accelerator for neutron production
1071
A novel deuteron accelerator concept, the deuteron cyclotron auto-resonance accelerator (dCARA) is presented here, with (a) an analytical theory to characterize a simplified model for dCARA, (b) simulated tracks of deuteron orbits in a more realistic model for dCARA, and (c) CST-Studio particle-in-cell simulations for high-current deuteron beams in a realistic dCARA. These predict that dCARA will produce a high-current multi-MeV beam of accelerated deuterons along an axis parallel to, but displaced from, the center conductor of a coaxial resonator immersed in a uniform static magnetic field. The example presented, where the magnetic field strength is 7.0 T (for cyclotron auto-resonance at 53.0 MHz), acceleration of a 100 mA deuteron beam from 60 keV to 35 MeV is predicted to occur along a 2.8 m long half-wave resonant cavity, with an efficiency of 88%. Such a beam could be highly competitive with that produced either with linacs or cyclotrons for an application to produce, via deuteron stripping, a high flux of neutrons with an energy spectrum centered near 14.1 MeV, as needed for testing inner-wall materials for a future deuterium-tritium fusion power reactor.
Paper: TUPC32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC32
About: Received: 16 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC34
Magnetic compression method for macro pulses of relativistic electron beam
1074
We developed a magnetic compression method for relativistic electron beam macro-pulses. Our device, with a significantly larger transfer function R56 compared to the classical chicane structure, enables nanosecond-scale compression of relativistic electron pulses using a compact apparatus measuring just a few meters. This paper introduces the principles of this compression method and presents the results of dynamic simulations.
Paper: TUPC34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC34
About: Received: 13 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPC35
DONES-ConP1 project: consolidating the start of the IFMIF-DONES construction phase
1076
IFMIF-DONES is an ESFRI facility based on a 5 MW deuteron accelerator currently under construction in Granada (Spain) as part of the European roadmap to fusion electricity. Its main goal is to characterize and qualify materials under a neutron field with an induced damage like the one faced in a fusion reactor, developing a material database for the future fusion nuclear reactors. Moreover, a list of medium neutron flux experiments in other irradiation areas for fusion and non-fusion applications have been identified previously and are under analysis. The construction phase was officially launched from March 2023, after setting up the steering committee for the DONES Program composed of several countries. To support the preparation of the key documentation and consolidate contributions from parties, a set of tasks is being developed within the framework of the new DONES Consolidation Phase project (DONES-ConP1). In this contribution, the main objectives of the project such as the drafting of the acceptance tests for the procurement, the first version of the irradiation plan for fusion and non-fusion applications, or the update of key project documentation will be discussed.
Paper: TUPC35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC35
About: Received: 20 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPC41
Adaptation of the Fermilab proton source to support new muon facilities
1100
The PIP-II proton accelerator will provide the intensity sufficient to power a new generation of high energy facilities at Fermilab. Extension of that linac to higher energy with following acceleration and bunching rings could provide the intensity needed to feed a muon production target for a high-energy μ+-μ- collider. Scenarios using a rapid-cycling synchrotron or an ~8 GeV Linac are presented and discussed. Use of the existing Fermilab accelerators is also discussed. Support for other high-intensity experiments such as muon-ion collisions, neutrino sources and lepton flavor conservation is also considered.
Paper: TUPC41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC41
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC44
Single bunch tracking on the ten-pass ER@CEBAF energy recovery beamline
1108
The proposed ten-pass energy recovery linac (ERL) demonstration (five accelerating, five decelerating) at the CEBAF accelerator, ER@CEBAF, involves a multi-GeV energy range of a continuous electron beam. New CEBAF transverse optics were designed for this ERL demonstration. This redesign incorporates additional components in Arc A, including a path length chicane and new quadrupoles to ensure proper dispersion localization. The new five energy recovery passes with a shared arc transport scheme challenge the overall beamline optics design, including large beta functions in the CEBAF spreaders and recombiners. Here we discuss results of bunch tracking performed using the elegant tracking code for the full ER@CEBAF beamline.
Paper: TUPC44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC44
About: Received: 06 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPC55
Various methods for computing dominant spin-orbit resonance strengths in storage rings
1129
The strength of a first-order spin-orbit resonance is defined as the amplitude of the corresponding Fourier component of the spin-precession vector. However, it is possible to obtain the resonance strength without computing the Fourier integral directly. If a resonance is sufficiently strong, then to a good approximation, one can neglect all other depolarizing effects when near the resonance. Such an approximation leads to the single resonance model (SRM), for which many aspects of spin motion are analytically solvable. In this paper, we calculate the strength of first-order resonances using various formulae derived from the SRM, utilizing spin tracking data, the direction of the invariant spin field, and jumps in the amplitude-dependent spin tune. Examples are drawn from the RHIC Blue ring.
Paper: TUPC55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC55
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPC70
Effects of dipole power converter ripple during empty-bucket channelling
1168
In 2023, an RF technique known as empty-bucket channelling was implemented operationally at the CERN Super Proton Synchrotron (SPS) to improve the quality of the spill provided to the North Area experiments. Empty-bucket channelling suppresses particle-flux variations during resonant slow extraction by accelerating particles between empty RF buckets and rapidly displacing particles into the tune resonance via chromatic coupling. The flux variations are often caused by the power converter ripple present in the synchrotron’s magnets, which modulates the beam dynamics during the extraction process. In a chromatic extraction, the quadrupole ripple is the main contribution to the modulation as it directly perturbs the transverse tune. When empty-bucket channelling is applied, however, dipole ripple additionally modulates the size of the empty RF bucket. In this contribution, the phenomenon is explored and the consequences for empty bucket channelling in the SPS are outlined.
Paper: TUPC70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC70
About: Received: 30 Apr 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPC78
Normalized uniformity-based common points layout optimization method for alignment installations
1196
The alignment installation work of Hefei Advanced Light Facility (HALF) is usually carried out in tunnels. Calculate the key component points to the global coor-dinate system through coordinate conversion, and accu-rately adjust them to the corresponding coordinate values for alignment and installation. However, long and narrow tunnels can easily cause dense common points, resulting in a loss of accuracy. Therefore, to quickly and accurately obtain the coordinate transformation parameters, this article proposes a common point selection method with uniformity normalization and selects the optimal com-mon points set based on the normalized uniformity in different directions. The feasibility of this method was verified based on experimental data. The results show that the conversion parameters solved by this method are more accurate, avoiding accuracy loss due to aggregation in a certain direction, and are suitable for long and narrow tunnels.
Paper: TUPC78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC78
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC79
Future upgrades for GANIL
1199
We will present the plans and ideas for the next upgrades as discussed for the GANIL-SPIRAL2 installation in France. Recently, a report "French roadmap for Nuclear, Particle, and Astroparticle physics, along with associated technical developments and applications." were produced. It particularly focused to “The future of GANIL”. This was further enriched through extensive discussions by an international expert committee led by Michel SPIRO. These endeavors aim to push the boundaries of research capabilities at GANIL-SPIRAL2 during the next decades. Since the starting up in 1983, 40 years ago, successful exploitation with stable beams at the cyclotrons of GANIL, the laboratory has continuously evaluated and enhanced its capabilities. The latest evolution was the starting up of the SPIRAL2 facility. Today GANIL, with its state-of-the-art installations, including cyclotrons, a linear accelerator, and experimental areas, presents unique opportunities for cutting-edge research. The next upgrades under discussion are to be presented. Involving increasing beam intensities, exploring new exotic nuclei. Endeavors that aim to push the boundaries of research capabilities at GANIL-SPIRAL2 for the next decades.
Paper: TUPC79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC79
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPC83
A high-power positron converter based on a recirculated liquid metal in-vacuum target
1210
An effective high-power positron converter for electron linear accelerators is not currently available from industry. A commercial source would allow research institutes to have ready access to high-brightness positrons for a wealth of material science, nuclear, particle, and accelerator physics projects. Xelera Research LLC has designed, built, and tested a prototype free-surface liquid-metal (GaInSn) jet converter. Free-surface liquid-metal jets allow for significantly greater electron beam power densities than are possible with solid targets. Higher power densities lead to greater positron production and, importantly, allow continuous wave (CW) operation. A modified version of the GaInSn converter prototype is planned to be constructed and tested at the Thomas Jefferson National Accelerator Facility.
Paper: TUPC83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC83
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPG29
Present status and future project of Synchrotron Light Sources at KEK
1286
Two synchrotron radiation sources, the 2.5 GeV Photon Factory Storage Ring (PF ring) and the 6.5 GeV Photon Factory Advanced Ring (PF-AR), have been in stable operation at the High Energy Accelerator Research Organization (KEK) for over 40 years. This paper first describes the current operational status and recent developments at PF. Next, a new concept of hybrid light source (PF-HLS) combining the advantages of a superconducting linac and a low-emittance storage ring is described. In the preliminary design, the energy range is from 2.5 GeV to 5.0 GeV, and the storage ring will be constructed in a green field with a circumference of 750 m. The design baseline for superconducting linac uses the International Linear Collider (ILC) specifications.
Paper: TUPG29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG29
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
TUPG33
Investigations in turn-by-turn optics measurements at KARA
1294
The Karlsruhe Research Accelerator (KARA) is a synchrotron light source user and test facility, operating at an electron beam energy ranging from 0.5 to 2.5 GeV. Performing optics measurements and comparing with the machine model promises an improved understanding of the lattice and the underlying beam dynamics. Horizontal and vertical turn-by-turn Beam Position Monitor data are acquired and used for performing optics measurements in this storage ring. The results of these studies are presented in this paper.
Paper: TUPG33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG33
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG34
Networking activities of the I.FAST project in the high brightness accelerator for light sources
1298
The Innovation Fostering in Accelerator Science and Technology (I.FAST) project aims to enhance innovation in the particle accelerator community, mapping out and facilitating the development of breakthrough technologies common to multiple accelerator platforms. Task 7.2 of the I.FAST project, Enabling Technologies for Ultra Low Emittance Rings, focuses on networking in the area of low emittance rings dominated by the recent X-ray storage ring upgrades and exploiting synergies with existing and future e+/e- colliders. Strengthening networking activities in essential technologies ranging from magnet design, RF systems, vacuum, injection systems to feedback systems and beam instrumentation leads to a state where technological difficulties are shared, so that the R&D path is strongly linked to other facilities and scientific fields. Such a state also stimulates joint organizations to collaborate on projects with organic links worldwide. To facilitate networking, Task 7.2 has so far organized several thematic workshops, and is planning further workshops to prepare opportunities to strengthen networking. In this contribution we present our activities in the past and for the future.
Paper: TUPG34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG34
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG35
ALS-U accumulator ring raft and dipole installation
1302
The ALS-U project is an upgrade to the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory that aims to deliver diffraction-limited x-ray beams with an increased beam brightness of two orders of magnitude for soft x-rays compared to the current ALS facility. A nine-bend achromat lattice Storage Ring (SR) and a three-bend achromat Accumulator Ring (AR) will be installed in the facility in two phases. The AR is currently being installed in the ALS facility during its regularly planned shutdowns while the SR upgrade will follow during a 12 months shutdown. AR rafts and dipoles are being installed with ground based tooling and overhead crane lifting methods. This paper focuses on the AR installation. In particular we will describe the engineering design, prototyping and testing of the customized ground based installation tooling, which led to a successful installation of the first AR production rafts and dipoles in the ALS tunnel.
Paper: TUPG35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG35
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG40
Status of beam commissioning at NanoTerasu
1320
NanoTerasu is a new 3 GeV compact soft X-ray (SX) light source having a circumference of 349 m constructed in Japan. The lattice structure is a type of multi-bend achromat with design emittance values of 1.14 nm·rad and 10 pm·rad, respectively. A target stored current is set to 400 mA to provide a high coherence and highly brilliant light from extreme ultraviolet to SX range. The injector LINAC commissioning was started in April 2023. After first 10 days, the beam energy successfully reached 3 GeV with the designed emittance. The 3 GeV C-band full-energy injector LINAC enables the extension to the SX free electron laser in the future. The storage ring beam commissioning was started on June 8th. We achieved the off-axis beam injection just adjusting beam injection trajectory from the beginning of the beam commissioning. As a result of the precise alignment of the magnets, the injected beam turned around 300 turns without the supply of RF power and the adjustment of the steering magnets on the first day of the commissioning. The stored current was reached 300 mA with top-up beam injection in November. The user operation will be started in April 2024. The creation of COD and tune correction tables for the insertion device is also in progress including non-linear magnetic field correction. We try to start the user operation with designed 400 mA top-up beam injection. The status of beam commissioning will be presented.
Paper: TUPG40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG40
About: Received: 12 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG46
Error analysis and commissioning simulations for the SSRF-U lattice
1342
SSRF-U, a 3.0 GeV diffraction limited storage ring lattice with emittance of 53.2 pm∙rad, is an alternative to SSRF for future upgrades. A large number of high-field intensity and multi-function magnets are used in this compact lattice, which greatly increases the error sensitivity to the beam. To quickly complete beam commissioning and achieve stable operation in the future, error analysis and commissioning simulations were studied during the design phase. In this paper, we present commissioning simulations for the SSRF-U and analyze the lattice error acceptance depending on the simulation results at each stage.
Paper: TUPG46
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG46
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG48
Operational status of synchrotron SOLEIL
1350
The synchrotron SOLEIL is the French third-generation 2.75 GeV synchrotron light source, a research laboratory at the forefront of experimental techniques for the analysis of matter down to the atomic level, and a service platform open to all scientific and industrial communities. We present the performance of the accelerators, which deliver extremely stable photon beams to 29 beamlines. We report on last year's overall performance figures and the operation of the brand-new cooling station. As the optimization of the energy and carbon footprint becomes more and more prevalent in France and Europe, actions for a more sustainable operation are given. Several incidents are also presented, together with the lessons learned to avoid recurrence. Major research and development activities related to component obsolescence and the SOLEIL II project will also be presented.
Paper: TUPG48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG48
About: Received: 20 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR02
Advancements in X-band technology at the TEX facility at INFN-LNF
1421
In anticipation of the Eupraxia@SPARC_LAB project at the INFN Frascati National Laboratories, an intensive testing and validation activity for the X-band RF system has commenced at the TEX test facility. The Eupraxia@SPARC_LAB project entails the development of a Free-Electron Laser (FEL) radiation source with a 1 GeV Linac based on plasma acceleration and an X-band radiofrequency (RF) booster. The booster is composed of 16 high-gradient accelerating structures working at 11.994GHz. All radiofrequency components comprising the basic module of the booster, from the power source to the structure, must undergo testing at nominal parameters and power levels to verify their reliability. For this reason, since 2021, several experimental runs have been conducted to test various components in X-band technology at the TEX facility. This paper presents the results obtained thus far from the different experimental runs, and it also outlines the future upgrade of the facility, which will enhance testing capabilities and the future prospects of the facility itself.
Paper: TUPR02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR02
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR10
Preliminary results on X-Band structures for the Eupraxia@SPARC_LAB project
1436
The Eupraxia@SPARC_LAB project involves the development of a 1 GeV normal conducting Linac with an S-band injector followed by an X-band booster. To achieve the final energy, the booster consists of 16 traveling wave accelerating structures operating at 11.994 GHz with a minimum working gradient of 60 MV/m. An intensive design activity, prototyping, and testing of these structures is underway at INFN-LNF. This paper comprehensively presents all the work conducted in the design and prototyping, along with preliminary test results obtained from the first RF prototype of the Eupraxia@SPARC_LAB X-band accelerating structure.
Paper: TUPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR10
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR14
Distributed coupling linac for efficient acceleration of high charge electron bunches
1448
Future colliders will require injector linacs to accelerate large electron bunches over a wide range of energies. For example the Electron Ion Collider requires a pre-injector linac from 4 MeV up to 400 MeV over 35 m*. Currently this linac is being designed with 3 m long traveling wave structures, which provide a gradient of 16 MV/m. We propose the use of a 1 m distributed coupling design as a potential alternative and future upgrade path to this design. Distributed coupling allows power to be fed into each cavity directly via a waveguide manifold, avoiding on-axis coupling**. A distributed coupling structure at S-band was designed to optimize for shunt impedance and large aperture size. This design provides greater efficiency, thereby lowering the number of klystrons required to power the full linac. In addition, particle tracking analysis shows that this linac maintains lower emittance as bunch charge increases to 14 nC and wakefields become more prevalent. We present the design and fabrication of this distributed coupling structure, as well as cold test data and plans for higher power tests to verify on the structure's real world performance.
Paper: TUPR14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR14
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR19
Design of an X-band parallel-coupled accelerating structure for future linacs
1454
As compared to conventional travelling-wave (TW) structures, parallel-coupled accelerating structures eliminate the requirement for the coupling between cells, providing greater flexibility in optimizing the shape of cells. Each cell is independently fed by a periodic feeding network for this structure. In this case, it has a significantly short filling time which allows for ultrashort pulse length, thereby increasing the achievable gradient. In this paper, a design of an X-band parallel-coupled TW structure is presented in detail.
Paper: TUPR19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR19
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR20
RF design of a C-band spherical pulse compressor for linac of Super Tau-Charm Facility
1457
Pulse compressors have been widely used to generate very high peak RF power in exchange for a reduction in the RF pulse length for linear accelerators. A C-band spherical pulse compressor is numerically studied for the linac of Super Tau-Charm Facility in this paper. Utilizing a dual-mode coupler for producing two orthogonal polarized TE11 modes, TE114 mode is chose for storing energy in resonant cavity enabling a Q0 over 1.3×105. By modulating the coupling factor to 8.6, an optimum average power gain of 4.8 can be achieved in the case of combing with a 3π/4 travelling wave accelerator. This paper concludes the optimum RF parameters of the pulse compressor, as well as the geometry tolerance is given for the next step machining.
Paper: TUPR20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR20
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR22
New design techniques on matching couplers for travelling wave accelerating structures
1464
Numerical optimizations on couplers of the traveling wave accelerating structures usually require lots of calculation resources. This paper proposes a new technique for matching couplers to an accelerating structure in a more efficient way. It combines conventional Kroll method with improved Kyhl method, thereby simplifying the tuning and simulation process. We will present the detailed design of a constant-gradient C-band accelerating structure based on this new method.
Paper: TUPR22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR22
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR23
Preliminary Design of a 500 MHz Normal-Conducting Cavity for Main Rings of Super Tau-Charm Facility
1467
A 500 MHz normal-conducting (NC) cavity is being developed for Super Tau-Charm Main Rings which have a current of 2 A and a synchronous radiation energy loss of 410 keV per turn. This NC cavity operates in a higher order mode of TM020. Through optimizations, it results in a high quality factor and a low R/Q. This feature is beneficial to reduce the required detuning frequency so that the coupled bunch instabilities (CBIs) driven by the ac-celerating mode are greatly suppressed. It employs ferrite absorbers inside coaxial slots located at the node of the TM020 mode to heavily damp all of dangerous parasitic modes except from the TM020 mode.
Paper: TUPR23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR23
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR26
Models for power combining magnetrons in a magic tee
1478
Industrial accelerator applications require efficient, scalable, continuous wave (CW) microwave power systems. Magnetrons are inexpensive and efficient devices for converting electrical energy into microwave power; however, their power output is limited to approximately 100 kW. Cost effective power combining magnetron systems would serve the accelerator industry by providing practical and affordable RF power to accelerator applications. In a magic tee configuration, two oscillators can be power combined and locked to a common frequency. Researchers at General Atomics, in collaboration with Thomas Jefferson National Accelerator Facility, have constructed an experiment to demonstrate the power combining of magnetrons in a such a configuration. An analytic model is presented describing the power combining efficiency of a 4-port magic tee, accounting for two magnetron output signals, an injection signal, and a reactive load. The Adler-Chen model is solved numerically using robust computational geometry techniques*. These complete solutions provide insight to the phenomena of magnetron frequency locking and optimal combining efficiency, which are compared to experiment.
Paper: TUPR26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR26
About: Received: 17 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPR27
The MESA high power 1.3 GHz CW solid state power amplifier systems
1482
The Mainz Energy recovering Superconducting Accelerator MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently under construction at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO (MilliAMpere BOoster) relies on normal conducting technology. The high power RF system is relying completely an solid state technology. After some in-depth testing of a 15 kW prototype amplifier in 2017-2019 a modified version of the amplifier modules was developed. In 2020 series production has begun at JEMA France and first amplifiers, a 74 kW, a 56 kW and two 15 kW have been delivered to KPH lately. In this paper we will present the results of the performance measurements of the amplifiers.
Paper: TUPR27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR27
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR28
LANSCE 805 MHz klystron reliability analysis
1486
Los Alamos Neutron Science Center (LANSCE) relies on 44 klystron modulator systems to feed the accelerating cavities and produce proton beam of 800 MeV. This paper focuses on the new VA-862A1 86kV 1.25 MW klystron units and aims to compare their performance with previously purchased units. Service hours for each klystron unit was used as the primary metric in the analysis and records from various sources cross-corroborated to confirm recorded information. Factors such as prior repair/rebuilds, factory acceptance tests and runtime notes were carefully inspected to provide a comprehensive view of the klystron performance during analysis. Klystron units currently being used in the LINAC were surveyed along with failed units and analysis performed to predict the next failure. The frequency and cause of failure was also compared with historical performance and failure data and results utilized for LANSCE SCCL performance optimization.
Paper: TUPR28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR28
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR37
Waveguide system for an SRF cryomodule in KEK
1495
A superconducting radio frequency (SRF) cryomodule (CM) for the International Linear Collider (ILC) Technology Network (ITN) is being developed at KEK. In the scope of this, a waveguide system is being designed. Its main features are a low center of gravity, a reduced number of corners and waveguide elements, and a compact bellow for connecting it to the input power coupler. Furthermore, the waveguide layout was designed to stay within the CM. This will avoid interference between components in the case of a multi-CM assembly. It is planned to adapt both the waveguide system and the installation process for the ITN. Analytical calculations and simulations have shown that most of the reflected power is dissipated in the load of the variable hybrid on removing the circulator. Thus, in the initial layout of the waveguide, the circulator is strategically installed to allow a future replacement with an H-corner integrated with a directional coupler, without disrupting the other waveguide components. Furthermore, a low-power test on a similar waveguide system showed that analytical calculations and simulation matched the measured values well.
Paper: TUPR37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR37
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPR39
Progress on magnetron R&Ds for industrial particle accelerators
1498
The magnetron as an efficient RF source for a compact industrial SRF accelerator has been proposed [1]. The performance of injection phase lock on two independent magnetron transmitters operated at 915 MHz, in CW mode with maximum power of 75 kW each has been demonstrated to satisfy for this application [2]. This industrial type magnetron has transformer and SCR rectifier on the DC anode power supply. Output power spectrum with phase locking can achieve noise reduction of -21 dBc at the 1st 60 Hz, -29 dBc at 1st 120 Hz with only -22.6 dBc injection power. Solenoid current increase of 16% can increase the magnetron relative natural frequency by 4e-4. Further solenoid current modulation with feedback control and the 2x75 kW power combining scheme with the WR975 magic-tee are to be further studied. We intend to use one 75 kW power station with InnoSys' switching DC power supplies to drive normal conducting and superconducting RF cavities for an industrial compact linac. We are also going to report on the 4x1.2 kW power combining experiment on the 2450 MHz magnetron system carried out at GA, including the control algorithm with modified magnetron heads with trim-coils and characterized at JLab.
Paper: TUPR39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR39
About: Received: 21 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR40
Development of prototype magnets for the ultralow emittance storage ring ALBA II
1502
The ALBA synchrotron light source is in the process of a significant upgrade, aiming to become a fourth-generation facility by reducing its emittance by at least 20 times. The initial phase of this project involves a comprehensive prototyping program designed to validate various critical technologies, such as magnets, vacuum systems, girders, etc., essential for facilitating the impending upgrade. This paper focuses on the development of the prototype magnets to implement the MBA lattice designed by our Beam Dynamics group. The lattice presents unique challenges, notably a remarkable degree of compactness necessitating magnet-to-magnet distances of just a few centimeters. Additionally, stringent strength requirements are imposed on both the quadrupolar (up to 110 T/m) and the sextupolar (up to 5000 T/m²) magnets. In this paper we will describe the design details of the initial set of resistive-type prototypes, as well as the preliminary efforts to develop alternative designs making use of permanent magnets. This dual-track approach reflects our dedication to both conventional methods and innovative solutions for the upgraded storage ring.
Paper: TUPR40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR40
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR42
Design, fabrication and measurements of a quadrupole wiggler prototype
1506
A quadruple wiggler consisting of a row of alternating polarity quadrupoles is used in a collinear wakefield accelerator under development at Argonne National Laboratory. We designed such a wiggler and fabricated a prototype consisting of four quadrupoles. The permanent magnet-excited quadrupole has a bore diameter of 3 mm, a length of 25 mm, and a peak magnetic field gradient of 0.94 T/mm. Fine translational and angular adjustment mechanisms were implemented in all quadrupoles to obtain better than one-micrometer alignment of the quadrupole wiggler assembly. The quadrupole wiggler prototype was measured and aligned employing the pulsed wire technique. We describe the design, fabrication, and alignment of this quadrupole wiggler prototype and describe the influence of the ambient temperature on the quadrupole wiggler alignment.
Paper: TUPR42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR42
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR48
Sextupole misalignment and defect identification and remediation in IOTA
1527
The nonlinear integrable optics studies at the integrable optics test accelerator (IOTA) demand fine control of the chromaticity using sextupole magnets. During the last experimental run undesirable misalignments and multipole composition in some sextupole magnets impacted operations. This report outlines the beam-based methods used to identify the nature of the misalignments and defects, and the subsequent magnetic measurements and remediation of the magnets for future runs.
Paper: TUPR48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR48
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPR51
Design of permanent dipole magnet in transport line for TPS
1537
To reduce the electric power consumption and advance the magnetic stability, a prototype of BTS dipole magnet in TPS transfer line between booster and storage ring came into sight. An 1 m long, high current dipole will be replaced by a permanent magnet with Sm2Co17. The new permanent dipole magnet will decrease total volume compared with original electric one, and the homogeneity of integral field is promoted as well. With simulation, the assembly deviation was also discussed. This article presents the magnet circuit design status of prototype to upgrade the transport line in TPS.
Paper: TUPR51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR51
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPR54
Transient finite-element simulations of fast-ramping muon-collider magnets
1548
Conceptual studies for a muon collider identify fast-ramping magnets as a major design challenge. Rise rates of more than 1 T/ms are attainable with normal-conducting magnets, incorporating iron yokes to make sure that stored magnetic energies and inductances stay below reasonable thresholds. Moreover, for energy efficiency, the magnets need to exchange energy with capacitors, such that the electric grid only needs to compensate for the losses. The design of such magnet systems is based on two- and three-dimensional finite element models of the magnets coupled to circuit models of the power-electronics equipment. The occurring phenomena necessitate nonlinear and transient simulation schemes. This contribution presents the analysis of a two-dimensional, nonlinear and time transient analysis of a bending magnet, energized by a symmetrical current pulse of a few ms.The magnet yoke is represented by a homogenized material refraining from the spatial discretization of the individual laminates, but nevertheless representing the true eddy-current and hysteresis losses.
Paper: TUPR54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR54
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPR55
Research on design of a novel permanent quadrupole magnet
1552
Research on a novel permanent quadrpole magnet (PQM) design is introduced in this paper. It can make the quadrupole magnetic field gradient continuously adjustable by modulating several permanent magnet blocks. Four poles of the magnet inform an integral whole to ensure good structural symmetry, which is essential to obtain high-quality quadrupole magnetic field permanent quadrupole magnet. Series of simula-tion calculations have been done to study the effects of four distinct types of pole position coordinate errors on the central magnetic field. By juxtaposing these results with those derived from optimal design scenario of PQM, the study underscores the critical role that pole symmetry plays in this context. Two integrated design methodologies were proposed, with one of the designs undergoing processing and coordinate detection. The results indicate that this design, is capable of meeting the specified requirements. This design effectively ad-dresses the issue of asymmetrical pole installation, thereby ensuring to a certain extent that well-machined pole can generate a high-quality magnetic field.
Paper: TUPR55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR55
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR57
Stress-strain state analysis of the first-grade titanium foil of the accelerator output window in a static state
1560
The stress-strain state of the titanium foils of the accelerator output windows at various thicknesses was studied with the choice of first-grade titanium foil as a brand. The latter is more affordable and accessible compared to a second-grade titanium foil. The deformation diagram, density, Young's modulus, and Poisson's ratio of the first-grade titanium were selected as initial data. Atmospheric pressure was used as an external pressure, and the pressure from the vacuum side was taken as zero. The latter is acceptable in simulations of ultrahigh vacuum assemblies since it does not affect the overall picture of the stress-strain state. In addition to studying the central nodes of the metal foil, the sealing nodes were also considered as an object of research, with the study of stress intensity, meridional and circumferential stresses, and maximum displacements of the center. Based on the results, a function was obtained that allows us to accurately calculate the displacements of the center of the first-grade titanium foil depending on its thickness. The analysis of the received data was carried out.
Paper: TUPR57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR57
About: Received: 03 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR58
Analysis of laser engineered surface structures’ roughness and surface impedance
1564
This study examines Laser Engineered Surface Structures (LESS) in the context of their potential application within particle accelerators. These structures are investigated due to their efficient reduction of secondary electron yield to counteract the formation of electron clouds, a phenomenon detrimental to accelerator performance. A critical aspect of their evaluation involves understanding their radio-frequency characteristics to determine their influence on beam impedance. LESS involves intricate surface modifications, integrating etched grooves and deposited particulates, resulting in a complex surface topology. Measurements are conducted on two distinct surface patterns, from which particulates are then removed with incremental cleaning. Acquired data form the basis for mathematical models elucidating observed results. Novel approaches are investigated in addition to several established surface roughness models, including analysis of geometrical attributes of the surface topology and the associated electric currents. The aim is to develop a framework that describes roughness's influence across varying scales to assist in selecting appropriate treatment parameters.
Paper: TUPR58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR58
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR70
Advanced charge selector for stripped heavy ion beams
1582
A new charge selector is currently under development at FRIB to intercept unwanted charge states of higher-power 17 - 20 MeV/u stripped heavy ion beams. The charge selector is located in the first bending segment of the FRIB linac, where high dispersion separates charge states to allow for their selection. The design concept is based on rotating graphite cylinders that act as an intermediate heat transfer medium, efficiently absorbing beam power and radiating it to a water-cooled heat exchanger. The power in the beam spot of up to 5 kW and the rms spot width as small as 0.7 mm present significant design challenges. Beyond thermal stress, the proposed design addresses the effects of radiation damage and implantation of the intercepted ions. The challenges of the engineering design associated with high temperatures, thermal expansion, rotation and linear actuation feedthrough into vacuum, as well as radiation shielding and remote handling, will be discussed. A comprehensive exploration of these challenges aims to contribute to the broader field of beam interception technology.
Paper: TUPR70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR70
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR76
Exploring convective heat transfer coefficients in fully developed flows: a combined CFD analysis and experimental validation for common geometries in particle accelerators
1593
Within the field of Particle Accelerators engineering, the design of cooling channels for its components has heavily relied on experimental correlations to compute convective heat transfer coefficients. These coefficients are believed to have a conservative factor which end up in oversized designs. The following study assesses this conservative factor for fully developed flows, in the laminar, turbulent and transition regimes. It will also focus on different geometries to do so. With this objective in mind, simulation models have been developed and correlated with experiments carried out at ALBA synchrotron. In the course of this research, various turbulence models and meshes have been examined for the development of the simulations. Heat transfer coefficients were derived from the Computational Fluid Dynamics (CFD) simulations and juxtaposed with empirical correlations. The specific geometries under investigation encompass a circular channel with a 10mm inner diameter, a rectangular section channel, and a pinhole geometry, the latter being frequently employed in accelerator technology.
Paper: TUPR76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR76
About: Received: 02 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPR81
Simulation study of ion beam used to produce Mo-99
1604
An 820 mA CW positive ion source is being developed to produce Mo-99 using the fusion of deuterium and tritium ion beams on a rotating target to produce neutrons for use in the production of radiopharmaceuticals. The ion source consists of an RF plasma source, a multi-aperture extractor, and 300 kV accelerating column. This paper will describe a simulation study of the beam through the extractor grid and the accelerator to the target. The uniformity of beam distribution on the target is an important aspect of the simulation.
Paper: TUPR81
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR81
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPR83
PSI's open-source FPGA DSP libraries
1607
Paul Scherrer Institute (PSI) has led significant advancements in accelerator electronics development, leveraging Field Programmable Gate Arrays (FPGA) based Digital Signal Processing (DSP) across various critical systems, including Low Level RF (LLRF), Longitudinal Beam Loss Monitoring (LBLM), charge particle measurement via Integrating Current Transformers (ICT), Timing, Filling Pattern Monitor (FPM), Beam Position Monitor (BPM) and other essential beam instruments. Over the past decade, PSI’s approach to develop in-house control system platform (e.g. CPCI-S.0), has encouraged innovation. The strategic reorganization within PSI, fostering collaboration among FPGA firmware engineers, led to the inception of Open-Source FPGA DSP libraries hosted on GitHub. Serving as a comprehensive repository, these libraries empower developers by providing common FPGA IPs, fundamental DSP algorithms and Fixed-Point (FP) arithmetic units. Their presence advances prototype development by enabling rapid assembly of several measurement and or control concepts. In this contribution, we present the features and the transformative impact of the PSI Open-source FPGA libraries with a focus on LLRF. This initiative has not only empowered our team to provide valuable insights, but has also streamlined the integration of new recruits and students, enabling the seamless continuation of FPGA design frameworks.
Paper: TUPR83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR83
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR84
Network status for PAL-XFEL
1611
The accelerator network of the Pohang Accelerator Laboratory (PAL) was initially designed and installed in 2015. It consists of three types of networks: a Public Network for external internet access, an Operation Network for accelerator operation and overall control, and a Control Network for device control and monitoring. From a hardware perspective, it comprises 2 firewalls, 1 intrusion prevention system, 4 backbones, 36 office network switches, and 77 switches for gallery and tunnel networks. Each network is physically or logically separated, and the backbone, serving as the main equipment, is configured in a redundant manner to prepare for failures
Paper: TUPR84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR84
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR85
Identifying downtime sources in CEBAF SRF linac systems for improving its reliability
1614
In this work, we will present some recent analysis of the reliability statistics of the CEBAF SRF linac systems. Based on the data collected by the existing Down Time Manager (DTM), the year-to-year downtime evolution trend of linac zones over the six-year period from FY18 to FY23 is established. An in-depth downtime analysis at a resolution beyond the linac zone level was carried out, by introducing an alternative system hierarchy consisting of the SRF linac sub-systems and components. This new paradigm was implemented in a pilot downtime study over the two-month period of CEBAF operation from 9/13/23 to 11/13/23, enabling localization of the responsible sub-systems (SRF, HPRF, LLRF, Beamline vacuum, Cryogenics, etc.) and hardware components (cavity, tuner, RF coupler, etc.) in the CEBAF SRF linac systems. Pinpointing downtime sources at the sub-systems and component levels holds the key to improving the CEBAF SRF systems reliability. It also helps identify areas of SRF technology development needed by future high-power high-reliability CW SRF linacs.
Paper: TUPR85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR85
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR86
Exploring high gradient limit with cryogenic experiments at FREIA laboratory
1618
Field emission (FE) and vacuum arcs limit the maximum achievable accelerating field of both normal and superconducting cavities. The performance of accelerating cavities can be improved after a long conditioning process. Understanding this process and the formation of vacuum arcs is important for all technologies where vacuum arcs cause device failure. The understanding could be more complete with novel diagnostic tools and tests in variable environments. The cryogenic HV system in FREIA laboratory is used to study different aspects of conditioning using DC pulses at a wide range of temperatures, down to 4K. We are currently measuring FE currents during conditioning for Cu, Nb and Ti electrodes in function of temperature and breakdown rate. We are also developing a new characterization method, evaluating the surface resistivity of the electrodes during conditioning. Changes in the surface resistivity could indicate the formation of dislocations below the surface, which has been speculated to be a very important process behind conditioning. We will present the results of conditioning with the FE measurements and the surface resistivity measurements.
Paper: TUPR86
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR86
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS01
Study of longitudinal effects during transition crossing of the EIC hadron storage ring
1622
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will accelerate all species except protons through transition to the desired storage energy. The effects at transition may cause unwanted emittance blowup beam loss due to bunch area mismatch and negative mass instability. In this paper, we will show the longitudinal dynamics of transition crossing in the HSR with current parameters using the accelerator code Beam Longitudinal Dynamics (BLonD).
Paper: TUPS01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS01
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS03
An update on the transition crossing schemes for the EIC hadron storage ring
1630
The Electron Ion Collider (EIC) Hadron Storage RIng (HSR) requires the crossing of transition for all species except for protons. The current scheme for the Relativistic Heavy Ion Collider (RHIC) utilizes the gamma transition quadrupoles will be adopted for the scheme of the HSR. With rebuilt straight sections, the jump quadrupoles responsible for tune compensation will need to be placed at the proper phase advance to mitigate the beta and dispersion waves generated. As an alternative method, the beam may be nonadiabatically kicked into a stable resonance island to place the beam above transition. This paper discusses transition crossing using the matched first order method and resonance island jump schemes applied to the latest HSR lattice.
Paper: TUPS03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS03
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS06
Status of helium ion beams commissioning at MedAustron ion therapy center
1637
MedAustron is a synchrotron-based cancer therapy center located in Lower Austria. Patients are treated with proton and carbon ion beams in an energy range of 62-252 MeV/u and of 120-400 MeV/u respectively. The facility features three clinical irradiation rooms, among which horizontal and vertical beam lines as well as a proton gantry are available for treatment. A fourth irradiation room (IR1) is dedicated to non-clinical research activities among which helium ion beams are currently under commissioning. Helium ions are also promising future candidates for clinical treatment due their favorable physical and biological properties. At MedAustron the beam commissioning up to IR1 is near completion. A large energy range (i.e. 39-402 MeV/u) has been commissioned with the support of Monte Carlo simulations performed by the future users. The beam properties in terms of spot size and beam roundness obtained at the isocenter fulfill the user requirements. In this work we present the helium commissioning status with the main focus on the recent results obtained from the commissioning of the synchrotron and transfer line up to the isocenter in IR1.
Paper: TUPS06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS06
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS07
Schedule management for large scale projects: the example of HL-LHC at CERN
1641
The High Luminosity Large Hadron Collider (HL-LHC) project seeks to significantly enhance the performance of the LHC to deliver ten times more data to the LHC Experiments. The project relies on cutting-edge systems and technologies deployed in the new facilities constructed to the HL-LHC requisites and replacing large existing equipment and systems in the LHC tunnel. The project complexity lies in the production and installation of innovative systems with strong interdependencies. A methodological schedule management approach is essential to ensure timely equipment delivery, anticipate potential risks and implement mitigation actions. This paper describes the schedule management aspects of the HL-LHC project, providing a robust framework adaptable to any large-scale project. It encompasses the management of the baseline changes, the monitoring of milestones, the planning and coordination of the new facilities installation, and the integration of the HL-LHC installations within the regular LHC maintenance program. Emphasizing the significance of key performance indicators (KPIs), the paper highlights the critical role of metrics as indicators of schedule robustness.
Paper: TUPS07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS07
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS08
HL-LHC magnet production: building a complex planning to identify bottlenecks
1645
The High-Luminosity LHC project aims to enhance the integrated luminosity of the LHC machine by a factor of 10, by upgrading various components located in the LHC tunnel just before the collision points, with cutting-edge technologies. Among these innovations are the new superconducting magnets equipped with a combination of $Nb-Ti$ and $Nb_3Sn$. conductors. Over 100 magnets are being produced, each undergoing multiple production and test stages across different facilities worldwide, including laboratories outside CERN. Various technology systems are integrated into the magnets, involving collaboration with different groups for assembly work. Recognizing the complexity of this production process, a comprehensive production and test schedule at CERN was established. This paper elucidates the schedule tools implemented to oversee the entire resource loaded process. The compiled data serves to identify strategic or technical bottlenecks in the production flow. By adopting such an approach and simulating various production scenarios, the aim is to proactively address potential conflicts, to ensure the optimal allocation of resources and the readiness for installation during the Long Shutdown 3.
Paper: TUPS08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS08
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS09
Magnetic field modelling and symplectic integration of magnetic fields on curved reference frames for improved synchrotron design: first steps
1649
Compact synchrotrons, such as those proposed for cancer therapy, use short and highly bent dipoles. Large curvature drives non-linear effects in both body and fringe fields, which may be critical to control to obtain the desired dynamic aperture. Similarly to current practice, for straight magnet, our long-term goal is to aim at finding a parametrization of the field map that requires few terms to capture the relevant long term dynamical effects. This parametrization will then be used to optimize the performance of the synchrotron by long-term tracking simulations and, at the same time, drive the development of the magnet design by providing measurable quantities that can be computed from field maps. This paper presents the first steps towards the goal of representing the field with a few key parameters.
Paper: TUPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS09
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS10
Concluding the operation and development of COSY
1653
The operation of the COler SYnchrotron COSY and its further development ended in October 2023. We briefly review the operation of the accelerator facility and continuous development of its sub-systems. Additionally, this work is put in context of the transformation process that COSY operation and the Institute of Nuclear Physics (IKP) of the Research Center Jülich went through starting 2015. Furthermore, the decommissioning strategy along with the possible further use of COSY components are discussed.
Paper: TUPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS10
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS12
Final preparation of accelerated and polarised protons at COSY Jülich
1657
2023 was the last year of operation for the Cooler Synchrotron (COSY) in Jülich, Germany. To prepare for the extraction of polarized protons at a momentum of 1950 MeV/c to an external target, full advantage of the most recent developments of the COSY control system was taken along with the established hardware of COSY. Challenges in beam development included the operation close to transition energy as well as seven depolarizing resonances (4 intrinsic and 3 imperfection resonances) which have to be crossed during the acceleration. To overcome the intrinsic resonances tune jumps were carried out with the Q-jump quadrupole system of COSY*. To identify the correct time window for the jump, the precise measurement of the tune** during the acceleration ramp was used. We present how the recent developments in the control system, along with the established techniques, enabled us to successfully accelerate and extract the polarized beam.
Paper: TUPS12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS12
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS13
SIS18 Operation with U²⁸⁺
1661
In SIS18 U²⁸⁺ is used to reach highest heavy ion beam intensities for FAIR-operation. The medium charge state avoids losses during stripping processes and shifts the space charge limit to higher number of particles. Nevertheless, these ions are subjected to ionization loss in collisions with residual gas particles. Via ion impact induced gas desorption a feedback between vacuum quality and beam emerges, yielding in a beam intensity limitation. The installation of a charge exchange collimator is one of the several upgrade measures which have been performed to shift this limit. They are equipped with a current measurement system to detect charge exchanged ions, which is routinely used during machine experiments. In this proceeding we present different beam based measurements showing dynamic vacuum effects. The non-linear dependence of the extraction intensity on the number of injected particles, ramp rate, and brake-time for vacuum relaxation will be shown. Stored heavy ion beams were used for charge exchange current measurements. They allow conclusions on the vacuum conditions and are presented as well.
Paper: TUPS13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS13
About: Received: 08 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS18
An overview of the LAMP front-end upgrade at LANSCE
1677
The Los Alamos Neutron Science Center (LANSCE) is one of the oldest operating high-average-power accelerators in the United States, having recently celebrated its 50th anniversary of operation. LANSCE is comprised of an 800-MeV linac capable of concurrently accelerating both H+ and H- ions, and can presently provide beam to six separate user stations. The LANSCE accelerator operates with much of its original equipment, including the Cockcroft-Walton injectors and drift-tube linac. As part of the proposed LANSCE Modernization Project (LAMP), a refurbishment and upgrade effort would replace the initial portion of the LANSCE accelerator, from ion sources to the end of the 100-MeV drift-tube linac. This paper describes the overall approach taken to establish performance goals, downselect a preferred technology approach, and identify viable pathways towards implementation.
Paper: TUPS18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS18
About: Received: 21 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPS28
Linac_Gen: integrating machine learning and particle-in-cell methods for enhanced beam dynamics at Fermilab
1695
Here, we introduce Linac_Gen, a tool developed at Fermilab, which combines machine learning algorithms with Particle-in-Cell methods to advance beam dynamics in linacs. Linac_Gen employs techniques such as Random Forest, Genetic Algorithms, Support Vector Machines, and Neural Networks, achieving a tenfold increase in speed for phase-space matching in Linacs over traditional methods, through the use of genetic algorithms. Crucially, Linac_Gen's adept handling of 3D field maps elevates the precision and realism in simulating beam instabilities and resonances, marking a key advancement in the field. Benchmarked against established codes, Linac_Gen demonstrates not only improved efficiency and precision in beam dynamics studies but also in the design and optimization of Linac systems, as evidenced in its application to Fermilab's PIP-II Linac project. This work represents a notable advancement in accelerator physics, marrying ML with PIC methods to set new standards for efficiency and accuracy in accelerator design and research. Linac_Gen exemplifies a novel approach in accelerator technology, offering substantial improvements in both theoretical and practical aspects of beam dynamics.
Paper: TUPS28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS28
About: Received: 21 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS29
Slow extraction of a dual-isotope beam from SIS18
1698
Recently, the heavy ion synchrotron SIS18 at GSI was for the first time operated with a dual-isotope beam, made up of 12C3+ and 4He+. Such a beam can be used to improve carbon radiotherapy by providing online information on dose deposition, where the helium ions serve as a probe beam traversing the patient while depositing a negligible dose. For this, the accelerator has to deliver a slowly extracted beam with a fixed fraction of helium over the spill. The difference in mass-to-charge ratio of 4He compared to 12C is small enough to permit simultaneous acceleration and to make the two isotopes practically indistinguishable for the accelerator instrumentation. Yet, it may cause a temporal shift between the two components in the spill owing to the sensitivity of slow extraction to tiny tune variations. We investigated different extraction methods, and examined the time-wise stability of the dual-isotope beam with a beam monitoring setup installed in the GSI biophysics experiment room. A constant helium fraction was obtained using transverse knock-out extraction with adjusted chromaticity.
Paper: TUPS29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS29
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS32
Intensity reach of the barrier-bucket multi-turn transfer for fixed-target proton beam from PS to SPS
1710
Fixed target beams are extracted in five turns from the Proton Synchrotron (PS) at CERN to fill almost half the circumference of the Super Proton Synchrotron (SPS) with each transfer. To avoid beam loss during the risetime of the extraction kickers a longitudinal gap is generated with an RF barrier-bucket scheme. However, the synchronization of the gap with the PS extraction and SPS injection kickers requires the RF system to operate without any beam feedback during the transverse splitting process at the flat-top. Low RF voltage is moreover required during the process to keep a small momentum spread. Both conditions are unfavorable for longitudinal stability and a campaign of beam measurements has been performed to explore potential intensity limitations. Up to 3.3e+13 protons have been accelerated and remained longitudinally stable at high energy. Longitudinal coupled-bunch instabilities occurring at the intermediate plateau below transition energy are moreover cured by a dipole-mode feedback system initially developed for LHC-type beams. The contribution summarizes the results of the beam tests, probing the limits of the fixed-target proton beam production.
Paper: TUPS32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS32
About: Received: 01 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS33
Snake matching the EIC's hadron storage ring
1714
Pairs of Siberian Snakes allow the avoidance of first-order spin resonances during energy ramping. However, a high density of first-order resonances correlates with the presence of higher-order resonances after the installation of snakes. Thus, one effective tactic of mitigating higher-order resonances is by weakening the surrounding first-order ones, equivalent to minimizing the spin-orbit coupling integrals. Such a proxy helps sidestep a multi-hour polarization transmission simulation for each lattice configuration. In a three-fold super-periodic ring, using 12 snakes is a sufficient condition for completely eliminating the spin-orbit coupling integrals at all energies and tunes. Since the HSR will only have up to 6 snakes, we opt to focus on suppressing the strongest first-order resonances instead of the whole spectrum. By varying the snake reflection axes and the betatron phase advance in two of the arcs, we search in a 7-dimensional lattice space for the weakest resonance structure using a variety of metrics and find the configuration with highest polarization transmission.
Paper: TUPS33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS33
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS34
Superconducting magnet string test for the SIS100 accelerator of FAIR
1718
The SIS100 accelerator, currently under construction in Darmstadt (Germany), consists of six arc and straight sections. Each of the six cryogenic arc sections comprises fourteen regularly repeating optical cells (lattice). Each standard cell includes two dipole magnets and two quadrupole units integrated in a quadrupole doublet module. The SIS100 String Test technically represents one standard cell of the arc section of the SIS100, terminated by and End Cap and a Bypass Line as a representation of the end of the arc section. The purpose of the SIS100 String Test is to validate all technical systems such as cryogenics, vacuum, interlock and quench detection and investigate their collective behavior. A wide spectrum of tests will be performed during cool down, powering at operational conditions and warm up. Additionally, the experience gained during the SIS100 String Test will be crucial for the installation, commissioning and operation of the SIS100. The planning, installation process and first experimental results of the String Test will be presented.
Paper: TUPS34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS34
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS38
Energy deposition in the new SPS's scrapers
1734
The successful injection of proton beams into the Large Hadron Collider (LHC) depends on an efficient scraping mechanism in the Super Proton Synchrotron (SPS). The beams accelerated in the SPS contain a significant non-Gaussian tail population. If not removed, this transverse tail population can cause high losses in the transfer lines and in the LHC injection elements. Subsequently, the Beam Loss Monitor (BLM) system may trigger a beam dump reducing the machine availability. As beam intensities increase to meet the parameters set by the LHC Injector Upgrade (LIU), the efficiency of the scraping operation becomes increasingly crucial. To fully cope with higher beam intensities in the framework of the High-Luminosity LHC (HL-LHC) project, an upgrade of the scraper system, consisting of two movable graphite blades, is being developed and scheduled for installation in January 2025. This article presents the results of a comprehensive simulation study that employs the FLUKA code coupled with SixTrack to assess energy deposition in the scrapers.
Paper: TUPS38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS38
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS39
Benchmarking power deposition from fast losses of heavy-ion beams at the onset of LHC Run 3
1738
In 2023, the LHC started its Run 3 operation with 208Pb82+ beams at 6.8 ZTeV, with a substantially higher number of bunches compared to past runs. Several new hardware systems were used operationally for the first time with high-intensity beams, including bent crystal collimators in the betatron cleaning insertion. Crystal-assisted collimation reduces the leakage of secondary ion fragments to the downstream dispersion suppressors, therefore decreasing the risk of quenching superconducting magnets. Nevertheless, one of the limitations encountered during the 2023 run were events with fast beam losses impacting the collimation system, which triggered multiple premature beam aborts on Beam Loss Monitors (BLMs). In this contribution, we present energy deposition simulations for these events, performed with the FLUKA tool, aiming to quantify the quench margin for the fast loss regime (~30 ms). To assess the predictive ability of the model, benchmarks against 2023 measurements are presented. The studies provide an important input for fine-tuning BLM thresholds in future heavy-ion runs, therefore increasing the tolerance to beam losses and hence the LHC availability.
Paper: TUPS39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS39
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS41
Crystal collimation for the HL-LHC upgrade using MERLIN++ accelerator physics library
1746
This paper details the implementation and benchmarking of crystal collimation within MERLIN++ accelerator physics library and demonstrates its application in simulating crystal collimation process for the High Luminosity upgrade of LHC at CERN. Crystal collimation is one of the key technologies suggested to enhance the current collimation system according to the requirements of HL-LHC upgrade due to its increased beam energy and luminosity. This paper outlines the proposed methodology for this study which includes implementing the demonstrated physics of particle crystal interaction in MERLIN++, benchmarking it with the existing experimental data for simulating the HL-LHC operational scenarios with the crystals as primary collimators. MERLIN++ has already been efficiently used for multiple LHC collimation studies which highlights its importance , making it an essential simulation tool for comparative analysis with other simulation tools, as relying on a single tool for concluding the HL-LHC collimation system is often insufficient. As collimation systems are fundamental for machine protection , accurately predicting the crystal collimation performance is of utmost importance to know how they will perform in HL-LHC to guarantee that the HL-LHC meets its intended objectives with crystal collimators.
Paper: TUPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS41
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS43
Optimization of a welding procedure for making critical aluminum welds on the LBNF absorber core block
1754
The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. A weld quality optimization was performed to produce National Aeronautical Standard (NAS) 1514 Class I [1] quality welds on the aluminum core blocks. This was not successful in all cases. An existing Gas Tungsten Arc Welding (GTAW) Welding Procedure Specification (WPS) was fine tuned to minimize, in most cases, and eliminate detectable tungsten inclusions in the welds. All the weld coupons, how-ever passed welding inspection as per the piping code: ASME B31.3 Normal Fluid Service [2]. Tungsten electrode diameter, type, and manufacturer were varied. Some of the samples were pre-heated and others were not. It was observed that larger diameter electrodes, 5/32 in., with pre-heated joints resulted in welds with the least number of tungsten inclusions. It is hypothesized that thinner electrodes breakdown easily and get lodged into the weld pool during the welding process. This breakdown is further enhanced by the large temperature differential be-tween the un-preheated sample and the hot electrode.
Paper: TUPS43
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS43
About: Received: 30 Apr 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS44
Multiphysics simulations of thermal shock testing of nanofibrous high power targets
1758
Increase of primary beam power for neutrino beam-lines leads to a reduced lifespan for production targets. New concepts for robust targets are emerging from the field of High Power Targetry (HPT); one idea being investigated by the HPT R&D Group at Fermilab is an electrospun nanofiber target. As part of their evaluation, samples with different densities were sent to the HiRadMat facility at CERN for thermal shock tests. The samples with the higher density, irradiated under a high intensity beam pulse, exhibit major damage at the impact site whereas those with the lower density show no apparent damage. The exact cause of this failure was unclear at the time. In this paper, we present the results of multiphysics simulations of the thermal shock experienced by the nanofiber targets that suggest the failure originates from the reduced permeability of the high density sample to air flow. The air present in the porous target expands due to heating from the beam, but is unable to flow freely in the high density sample, resulting in a larger back pressure that blows apart the nanofiber mat. We close with a discussion on how to further validate this hypothesis.
Paper: TUPS44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS44
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS45
Bayesian optimization scheme for the design of a nanofibrous high power target
1762
High Power Targetry (HPT) R&D is critical in the context of increasing beam intensity and energy for next generation accelerators. Many target concepts and novel materials are being developed and tested for their ability to withstand extreme beam environments; the HPT R&D Group at Fermilab is developing an electrospun nanofiber material for this purpose. The performance of these nanofiber targets is sensitive to their construction parameters, such as the packing density of the fibers. Lowering the density improves the survival of the target, but reduces the secondary particle yield. Optimizing the lifetime and production efficiency of the target poses an interesting design problem, and in this paper we study the applicability of Bayesian optimization to its solution. We first describe how to encode the nanofiber target design problem as the optimization of an objective function, and how to evaluate that function with computer simulations. We then explain the optimization loop setup. Thereafter, we present the optimal design parameters suggested by the algorithm, and close with discussions of limitations and future refinements.
Paper: TUPS45
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS45
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS48
Dielectric wakefield accelerators: THz radiation for medical applications
1770
The THz spectrum reveals distinctive vibrational and rotational modes, and when charged particle beams produce THz radiation, it becomes a promising source for generating narrowband, high-energy radiation. Particularly in dielectric wakefield accelerators, where a dielectric-lined channel is traversed by a relativistic electron beam, coherent Cerenkov radiation (CCR) is generated. The frequency and amplitude of CCR are dependent on structural geometry and drive beam parameters. Simulating a μm, pC driver beam in a dielectric wakefield structure yields longitudinal fields of MV/m, with a fundamental mode associated with a resonant peak corresponding to the process of demethylation in DNA. Achieving higher frequencies requires a thin dielectric layer or Bragg-like boundaries in the structure to constructively reinforce the fundamental frequency.
Paper: TUPS48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS48
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS49
Enhancing plasma wakefield accelerator analysis through machine learning
1774
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.
Paper: TUPS49
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS49
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS50
ML-enhanced commissioning of the APS-U accelerator complex
1778
The Advanced Photon Source (APS) facility has just completed an upgrade to become one of the world’s brightest storage-ring light sources. For the first time, machine learning (ML) methods have been developed and used as part of the baseline commissioning plan. One such method is Bayesian optimization (BO) – a versatile tool for efficient high-dimensional single and multi-objective tuning, as well as surrogate model construction and other purposes. In this paper we will present our development work on adapting BO to practical control room problems such as tuning linac and booster transmission efficiency, injection stabilization, enlarging storage ring dynamic and momentum apertures, and various other tasks. We will also show first experimental results of these efforts, including achieving initial beam capture in the APS-U storage ring. Given the success of BO methods at APS, we are working on tighter ML method integration into the standard control room procedures through a dedicated graphical interface.
Paper: TUPS50
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS50
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS53
Optimization of AGS bunch merging with reinforcement learning
1782
The RHIC heavy ion program relies on a series of RF bunch merge gymnastics to combine individual source pulses into bunches of suitable intensity. Intensity and emittance preservation during these gymnastics require careful setup of the voltages and phases of RF cavities operating at several different harmonic numbers. The optimum setting tends to drift over time, degrading performance and requiring operator attention to correct. We describe a reinforcement learning approach to learning and maintaining an optimum configuration, accounting for the relevant RF parameters and external perturbations (e.g., a changing main dipole field) using a physics-based simulator at Brookhaven Alternating Gradient Synchrotron (AGS).
Paper: TUPS53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS53
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS54
Bayesian optimization for beam centroid correction at ISAC
1786
Beam tuning in a post-accelerator facility such as TRIUMF’s ISAC involves a considerable amount of overhead and often leads to tunes which diverge from the theoretical optimum for the system, introducing undesirable effects such as aberrations or chromatic couplings. Bayesian Optimization for Ion Steering (BOIS) has been developed and tested to perform centroid corrective steering, after the transverse optics have been set to theory, in a method which is fully online and easy to deploy. Naïve multi-objective adaptations, scaleBOIS and boundBOIS have been introduced to perform corrective transverse steering with minimal transverse fields . Tests in the low-energy electrostatic transport beamlines at ISAC I performed comparably to human operators. This work holds promise for enhancing the efficiency and reliability of beam delivery via autonomous tuning methods, supporting TRIUMF's scientific mission.
Paper: TUPS54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS54
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS59
Data-driven model predictive control for automated optimization of injection into the SIS18 synchrotron
1800
In accelerator labs like GSI/FAIR, automating complex systems is key for maximizing physics experiment time. This study explores the application of a data-driven model predictive control (MPC) to refine the multi-turn injection (MTI) process into the SIS18 synchrotron, departing from conventional numerical optimization methods. MPC is distinguished by its reduced number of optimization steps and superior ability to control performance criteria, effectively addressing issues like delayed outcomes and safety concerns, including septum protection. The study focuses on a highly sample-efficient MPC approach based on Gaussian processes, which lies at the intersection of model-based reinforcement learning and control theory. This approach merges the strengths of both fields, offering a unified and optimized solution and yielding a safe and fast state-based optimization approach beyond classical reinforcement learning and Bayesian optimization. Our study lays the groundwork for enabling safe online training for the SS18 MTI issue, showing great potential for applying data-driven control in similar scenarios.
Paper: TUPS59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS59
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS60
Towards few-shot reinforcement learning in particle accelerator control
1804
This paper addresses the automation of particle accelerator control through reinforcement learning (RL). It highlights the potential to increase reliable performance, especially in light of new diagnostic tools and the increasingly complex variable schedules of specific accelerators. We focus on the physics simulation of the AWAKE electron line, an ideal platform for performing in-depth studies that allow a clear distinction between the problem and the performance of different algorithmic approaches for accurate analysis. The main challenges are the lack of realistic simulations and partially observable environments. We show how effective results can be achieved through meta-reinforcement learning, where an agent is trained to quickly adapt to specific real-world scenarios based on prior training in a simulated environment with variable unknowns. When suitable simulations are lacking or too costly, a model-based method using Gaussian processes is used for direct training in a few shots only. The work opens new avenues for implementing control automation in particle accelerators, significantly increasing their efficiency and adaptability.
Paper: TUPS60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS60
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPS61
Preliminary results on the reinforcement learning-based control of the microbunching instability
1808
Reinforcement Learning (RL) has demonstrated its effectiveness in solving control problems in particle accelerators. A challenging application is the control of the microbunching instability (MBI) in synchrotron light sources. Here the interaction of an electron bunch with its emitted coherent synchrotron radiation leads to complex non-linear dynamics and pronounced fluctuations. Addressing the control of intricate dynamics necessitates meeting stringent microsecond-level real-time constraints. To achieve this, RL algorithms must be deployed on a high-performance electronics platform. The KINGFISHER system, utilizing the AMD-Xilinx Versal family of heterogeneous computing devices, has been specifically designed at KIT to tackle these demanding conditions. The system implements an experience accumulator architecture to perform online learning purely through interaction with the accelerator while still satisfying strong real-time constraints. The preliminary results of this innovative control paradigm at the Karlsruhe Research Accelerator (KARA) will be presented. Notably, this represents the first experimental attempt to control the MBI with RL using online training only.
Paper: TUPS61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS61
About: Received: 14 May 2024 — Revised: 29 May 2024 — Accepted: 29 May 2024 — Issue date: 01 Jul 2024
TUPS62
The reinforcement learning for autonomous accelerators collaboration
1812
Reinforcement Learning (RL) is a unique learning paradigm that is particularly well-suited to tackle complex control tasks, can deal with delayed consequences, and can learn from experience without an explicit model of the dynamics of the problem. These properties make RL methods extremely promising for applications in particle accelerators, where the dynamically evolving conditions of both the particle beam and the accelerator systems must be constantly considered. While the time to work on RL is now particularly favorable thanks to the availability of high-level programming libraries and resources, its implementation in particle accelerators is not trivial and requires further consideration. In this context, the Reinforcement Learning for Autonomous Accelerators (RL4AA) international collaboration was established to consolidate existing knowledge, share experiences and ideas, and collaborate on accelerator-specific solutions that leverage recent advances in RL. Here we report on two collaboration workshops, RL4AA'23 and RL4AA'24, which took place in February 2023 at the Karlsruhe Institute of Technology and in February 2024 at the Paris-Lodron Universität Salzburg.
Paper: TUPS62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS62
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS64
Estimation and control of accelerator beams by latent space tuning of generative models
1820
In this work we explore the estimation and control of a particle accelerator simulation of the 800 MeV linac at Los Alamos National Lab. We use a convolution neural network model with a low dimensional latent space to predict the phase space projections of the beam and beam loss, which are mapped from accelerator settings. In deploying the model, we assume phase space predictions cannot be measured but beam loss can, and we apply a feedback using the error in beam loss prediction to tune the latent space. With beam loss and phase space predictions well correlated, we apply constrained optimization techniques, simultaneous with phase space prediction, to control the beam phase space while keeping beam loss from reaching unsafe levels.
Paper: TUPS64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS64
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS65
Radiographic source prediction for linear induction accelerators using machine learning
1824
The penetrating radiography provided by the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is a key capability in executing a core mission of the Los Alamos National Laboratory (LANL). Historical data from the two DARHT Linear Induction Accelerators (LIAs), built as hdf5 data structures for over a decade of operations, are being used to train machine learning models to assist in beam tuning. Adaptive machine learning (AML) techniques that incorporate physics-based models are being designed to use noninvasive diagnostic measurements to address the challenge of predicting the radiographic spot size, which depends on the time variation in accelerator performance and the density evolution of the conversion target. Pinhole collimator images recorded by a gamma ray camera (GRC) provide a direct measurement of the radiograph imaging quality but are not always available. A framework is being developed to feed results of these invasive measurements back into the accelerator models to provide virtual diagnostic measurements when these measurements are not available.
Paper: TUPS65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS65
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS66
Generative deep learning for 6D phase space diagnostics via physics-constrained neural networks, physics models, and adaptive feedback
1827
We present a unifying approach to generative deep learning-based 6D phase space diagnostics which combines neural networks, physics models, and adaptive feedback. Our approach includes a physics-constrained neural network (PCNN) for calculating the electromagnetic fields of intense relativistic charged particle beams via 3D convolutional neural networks. Unlike the popular physics-informed neural networks (PINNs) approach, in which soft physics constraints are added as part of the network training cost function, our PCNNs respect hard physics constraints, such as ▽·B=0, by construction. Our 3D convolutional PCNNs map entire large (256×256×256 pixel) 3D volumes of time-varying current and charge densities to their associated electromagnetic fields. We demonstrate the method on space charge dominated, relativistic (5 MeV), short (hundreds of fs), high charge (2 nC) electron beams, such as those in the injector sections of modern free electron laser and plasma wakefield accelerators. We show that the method is accurate, respects physics constraints, and that the trained 3D convolutional PCNNs perform electromagnetic calculations orders of magnitude faster than traditional solvers which require a O(N^2) process for calculating the space charge fields of intense charged particle beams. We show how we combine this with an online physics model, adaptive feedback, and automatic differentiation for real-time predictions of the 2D projections of the 6D phase space of charged particle beams.
Paper: TUPS66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS66
About: Received: 12 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS68
SRF cavity fault prediction using deep learning at Jefferson Lab
1831
In this study, we present a deep learning-based pipeline for predicting superconducting radio-frequency (SRF) cavity faults in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. We leverage pre-fault RF signals from C100-type cavities and employ deep learning to predict faults in advance of their onset. We train a binary classifier model to distinguish between stable and impending fault signals, where each cryomodule has a uniquely trained model. Test results show accuracies exceeding 99% in each of the six models for distinguishing between normal signals and pre-fault signals from a class of more slowly developing fault types, such as microphonics-induced faults. We describe results from a proof-of-principle demonstration on a realistic, imbalanced data set and report performance metrics. Encouraging results suggest that future SRF systems could leverage this framework and implement measures to mitigate the onset in more slowly developing fault types.
Paper: TUPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS68
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS69
SRF cavity instability detection with machine learning at CEBAF
1835
During the operation of the Continuous Electron Beam Accelerator Facility (CEBAF), one or more unstable superconducting radio-frequency (SRF) cavities often cause beam loss trips while the unstable cavities themselves do not necessarily trip off. The present RF controls for the legacy cavities report at only 1 Hz, which is too slow to detect fast transient instabilities during these trip events. These challenges make the identification of an unstable cavity out of the hundreds installed at CEBAF a difficult and time-consuming task. To tackle these issues, a fast data acquisition system (DAQ) for the legacy SRF cavities has been developed, which records the sample at 5 kHz. A Principal Component Analysis (PCA) approach is being developed to identify anomalous SRF cavity behavior. We will discuss the present status of the DAQ system and PCA model, along with initial performance metrics. Overall, our method offers a practical solution for identifying unstable SRF cavities, contributing to increased beam availability and facility reliability.
Paper: TUPS69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS69
About: Received: 13 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS70
The Data Platform: an independent system for management of heterogeneous, time-series data to enable data science applications
1839
The Data Platform is a fully independent system for management and retrieval of heterogeneous, time-series data required for machine learning and general data science applications deployed at large particle accelerator facilities. It is an independent subsystem within the larger Machine Learning Data Platform (MLDP) which provides full-stack support for such facilities and applications [1]. The Data Platform maintains the heterogeneous data archive along with all associated metadata and post-acquisition user annotations. It also facilitates all interactions between data scientists and the data archive, thus it directly supports all back-end data science use cases. Accelerator facilities include thousands of data sources sampled at high frequencies, so ingestion performance is a key requirement and the current challenge. We describe the operation, architecture, performance, and development status of the Data Platform.
Paper: TUPS70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS70
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS71
A data science and machine learning platform supporting large particle accelerator control and diagnostics applications
1843
Osprey DCS is developing the Machine Learning Data Platform (MLDP) supporting data science applications specific to large particle accelerator facilities and other large experimental physics facilities. It represents a “data-science ready” host platform providing integrated support for advanced data science applications used for diagnosis, modeling, control, and optimization of these facilities. There are three primary functions of the platform: 1) high-speed data acquisition, 2) archiving and management of time-correlated, heterogeneous data, and 3) comprehensive access and interaction with archived data. The objective is to provide full-stack support, from low-level hardware acquisition to broad data accessibility within a portable, standardized platform offering a data-centric interface for accelerator physicists and data scientists. Osprey DCS has developed a working prototype MLDP* and is now pursuing full-scale development. We present an overview of the MLDP including use cases, architecture, and deployment, along with the current development status. The MLDP is deployable at any facility, however, the low-level acquisition component is EPICS based.
Paper: TUPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS71
About: Received: 01 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS72
Progress on combining digital twins and machine learning-based control for accelerators at SLAC
1846
Advances in high-performance computing have enabled detailed physics simulations, including those with nonlinear collective effects such as space charge, to be deployed online in a control room setting to aid operator intuition and be used directly in automatic tuning. Simultaneously, machine learning (ML) has enabled deployment of detailed models online with sub-second execution time, opened up new avenues for adapting simulation models to more closely match real accelerator behavior, and enabled novel ways to combine detailed physics simulations and ML-based tuning. This contribution will provide an overview of how these tools are being developed and successfully applied at SLAC, with an emphasis on experimental demonstrations. This includes improvements in adaptive calibration methods, novel approaches to simulation (e.g. differentiable physics combined with ML), and the use of system models in ML-based tuning (e.g. Bayesian optimization with system model priors, iterative simulation and ML tuning to aid LCLS-II injector commissioning). Discussion of the software infrastructure required to achieve this and deploy these solutions into regular operation will also be discussed.
Paper: TUPS72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS72
About: Received: 22 May 2024 — Revised: 03 Jun 2024 — Accepted: 03 Jun 2024 — Issue date: 01 Jul 2024
TUPS74
Breaking new ground in data-intensive science: first insights from the LIV.INNO center for doctoral training
1850
LIV.INNO is a new initiative which will train around 40 PhD students over three cohorts. It fosters innovation in data-intensive science, serves as a dynamic platform for collaboration between leading research organizations and the next generation of scientists. Within this context, several projects focus on research that intersects between data science and particle accelerator research. This contribution showcases the early results from studies into optical transition radiation diagnostics for low energy ion beams, tailored Monte Carlo simulations for reactor ap-plications, and the reconstruction of the transverse beam distribution using machine learning. These early insights highlight the many benefits from collaborative R&D in data-rich accelerator environments. A summary of the training events offered by the center is also given.
Paper: TUPS74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS74
About: Received: 11 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPS82
Characterization of meter-scale Bessel beams for plasma formation in a plasma wakefield accelerator
1865
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.
Paper: TUPS82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS82
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEXN1
Superconducting magnets technology for a European heavy ion gantry
1880
Various initiatives in Europe have been launched to study superconducting magnets for a rotatable gantry suitable to deliver up to 430 MeV/u carbon ions for hadron therapy. Different technologies and layouts are being considered: the baseline solution is developed within the EuroSIG collaboration and consists of a strongly curved cos-$\theta$ dipole based on the classical NbTi superconductor. The HITRIplus and I.FAST projects are dedicated to the study of the novel Canted Cosine Theta (CCT) dipoles based on NbTi and also HTS. Common design targets were set to allow a direct comparison of the different solutions: 4 T central field in an 80 mm bore, a curvature radius of 1.65 m, and a ramp rate of 0.15 – 0.4 T/s. The progress in the construction of four different demonstrator magnets is discussed and a preliminary comparison is proposed.
Paper: WEXN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEXN1
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEAN1
First dual isotope beam production for simultaneous heavy ion radiotherapy and radiography
1893
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.
Paper: WEAN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEAN1
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEAN3
Latest progress of ACE3P multiphysics modeling capabilities
1901
SLAC developed ACE3P is a parallel multi-physics electromagnetics (EM) simulation toolkit aiming for virtual prototyping of accelerator and RF component design, optimization and analysis. In this paper, we will present the latest progress on ACE3P modeling capabilities. First, for the time domain solver T3P, modeling of nonlinear materials with higher-order electric susceptibilities has been developed. It can be used to design the devices for THz accelerators and quantum information science. Second, for the particle tracking module Track3P, external DC fields calculated by the electrostatic solver embedded in the DC gun module Gun3P can be read in to model the use of DC bias in mitigating multipacting in accelerator structures. Third, a surface impedance boundary condition to treat a thin layer of lossy materials has been implemented in the frequency domain S-parameter module S3P. This enables calculation without explicitly building an extremely fine mesh in the layer and substantially reduces the computational cost when a much larger mesh would have been needed to resolve the field in the layer. Fourth, a code integration effort has been embarked to integrate Track3P with the radiation transport code Geant4 for modeling radiation effects for dark current in accelerator structures. The applications using these new model capabilities will be presented in the paper as well.
Paper: WEAN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEAN3
About: Received: 28 May 2024 — Revised: 29 May 2024 — Accepted: 29 May 2024 — Issue date: 01 Jul 2024
WEYD1
Status and outlook on slow extraction operation at J-PARC main ring
1905
The Main Ring (MR) at J-PARC (Japan Proton Accelerator Research Complex) is a proton synchrotron that accelerates protons from 3 GeV to 30 GeV. One of the two MR's extraction modes is slow extraction using third-order resonance toward the Hadron Experimental Facility, where various particle and nuclear physics experiments are conducted. There are two major points in the slow extraction: beam loss reduction and flat spill structure of the extracted beam. In the beam operation of 2021, we achieved a beam power of 65 kW with a high extraction efficiency of 99.5% and a spill duty factor of 60%, but requirements for further improvements from physics experiments have never stopped. From 2021 to 2022, various devices in the MR were upgraded. The primary purpose of this upgrade was to increase the beam power by shortening the acceleration time and increasing the repetition rate. To achieve this goal, we rebuilt most parts of the main magnet power supplies. The new power supplies are also expected to be significantly improved in the current ripple. Thus the time structure of the slow extracted beam is also expected to be greatly improved. In addition, plans are underway for further reduction of the beam loss through the use of beam diffusers and bent silicon crystals and for improvement of the spill structure by feedback algorithms reconstruction. This talk presents the status of the MR and the prospects of the slow extraction after the MR upgrade.
Paper: WEYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEYD1
About: Received: 20 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WECD1
FCC-ee large-scale project installation planning: challenges & proposals
1934
CERN is contemplating further advancements in the energy frontier through the Future Circular Collider (FCC) study, envisioning a 90.7 km underground accelerator with multiple energy stages over time. Following the European Strategy for Particle Physics recommendation in 2020, CERN initiated a feasibility study to scrutinize all aspects of the FCC project. A crucial component of this study involves developing a timeline from project approval to the beam operation of FCC-ee, the first collider with electron and positron. Since the last planning iteration in 2018, modifications in the machine layout and shaft configuration necessitated a re-evaluation of the planning. This paper focuses on the updated planning for FCC-ee, spanning from civil engineering completion to beam operation. It compiles pertinent elements, including the civil engineering release date, layout data, and human resources regulations and limitations. These elements were analyzed systematically to derive a sector sequence. Employing a bottom-up approach in conjunction with resource constraints, an overarching plan for the FCC-ee machine until the start of operations was formulated.
Paper: WECD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECD1
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WECD3
The US effort towards a muon collider
1937
A multi-TeV muon collider has the unique potential to provide both precision measurements and the highest energy reach in one machine that cannot be paralleled by any currently available technology. There has been significant physics interest on Muon Colliders recently as indicated by the number of publications, relevant workshops, Snowmass activities but also the P5 report. This study describes a possible set of R&D and deliverables of the muon collider accelerator R&D program in the U.S. We describe high-priority studies to be performed in the first phase that will address critical questions for deciding the future plan for a muon collider design. The goal of these studies is to firm up choices for the most challenging components of a muon collider design, and to propose and begin testing and prototyping of components and systems that are needed to have confidence in and inform our specification choices. Key areas wherein the US can provide critical contributions to the newly formed international muon collider collaboration will be discussed as well.
Paper: WECD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECD3
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WECN2
Novel materials for next-generation accelerator target facilities
1945
As beam power continues to increase in next-generation accelerator facilities, high-power target systems face crucial challenges. Components like beam windows and particle-production targets must endure significantly higher levels of particle fluence. The primary beam’s energy deposition causes rapid heating (thermal shock) and induces microstructural changes (radiation damage) within the target material. These effects ultimately deteriorate the components’ properties and lifespan. With conventional materials already stretched to their limits, we are exploring novel materials including High-Entropy Alloys and Electrospun Nanofibers that offer a fresh approach to enhancing tolerance against thermal shock and radiation damage. Following an introduction to the challenges facing high-power target systems, we will give an overview of the promising advancements we have made so far in customizing the compositions and microstructures of these pioneering materials. Our focus is on optimizing their in-beam thermomechanical and physics performance. Additionally, we will outline our imminent plans for in-beam irradiation experiments and advanced material characterizations.
Paper: WECN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECN2
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WECN3
The testing experience of the cryomodules for the ESS beam on target phase at 2 MW capability
1949
ESS is completing the installation of the first phase of operation, which will start in fall 2024 on the partial beam dump and proceed with operation on the target in 2025, after receiving the intentional neutron production license from the authorities. All modules for this operation phase, with an energy reach of 870 MeV and a power capability of 2 MW, will be tested by spring 2024. The CM performance, associated statistics and the resulting linac composition is discussed here. Testing activities for the remaining CM for the full ESS 5 MW scope will continue until mid 2026.
Paper: WECN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECN3
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPC01
Optimization of the ASU CXLS beamline in simulation via Bayesian methods
1953
Single objective Bayesian optimization is used in the simulation of the compact X-ray light source (CXLS) at Arizona State University, an inverse Compton based X-ray source, to optimize the 6D electron distribution prior to final focusing at the interaction point. For inverse Compton X-ray sources, a small 6D emittance as well as a small pulse (both transversely and longitudinally) are essential for producing bright X-ray pulses. Using IMPACT-T on a 200 pC initial charge with an RF photoinjector operating in blow-out mode, we vary parameters, such as transverse laser diameter on the cathode, RF gun phase, solenoid strength, as well as linac amplitude and phase, to balance minimizing the 6D emittance and spatial profiles. We test objective functions that are combinations of beam parameters, such as energy spread before final focus, pulse duration, and normalized emittance.
Paper: WEPC01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC01
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPC04
Beam dynamics modelling of the SLS linear accelerator
1961
The storage ring from the SLS is currently in the process of a significant upgrade to a new multi-bend achromat that aims to improve the performance of the machine by allowing it to deliver even brighter beams to the beamlines. The linear accelerator of the SLS is an ageing piece of infrastructure that needs to continue to run for the few decades to continue to feed SLS 2.0 reliably. In this work, we investigate potential upgrades to the linac with the aim of reducing the overall complexity of the system.
Paper: WEPC04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC04
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC05
Quantitative description and correction of longitudinal drifts in the Fermilab linac
1964
The Fermilab Linac accepts the 0.75 MeV H- ions from the front end and accelerates them to 400 MeV for injection into the Booster. Day-to-day drifts of the longitudinal trajectory in the Linac, reconstructed from phase readings of Beam Position Monitors, are at the level of several degrees. They are believed to cause additional losses both in the Linac and Booster, and are addressed by empirically adjusting the phases of Linac cavities. This work explores the option of expressing these drifts in terms of phase shifts in two cavities at the low-energy part of the Linac. Such description allows for a simplified visual representation of the drifts, suggest a clear algorithm for their compensation, and provides a tool for estimating efficiency of such compensation.
Paper: WEPC05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC05
About: Received: 22 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC06
Characterisation and optimisation of a C-band photo-injector for compact light sources
1968
We performed an optimisation study of a C-band photoinjector for high-charge electron beams. Such a device is capable of producing high brightness electron beams, with low energy spread and small transverse emittance, which are properties required by Inverse Compton Scattering radiation sources and compact light sources in general. This work aimed to carry out, via numerical simulations, optimisation and benchmark results of the beam generated by such photoinjector, in the pursuit of its real application in the context of current projects, namely EuPRAXIA@SPARC_LAB, and proposals such as BoCXS at the University of Bologna.
Paper: WEPC06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC06
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC10
Experimental testing of a ceramic enhanced accelerator cavity
1972
It is desirable to decrease the dimensions and power loss of accelerator components as much as possible when using accelerated charged particle beams on a rocket or satellite for ionospheric and magnetospheric research applications. We present the experimental results of a radiofrequency (RF) pillbox cavity loaded with a low-loss, high-permittivity ceramic placed concentrically within the cavity. We use high-electron mobility transistors (HEMTs) to power the RF at a frequency of 5.712 GHz. At this frequency, the cavity operates at a TM020 mode. The ceramic enhances the cavity's accelerating field confined within the scope of the ceramic insertion, increasing the shunt impedance, and improving the power coupling from the RF to the electron beam with the same gradient as a conventional TM010 mode cavity. Moreover, because the power coupling to the beam is improved, we were able to reduce the longitudinal dimension of the cavity compared to the conventional cavity. We show that the cavity accelerated the beam by approximately 12 keV. We also show that the cavity and ceramic can survive a flight to space by conducting vibration and shock tests that replicate the rocket launch environment.
Paper: WEPC10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC10
About: Received: 16 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC12
Low-emittance beam generation at Argonne Wakefield Accelerator’s upgraded drive-beam photoinjector
1975
The Argonne Wakefield Accelerator (AWA) facility’s main beamline -- the drive-beam linac -- can produce electron bunches over a wide range of charges (100 pC up to 100 nC). A planned upgrade of the beamline includes the installation of a symmetrized RF gun and linac cavities with the ultimate goal of improving beam brightness. Simulations were done to explore the performance of the upgraded photoinjector to produce very low-emittance beams in conjunction with low mean-transverse-energy photocathodes. Additionally, selective collimation is also explored to further increase the beam brightness. An experiment to validate the devised operational modes will be discussed along with preliminary results on diagnostics tests.
Paper: WEPC12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC12
About: Received: 25 May 2024 — Revised: 27 May 2024 — Accepted: 28 May 2024 — Issue date: 01 Jul 2024
WEPC17
Design of a Ku-band side-coupled standing wave 2.5 MeV accelerator
1993
Compact accelerator systems are assuming an increasingly significant role within the domain of radiotherapy. As processing technology continues to mature, X-band accelerators have garnered extensive utilization. This study introduces a design for a side-coupled traveling-wave Ku-band accelerator tube, leveraging established processing methodologies. The envisaged particle output energy stands at 2.5 MeV, with a microwave power source requiring a 300 kW input sourced from a klystron. The microwave design outcomes, derived using ANSYS HFSS, are delineated herein, alongside considerations pertaining to dynamic output and engineering design. Subsequent stages will subject this accelerator tube to processing tests, with the overarching objective of effectively supplanting the natural radiation source Co60 within the realm of radiotherapy.
Paper: WEPC17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC17
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC20
Experimentally verified reduction of local reflection of traveling-wave accelerating structure by output coupler undercoupling
2003
Hefei Advanced Light Facility (HALF) injector comprises 40 S-band 3-meter traveling wave accelerating structures, capable of delivering electrons of full energy 2.2 GeV into the storage ring. To mitigate the emission degradation caused by dipole and quadrupole fields in the coupler cavity, the coupler design incorporates a racetrack and a short-circuit waveguide to eliminate this impact. This article presents an introduction to design of the traveling wave structure and the results of cold and high-power testing. We performed tuning and preliminary measurements on accelerating structure, resulting in meeting the single-cell phase deviation and accumulated phase deviation requirements of the project objectives while maintaining good measurement consistency.
Paper: WEPC20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC20
About: Received: 05 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPC33
Review of MeV energy scale accelerators, their capabilities, and common applications
2036
High Energy Density Physics (HEDP) is mostly related to charged particle beams, lasers, and plasma systems. Most of the available charged particle beam systems are either of low energies (keV scale, for example, medical x-rays) or of very high energies (>GeV, for example, SLAC accelerators, CERN for fundamental research). We need MeV energy scale accelerators to study the Bragg peaks of materials and for many other reasons, such as x-ray imaging of materials, medical isotopic production, dynamic structure analysis, plasma behavior studies, plasticity tests for drinking and ocean water, and more. To generate high-energy primary e-beams, an RF accelerator or induction accelerator is first to be considered, which are well known to the accelerator and beam physics communities. But RF accelerators have the limitation of acceleration in the range of several hundred micro-ampere-level currents. The induction accelerator can transport kA-level current, but the pulse duration is compressed to a nanosecond scale. We will review the performance of known medium-energy accelerators in search of their applications, high current (mA), and long pulse (ms) capability.
Paper: WEPC33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC33
About: Received: 09 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC39
Picometer scale emittance from plasmonic spiral photocathode for particle accelerator applications
2046
In this work we demonstrate the generation of a record low root mean square normalized transverse electron emittance of less than 40 pm-rad from a flat metal photocathode – more than an order of magnitude lower than the best emittance that has been achieved from a flat photocathode. This was achieved by using plasmonic focusing of light to a sub-diffraction regime using plasmonic Archimedean spiral structures resulting in a 50 nm root mean square electron emission spot. The emitted electrons show free electron dispersion with ∼90% of the total kinetic energy in the transverse direction. Such nanostructured electron sources exhibiting simultaneous spatio-temporal confinement to nanometer and femtosecond levels can be used for developing advanced electron sources to generate unprecedented electron beam brightness for various accelerator applications.
Paper: WEPC39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC39
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPC54
Fabrication of semiconductor photocathodes at ACERT
2086
Photocathodes play key roles in supplying electron beams for diverse research facilities. Among them, semiconductor photocathodes stand out for their high quantum efficiency (QE). Typically, a high QE, long operation time, low thermal emittance and fast response time are desired for the accelerator community. However, the performance of semiconductor photocathodes is extremely sensitive to growth conditions. In this presentation, I will delve into recent advancements in semiconductor photocathodes fabrication at Applied Cathode Enhancement and Robustness Technologies (ACERT) of Los Alamos National Laboratory (LANL). These updates allow us to fine tune growth parameters and fabricate photocathodes with high QE and low emittance at high gradient to meet the requirements of photocathodes for Cathodes and Radiofrequency Interactions in Extremes (CARIE) project at LANL. Specifically, I will highlight our progress in developing a control system that enables to accurately control growth parameters. Furthermore, I will show our preliminary results focusing on the fabrication of CsSb and CsTe photocathodes using both sequential and co-deposition methods.
Paper: WEPC54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC54
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC55
A laser heated thermionic cathode
2090
There is increasing interest in developing accelerator technologies for space missions, particularly for fundamental science. In order to meet these mission needs, key accelerator technologies must be redesigned to be able to function more reliably and efficiently in a remote and harsh environment. In this work we focus on a modest electron injector system, specifically the traditional thermionic cathode. Typically such cathodes are resistively heated by a power supply that is floated at the cathode accelerating negative high voltage. This can increase engineering complexity and add a significant load to the accelerating voltage supply. We pursue laser heating a thermionic cathode in order to remove the heater power supply from the injector system, allowing for reduced engineering complexity and power requirements for the injector. To date we have shown that a simple tantalum disk cathode can be heated by a laser with similar emission performance to the same disk resistively heated.
Paper: WEPC55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC55
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC57
Design and implementation of an instrumentation & control system for cathodes and radio-frequency interactions in extremes (CARIE) project
2093
The Accelerator Operations and Technology division at Los Alamos Neutron Science Center (LANSCE) is working on designing and implementing an Instrumentation and Controls System (ICS) for the Cathodes and Radio-frequency Interactions in Extremes (CARIE) project. The system will utilize open-source Experimental Physics and Industrial Control System (EPICS) developed for scientific facilities for control, monitoring, and data acquisition. The hardware form factors will include National Instrument’s (NI) cRIO automation controller for industrial-like slow inputs/outputs and NI’s PXIe for high-speed data acquisition for diagnostic signals featuring masked and event-based time window capture. In this paper, we will discuss the reasons that led to the design, the hardware and software design specifics, the challenges that we faced during implementation, including the EPICS device support for NI PXIe, as well as the advantages and drawbacks of our system given the experimental nature of the CARIE project.
Paper: WEPC57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC57
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPC60
Status of the CARIE high gradient photocathode test facility at LANL
2101
This presentation will report on the status of assembling and commissioning of the Cathodes And Radio-frequency Interactions in Extremes (CARIE) C-band high gradient photoinjector test facility at Los Alamos National Laboratory (LANL). The construction of CARIE began in October of 2022. CARIE will house a high gradient copper RF photoinjector with a high quantum-efficiency cathode and produce an ultra-bright 250 pC electron beam accelerated to the energy of 7 MeV. The 50 MW 5.712 GHz Canon klystron will power the facility. The klystron was received and installed in fall of 2023. The WR187 waveguide line brings the power from the klystron into a concrete vault that is rated to provide radiation protection for an electron beam powers up to 20 kW. The first RF injector that was fabricated is made of copper and does not have cathode plugs. This injector will be commissioned to validate operation of the CARIE facility. The second injector that will accommodate cathode plugs and novel photocathodes was designed and will be fabricated. The status of the facility, the designs of the photoinjector and the beamline, and plans for photocathode testing will be presented.
Paper: WEPC60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC60
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC68
Application of a reduced phase velocity high brightness photogun for MeV ultrafast electron diffraction
2129
MeV ultrafast electron diffraction has become a new frontier for the study of molecular dynamics. With the temporal resolution of MeV-UED being limited by the electron bunch length at the target, electron sources used for this technique are becoming ever more intricate in the the push for shorter bunches length. However, moving to these complex setups makes them less feasible in a small-scale setting, such as universities, where keV-UED setups have become common place. In this paper, we use a novel travelling-wave RF photogun without any additional bunch compressor to generate ultra-short electron pulses whose lengths rival that of the most intricate magnetic or ballistic compression schemes. The broadband nature of the TW device allows for unique operation schemes that combines significant acceleration and compression all within the TW photogun. Such a device, when combined with state-of-the-art synchronization systems and lasers will be demonstrated to cross the so-called ‘50-fs time-resolution barrier’ and push towards the femtosecond regime.
Paper: WEPC68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC68
About: Received: 03 Jun 2024 — Revised: 03 Jun 2024 — Accepted: 03 Jun 2024 — Issue date: 01 Jul 2024
WEPC84
Comparison of WarpX and GUINEA-PIG for electron positron collisions
2166
As part of the Snowmass'21 planning exercise, the Advanced Accelerator Concepts community proposed developing multi-TeV linear colliders and considered beam-beam effects for these machines [1]. Such colliders operate under a high disruption regime with an enormous number of electron-positron pairs produced from QED effects. Thus, it requires a self-consistent treatment of the fields produced by the pairs, which is not implemented in state-of-the-art beam-beam codes such as GUINEA-PIG. WarpX is a parallel, open-source, and portable particle-in-cell code with an active developer community that models QED processes with photon and pair generation in relativistic laser-beam interactions [2]. However, its application to beam-beam collisions has yet to be fully explored. In this work, we benchmark the luminosity spectra, photon spectra, and the recently implemented pair production processes from WarpX against GUINEA-PIG in ultra-tight collisions and ILC scenarios. This is followed by a run-time comparison to demonstrate the speed-up advantage of WarpX. Ultimately, this work ensures a more robust modeling approach to electron-positron collisions, with the goal of scaling up to 15 TeV.
Paper: WEPC84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC84
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPG07
Measurements and computer simulations of the effect of magnet vibrations on the electron beam orbit in the NSLS-II storage ring
2187
One major factor contributing to electron beam stability in a storage ring is the mechanical vibrations of magnets. At NSLS-II, we employ electromagnetic actuators to induce controlled vibrations in the support girders of the magnets. Beam position monitors distributed around the ring measure the spatial and frequency distribution of beam oscillations. The collected data is used to create and validate a computer model through a simulated commissioning tool, simulating beam motion caused by magnet vibrations. This computational model is useful for establishing mechanical stability specifications for the low-emittance upgrade of NSLS-II.
Paper: WEPG07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG07
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPG12
Measurements of the transverse beam emittance at the AREAL linac
2206
One of the main tasks for advanced experiments in modern accelerators is the generation of low-energy and high-brightness beams. The Advanced Research Electron Accelerator Laboratory (AREAL) is a linear electron accelerator based on a photocathode RF gun. The basic aim of this facility is to generate electron bunches of sub-picosecond duration with an extremely small beam emittance for ultrafast processes in advanced experimental studies in the fields of accelerator technology and dynamics, material and life sciences. In this paper, the current status and plans for further upgrades of the diagnostic system, along with the techniques used for transverse beam emittance measurements, are presented.
Paper: WEPG12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG12
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG14
Detailed simulation study of wakefield induced beam dynamics in the dielectric dechirper at CLARA
2210
Minimising the energy spread within the electron bunch is essential for optimal performance of free electron lasers. Wakefields from corrugated and dielectric structures have been demonstrated to be effective in bunch dechirping. However, the repercussions in beam quality are not yet well understood. Here, a dielectric wakefield structure, manufactured to be included at the CLARA facility, has been studied with simulations. It consists of two planar and orthogonally oriented dielectric waveguides with an adjustable dielectric gap. This structure allows the longitudinal wakefield to compensate the energy spread whilst controlling the undesirable effect of the transverse wakefields on the beam quality. Simulations have been performed at different bunch lengths, bunch energy spreads and dielectric gaps to allow a better understanding of longitudinal and transverse wakefields beam effects within the dechirper.
Paper: WEPG14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG14
About: Received: 10 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPG15
Passive longitudinal bunch diagnostics with a dielectric Wakefield streaker at CLARA
2214
Passive streaking devices have been proposed and developed at several facilities worldwide, providing a flexible and cost-effective longitudinal bunch profile diagnostic. A passive streaker, using wakefields excited in dielectric lined waveguides, is planned to be installed in the FEBE experimental chamber at CLARA Phase-2. We present experimental tests of bunch reconstruction performed during dielectric wakefield acceleration experiments at Phase-1 of CLARA, with 100 pC, 35 MeV electron beams. These profiles have been compared to simulated beam profiles, produced using S2E simulation codes Elegant and ASTRA. Conclusions have been drawn on the operation of passive streakers, applicable to the design and operation of the future streaker at CLARA.
Paper: WEPG15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG15
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG23
High-resolution bunch profile measurements for enhanced longitudinal beam diagnostics
2244
Efficient operation of the Large Hadron Collider (LHC) relies on accurate longitudinal beam measurements to diagnose beam instabilities and verify the correctness of bunch-shaping techniques. To achieve this goal, a diagnostic system was developed to perform high-resolution measurements of longitudinal bunch profiles. High-performance oscilloscopes, synchronized to precise accelerator events, are employed to carry out the measurements, acquiring data from wideband wall-current monitors installed in the machine. This paper provides details on the implementation of the system, highlighting its current and future applications that will play a key role in increasing beam intensity in the LHC.
Paper: WEPG23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG23
About: Received: 02 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPG26
Overview of beam intensity issues and mitigations in the CERN-SPS fast wire scanners
2248
A new design of fast wire scanner was installed in the CERN injector complex as part of the upgrades linked to the High-Luminosity LHC Project. Initial operations with these beams were good, but during the planned intensity ramp-up one early 2023, all four SPS scanners failed at the same time. An urgent program was put in place to understand and address this failure with experts from across the accelerator fields. Many measurements and simulations were performed and solutions implemented. This paper gives an overview of the issues seen, understanding and mitigations put in place to allow the instrument to perform at the maximum planned operational intensities.
Paper: WEPG26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG26
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG37
Beam tomography using MCMC
2291
Beam tomography is a method to reconstruct the higher dimensional beam from its lower dimensional projections. Previous methods to reconstruct the beam required large computer memory for high resolution; others needed differential simulations, and others did not consider beam elements' coupling. This work develops a direct 4D reconstruction algorithm using Markov Chain Monte Carlo.
Paper: WEPG37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG37
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPG51
Resonant spin depolarization at the test facility KARA: overview of recent efforts
2335
The Karlsruhe research accelerator KARA offers a setup to measure the beam energy with resonant spin depolarization. The depolarization is excited by the stripline kickers of the bunch-by-bunch feedback system and the resonant frequency is measured via change in Touschek lifetime. Energy measurements with resonant spin depolarization are implemented as a standard routine in the control system and are used regularly to measure both the beam energy and the momentum compaction factor for different energies and optics regimes. Long-time experience with the setup, short polarization time, and variation options of beam energy in combination with much available beam time qualify KARA as a test facility for systematic studies. Such studies are of particular interest for future colliders designed for precision studies like FCC-ee, as resonant spin depolarization is known for its high accuracy. This contribution presents the resonant spin depolarization setup at KARA and selected results of recent measurement campaigns.
Paper: WEPG51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG51
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPG65
MENT-Flow: maximum-entropy phase space tomography using normalizing flows
2375
Generative models can be trained to reproduce low-dimensional projections of high-dimensional phase space distributions. Normalizing flows are generative models that parameterize invertible transformations, allowing exact probability density evaluation and sampling. Consequently, flows are unbiased entropy estimators and could be used to solve the high-dimensional maximum-entropy tomography (MENT) problem. In this work, we evaluate a flow-based MENT solver (MENT-Flow) against exact maximum-entropy solutions and Minerbo's iterative MENT algorithm in two dimensions.
Paper: WEPG65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG65
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPG66
Effects of delta ray electrons on measurement uncertainties of harp system
2378
A harp system, which is a multi-wire beam profile monitoring (MWPM) system, is planned upstream of the spallation target to make in situ calibration of beam current density configuration on the target along with beam imaging from luminescent coating on the beam entrance window at the Second Target Station (STS) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). This beam interception-based beam diagnostics system on the target will be used to ensure that the maximum beam loads on the target are within the design range during neutron production. Current design of the harp consists of three layers of measurement wires each of which is sandwiched between voltage biasing wire planes. The signal obtained from each measurement wire layer is disturbed by secondary electrons (SE) and delta rays produced by beam-matter interactions in neighboring wires and ionization of residual gases in accelerator vacuum. While the backgrounds from SE can be suppressed by voltage biasing, the delta-ray electrons with kinetic energies above keV ranges overcome the electric potential bias. In this paper, we study the effects of delta-rays on the measurement uncertainties of MWPM using the particle transport simulation code FLUKA. Furthermore, the cases where the harp system is installed in the proximity of a large delta ray sources such as proton beam window or in the core vessel filled with sub-atmospheric gas have been studied.
Paper: WEPG66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG66
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPG67
SiPM integration testing for FACET-II pair spectrometer
2382
A pair spectrometer, designed to capture single-shot gamma spectra over a range extending from 10 MeV through 10 GeV, is being developed at UCLA for installation at SLAC’s FACET-II facility. Gammas are converted to electrons and positions via pair production in a beryllium target and are then subsequently magnetically analyzed. These charged particles are then recorded in an array of quartz Cherenkov cells attached to silicon photomultipliers (SiPMs). As the background environment is challenging, both in terms of ionizing radiation and electromagnetic pulse radiation, extensive beamline testing is warranted. To this end, we present Geant4 Monte Carlo studies, assembly of the SiPMs, and future testing plans.
Paper: WEPG67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG67
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPG77
Charge measurement systems on CLARA at Daresbury laboratory
2400
CLARA is a 250 MeV electron facility at Daresbury Laboratory, which will provide short bunches between 1 and 250 pC for a variety of experiments, including novel acceleration experiments. As part of the Phase 2 upgrade new charge measurement systems have been installed. This paper presents the charge measurement systems that will be used on CLARA, as well as commissioning results without beam for some of those systems. CLARA will include a Wall Current Monitor (WCM), 3 Integrating Current Transformers (ICTs) and five Faraday cups. The ICTs are commercial systems by Bergoz, while a custom front-end has been designed for the WCM and Faraday cups, which includes calibration circuitry and switchable gain. Calibration results, including measurements of resolution, are presented for the in-house front-end design.
Paper: WEPG77
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG77
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPG84
Status of the new bunch length measurement system downstream of the injector of the S-DALINAC
2415
Energy-recovery linacs provide high beam currents with lower RF power requirements compared to conventional machines while maintaining the high beam quality of a linac. The S-DALINAC is a thrice-recirculating accelerator operating at a frequency of 3 GHz that is capable of being operated as a multi-turn superconducting energy-recovery linac. Its efficiency is currently limited by the bunch length, which by now is measured using the RF zero-crossing method. In order to improve both accuracy and measurement time a new setup using a streak camera is developed. Optical transition radiation from electron bunches passing an aluminum-coated Kapton screen is used to produce light pulses that can be measured with the streak camera. An imaging system consisting of multiple mirrors is used to maintain a high temporal resolution for the measurement and to support in shielding the streak camera from harmful radiation. The device will be used at two different measurement setups downstream of the injector. The design and current status of the measurement setup will be presented.
Paper: WEPG84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG84
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPG86
Gas jet dosimeter measurements at DCF for medical accelerator applications
2418
Achieving non-invasive in-vivo dosimetry is a critical objective in the field of ion beam therapy. The comprehensive real-time characterization of the ion beam is highly desirable to ensure the safety of patients, treatment precision, and the efficiency of the treatment facility. However, current methods have limitations in terms of the information they provide and can be invasive to the beam. This contribution focuses on the development of a non-invasive, gas jet-based in-vivo dosimeter for use in treatment facilities. This technique relies on a non-disruptive interaction of a low-density supersonic gas jet curtain with the primary treatment beam. An existing gas jet monitor-based ionization profile monitor was modified and coupled with the accelerator beamline at the Dalton Cumbrian Facility (DCF), UK (United Kingdom). The aim of the test was to conduct proof-of-concept measurements for the profile and dosimetry of beams having characteristics similar to the medical treatment facilities. Measurements were carried out for proton and carbon beams of varied sizes, energies, and currents. The results obtained from these measurements demonstrated the feasibility of such a dosimeter and are instrumental for its improvement. This contribution introduces the design of the adapted gas jet dosimeter, discusses the findings from the measurements, highlights the dosimetry challenges addressed and outlines the scope of improvement for an online non-invasive gas jet in-vivo dosimeter.
Paper: WEPG86
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG86
About: Received: 09 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPG88
Design of a constant-gradient backward-traveling-wave accelerating structure for irradiation
2426
To develop a high-power, high-efficiency electron irradiation accelerator system with an adjustable electron beam, a novel constant-gradient backward-travelling-wave (BTW) accelerating structure has been designed. This accelerator tube implements a backward-travelling-wave design, which offers the advantages of short filling time and low power reflection, which are characteristic of traveling-wave acceleration structures, and can incorporate a nosecone design to achieve high shunt impedance. The constant-gradient concept is adopted to further enhance the electron beam power and beam efficiency. This paper presents the design of the BTW accelerating structure, encompassing parameter estimation and comprehensive three-dimensional simulations to validate the concept.
Paper: WEPG88
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG88
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG94
Detailed characterization of coherent synchrotron radiation effects using generative phase space reconstruction
2442
Coherent synchrotron radiation (CSR) in linear accelerators (linacs) is detrimental to applications that require highly compressed beams, such as FELs and wakefield accelerators. However, traditional measurement techniques lack the precision to fully comprehend the intricate multi-dimensional aspects of CSR, particularly the varying rotation of transverse phase space slices along the longitudinal coordinate of the bunch. This study explores the effectiveness of our generative-model-based high-dimensional phase space reconstruction method in characterizing CSR effects at the Argonne Wakefield Accelerator Facility (AWA). We demonstrate that the reconstruction algorithm can successfully reconstruct beams that are affected by CSR.
Paper: WEPG94
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG94
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG95
Simulation of the C-band transverse deflection structure with variable polarization for super tau charm facility
2446
Transverse deflection structures (TDS) have been widely used as diagnostic devices to characterize longitudinal properties of electron bunches in a linear accelerator. However, the conventional TDS can only measure either the horizontal or the vertical slice envelopes of electron bunches. In order to give full control of the angles of the transverse streaking field inside of the TDS to characterize the projections of the beam distribution on different transverse axes, we numerically investigate an X-band TDS with variable polarization in this paper. Through variable streaking direction, the orientation of the streaking field of the TDS is adjusted to an arbitrary azimuthal angle. This helps facilitate the development of next-generation TDS for the characterization of electron bunches, such as slice emittance measurement on different planes.
Paper: WEPG95
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG95
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR12
First comparison studies in dynamic aperture for nested magnets and baseline lattice in the FCC-ee
2485
A significant project such as the FCC-ee (with 91.17 km circumference) entails numerous challenges to ensure the stability and performance of the machine. In the pursuit of contributing to the improvement of energy consumption during its operation, the exploration of Nested Magnets (NMs) as a means to reduce synchrotron radiation has been undertaken. This paper presents first studies on the Dynamic Aperture (DA) and the Momentum Acceptance (MA) of this novel design to guide the next developments.
Paper: WEPR12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR12
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR16
Report on an international accelerator school - ISBA23
2500
The sixth International School on Beam dynamics and Accelerator technology (ISBA23) was held for 10 days from August 3rd to 12th, 2023 at Pohang in Korea. ISBA23 was jointly hosted by Korea Atomic Energy Reꠓsearch Institute (KAERI) and Korea Accelerator and Plasma Research Association (KAPRA). After screening 83 registrant’s resumes and letters of recommendation, 70 students from Korea, Japan, China, Taiwan, India, and Thailand were finally admitted to the school. For 10 days, 20 professional scientists from Korea, Japan, China, Taiwan, Thailand, Germany, and the USA gave 30 valuable lectures and 14 hands-on training sessions with ASTRA and ELEGANT accelerator codes. Thanks to the generous financial support from 14 sponsors, the school was successfully completed. This is the first time that ISBA has been held outside of Japan, and it is a big step toward becoming a truly international accelerator school. We report on ISBA23, which is the biggest international accelerator school in Asia.
Paper: WEPR16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR16
About: Received: 24 May 2024 — Revised: 29 May 2024 — Accepted: 29 May 2024 — Issue date: 01 Jul 2024
WEPR25
Conceptual RF design and modelling of a 704 MHz cavity for the muon cooling complex
2532
The Muon Cooling Complex is a crucial component of the future high-energy Muon Collider, where the ionization cooling technique is employed to reduce muon beam emittance by several orders of magnitude. This cooling technique necessitates the utilization of normal conducting, RF-accelerating cavities operating within a multi-Tesla magnetic field. This study illustrates the conceptual RF design of a 704 MHz copper cavity equipped with beryllium windows for the muon cooling demonstrator. Based on the specifications from the beam dynamics, frequency-domain eigenmode simulations have been conducted to calculate the primary RF figure of merits for the cavity. Subsequently, the cavity geometry has been optimized based on the results obtained from the eigenmode simulations. In a selected case, more advanced engineering analyses, including thermo-mechanical and Lorentz Force Detuning (LFD) simulations, have been performed to enable operation at gradients of up to 44 MV/m within strong solenoidal magnetic fields of up to 7.2 T.
Paper: WEPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR25
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR29
Update of the PLACET2 code for the low-energy acceleration stages of the muon collider
2548
This work describes improvements made to the tracking code PLACET2 to make it possible to simulate the acceleration from 250 MeV to 63 GeV in a future muon collider. This software was selected because of its unique ability to optimally simulate recirculating linacs, which are part of the proposed layout for this initial muon acceleration stage. PLACET2 has been updated to simulate non-relativistic particles and to consider particle beams of different species, charges and masses. The main changes were introduced in the longitudinal dynamics, synchrotron radiation and wakefield descriptions. In addition, the decay of particles has been added as a new feature. The changes were benchmarked in different tests against RF-Track, a code able to simulate low energy muon beams and their decay. Finally, the lattice of the 16.6 GeV arc in the initial acceleration stage of the muon collider was simulated with both PLACET2 and RF-Track, providing another test. All the results showed excellent agreement between both codes, verifying the implementation in PLACET2.
Paper: WEPR29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR29
About: Received: 07 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR34
An engineering prototype of a late stage ionization cooling cell for a muon collider
2564
Achieving the low emittances necessary for a muon collider requires ionization cooling. Much of that cooling occurs in compact cooling cells where superconducting coils and conventional RF cavities are closely interleaved [1]. The real challenges for these cooling cells reside in their engineering challenges: high field solenoids, RF cavities, and absorbers, often designed near technological limits, placed in close proximity to each other. We thus propose to build a prototype ionization cooling cell to demonstrate the capability of constructing an ionization cooling channel reaching the lowest emittances and to provide engineering input for the design of such beamlines. The magnets and cavities will be powered at their design values, and an absorber will be included along with a mechanism for heating the absorber similarly to how a beam would.
Paper: WEPR34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR34
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR46
Experimental designs of coherent synchrotron radiation in complex beams
2601
Coherent synchrotron radiation (CSR) is one critical beam collective effect in high-energy accelerators, which impedes the generation of high-brightness beams. The Argonne Wakefield Accelerator (AWA) facility is unique in the experimental investigation of CSR effects in complex beams, offering a large parameter space for the bunch charge and size, various bunch profiles (round and flat beams), and the capability of generating shaped bunches through both laser shaping and the emittance exchange approach. This presentation will outline planned experiments at AWA and their designs, including a CSR shielding study using a dipole chamber with a variable gap size, and the effect of CSR on the beam phase space in a laser-shaped short electron bunch. This work is part of a comprehensive study involving self-consistent CSR code development and experimental investigation. The experimental component aims to provide benchmarking with the advanced codes under development, explore the boundaries of 1/2/3D CSR effects on beam dynamics, evaluate CSR effects in complex beams, and eventually propose CSR mitigation strategies.
Paper: WEPR46
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR46
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR52
Bmad-Julia: a Julia environment for accelerator simulations including machine learning
2612
Bmad-Julia is a new, open-source software project for modern accelerator simulations with an emphasis on Machine Learning. As compared to existing accelerator codes, reverse differentiability, e.g. for the optimization of neural networks, will be embedded. Multiple standalone Julia packages are being developed that provide fundamental tools and methods commonly needed in accelerator simulations, it is envisaged that Bmad-Julia will be able to serve as the basis for developing new programs to meet the ever changing simulation requirements of high energy machines. By avoiding the necessity of "reinventing the wheel", programs that make use of Bmad-Julia packages can be developed in less time and with fewer bugs than programs developed from scratch. Included will be a package for accelerator lattice instantiation and bookkeeping, a package for handling physical and atomic constants, and a package for truncated Power Series Algebra (TPSA) with routines for manipulations and analysis including map inversion, partial map inversion, normal form decomposition, Poisson bracket, etc. Ultimately, all features of today’s versatile Bmad toolkit will be transferred, including polarized beams, radiation effects, beam scattering, symplectic tracking, and long-term dynamics. Discussed is the present state of the project as well as plans for the future.
Paper: WEPR52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR52
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPR56
Xsuite: an integrated beam physics simulation framework
2623
Xsuite is a modular simulation package bringing to a single flexible and modern framework capabilities of different tools developed at CERN in the past decades notably MAD-X Sixtrack Sixtracklib COMBI and PyHEADTAIL. The suite consists of a set of Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be flexibly combined together and with other accelerator-specific and general-purpose python tools to study complex simulation scenarios. Different computing platforms are supported including conventional CPUs as well as GPUs from different vendors. The code allows for symplectic modeling of the particle dynamics combined with the effect of synchrotron radiation impedances feedbacks space charge electron cloud beam-beam beamstrahlung and electron lenses. For collimation studies beam-matter interaction is simulated using the K2 scattering model or interfacing Xsuite with the BDSIM/Geant4 library and with the FLUKA code. Methods are made available to compute and optimize the accelerator lattice functions, chromatic properties and equilibrium beam sizes. By now the tool has reached a mature stage of development and is used for simulations studies by a large and diverse user community.
Paper: WEPR56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR56
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR59
Developing nested auto-differentiation tracking code for beam dynamics optimization
2635
An innovative particle tracking code is in development using the Julia programming language, utilizing the power of auto-differentiation (AD). With the aid of specifically designed truncated power series algebra (TPSA) methods and built-in Julia AD packages, this code enables automatic calculation of derivatives with respect to selected parameters of interest. This tracking code provides a flexible and powerful solution for accelerator physicists applicable across various research topics, especially for beam dynamics optimization works.
Paper: WEPR59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR59
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPR60
Algorithmic access to beam control and beam diagnostics at COSY Jülich
2638
During the last years of operation of the COSY facility, significant improvements were made in beam control and diagnostics. Many systems have been upgraded from a Tcl/Tk based control system to EPICS. One of the advantages of EPICS is the coherent communication via Process Variables (PVs). This allowed us not only to control the synchrotron and its injection beam line (IBL) through GUIs but also allowed us to control the beam with algorithms. In our case, these algorithms covered a range of applications from variation of the currents of the electromagnets up to more advanced techniques of AI/ML such as Bayesian Optimization or beam control with Reinforcement Learning. Due to the unified nature of the PVs, the algorithms can be fed with a plethora of input parameters such as beam positions, beam current, or even live images of a camera. Depending on the algorithm, it is also possible to switch the target quantity (e.g. from measured current at the beam cups to the intensity of the injected beam at COSY). The algorithms can also trigger model calculations and access their results, if desired. We present an overview of different applications and our efforts to prepare COSY for them.
Paper: WEPR60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR60
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPR63
Development of novel magnetically-focussed minibeams for in vivo and in vitro end stations for LhARA
2649
Radiotherapy is an effective, non-invasive, widely used treatment for cancerous tumours that uses x-ray photon, electron and ion beam sources. The Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is a novel laser-driven accelerator system under development that aims to prove the principle of the laser-driven approach to Particle Beam Therapy (PBT). This study aims at the development of a novel system to deliver different light ion minibeams to the in vivo and in vitro end stations. The desired minibeams will be delivered by magnetically focusing and steering the incoming proton and light ion beams, without the use of collimators. Minibeams with a diameter of approximately 1 mm spot will be delivered at an energy of 15 MeV to the in vivo and in vitro end stations. An update on the status of the development of this magnetic focusing technique will be presented here.
Paper: WEPR63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR63
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR64
Data processing for profile monitor of HEPS linac
2652
Profile Monitor (PR) is used to observe and measure the beam profile in the Linac and transport line of the High Energy Phone Source (HEPS). To obtain more precise results, we implemented several widely used fitting algorithms in the framework Pyapas. We carried out detailed testing and comparison of these fitting methods based on simulated results and actual measurement data, respectively, and found the most suitable method under different beam conditions. These methods have been used in various applications for HEPS commissioning, including emittance measurement, energy and energy spread measurement, and RF phase scan. This paper provides an introduction to these algorithms. Subsequently, taking the emittance measurement application as an example, the results of error analyses are presented.
Paper: WEPR64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR64
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR65
ImpactX space charge modeling of high intensity linacs with mesh refinement
2656
The code ImpactX represents the next generation of the particle-in-cell code IMPACT-Z, featuring s-based symplectic tracking with 3D space charge, parallelism with GPU acceleration, adaptive mesh-refinement, modernized language features, and automated testing. While the code contains features that support the modeling of both linear and circular accelerators, we describe recent code development relevant to the modeling of high-intensity linacs (such as beam transport for the Fermilab PIP-II upgrade), with a focus on space charge benchmarking and the impact of novel code capabilities such as adaptive mesh refinement.
Paper: WEPR65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR65
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR69
Progress & developments of BDSIM
2664
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.
Paper: WEPR69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR69
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR70
A review of the Beam Delivery Simulation (BDSIM) user community
2668
Beam Delivery Simulation (BDSIM) is a Monte Carlo particle tracking simulation tool for modelling energy deposition in 3D models of particle accelerators. Initially conceived in 2001 to model the collimation system in the International Linear Collider (ILC), in recent years BDSIM has undergone a significant transformation across virtually its entire code base. As a result of its newer features, functionality, and performance, BDSIM is becoming increasingly adopted throughout the particle accelerator community for a wide variety of applications. Here, we review recent BDSIM studies by members of the BDSIM user community, including but not limited to linear and circular High Energy Physics (HEP) colliders, HEP fixed target experiments, diagnostics and collimation at light sources, and medical accelerators including start-to-end proton therapy machines and radiobiology research beam line design projects.
Paper: WEPR70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR70
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR71
Simulation of coupled space charge and wakefield effects for a prototype TW-gun at SwissFEL
2672
In the injector section of electron linacs, both internal space charge forces and wakefield effects influence the beam dynamics. So far, existing simulation approaches can not account for both effects simultaneously. To fill this gap, we have developed a computational method to account for both effects self-consistently*. It couples a space charge solver in the rest frame of the bunch with a wakefield solver by means of a scattered field formulation. The novelty of this approach is that it enables us to simulate the creation of wakefields throughout the emission and acceleration process. In our contribution, we present extensive studies of the coupled wakefield and space charge effects in a traveling wave electron gun under development at the Paul Scherrer Institute. Wakefields created by the multi-cell design and the transition to the beam pipe are accounted for. Hence, the respective influences of these causes for geometric wakefields on particle dynamics are compared, providing detailed insights into the coupling of wakefields on bunches at low energies. Specifically, uncorrelated energy spread and emittance are investigated which are of key interest for FEL operation.
Paper: WEPR71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR71
About: Received: 08 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR73
C-band high-gradient linac design considerations for HPC modeling
2676
Linacs are an integral part of high-gradient accelerating structures for X-ray Free Electron Laser (XFEL) facilities. For high energy (42+ keV) x-rays, this translates into a longer linac (linear accelerator), which in turn translates into increased cost due to the larger footprint. One such case is the DMMSC (Dynamic Mesoscale Material Science Capability) at Los Alamos National Laboratory. C-band devices are an attractive option, as they offer suitable electron beam properties and are significantly smaller than conventional L- or S- band structures. This need for state-of-art designs dictates increasingly complex structures such that CPU-intensive simulations are now a key part of accelerator component design. As that happens, high performance computing (HPC) becomes a necessary component of the design process. The Argonne Leadership Computing Facility offers a route to rapid design evaluation through successive simulations while varying, for example, geometric features and particle beam properties.
Paper: WEPR73
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR73
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR74
Electron cloud simulations in the Fermilab booster
2680
As part of Fermilab's Proton Improvement Plan-II (PIP-II), the Fermilab Booster synchrotron will operate at a higher intensity, increasing from 4.5×10^12 to 6.7×10^12 protons per pulse (ppp). A potential challenge for achieving high-intensity performance arises from rapid transverse instabilities induced by electron clouds (EC). This research presents electron cloud simulations using PyECLOUD, which is an advanced computational tool that incorporates measurements of the secondary electron yield (SEY) from the Booster's combined function magnet material. By systematically varying beam parameters in PyECLOUD, such as bunch structure, SEY, bunch length, and intensity, it becomes possible to forecast the impact of EC effects on the beam stability of the PIP-II era Booster.
Paper: WEPR74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR74
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS05
Summary of the LANL mini-workshop on source region options for LAMP
2702
The core components of the LANSCE accelerator complex – the beam source area, drift-tube and cavity-coupled linear accelerators – are more than 50 years old; a critical subsystem for beam delivery to the Lujan Center, the proton storage ring (PSR), is more than 20 years old. The proposed LAMP project is intended to begin a revitalization and update of the LANSCE accelerator complex, starting with the beam source region, drift-tube linac, and PSR. To help assure we have selected an optimal candidate design for the source region, an internal workshop was held in August 2023 to consider options for providing two beam species at the peak and average currents, and beam macropulse formats, required by the various LANSCE user stations. This document describes the workshop goals and processes, presents the various configurations considered, and lists the results of the downselect process and potential paths forward.
Paper: WEPS05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS05
About: Received: 08 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS09
Niobium-tin as a transformative technology for low-beta linacs
2709
Niobium-tin has been identified as the most promising next-generation superconducting material for accelerator cavities. This is due to the higher critical temperature (Tc = 18 K) of Nb3Sn compared to niobium (TC = 9.2 K), which leads to greatly reduced RF losses in the cavity during 4.5 K operation. This allows two important changes during cavity and cryomodule design. First, the higher Tc leads to negligible BCS losses when operated at 4.5 K, which allows for a higher frequency to be used, translating to significantly smaller cavities and cryomodules. Second, the reduced dissipated power lowers the required cryogenic cooling capacity, meaning that cavities can feasibly be operated on 5-10 W cryocoolers instead of a centralized helium refrigeration plant. These plants and distribution systems are costly and complex, requiring skilled technicians for operation and maintenance. These fundamental changes present an opportunity for a paradigm shift in how low-beta linacs are designed and operated. Fabrication challenges and first coated cavity test results are discussed.
Paper: WEPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS09
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS15
Novel materials for beam acceleration
2730
Bulk niobium is currently the standard material for constructing superconducting radio frequency (SRF) cavities for acceleration in particle accelerators. However, bulk niobium is limited, and new materials and surface treatments may allow greater performance to be reached. We present progress on novel materials and treatments for SRF cavity fabrication.
Paper: WEPS15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS15
About: Received: 20 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS23
First conduction cooled photoinjector status
2747
SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb3Sn and conduction cooling. SRF gun can provide a CW operation capability while consuming only 2W of RF power which eliminates the need of an expensive high power RF system and saves a facility footprint. Euclid is developing a continuous wave (CW), 1.5-cell, MeV-scale SRF conduction cooled photogun operating at 1.3 GHz. We aim for generation of the first beam in 2024. In this paper, we present the most up-to-date progress including results of the first cool down of the gun-cavity in the newly developed conduction cooled cryomodule and LLRF system development.
Paper: WEPS23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS23
About: Received: 17 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS28
Study of the generalized electron emission theory in a superconducting cavity
2757
Research is being conducted on field emission, thermionic emission, generalized electron emission, and electron emission from superconducting cavities. Generalized electron emission theories, which encompass field emission and thermionic emission, are currently under investigation. In field emission, electrons are emitted from metals due to a strong local electric field, while in thermionic emission, electrons are emitted due to high local temperatures. Field emission is being explored in relation to dimensions, and thermionic emission is likewise examined as a function of dimensions. The distribution of the electric field is illustrated over surface curvature. Furthermore, field emission characteristics are specifically analyzed within the context of superconducting RF cavities.
Paper: WEPS28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS28
About: Received: 11 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPS33
Impact of medium temperature heat treatment on flux trapping sensitivity in SRF cavities
2764
The effect of mid-T heat treatment on flux trapping sensitivity was measured on several 1.3 GHz single cell cavities subjected to vacuum annealing at temperature of 150 - 400 $^\circ$C for a duration of 3 hours. The cavity was cooldown with residual magnetic field $\sim$0 and $\sim$20 mG in the Dewar with cooldown condition of full flux trapping. The quality factor as a function of accelerating gradient was measured. The results show the correlation between the treatment temperature, quality factor, and sensitivity to flux trapping. Sensitivity increases with increasing heat treatment temperatures within the range of (200 - 325 $^\circ$C/3h). Moreover, variations in the effective penetration depth of the magnetic field and the density of quasi-particles can occur, influencing alterations in the cavity's electromagnetic response and resonance frequency.
Paper: WEPS33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS33
About: Received: 13 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPS34
Investigation of hot-spots due to trapped flux in niobium superconducting radiofrequency cavities
2768
One of the significant sources of residual losses in superconducting radio-frequency cavities is magnetic flux trapped during the cool-down due to the incomplete Messier effect. If the trapped vortices are non-uniformly distributed on the cavity surface, the temperature mapping revealed the “hotspots” at the location of high density of pinned vortices. Here, we performed a rf test on 1.3 GHz single cell cavity with the combination of the temperature mapping system. The temperature mapping reveled the development of the hot spots with the increase in rf field inside the cavity. When magnetic field is trapped locally on the surface of cavity, the hot-spots strength increase rapidly, showing the direct correlation of vortex induced hot spot and corresponding rf loss.
Paper: WEPS34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS34
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS37
REBCO sample testing at high power X-band
2772
SRF materials such as niobium have been extremely useful for accelerator technology but require low temperatures operation < 9 K. The development of high temperature superconductors (HTS) is promising due to their to their high critical temperature 89.5 K. This work intends to determine the high-power RF performance of such materials at X-band (11.424 GHz). Two kinds of REBCO coatings (thin film deposition and soldered tapes) on a copper substrate were tested. Testing was done in a hemispherical TE mode cavity due to its ability to maximize the magnetic field on the sample and minimize the electric field. We will report conductivity vs temperature at low and high power. We determine the quench field in the REBCO sample and explain the evidence which shows that the quenching is most likely due to reaching the critical current and not due to average applied heat load for powers up to 1.6 kW.
Paper: WEPS37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS37
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS39
V₃Si: an alternative thin film material for superconducting RF cavities
2779
Superconducting materials, like V3Si, NbN, NbTiN and Nb3Sn, are potential alternatives to Nb for next generation thin film SRF cavities. In comparison to the Nb, their relatively high Tc could allow for operation at higher temperatures (≥ 4 K) and the higher critical field could lead to for higher accelerating gradients. We investigate optimum deposition parameters and substrates for V3Si, using single target physical vapor deposition (PVD). We report on the superconducting properties such as Tc and surface resistance using RRR and low power RF, stoichiometry using RBS, SIMS, XPS and EDX and surface quality using AFM and white light interferometry.
Paper: WEPS39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS39
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS41
Design, construction and operation of a surface-treatment platform for SHINE superconducting cavities
2785
The SHINE project requires more than six hundred 1.3GHz cavities and sixteen 3.9GHz cavities for the superconducting accelerator. These cavities are from both domestic and foreign companies. The cavities fabricated in domestic companies requires correspond-ing capacity of surface-treatment. For the R&D of surface-treatment technology and mass production of SRF cavities, we have been constructing a new surface-treatment platform near Shanghai for SHINE project. In this paper, we report the design, construction, commissioning and operation of this platform.
Paper: WEPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS41
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS42
Cryomodules development for SHINE project
2788
SHINE project requires about 75 cryomodules with superconducting radio-frequency cavities to accelerate the beam to 8 GeV. Key components, technologies of cryomodule have been developing through prototypes and pre-series cryomodules. Up to now, several sets of cryomodule with high-Q cavities have been assembled and tested. We present the development status of SHINE cryomodules, including prototype cryomodules and the first ones for project.
Paper: WEPS42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS42
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS46
Buffered chemical polishing process for SHINE 3.9 GHz cavities
2798
The linear acceleration part of the SHINE project consists of two 3rd harmonic cryogenic modules which are operating at 3.9 GHz. Each of the cryomodules consists of eight 3.9 GHz 9-cell superconducting cavities. The SHINE specifications of the 3.9 GHz cavities are Qo >2.0e+9@13.1 MV/m and maximum accelerating gradient >15 MV/m. The 3.9 GHz cavities were treated with buffered chemical polishing (BCP) baseline combined with 2-step low-temperature baking surface treatment process to meet the specifications. In order to achieve the required performance, the BCP process had been optimized at the SHINE Wuxi surface treatment platform, especially the acid ratio. Vertical tests of all 3.9 GHz bare cavities treated with the optimized BCP process showed Qo up to 3.0e+9@13.1 MV/m and maximum accelerating gradient over 20 MV/m. The optimized BCP process applied to the 3.9 GHz cavities and related vertical test results were presented in this paper.
Paper: WEPS46
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS46
About: Received: 16 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS48
Comparison on the superconducting properties of Nb and NbTiN thin films produced by both HiPIMS and bipolar HiPIMS
2802
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.
Paper: WEPS48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS48
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS49
Tailoring the production of Nb superconducting films for SRF cavities: mass/energy spectroscopy and film characterisation
2806
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.
Paper: WEPS49
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS49
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS52
In situ plasma processing of superconducting cavities at JLab, 2024 update
2814
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.
Paper: WEPS52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS52
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS58
Decoupling of nitrogen and oxygen impurities in nitrogen doped SRF cavities
2825
The performance of superconducting radiofrequency (SRF) cavities is critical to enabling the next generation of efficient, high-energy particle accelerators. Recent developments have focused on altering the surface impurity profile through in-situ baking, furnace baking, and doping to introduce and diffuse beneficial impurities such as nitrogen, oxygen, and carbon. However, the precise role and properties of each impurity are not well understood. In this work, we attempt to disentangle the role of oxygen and nitrogen impurities through time-of-flight secondary ion mass spectrometry of niobium samples baked at temperatures varying from 75-800°C with and without nitrogen injection. From these results, we developed treatments recipe that decouple the effects of oxygen and nitrogen in doping treatments. Understanding how these impurities and their underlying mechanisms drive further optimization in the tailoring of impurity profiles for high performing SRF cavities.
Paper: WEPS58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS58
About: Received: 21 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS59
Microscopic understanding of the effects of impurities in low RRR SRF cavities
2829
The SRF community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurities of niobium coupons with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low RRR cavities so that the mechanism of impurity-based improvements can be better understood and improved upon. The combination of RF testing, temperature mapping, frequency vs temperature analysis, and materials studies reveals a microscopic picture of why low RRR cavities experience low BCS resistance behavior more prominently than their high RRR counterparts. We evaluate how differences in the mean free path, grain structure, and impurity profile affect RF performance. The results of this study have the potential to unlock a new understanding on SRF materials and enable the next generation of high Q/high gradient surface treatments.
Paper: WEPS59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS59
About: Received: 22 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS61
Mapping the stray magnetic field at the Relativistic Heavy Ion Collider tunnel
2836
A new Rapid Cycling Synchrotron (RCS) [1] is designed to accelerate the electron bunches from 400 MeV up to 18 GeV for the Electron Ion Collider (EIC) [2] being built at Brookhaven National Laboratory (BNL). One of the two Relativistic Heavy Ion Collider (RHIC) rings will serve as the Hadron Storage Ring (HSR) of the EIC. Beam physics simulations for the RCS demonstrate that the electron beam is sensitive to the outside magnetic field in the tunnel. Significant magnetic fields are expected due to the HSR and the Electron Storage Ring (ESR) being at full energy during the RCS operation. The earth magnetic field at the location of the RCS center was measured throughout the circumference of 3870 m tunnel without RHIC operation. In addition, the fringe magnetic field from RHIC magnets at several locations during RHIC operation was measured and compared with simulation at different ramping currents. A robotic technology is being developed to automatically measure the stray magnetic field at any location during the RHIC (or future EIC) operation.
Paper: WEPS61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS61
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS63
Mechanical design of the 12 T superconducting dipole. An accelerator-fit, Nb₃Sn double aperture magnet
2843
In the context of the High Field Magnet programme, the 12 T Nb3Sn activity aims to design and manufacture a 2-meter-long, 12 T, cosθ, double aperture dipole. To reach magnetic fields higher than 10 T in accelerator magnets, brittle epoxy-impregnated Nb3Sn Rutherford cables are employed, which makes it difficult to predict the coil's mechanical limit and, in extenso, the magnet's performance. To tackle this challenge, expensive procedures are often implemented. The 12 T mechanical design presented in this paper aims to prioritize intrinsically safe structures and minimize the number of components. This approach is intended to counteract issues stemming from fabrication tolerances and assembly tool misalignment. To prevent coil over-compression, mechanical stoppers are integrated within the magnet structure. The design is committed to focus on solutions that can be applied on short demonstrators but also scaled to long magnets that need to be produced in large quantities in series. This paper aims to introduce the magnet's mechanical design, its underlying principles, and the advantages it offers.
Paper: WEPS63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS63
About: Received: 10 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS64
Measurement of integrated gradient and field quality on the first Q2 magnets for HL-LHC
2847
The Q2 insertion quadrupoles for the High Luminosity upgrade of the LHC are currently being produced and tested. The test of the first units provides valuable information about the field quality of superconducting accelerator magnets built from Nb3Sn coils. This paper presents the results of the magnetic measurements performed on the prototype and series magnets with emphasis on field quality and field repeatability. The stability of the integral gradient is analyzed in view of the final installation in the machine.
Paper: WEPS64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS64
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS68
Development and test of a large-aperture Nb3Sn cos-theta dipole coil with stress management
2858
The stress-managed cos-theta (SMCT) coil is a new concept which was proposed and is being developed at Fermilab in the framework of US Magnet Development Program (US-MDP) for high-field and/or large-aperture accelerator magnets based on low-temperature and high-temperature superconductors. A 120-mm aperture two-layer Nb3Sn SMCT dipole coil has been developed at Fermilab to demonstrate and test the SMCT concept including coil design, fabrication technology and performance. The first SMCT demo coil was fabricated and assembled with 60-mm aperture Nb3Sn coil inside a dipole mirror configuration and tested separately and in series with the insert coil. This paper summarizes the design, parameters, and quench performance of the 120-mm aperture SMCT coil in a dipole mirror configuration.
Paper: WEPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS68
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS71
Superconducting magnets for SIS100 and Super-FRS at FAIR – overview and progress
2862
At the FAIR project in Darmstadt, Germany, superconducting magnets will be utilized for the main accelerator, the SIS100 heavy ion synchrotron, and for the fragment separator Super-FRS. For SIS100, the magnets are fast ramped with a rate of up to 4 T/s while large apertures are required for Super-FRS. In total, several hundred magnets need to be produced, qualified and characterized for the operation at FAIR. For both machines, series production is ongoing and testing programs at operational conditions have been established for quality assurance of the high demanding magnet modules. In the presentation, an overview is given on the design and operation principles of the various magnet types and module combinations. The complex project landscape involving several sites for production, module integration, and cold testing is pictured. The project progress and key testing results are highlighted and an outlook for the installation and commissioning plans at FAIR is given.
Paper: WEPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS71
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS76
Upgrading of the INFN-LNF magnetic measurements laboratory
2879
The magnetic measurements laboratory of the Frascati National Laboratories of INFN is one of the pole of the Innovative Research Infrastructure for applied Superconductivity (IRIS). This infrastructure aims at upgrading laboratories to carry out basic research on magnetism and superconducting materials, test of superconducting magnets, wires, tapes, cables. The LNF pole will be devoted to testing SC coils and magnets at room temperature. These measurements are recommended during the manufacturing phase, since they allow the validation of the assembly and the detection of defects at early stages of production, before the cryogenic tests are carried out. Part of the equipment is already available, including a stretched wire bench, a rotating coil system, a NMR probe, gaussmeters, instruments for high precision electrical measurements. The IRIS upgrade will include a 3D Hall probe mole system, a pulsed wire bench, a 5-axes coordinatometer, high-stability power supplies of various sizes, a calibration system. The flexibility of the instruments will allow to cover a large range of magnetic measurements, from point maps to integrated fields, from multipolar analysis to fiducialization.
Paper: WEPS76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS76
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS78
First year of data taking with the electricity meter network for sustainable operation of the KIT accelerator facilities for the KITTEN project
2883
In times of climate change and with increasing challenges of the power grid stability due to unstable renewable energy sources, it is not sufficient to know the electric energy consumption of accelerator facilities. In order to optimize the operation of the research infrastructure in terms of stability, reliability and sustainability, the knowledge of the dynamics of energy consumers, and generators is mandatory. Since a few years, KIT's accelerator teams collaborate with its EnergyLab 2.0, Europe's largest research infrastructure for renewable energies, within the KIT test field for energy efficiency and grid stability of large-scale research infrastructures (KITTEN). At the research accelerators KARA and FLUTE a dense network of power meters, more than 100 sensors of different kind, operate to observe from individual components to infrastructural components and the central electricity distribution. With more than one year of data taking for most of the sensors, we are already able to quantify implemented energy-savings measures. In this contribution the findings of the installation and the first analysis and savings within the more than one year data taking will be presented.
Paper: WEPS78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS78
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS79
Optimization studies on accelerator sample components for energy management purposes
2887
The large amount of energy required to operate large-scale facilities with particle accelerators within has been considered as one of the important research topics over the past years. This sheds light on the importance of the research field of energy management that entitles, with a view to long-term operations, the implementation of smart and sustainable technologies. One of the key technologies in accelerators are superconductor (SC)-based designs. The vanishing electrical resistance together with the ability to provide field values well above those from conventional conductors is the main motivation behind exploiting superconducting wires in building coils and magnets for large-scale accelerators. However, these superconductors can also quench under certain conditions, driving the wires into the normal state and potentially allowing for overheating and destruction of the conductor material and/or the whole design. This work will present the results of optimization-based analyses performed on accelerator SC-sample components aiming at goal designs that are more energy efficient at a reference operational field or current. A compromise between getting the best performance for excellent science from a design (with superconductivity preserved and safe operation maintained) and reducing its power consumption (and eventually its effective cost) will be addressed too.
Paper: WEPS79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS79
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
WEPS80
Lessons learned from hardware failure during HL-LHC AUP cabling
2891
The cabling facility at Lawrence Berkeley National Laboratory has experienced a heavy increase in workload during the US-HiLumi Accelerator Upgrade Project (AUP). Several critical components have experienced unexpected failure over the project’s lifetime for reasons at least partly attributable due to increased wear and tear on the hardware subsystems. This work presents three case studies of varying severity and lessons learned from each failure. Suggested strategies to ensure operational readiness and uptime for legacy systems are also discussed.
Paper: WEPS80
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS80
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS82
Single unified model of a CCT dipole using 3DEXPERIENCE platform
2900
The concept of a single unified model for designing accelerator magnets has long been sought. Any meaningful virtual twin model must embody the ability to simulate the electromagnetic, thermal and structural performance of the device, as well as retaining the full geometric, materials and manufacturing information. Not only this, but the virtual twin must be able to respond to a design change and identify that either some of the simulations need to be repeated to capture the effect of the design change or to reliably identify that the last simulation results available were from a previous virtual prototype. As the fields of interest in these magnets are particularly sensitive to small geometric perturbations, accurate simulation capabilities are required to capture both electromagnetic and mechanical effects. Finally, the ability to optimize the design accounting for input from multiple areas of physics is paramount. In this paper, the authors report how the Dassault Systemes 3DEXPERIENCE Platform has been used to create a robust and efficient virtual twin model of a canted cosine theta dipole structure, leveraging the electromagnetic simulation tools CST Studio Suite® and Opera®, the structural solvers available on the 3DEXPERIENCE Platform, and the embedded optimization functionalities. All of the physics simulation and optimization processes share a single parametrized CAD geometry, which provides the flexibility for model design variation and rapid prototyping.
Paper: WEPS82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS82
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS84
CERN accelerates sustainability
2906
CERN is pursuing several initiatives to reduce its impact on the environment through an integrated approach to address all the objectives set by the relevant United Nations (UN) Sustainable Development Goals (SDG). In particular CERN is committed to respect the net-zero paradigm for future machines and has established a Sustainable Accelerators Panel to harmonize the approach to sustainability of the various studies for future accelerators. In this paper we will describe the efforts taken in managing responsibly our technical installations and the process we are setting up to perform the lifecycle assessment of the different future projects to better understand the main drivers of CO2 emissions in order to minimize them by design.
Paper: WEPS84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS84
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS85
An update on IRIS demonstrators
2909
IRIS (Innovative Research Infrastructure on applied Superconductivity) is a major project to build a research infrastructure in applied superconductivity, recently approved in Italy and led by INFN Milano. In this framework, we are developing two superconducting energy savings devices, both working at 20 K either in helium gas flow or by cold-heads: An HTS dipole (Energy Saving Superconducting Magnet) and a 1 GW rated superconducting line (Green SuperConducting Line). ESMA is an HTS ReBCO metal insulated racetrack dipole, this magnet will be 1 m long with a medium-sized round bore of 70 mm diameter and a maximum central field of 10 T. The paper reports the design updates, presenting and discussing the main technological choices (coil layout, ramping time, etc.). An R&D plan is supporting the technology choices and the construction that will be carried out in Industry will also be included. We are also developing a 130 m long MgB2 Superconducting Line (GSCL), capable of carrying 40 kA at 25 kV, an almost zero-dissipation DC transmission line. The paper will present the up-to-date status of the IRIS energy-saving devices, ESMA and GSCL: design, tests, and production.
Paper: WEPS85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS85
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS86
A life cycle assessment of the ISIS-II neutron and muon source
2912
The ISIS-II Neutron and Muon source is the proposed next generation of, and successor to, the ISIS Neutron and Muon Source based at the Rutherford Appleton Laboratory in the United Kingdom. Anticipated to start construction in 2031, the ISIS-II project presents a unique opportunity to incorporate environmental sustainability practices from its inception. A Life Cycle Assessment (LCA) will examine the environmental impacts associated with each of the ISIS-II design options across the stages of the ISIS-II lifecycle, encompassing construction, operation, and eventual decommissioning. This proactive approach will assess all potential areas of environmental impact and seek to identify strategies for minimizing and mitigating negative impacts, wherever feasible. This presentation will provide insights into the process and first results of the LCA of the entirety of the ISIS-II project.
Paper: WEPS86
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS86
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THAN2
Beam profile measurement of the ultra-slow muon for the transmission muon microscope
2933
We have performed a beam profile measurement of the ultra-slow muon for the transmission muon microscope, which is being developed at the Japan Proton Accelerator Research Complex (J-PARC). A laser ionization of thermal muonium generates the ultra-slow muon. The generated ultra-slow muon is extracted by an electrostatic lens and transported to the beam profile monitor, which consists of a micro-channel plate and delay-line anode. In this paper, the results of profile measurements and the beam commissioning status of the ultra-slow muon beamline are reported.
Paper: THAN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THAN2
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THYN1
First results of AUP Nb3Sn quadrupole horizontal tests
2943
The Large Hadron Collider will soon undergo an upgrade to increase its luminosity by a factor of ~10. A crucial part of this upgrade will be replacement of the NbTi final focus magnets with Nb3Sn magnets that achieve a ~50% increase in the field strength. This will be the first ever large scale implementation of Nb3Sn magnets in a particle accelerator. This talk will present the program to fabricate these components and first results from horizontal tests of fully assembled cryoassemblies.
Paper: THYN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THYN1
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THBN1
Progress in the design of the magnets for a Muon Collider
2956
Magnets have been identified as one of the critical technologies for a proton-driven Muon Collider. Within the scope of the International Muon Collider Collaboration we have progressed in the review of requirements, and the development of concepts towards the initial engineering of several of the most critical magnets identified from our previous work. In this paper we present an update of the accelerator magnet configuration for all the parts of the Muon Collider complex, from muon production to collision. We then give details on the specific technologies that have been selected as baseline. Overall, it is clear that a Muon Collider requires very significant innovation in accelerator magnet technology, mostly relying on the success of HTS magnet development. We include in our description a list of options and development staging steps intended to mitigate technical, cost and schedule risk.
Paper: THBN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THBN1
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THBN3
Lifetime of non-evaporable getter thin films over repeated activation
2960
Non-evaporable getter (NEG) coatings are used in accelerator beamlines to create an area of distributed pumping, allowing less external pumps to be installed, and smaller diameter tubes to be used. Both giving way to greater space for magnet arrays to better control the beam within, allowing more efficient accelerators to be produced. To work, NEG coatings must be activated by heating to a set temperature for 24 hours. This temperature depends on the properties of the NEG coating, and requirements of the system. The coating is then able to pump residual gasses out of the vacuum system, until it becomes saturated and will once again need activating. Over its a lifetime, a NEG coating will be activated and saturated numerous times, each time reducing the available sites for molecules to diffuse to during activation. Thus, eventually, the NEG coating will lose its capability, and will no longer be able to reach the same pumping capacity from the same activation regime. This study investigates the limits of NEG lifetimes, looking at the effect of multiple activations on the same coating. Samples of diameter 35 mm and length 50 cm were characterized by CO and H2 injections, from which the sticking probabilities and NEG coating capacity could be obtained. The samples were activated numerous times to see any degradation of the NEG coating. The results will be presented and discussed at IPAC 2024.
Paper: THBN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THBN3
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC08
Beam-based alignment of magnetic system in AREAL linear accelerator
2978
In this paper the beam-based alignment for solenoid and quadrupole magnets in the AREAL linear accelerator is presented. The AREAL accelerator, at this stage, operates with one solenoid, one quadrupole, corrector, and dipole magnets. The adjustment of solenoid and quadrupole magnets is crucial for the stable operation of the accelerator and for forming the desired beam required for the AREAL upgrade program. This work also takes into account the influence of the RF field radial component on the off-axis beam parameters and trajectory due to laser spot misalignment on the cathode. The study involves theoretical, simulation, and experimental comparisons.
Paper: THPC08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC08
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC18
Direct measurements of RHIC BPM data at the IP using linear regression
3011
Many mature methods to measure the betatron function of a lattice rely on beam position monitor (BPM) data and the model of the whole machine. In this study, specific sections of the Relativistic Heavy Ion Collider (RHIC) were analyzed, taking advantage of BPMs separated by drift spaces near interaction points (IPs) and B3/B4 magnet sections of RHIC. This (local) approach would provide a alternative measure of the linear optics at specific regions which can be compared to previous (global) methods. This process utilizes the phase transfer matrix built from existing BPM data from RHIC using Linear Regression (LR) techniques. Non-AC dipole BPM data as well as AC dipole data was used to measure the linear optics. It was found that the local method yields comparable beta beat to global methods; however, it differs significantly around IP6. This study demonstrates that using LR analysis has advantages and disadvantages, and that further studies are needed to improve the method.
Paper: THPC18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC18
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC20
Experimental measurements for extracting nonlinear invariants
3015
Nonlinear integrable optics are a promising alternative approach to lattice design. The integrable optics test accelerator (IOTA) at Fermilab has been constructed for dedicated studies of magnetostatic elliptical elements as described by Danilov and Nagaitsev. The most compelling verification of correct implementation of the NIO lattice is direct observation of the analytically expected invariants. This report outlines the experimental and analytical methods for extracting the nonlinear invariants of motion from data gathered in the last IOTA run.
Paper: THPC20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC20
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC21
Measured dynamic aperture and detuning of nonlinear integrable optics
3019
One of the most promising advantages of nonlinear integrable optics is strong amplitude dependent tune shift without degrading the dynamic aperture. The integrable optics test accelerator (IOTA) at Fermilab is constructed around nonlinear lattice elements of the elliptical type as described by Danilov and Nagaitsev. Detuning and dynamic aperture scans in IOTA were performed using a fast dipole kicker and a low emittance electron beam. The evolution of the dynamic aperture and detuning for different configurations of the integrable optics lattice are presented.
Paper: THPC21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC21
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC22
Space charge dominated momentum spread and compensation strategies in the post-linac section of Proton Improvement Plan-II at Fermilab
3023
The upcoming Proton Improvement Plan-II (PIP-II), designated for enhancements to the Fermilab accelerator complex, features a Beam Transfer Line (BTL) that channels the beam from the linac exit to the booster. In the absence of longitudinal focusing beyond the superconducting linac, the beam experiences an elevated momentum spread, primarily due to nonlinear space-charge forces, surpassing the allowable limit of 2.1e-4. This study presents a detailed examination of the space-charge-induced momentum spread and outlines mitigative strategies. The investigation includes the fine-tuning of a de-buncher cavity, analyzed in terms of operating frequency, longitudinal location, and gap voltage, under both standard and perturbed beam conditions—specifically accounting for momentum jitter and energy variation. The impact of buncher cavity misalignments on the beam's longitudinal phase space is also assessed. The paper concludes by recommending an optimized cavity configuration to effectively mitigate the observed increase in momentum spread along the BTL.
Paper: THPC22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC22
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC23
Machine-assisted discovery of integrable symplectic mappings
3027
Integrable systems possess a hidden symmetry associated with the existence of conserved quantities known as integrals of motion. These systems play an important role in understanding general dynamics in accelerators and have potential for future designs. This work will cover two automated methods for finding integrable symplectic maps of the plane. The first algorithm is based on the observation that the evolution of an integrable system in phase space is confined to a lower-dimensional submanifold of a specific type. The second algorithm relies on an analysis of dynamical variables. Both methods rediscover some of the famous McMillan-Suris integrable mappings and ultra-discrete Painlev\'e equations. Over 100 new integrable families are presented and analyzed, some of which are isolated in the space of parameters, while others are families with one parameter (or the ratio of parameters) being either continuous or discrete. In addition, the newly discovered maps are related to a general 2D symplectic map through the use of discrete perturbation theory. A method is proposed for constructing smooth near-integrable dynamical systems based on mappings with polygon invariants.
Paper: THPC23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC23
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC24
Optics corrections and performance improvements in the Bessy II Booster
3031
The BESSY II Booster has been reliably delivering beam to the storage ring for several decades. As part of an effort to better understand and control beam dynamics in the Booster, new instrumentation, including Libera Spark ERXR beam position processors, has recently been installed and commissioned. These instrumentation upgrades have enabled measurements and corrections of optics parameters throughout the acceleration ramp which were not previously possible, leading to understanding and mitigation of mechanisms for beam loss and instabilities. Here we describe the beam position measurement system, corrections to the tune and chromaticity, and the resulting improvements to the top-up operation of BESSY II.
Paper: THPC24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC24
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC25
Transmission characteristics of dark current in UED
3035
The high gradient of the photocathode radio-frequency electron gun (RF gun) increases the potential for field emission from the metal surface. Consequently, emitted electrons escaping from the RF gun result in the generation of a dark current, thereby degrading the gun's performance. A thorough investigation into the dark current phenomenon within the accelerator structure plays a crucial role in assessing the performance of the RF cavity and cathode, ensuring the accelerator operates under normal conditions. This paper focuses on establishing a transport matrix for off-axis particles in the RF gun and solenoid. This matrix predicates that field-emitted electrons tend to deviate from the center of the cathode. The study delves into both transverse and longitudinal dynamics characteristics of particles. By numerically tracking the path of dark electrons, we achieved a notable alignment between theoretical prediction and simulation results.
Paper: THPC25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC25
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC27
Quasi-isochronous conditions and high order terms of momentum compaction factor at the compact storage ring
3039
The compact storage ring project for accelerator research and technology (cSTART) is realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). Flexible lattice of a ring benefits variety of operation modes. Different physical experiments are planned at cSTART. In particular, deep variation of momentum compaction factor with simultaneous control of high order terms of alpha would demonstrate the capture and storage of ultra-short bunches of electrons in a circular accelerator. Computer studies of linear and non-linear beam dynamics were performed with an objective to estimate arrangement and performance of dedicated three pole chicane magnets to provide quasi-isochronous conditions for electrons. Additional families of so called “longitudinal” sextupoles and octupoles were added in a ring model to control slope and curvature of momentum compaction factor as function of energy offset of particles in a bunch.
Paper: THPC27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC27
About: Received: 03 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC30
Start-to-end simulations of the LAMP accelerator front-end
3049
The Los Alamos Neutron Science Center (LANSCE) accelerator delivers high intensity proton beams for fundamental science and national security applications since 1972. LANSCE is capable of simultaneous H+ and H- beam operations to multiple experiments requiring different time structures. This is achieved upstream in the facility with a combination of two 750 kV Cockcroft-Walton (CW) generators, a chopper and radiofrequency cavities, before going into the 800-MeV linac. The proposed LANSCE Modernization Project (LAMP) is evaluating critical machine upgrades necessary to continuous beam operations in decades to come. A significant component of LAMP is replacing the two CW with a dual-species 3-MeV Radiofrequency Quadrupole (RFQ). This change requires a full re-design of the LAMP front-end accelerator to deliver the existing and expanded capabilities of the facility. This contribution will discuss the LAMP front-end accelerator layout based on the general beam requirements and on standard accelerator codes, showcasing the start-to-end propagation of H+ and H- beams from the source to the linac entrance.
Paper: THPC30
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC30
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPC38
Exploratory splitter bend system designs for FFA@CEBAF
3079
An upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (JLAB) is anticipated to provide an electron beam of over 20 GeV using the existing superconducting-RF linear accelerator and new fixed-field alternating (FFA) gradient recirculation arcs made up of Halbach-style permanent magnets. In the current design, the FFA arcs will carry six beams with energies of approximately 11, 13, 16, 18, 20, and 22 GeV which will require horizontal splitter lines to match the beam from the preceding linac. In this paper, we describe two alternative splitter beamline designs that are tuned to match the beam's Twiss parameters, R56, time-of-flight, bend-plane offset, and dispersion into the FFA cells.
Paper: THPC38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC38
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC56
Simulation of beam loading compensation with RF-Track
3136
The beam loading effect results in a gradient reduction of the accelerating structures due to the excitation of the fundamental mode when the beam travels through the cavity. A recent implementation of this process in the tracking code RF-Track allows the simulation of realistic scenarios, thus revealing the impact of this phenomenon in start-to-end accelerator designs. In this paper, we present the latest update of the beam loading module which allows the simulation of the compensation of this effect and we explore the potential of the developed tool in heavy-loaded scenarios.
Paper: THPC56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC56
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC59
Investigation of transverse narrow-band impedance by coupled-bunch instability measurement in circular accelerator
3148
The transverse narrow-band impedance makes a major contribution to the transverse coupled-bunch instability, which may deteriorate the beam quality in multi-bunch, high-intensity circular accelerators. Thus, strict restriction on the transverse narrow-band impedance are implemented during the initial accelerator design phase. However, slight component structure deviations during the construction of accelerators and component modifications during the subsequent operation may lead to impedance difference from the design value. It is therefore more meaningful to obtain the impedance parameters of circular accelerators by beam experimental measurement during the machine operation. In this paper, by mode distribution of coupled-bunch instability and its growth rate, a method was proposed to obtain the transverse narrow-band impedance which is represented with an LRC resonator. In order to verify the effectiveness of the method, the numerical calculation with three known LRC resonators was used to check their difference and the fitted LRC resonator parameters are in good agreement with the setting values.
Paper: THPC59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC59
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC64
Impedance model for the Fermilab Recycler ring
3167
We present an impedance model of the Fermilab Recycler ring using PyHEADTAIL. The model is constructed by incorporating analytical expressions for the wakefields of beamline components that contribute significantly to impedance. The effects of indirect space charge are included as an inductive impedance. Benchmarking against measured coherent Betatron tune shifts, the impedance model is found to capture 73.4% of observed tune shifts. Our findings serve as a stepping stone for the development of a realistic impedance model crucial for studying impedance-driven instabilities at higher intensity.
Paper: THPC64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC64
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC66
Crossing transition in the EIC HSR with a resonance island jump scheme
3171
The Resonance Island Jump (RIJ) scheme for transition crossing in the Hadron Storage Ring of the Electron-Ion Collider is radically new, and untested. Beam experiments in RHIC will be necessary if it becomes necessary to consider the RIJ scheme as a serious alternative to upgrading the first order linear jump scheme currently implemented in RHIC. This paper outlines the theoretical foundations of the RIJ scheme, and considers how a beam experiment in RHIC could be performed.
Paper: THPC66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC66
About: Received: 11 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC69
Full-cycle simulations of the Fermilab booster
3183
The PIP-II project currently under construction at FNAL will replace the existing 400 MeV normal conducting linac with a 800 MeV superconducting linac. The beam power in the downstream rapid-cycling Booster synchrotron will be doubled by raising the machine cycle frequency from 15 to 20 Hz and by increasing the injected beam intensity by a factor 1.5. This has to be accomplished without raising uncontrolled losses beyond the administrative limit of 1 W/m. In addition, slip-stacking efficiency in the Recycler — the next machine in the accelerator chain- sets an upper limit on the longitudinal emittance of the beam delivered by the Booster. As part of an effort to better understand potential losses and emittance blow-up in the Booster, we have been conducting full cycle 6D simulations using the code pyORBIT. The simulations include space charge, wall impedance effects and transition crossing. In this paper, we discuss our experience with the code and present representative results for possible operational scenarios.
Paper: THPC69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC69
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC74
Generation femtosecond proton beam for laser plasma acceleration
3202
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.
Paper: THPC74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC74
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC76
Discussion of space charge effects of a beam train containing infinitely many bunches
3210
In an electron linear accelerator, the continuous beam emitted by an electron gun will become an equally spaced beam train after passing through the bunching section. If the current of the beam is large, its expansion may be more intense than the case where only a single bunch is considered, resulting from the space charge forces between different bunches. In this article, using an algorithm capable of calculating the space charge effects of a beam train containing infinitely many bunches with uniform spacing, we compare bunch trains with different parameters to find the pattern of their space charge effects.
Paper: THPC76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC76
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC82
Design of the low-emittance complex bend lattice
3233
The demands of a higher brightness photon beam push the electron beam emittance of storage rings towards a diffraction-limited level. The concept of multi-bend achromat (MBA) structure and its variations, containing multiple dipoles in a cell, has been widely employed in the fourth-generation storage ring light sources. Recently, a novel concept of lattice structure, called complex bend lattice, extends the option for low emittance ring lattice design. This paper presents the developed low-emittance complex bend lattices. The benefits of using complex bends include low natural emittance, long straights for IDs, more free space for accelerator equipment, and reduced power consumption for magnets.
Paper: THPC82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC82
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPC83
Test of parallel beam-based alignment at NSLS-II
3237
Misalignment of magnets in the storage rings causes trajectory deviation when the beam traverses through magnets, resulting in the degraded performance of linear optics and nonlinear dynamics. The beam-based alignment (BBA) technique is commonly used to steer the beam passing through the centers of magnets. Recently, a new method has been developed to determine the centers of multiple magnets simultaneously [1]. In this paper, the test of this fast BBA method at NSLS-II is presented.
Paper: THPC83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC83
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG02
Performance optimization design of photocathode injector based on multi-objective genetic algorithm
3244
Generating beam with nC-level charge is of great significance for particle colliders. In order to achieve lower emittance and length of bunch, based on the photocathode injector, we designed a L-band gun and L-band accelerating tube. However, with many coupled parameters, it is difficult to optimize its performance to the limit when optimizing them separately. Therefore, we employed a multi-objective genetic algorithm for searching in the multi-dimensional parameter space and utilized a deep Gaussian process as a surrogate model to solve the high-dimensional parameter optimization problem. Through optimization, we successfully obtained the normalized transverse emittance of 3.4 π mm·mrad and the bunch length of 1.0 mm for a fixed charge of 5 nC. This indicates that our method can effectively improve the performance of the photocathode injector.
Paper: THPG02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG02
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG03
Temporal profile shaping for a dispersive section using a multi-objective genetic algorithm
3247
Our research focuses on the design of a beamline. Due to the numerous beamline components involved, without strict optimization of each component's parameters, the transmitted temporal profile of beam may distort, failing to meet the expected requirements. Additionally, different initial temporal profile of the beam will undergo longitudinal shaping during transmission through the beamline. Therefore, we aim to determine the combination of initial beam temporal profile at the cathode and the parameters of the beamline components based on the specific beam distribution at the exit. We propose the application of an improved multi-objective genetic algorithm to solve this problem. Through multiple optimization iterations for a given temporal profile, our algorithm consistently identifies multiple suitable combinations of initial beam temporal profile and beamline component parameters to produce the desired specific temporal profile of the beam.
Paper: THPG03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG03
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG11
Long range plasma experiment beam transport with UCLA MITHRA beam line
3271
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.
Paper: THPG11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG11
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG18
Cost-effective asset management for accelerator control systems: design and implementation for the ALS-U controls system
3289
This paper presents a cost-effective asset management system (AMS) designed to optimize the workflow of the accelerator control system for the Advanced Light Source Upgrade (ALS-U) project at LBNL. The AMS stores all essential information about equipment, including location, owner, hardware details, and firmware versions. Its user-friendly interface provides consistent access throughout the equipment lifecycle, from quality assurance to installation, through label printing, QR codes, and the Web application. By streamlining workflows and improving data consistency, the AMS contributes significantly to the efficiency and success of the ALS-U project.
Paper: THPG18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG18
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG19
ALS-U accelerator motion design and realization
3292
Transitioning from the aging ALS Geo MACRO motor controller, this paper details the meticulous selection process for a new, cost-effective standard to fulfill the diverse motion requirements of the upcoming ALS-U project. Targeting primarily simple stepper motors with varying current demands, the chosen solution seamlessly integrates into the existing ALS-U EPICS environment while preserving the established ALS motion architecture and EPICS IOC support. Notably, the solution maintains independence from Delta-Tau technology while comprehensively accommodating the project's required range of servo/stepper motor types and offering dedicated support for critical subsystems like Beam Scraper and Cold Finger motion. This document delves into the exhaustive selection process, from comprehensively summarizing the current architecture and ALS-U requirements to meticulously analyzing the results of a year-long evaluation of diverse vendor offerings.
Paper: THPG19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG19
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG35
Generation of symmetrical optical caustic beams for precise alignment
3333
Generating layers of symmetrical optical caustic beams using a specific configuration of cylindrical lenses is an innovative idea with potential application in precision alignment and other fields. The technique allows the generation of layers of non-diffracting beams with opposite accelerating directions. This approach can be extended in two dimensions or to create rotationally symmetric beams. Prior methods have produced similar beams using spatial light modulators, but the presented approach with cylindrical lenses reduces setup complexity and cost, thereby opening the possibility for new applications. In the context of particle accelerators, these include particle acceleration using high-power lasers and alignment of accelerator components. The presented research emphasizes the possibility for this technique to be used as a reference line for precise alignment. It allows the generation of reference lines with a thickness in the order of millimeters for distances of tens to hundreds of meters, which is advantageous for large accelerator facilities. A brief description of the sensors used to detect misalignment is also presented.
Paper: THPG35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG35
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPG37
Parallel quadrupole modulation for fast beam-based determination of magnet centers
3341
A method to simultaneously determine the magnetic centers of multiple magnets with beam-based measurements is proposed. Similar to the quadrupole modulation system (QMS) method that is widely used for beam-based alignment measurement, the strengths of the group of selected magnets are modulated. The orbit shifts induced by the modulation are used to deduce the kicks applied at the magnet locations with the help of orbit response matrix calculated with the lattice model. By varying the beam orbit at the magnets, with a pair of corrector of magnets or local orbit bumps, and repeating the modulation measurement at each orbit, the magnet centers can be determined through fitting the calculated kicks versus the beam orbit. Demonstration of the method on a storage ring is presented. The method can also been applied to nonlinear magnets.
Paper: THPG37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG37
About: Received: 10 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPG38
Reducing background/noise in stretched wire alignment technique measurements
3345
The stretched-wire alignment technique is one method of magnet alignment for linear induction accelerators. The applications of the Stretched-Wire Alignment Technique (SWAT) have been implemented for aligning magnets/solenoids on the Scorpius linear induction accelerator which will be sited at the Nevada National Security Site and the Flash X-Ray (FXR) linear induction accelerator at Lawrence Livermore National Laboratory’s Contained Firing Facility. This article describes both systematic (repeatable) and random sources of background/noise as well as practical ways to either eliminate or mitigate them to acceptable levels. Systematic sources include reflections from wire ends, rapid sag due to ohmic heating of the wire, magnetic materials, and shot rate. Random sources include air currents, vibration of nearby equipment, mechanical stability of test equipment, and the instruments used to measure the wire motion. Mitigations include curve fitting and adaptive noise signal cancellation, and mechanical damping. Finite Element Analysis (FEA) was used to interpret results.
Paper: THPG38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG38
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG44
The LCLS-II beam loss monitor readout system
3362
The Linac Coherent Light Source II (LCLS-II) is a new addition to the SLAC accelerator complex. It is a 4 GeV, 120 kW superconducting Linac operating in continuous RF mode at 1.3 GHz with a beam repetition rate of up to 1 MHz. The prior generation of protection system beam loss monitors, whose operation is based on ion collection principles, are not suitable for operation in LCLS-II due to their slow recovery times. A new group of detectors have been identified and evaluated. These fall into three categories: Cherenkov detectors using optical fibers and photomultiplier pickups for distributed losses. Point detectors based on diamond pickups, and YAG:ce screens with photodiode pickups for burn through detection. These new detector elements require that new readout and signal processing electronics to be developed. In addition, because these detectors are part of the SLAC Beam Containment System (BCS), a certified safety system, a self-check mechanism is required to continuously verify the health of the detector and readout. This paper describes the design, operation and performance of the readout electronics.
Paper: THPG44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG44
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPG47
Upgrade of LLRF control system for infrared free-electron laser
3372
Hefei Infrared Free-Electron Laser device (IR-FEL) is a user experimental device dedicated to energy chemistry research that can generate high brightness mid/far infrared lasers. It is driven by an S-band linear accelerator with a maximum electron energy of 60 MeV. The stability of the final output laser is determined by the energy stability and spread of the electron beam, and the Low-Level RF control system (LLRF) is opitimized to improve the energy stability of the electron beam. There are two klystrons in the linear accelerator of IR-FEL, and the periodic oscillation of out power output of the klytrons is existed (approximately ± 0.2%~2% for amplitude). The oscillation period of two klystrons are exchanged in the case of exchanging the filament power supplies of two klystrons. The pulse-to-pulse feedforward and in-pulse feedback algorithm are developed to compensate the periodic fluctuations of the output power of the klystrons, and the IQ demodulation is changed to the Non-IQ demodulation (13/3) to separate and suppress the odd harmonic. After the optimization, the stability of klystron output signal has been improved from 0.12%/0.07° (rms) to 0.04%/0.09° (rms).
Paper: THPG47
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG47
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG48
Development of RF reference distribution system for Hefei Advanced Light Facility
3375
The Hefei Advanced Light Facility (HALF) is a diffraction-limited storage ring-based light source consists of a 180 m linear accelerator and a 480 m storage ring. The RF reference signal included 499.8 MHz and 2856 MHz are generated from two phase-locked master oscillators and transmitted to the RF system, beam position monitor system, timing system and beamline station by the phase stabled coaxial cables which are installed in the ±0.1℃ thermostatic bath. The RF Reference Distribution System (RF-RDS) are developed to realize the phase synchronization and transmission with low phase noise for long distance. The continues wave amplifier is manufactured to generate RF power of 10 W, with the added phase noise being less than 1 fs (10 Hz~10 MHz). The phase noise of each receiving terminal is estimated to be less than 30 fs (10 Hz~10 MHz). The design of RF-RDS and experimental result are discussed in this paper.
Paper: THPG48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG48
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG50
Lifetime studies of magnet protection systems for the Large Hadron Collider at CERN
3378
In the architecture of the protection of the superconducting magnets of the Large Hadron Collider (LHC), systems such as Quench Heater Discharge Power Supplies (HDS), Local Protection Interface Module (LIM), Linear Redundant Power Supplies (LPR), and Power Packs (LPUS) are crucial. Thousands of these devices, some in operation since 2007, directly impact LHC’s availability and reliability. This paper delves into comprehensive lifetime studies on these critical systems. The methodology involves estimating their remaining operational lifespan through detailed analyses of failure modes, assessing electronic component criticality, accelerated aging of electrolytic capacitors, inspections, and irradiation tests at both component and system levels. The study concludes by presenting essential findings, including the estimated remaining lifetime of each equipment. Additionally, the paper recommends future developments to enhance system robustness, offering valuable insights for maximizing the longevity of these critical devices. This research significantly contributes to ensuring the sustained reliability and performance of the LHC's magnet protection systems.
Paper: THPG50
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG50
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG52
Design, manufacturing and validation of the new quench heater discharge power supplies for the protection of superconducting magnets for the High-Luminosity LHC Project at CERN
3386
The Quench Heater Discharge Power Supplies (HDS) are magnet protection devices installed in the Large Hadron Collider (LHC) that, upon detection of a magnet quench, release energy into the copper-plated stainless-steel strip heaters, inducing a resistive transition all along the superconducting coils. Such a distributed internal heating ensures an even energy dissipation across the entire volume, preventing local overheating and magnet damage. Over 6000 HDS units have been operational in the LHC tunnel since 2007. The new HDS design for protection of the High Luminosity LHC (HL-LHC) Inner Triplet magnets, to be installed in the Long Shutdown starting in 2026, calls for a more advanced design with up-to-date components resulting in a higher reliability of the HDS units. Several HDS prototypes were produced at CERN, eventually culminating in the development of the HL-LHC HDS version to be installed in the accelerator. This paper describes the design of the upgraded HDS units and the comprehensive safety and electromagnetic compatibility (EMC) tests, coupled with extensive operational tests, including irradiation tests, that have been conducted.
Paper: THPG52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG52
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG58
Radiation levels from a beam gas curtain instrument at the LHC at CERN
3393
A prototype Beam Gas Curtain (BGC) monitor was installed at the Large Hadron Collider (LHC) at CERN to provide 2D images of the transverse beam profile during the ongoing Run 3 (2022 to date) and in view of the High Luminosity LHC upgrade (HL-LHC). By design, the BGC operation generates collisions between the beam particles and an injected gas jet proportionally to the beam intensity and the gas density, possibly causing radiation-induced issues to the downstream LHC equipment. In this work, the radiation showers from the BGC are characterized using measured data from different LHC radiation monitors during the Run 3 BGC operation, along with Monte Carlo simulations with the FLUKA code. Finally, predictions of the expected radiation showers during the operation of the BGC in the HL-LHC era are discussed.
Paper: THPG58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG58
About: Received: 10 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG59
Testing aspects of the CERN beam interlock system prior to installation in the accelerator
3397
The Beam Interlock System (BIS) is the backbone of the machine protection system throughout the accelerator complex at CERN, from LINAC4 to the LHC. After 15 years of flawless operation, a new version of the BIS is currently being produced and will be installed in the LHC, SPS and North Area during CERN’s Long Shutdown 3, planned to start in 2026. Overall, more than 3,000 Printed Circuit Boards will be produced and assembled outside CERN. In addition, more than 120,000 lines of firmware and supporting scripts are written to implement the critical and monitoring functionalities of the BIS. Both hardware and firmware need to be thoroughly tested before installation and operation to guarantee the high levels of reliability and availability required by the operation of the accelerators. In this paper we present the testing methodology including the development of dedicated testbeds for hardware validation, the use of comprehensive simulation and continuous integration for firmware development, and the implementation of automated tests for system-level functional validation.
Paper: THPG59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG59
About: Received: 06 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPG65
Equipment protection system against unexpected abnormalities during high-intensity proton beam operation at J-PARC MR
3420
The J-PARC MR synchrotron began high repetition operation with shortened accelerator cycles in 2022. So far, FX has been supplying a 2x10e+14 proton per pulse (ppp) beam to the Neutrino Experimental Facility with a repetition rate of 1.36 seconds, and SX has been supplying a 0.6x10e+14 ppp beam to the Hadron Experimental Facility with a 5.20 seconds repetition. The amount of heat per accelerated proton beam pulse exceeds 1 MJ, and it is an important issue to avoid damage to the equipment caused by high-intense beam due to abnormalities during beam acceleration. Since the MR is operated in different extraction modes, i.e. FX and SX, the countermeasures are also different, and the adequate protection system also needs to be considered, respectively. Therefore, the countermeasures have been put in place, including a high-speed beam abort system and/or a fast sequential interlock between devices. This report summarizes the systems to protect equipment from abnormalities that unexpectedly occur during high-intensity proton beam acceleration.
Paper: THPG65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG65
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG66
Machine protection system for TEX facility
3424
In the context of LATINO (Laboratory in Advanced Technologies for INnOvation) and Rome Technopole Projects founded by Regione Lazio and NextGenerationEu, and directly involved in the EuPRAXIA@SPARC_Lab flagship project, a testing facility for X-band (TEX) has been established at the Frascati National Laboratories of INFN. TEX is dedicated to the examination of radiofrequency X/C-band, aiming to develop and test the technologies and systems of a particle accelerator operating under such conditions. Given the complex nature of such a system and the advancement of technology to the forefront of the state of the art, it is imperative to have an advanced Machine Protection System (MPS) characterized by high reliability, availability, and safety, in accordance with IEC-61508 standards. Currently in development is a prototype MPS designed to autonomously initiate procedures to control operations and avert anomalies. An EPICS supervisor oversees the management of all devices and monitoring connected subsystems. Additionally, a real-time interlock system, based on distributed FPGA, is employed to swiftly respond to vacuum and RF systems during the next RF pulse.
Paper: THPG66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG66
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG79
An automated quad scan based emittance measurement software
3453
Beam emittance plays the crucial role in a Beam transportation system. At a fixed-target beamline off the AGS Booster Synchrotron, beam emittance is determined through measuring the beam width via a segmented multi-wire ion chamber (SWIC) and varying quadrupole strength. The width of the beam signal (as Full Width Half Max) on the SWIC passes through a minimum value and the resulting dataset of FWHM per magnet current is used to fit a function. Using this technique, new controls software has been developed to set up measurements, acquire data, and perform analysis through a python-based scripts to calculate the emittance along the NASA Space Radiation Laboratory (NSRL) beamline. Initial results of the program are presented to for various points along the beamline in a variety of conditions.
Paper: THPG79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG79
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG82
Using a particle-in-cell model for accelerator control room applications
3461
Many accelerator control rooms rely on envelope models to simulate beam dynamics because they are fast and accurate at tracking the beam core. Particle-in-Cell (PIC) models, however, can track particles inside and outside the core and, with the improvements of computers, are now fast enough to be used in control rooms. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is currently developing a tool to use a Particle-in-Cell model for control room applications. This report covers the progress so far and the future goals of using PyORBIT, a Particle-in-Cell simulation model, in the SNS control room.
Paper: THPG82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG82
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG85
Updates to Xopt for online accelerator optimization and control
3469
The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. These algorithms have been implemented in the python package Xopt, which has been used to solve online and offline accelerator optimization problems at a wide number of facilities, including at SLAC, Argonne, BNL, DESY, ESRF, and others. In this work, we describe updates to the Xopt framework that expand its capabilities and improves optimization performance in solving online optimization problems. We also discuss how Xopt has been incorporated into the Badger graphical user interface that allows easy access to these advanced control algorithms in the accelerator control room. Finally, we describe how to integrate machine learning based surrogate models provided by the LUME-model package into online optimization via Xopt.
Paper: THPG85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG85
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG87
Autofocusing accelerator beams
3473
A novel tuning approach, Model Coupled Accelerator Tuning (MCAT), has been applied to the separated function DTL at TRIUMF's Isotope Separator and Accelerator (ISAC). A digital twin of the rare-isotope postaccelerator is used for transverse and longitudinal tune optimizations, which are then loaded directly into the control system. Beam-based testing produced accelerated beam with a 0.26% error in output energy, with a 1.6% energy spread. This method significantly reduces the operational complexity of tuning interventions, rendering them more efficient. An analysis of the high energy beam lines (HEBT) is also presented, including analysis of dispersive couplings in certain sections of the beamline. A mitigation strategy involving buncher cavities is discussed.
Paper: THPG87
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG87
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR01
ELISA: a compact linear accelerator for societal applications
3477
The experience gained at CERN by the R&D for LINAC4 has been exported to medical and societal applications. With an innovative design of the Radio Frequecy Quadrupole (RFQ) at high frequencies, it is possible to build very com- pact structures, reproducible in industry and with the po- tential of full portability. ELISA (Experimental LInac for Surface Analysis) is a linear proton accelerator installed in the Science Gateway exhibition at CERN since October 2023. With a footprint of only 2×1 square meters, ELISA consists of an ion source, a one-meter-long RFQ working at 750 MHz and an analysing line dedicated to Particle Induced X-ray Emission (PIXE). The system can accelerate a proton beam (extracted from the source at 20 keV) up to an energy of 2 MeV. In this paper the ELISA source commissioning is presented, with a multi-parameter optimization performed both computationally and experimentally and the ultimate optimization of beam emittance at 20 keV, finally achieving the required brilliance of the source. High energy beam com- missioning will also be discussed, including RFQ voltage scan to study the transmission and characterize the ELISA RFQ.
Paper: THPR01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR01
About: Received: 12 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR08
Improvements to 4-rod RFQs with additive manufacturing processes
3494
The institute of applied physics (IAP), university of Frankfurt, has been working for years on the development of increasingly powerful 4-Rod RFQ accelerators for hadron acceleration. The need for such accelerators has increased significantly in the recent past, as accelerator-driven neutron sources are becoming increasingly important following the closure of various test reactors. High beam currents, particle energies and operational stability are often required from those LINACs. In order to meet these requirements, the copper structure of the RFQ is to be manufactured using a new type of pure copper 3D printing in order to be able to introduce optimized cooling channels inside the copper parts. Comprehensive multiphysics simulations with ansys, cst and autodesk CFD will first be carried out to evaluate the operational stability and performance. In addition, it will be clarified whether the printed copper fulfills the necessary vacuum and conductivity requirements after CNC processing, or whether galvanic copper plating should be carried out.
Paper: THPR08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR08
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPR09
High-power RF conditioning and 700 keV beam commissioning of the revised RFQ for the Frankfurt Neutron Source
3497
We report the successful high power RF conditioning of the revised 175 MHz FRANZ RFQ up to 80 kW CW, as well as successful beam commissioning up to 700 keV in pulsed operation. After a revision of the RFQ electrodes, the RFQ accelerates protons from 60 keV to 700 keV. The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)7Be reaction with a 2 MeV proton beam.
Paper: THPR09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR09
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR10
RF conditioning of an IH-DTL cavity made using additive manufacturing
3501
Additive manufacturing ("AM") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for direct additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel, as well as pure copper using AM. We present the most recent results of vacuum, low level RF, as well as RF conditioning of the cavity.
Paper: THPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR10
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR12
Simultaneous acceleration of multiple beams in novel LANSCE front end
3505
We present the 100 MeV injector design for the LANSCE Accelerator Facility, which is designed to replace the existing 750-keV Cockcroft-Walton-columns-based injector. This new Front End includes two independent low-energy transports for H+ and H- beams merging at the entrance of a single RFQ, with the subsequent acceleration of particles in the new Drift Tube Linac. The challenge of this design is associated with the necessity of simultaneous acceleration of protons and H- ions with multiple beam flavors in a single RFQ and DTL. The LANSCE operation regime provides simultaneous delivery of beams to five experimental areas, with a forecasted increase in the number of targets in the future. Each beam is characterized by a unique time structure, pulse length, emittance, and charge per bunch. The paper presents the details of this design and injector parameters.
Paper: THPR12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR12
About: Received: 11 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR13
Conditioning of rod-style RFQ in support of LANSCE front-end upgrade
3508
The Los Alamos Neutron Science Center (LANSCE) front-end injection scheme requires an upgrade to a Radio-Frequency Quadrupole (RFQ) in order to replace the obsolete Cockroft-Waltons used in present operation. A test stand using a rod-style RFQ is under development in support of this upgrade, and conditioning of the RFQ to the expected peak and average power levels was completed to ensure its feasibility. The RFQ conditioning also revealed thermal issues with the RF power coupler and issues in managing the power reflected from the RFQ. These issues and their mitigation will be discussed in light of the capability of the test stand, and future plans will also be discussed.
Paper: THPR13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR13
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR14
Importance of quadrupole magnet fringing fields in low energy beam transport: example in the LIPAc 5 MeV D+ beamline
3512
The hard-edge model for a quad field distribution is widely assumed in particle simulations at the early design phase of beam transport lines or circular accelerator rings to quickly evaluate their beam optics. However, the model assuming a rectangular field distribution even with an effective length is not an appropriate approximation for low-energy beams (<50 MeV). This approximation is known not to necessarily lead to the correct beam optics. The evaluated beam size based on this hard-edge model has tended to be different from measured ones and simulation results employing the exact field distribution fully implementing fringing fields. We try to study the magnetic field gradients of single quads installed in the Linear IFMIF Prototype Accelerator beamline. We define a characteristic magnetic field gradient gc [T/m] of the quad, which is determined only by the distance relations for the target quad, steerer, and BPM. Simulation results, where the hard-edge and file-map models are assumed, are compared with those measured using a 5 MeV deuteron beam. The details of the comparison of the results and the effect of the fringe fields on the beam optics are discussed in this paper.
Paper: THPR14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR14
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR15
Simple estimate, detailed computer simulation and measurement of the transverse kick in the SLAC accelerating structure
3516
We discuss the result of calculation and measurement of the transverse kick in the SLAC accelerating section in a single bunch and multi-bunch regimes. We present a simple estimate, which can be used in practical situations.
Paper: THPR15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR15
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR20
Design of IH-DTL with PMQ focusing for medical RI production
3536
In recent years, plans for cancer treatment using medical RI have been progressing worldwide. The stable supply is difficult due to the aging of small nuclear reactors and dependence on imports from abroad. Manufacturing using accelerators could realize a stable supply in Japan. To give an example of Astatine-211, the production of an alpha-ray drug requires helium nuclei of 7 MeV/u or more. This time, we are designing an accelerator system with the aim of accelerating helium ions with a peak current value of 30mA and a duty cycle of 5%. As an accelerator following the radio-frequency quadrupole linac (RFQ), which accelerates up to 0.6 MeV/u, we are considering the design of an interdigital H-mode drift tube linac (IH-DTL) with permanent magnet quadrupoles (PMQ) in the drift tubes. This accelerator is designed to operate at 200 MHz to use the commercially available semiconductor power supply for saving space and electricity and improving maintainability. In this presentation, we report on the basic design of the IH-DTL with PMQ.
Paper: THPR20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR20
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPR25
Design automation of pre-separator wedges for FRIB advanced rare isotope separator
3549
At the Facility for Rare Isotope Beams (FRIB) unique pre-separator wedges are required for each experiment. As the number of experiments and wedges needed increases every year, reduction in design time and increase in accuracy is critical (FY23 utilized 40 unique wedges, FY24 approx. 60 are planned, and eventually 100 annually). Design automation is achieved by DriveWorksXpress, which reduced design/drafting time by 60%. A form was created with parameters (inputs) listed for each component of the wedge assembly (e.g., wedge height, wedge on axis thickness, wedge angle, etc.). The dimensions and file properties of each component are then able to reference the input values for each parameter from the form and automatically adjust the model and assembly accordingly. Automation on drawing drafting is achieved at the same time. The reduction in design time resulted in completing the design task more efficiently. A reduction in design error and human error was also observed, reducing manufacturing down time and effort required during the release process. These benefits have streamlined the mechanical design process for the pre-separator wedges.
Paper: THPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR25
About: Received: 09 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPR29
High fidelity numerical modelling and condition monitoring applied to septum magnets at CERN
3556
The CERN Accelerator Beam Transfer group has recently launched a study to investigate the life cycles of pulsed septum magnets. The development is aiming to enhance the prediction of anomalies, leading to reduced life cycles of these beam transfer equipment. For this reason, the standard vacuum operated, direct drive septa magnet has been chosen to investigate critical design features. In the initial project phase, a so called High-Fidelity (HF) numerical simulation has been carried out, providing insight on critical components, like brazed joints, reducing the fatigue life. In parallel a dedicated test setup with state-of-the-art instrumentation has been developed, allowing to confirm the predicted system response. The novel approach for the beam transfer equipment will allow to review presently established design criteria. In a further iteration, the project is now aiming to demonstrate an anomaly detection and their prediction based on novel machine learning techniques. This paper presents the initial phase of developing the HF model, as well as the results of the instrumented magnet tests which will be compared to results from the numerical simulations.
Paper: THPR29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR29
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR36
Automated anomaly detection on European XFEL klystrons
3575
High-power multi-beam klystrons represent a key component to amplify RF to generate the accelerating field of the superconducting radio frequency (SRF) cavities at European XFEL. Exchanging these high-power components takes time and effort, thus it is necessary to minimize maintenance and downtime and at the same time maximize the device's operation. In an attempt to explore the behavior of klystrons using machine learning, we completed a series of experiments on our klystrons to determine various operational modes and conduct feature extraction and dimensionality reduction to extract the most valuable information about a normal operation. To analyze recorded data we used state-of-the-art data-driven learning techniques and recognized the most promising components that might help us better understand klystron operational states and identify early on possible faults or anomalies.
Paper: THPR36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR36
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR37
Towards unlocking insights from logbooks using AI
3579
Electronic logbooks contain valuable information about activities and events concerning their associated particle accelerator facilities. However, the highly technical nature of logbook entries can hinder their usability and automation. As natural language processing (NLP) continues advancing, it offers opportunities to address various challenges that logbooks present. This work explores jointly testing a tailored Retrieval Augmented Generation (RAG) model for enhancing the usability of particle accelerator logbooks at institutes like DESY, BESSY, Fermilab, BNL, SLAC, LBNL, and CERN. The RAG model uses a corpus built on logbook contributions and aims to unlock insights from these logbooks by leveraging retrieval over facility datasets, including discussion about potential multimodal sources. Our goals are to increase the FAIR-ness (findability, accessibility, interoperability, and reusability) of logbooks by exploiting their information content to streamline everyday use, enable macro-analysis for root cause analysis, and facilitate problem-solving automation.
Paper: THPR37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR37
About: Received: 16 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPR38
Monte Carlo estimation of emittance growth during injection into the LANSCE PSR
3583
The Los Alamos Neutron Science Center (LANSCE) accelerator uses charge exchange injection to accumulate a high-intensity proton beam in the Proton Storage Ring (PSR). H- ions are accelerated to 800 MeV and then stripped of their electrons by a thin foil at the ring injection site. The Monte Carlo N-Particle (MCNP) radiation transport code has been used to estimate the effect foil thickness has on the emittance growth of the ion beam. Results for the scattering angle of individual particles and emittance growth of the injected beam are presented for a range of foil thicknesses.
Paper: THPR38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR38
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR42
A double multi-turn injection scheme for mixed ¹²C⁶⁺ and ⁴He²⁺ beams
3599
With a very low relative charge-to-mass ratio offset of approximately 0.065%, helium (⁴He²⁺) and carbon ions (¹²C⁶⁺) are interesting candidates for being simultaneously accelerated in hadron therapy accelerators. At the same energy per nucleon, helium ions exhibit a stopping range approximately three times greater than that of carbon ions. They can therefore be exploited for online range verification in a detector downstream of the patient during carbon ion therapy. The synchrotron-based MedAustron Ion Therapy Center provides the opportunity to study the feasibility of such a mixed beam-based in-vivo range verification system due to the availability of 120-402.8 MeV/u carbon beams and the ongoing commissioning of 39.8-402.8 MeV/u helium beams. One possibility for creating this mixed beam is accelerating ⁴He²⁺ and ¹²C⁶⁺ sequentially through the LINAC and subsequently “mixing” the ion species at injection energy in the synchrotron with a double injection scheme. This contribution introduces this newly proposed injection scheme, outlines challenges and presents first feasibility estimates obtained through measurements and particle tracking simulations.
Paper: THPR42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR42
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR45
Research on ultra-high energy electron beams for FLASH radiation therapy at ELSA
3610
Ultra-high energy electrons (UHEE) are used to investigate their effect on tumor cells and healthy tissue in short pulses of microseconds at the electron accelerator facility ELSA. This may enable highly efficient treatment of deep-seated tumors due to the FLASH effect. In a preliminary setting electrons with an energy of 1.2 GeV are used to irradiate cell samples which are located inside a water volume, representing the human body. Irradiation occurs with dose rates of up to 10 MGy/s due to the short pulse lengths of 250 ns. The relative biological effectiveness (RBE) can be determined by assessing the cell survival of tissues under FLASH and conventional conditions. For a precise dose determination, dose measurements via radiochromic films are utilized and compared to simulations with Geant4, that reproduce the electromagnetic shower process.
Paper: THPR45
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR45
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR48
FLASHlab@PITZ beamline upgrade towards full functionality – status and plans
3621
At the Photo Injector Test facility at DESY in Zeuthen (PITZ), an R&D platform for electron FLASH cancer radiation therapy and radiation biology is being prepared: FLASHlab@PITZ. The design of the full beamline with optimized beam properties was finished; the setup is currently being finalized and the mechanical design and manufacturing is underway. The beamline runs in parallel to the SASE THz beamline at PITZ and is connected to it with a dogleg. Beam dynamics simulations were conducted to assure excellent beam quality at the experimental area. A fast kicker system will be installed which is capable of distributing electron bunches from a single bunch train freely over an area of 25mm x 25mm within one microsecond. When the full FLASHlab@PITZ beamline is ready in 2024, the accelerator will deliver 22 MeV electrons to generate dose rates from 0.01 Gy/s up to 10e+14 Gy/s to an experimental area, which can accommodate a variety of setups for irradiation studies. The flexible arrangement of the experimental area will make it possible for external users to collaborate with PITZ and conduct experiments with existing or newly designed irradiation setups.
Paper: THPR48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR48
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR49
Electronic brachytherapy replacement of iridium-192
3625
The replacement of radionuclides used for cancer therapy with accelerators offers several advantages for both patients and medical staff. These include the elimination of: unwanted dose, specialized storage and transportation, and isotope production/replacement. Several electronic brachytherapy devices exist, and typically utilize an x-ray tube around 50 keV. These have primarily been used for skin cancer, though intraoperative applications are becoming possible. For several types of cancer, Iridium-192 has been the only brachytherapy treatment option, due to its high dose rate and 380 keV average energy. An accelerator-based alternative to Ir-192 has been developed, comprised of a 9.4 GHz, 1 MeV compact brazeless accelerator, narrow drift tube, and target. The accelerator is supported and positioned through the use of a robotic arm, allowing for remote delivery of radiation for internal cancer treatment. Preliminary results including dose rate and profile and plans for complete system demonstration will be presented.
Paper: THPR49
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR49
About: Received: 21 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR52
Medical irradiation studies at KIT accelerators
3635
Radiation therapy is an important oncological treatment method in which the tumor is irradiated with ionizing radiation. In recent years, the study of the beneficial effects of short intense radiation pulses (FLASH effect) or spatially fractionated radiation (MicroBeam/MiniBeam) have become an important research field. Systematic studies of this type often require research accelerators that are capable of generating the desired short intense pulses and, in general, possess a large and flexible parameter space for investigating a wide variety of irradiation methods. The KIT accelerators give access to complementary high-energy and time-resolved radiation sources. While the linac-based electron accelerator FLUTE (Ferninfrarot Linac- und Testexperiment) can generate ultrashort electron bunches, the electron storage ring KARA (Karlsruhe Research Accelerator) provides a source of pulsed X-rays. In this contribution, first dose measurements at FLUTE and KARA, as well as simulations using the Monte Carlo simulation program FLUKA are presented.
Paper: THPR52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR52
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR54
The Laser-hybrid Accelerator for Radiobiological Applications (LhARA): an update towards the conceptual design
3639
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications, is a proposed facility designed to advance radiobiological research by delivering high-intensity beams of protons and ions in unprecedented ways. Designed to serve the Ion Therapy Research Facility (ITRF), LhARA will be a two-stage facility that will employ laser-target acceleration in the first stage, generating proton bunches with energies around 15 MeV via the TNSA mechanism. A series of Gabor plasma lenses will efficiently capture the beam, directing it to an in-vitro end station. In the second stage, protons will be accelerated in a fixed-field alternating gradient ring, reaching up to 127 MeV, while ions can achieve up to 33.4 MeV/u. The resulting beams will be directed to either an in-vivo end station or a second in-vitro end station. The demonstrated technologies have the potential to shape the future of hadron therapy accelerators, offering versatility in time structures and spatial configurations, with instantaneous dose rates surpassing the ultra-high dose rates required for studies into the FLASH effect. Here, we present a status update of the LhARA accelerator as we approach a full conceptual design.
Paper: THPR54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR54
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR55
SAFEST project, a compact C-band RF linac for VHEE FLASH radiotherapy
3643
FLASH Therapy, an innovative cancer treatment, minimizes radiation damage to healthy tissue while maintaining the same efficacy in tumor cure as conventional radiotherapy. Successful integration of FLASH therapy into clinical practice, specifically for treating deep-seated tumors with electrons, relies on achieving Very High Electron Energy (VHEE) within the 50-150 MeV range. In collaboration with INFN, Sapienza University actively develops a compact C-band high-gradient VHEE FLASH linac called SAFEST. This paper presents the general layout and the main characteristics of the machine and the first prototype set for deployment at Sapienza University of Rome. This endeavor is a significant step towards the clinical implementation of FLASH Therapy.
Paper: THPR55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR55
About: Received: 06 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR57
Design study of a compact IH-DTL-based injector for proton therapy facilities
3647
A new proton injector based on the 425-MHz radio frequency quadrupole (RFQ) and interdigital H-mode drift tube linac (IH-DTL) has been designed. The injector is ~7 m long and comprises an electron-cyclotron-resonance (ECR) ion source, a low-energy beam transport, an RFQ, an IH-DTL, two triplets, a medium-energy beam transport, and a debuncher. The IH-DTL is specially designed with two tanks with different bunching phases, which can contribute to excellent transverse and longitudinal beam quality. The ion source produces an 18-mA proton beam with the energy of 30 keV. The output energy of the injector is 7 MeV with the transmission efficiency of 86.2%. A three-dimensional electromagnetic simulation was conducted, and the results agreed with the design. A systematic and mechanical design of the entire proton injector was also performed for the following research and development. The injector has great performance and is planned to be utilized in Shanghai APACTRON Proton Therapy facility (SAPT). In the future, it can also promote advanced proton accelerators for medical applications.
Paper: THPR57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR57
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR60
Development of a multi-angle ultrahigh dose rate MV-level X-ray radiation system for FLASH radiotherapy clinical transformation
3656
In this work, MAX FLASH system (Multi-Angle ultrahigh dose rate megavolt-level X-ray radiation system for FLASH radiotherapy) is presented. This system consists of a rapid RF power distribution network and five linacs vertically installed at different coplanar angles. The distribution network can switch all power to one terminal linac between pulses. Electron beams are accelerated to 10 MeV with more than 400 mA peak currents in the high-performance linac and then convert into X-ray at a compact rotating target. The system aims for a compact FLASH radiotherapy clinical facility with a gantry 3 meter in diameter and 2.5 meter in length, which can be installed in most of hospital radiotherapy treatment rooms. There is reserved space in the gantry for a coplanar CBCT to implement for image guidance. The gantry can rotate to an optimized angle for a better conformality before radiation while the system remains stationary and switches the operating linac during radiation. Construction of the first system prototype, with 40 Gy/s dose rate at 80 cm source-axis-distance, is supposed to be finished in the summer of 2024.
Paper: THPR60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR60
About: Received: 12 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR70
Development of a compact electron cyclotron resonance accelerator for industrial and security applications
3678
We describe the development of a novel accelerator, an electron Cyclotron Resonance Accelerator (eCRA) [1], to produce high power electron beams and X-ray beams for medical, research, sterilization, and national security applications. The several attractive features of eCRA include: a compact robust room-temperature single-cell RF cavity as the accelerating structure; continuous ampere-level high current output; and production of a self-rastering electron beam, thus eliminating the need for a separate beam scanner. Progress on the eCRA development, including numerical simulation, engineering design, and on-going experimental efforts will be reported here.
Paper: THPR70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR70
About: Received: 24 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPR71
Container stripping: enhanced classification of materials within cargo containers
3681
For cargo and vehicle inspection, where high energy linear accelerators are used, materials within radio-graphic images can be classified using their atomic number (Z). The identification and classification of materials and objects within cargo containers can be difficult, due to the nature of energy spectra and their impact on the discrimination of materials. This can also be impacted by system-level factors, such as the stability of the linear accelerator and the alignment of the system. By removing the container from images of cargo, materials inside can be classified with higher confidence. When a low-Z, low density organic material is obscured by a 5 mm thick steel container, its effective-Z value changes and it can colorise as green rather than orange. This could lead to mis-classification of materials by an operator, potentially leading to the mis-identification of threatening materials. Further to the container removal, extra layers can be ‘stripped’ away to better reveal certain areas of interest. In future, this could be tied in with operator-assisting algorithms, as part of an enhanced image quality analysis package.
Paper: THPR71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR71
About: Received: 08 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR72
The X-ray imaging laboratory: a radiation test facility for validating industrial linacs
3684
The X-ray Imaging Laboratory is a radiation test facility developed by Rapiscan systems at their facility in Stoke-On-Trent, UK. The X-ray Imaging Laboratory comprises two areas: the Test Facility and the Linac Development Area. The Test Facility is a state-of-the-art facility designed for subsystem and system level testing of x-ray imaging hardware utilizing normal conducting electron linacs with energies of up to 6MeV. The Test Facility is primarily focused on utilizing mature industrial linacs to produce x-rays for imaging validation. The Linac Development Area is a new facility focused on testing linear accelerator components and subsystems for a new generation of industrial electron linacs. The Linac Development Area includes a high voltage test area and a radiation test bunker. This allows for testing of critical components, such as modulators, in isolation in the high voltage test area and then as part of an industrial linac in the radiation test bunker.
Paper: THPR72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR72
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR73
Status of ABC production line at Varex Imaging Corporation
3687
During past 7 years at Varex Imaging Corporation, we have created a pilot production line for Accelerator Beam Centerlines (ABC), replacing supply of Beam Centerlines (BCL) by Varian after the Component Division separated from Varian in 2017, becoming an independent public company. Our ABC production growth rate seems to double every year, and in last quarter of 2023 Fiscal Year, we delivered 35 ABCs, satisfying Industrial group full demand in such ABCs. In this 2024 Fiscal Year started on 1 October 2023, our goal is to deliver 12 units per month, but the stretch goal is to produce anywhere between 160 and 200 ABCs, which will include ABCs for 3, 6, and 9 MeV Linacs mostly for security screening, for Non-Destructive Testing (NDT), also a few units for our customers in radiation therapy business. We drive to complete the transition away from Varian to 100% in-house ABC production in 2025,
Paper: THPR73
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR73
About: Received: 07 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR79
Alternative gamma-ray source based on 2.2 MeV linear accelerator with field emission cathode
3698
High energy gamma-ray generators have the potential to be used in place of radioisotope sources, thus eliminating the security risk posed by radioisotopic sources. Euclid Techlabs design of nonradioisotopic gamma-ray source is based on ultra-compact linear accelerator with affordable magnetron RF power feeding. Wide aperture 15 cell X-band linac with embedded field emission cathode operates without expensive high voltage electron gun and bulky magnetic focusing system. 2.2 MeV output electron energy and 1 μA average accelerated beam current on composite target can provide gamma-ray spectrum similar to 2nd category Cs-137 radioisotope source.
Paper: THPR79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR79
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR83
Electrical fire safety assessment of the synchrotron accelerator experimental station in NSRRC
3704
The synchrotron facility and experimental station in the National Synchrotron Radiation Research Center (NSRRC) uses many electrical appliances, the improper use of which can cause fires, resulting in property damage and personal injury. Therefore, the usage of these electri-cal appliances must be assessed. This study conducted a comprehensive inspection and evaluation of the electrical appliances used in NSRRC, including extension cords and electrical connections; this was done to not only reduce the risk of fire but also emphasize the importance of electrical safety habits. We connected an extension cord reel in the NSRRC to a pump or a dehumidifier and used a thermal imaging cam-era to measure the temperature of the cord and these two appliances. We tested the extension cord reel when it was coiled up in the reel and straightened to determine which electrical appliances or extension cord states were prone to high temperatures and fires. The results showed that the extension cord was 18–20°C hotter when it was coiled than when it was straight. Therefore, we recommend that at least two-thirds of the length of the extension cord should be extended out of the reel when it is used.
Paper: THPR83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR83
About: Received: 05 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPR85
Solid-state driven X-band linac for electron microscopy
3710
Current transmission electron microscopes (TEM) accelerate electrons to 200-300 keV using DC electron guns with a nanoamp of current and very low emittance. However at higher voltages these DC sources rapidly grow in size, oftentimes several meters tall for 1 MeV microscopes. Replacing these electron guns with a compact linac powered by solid-state sources could dramatically lower cost while maintaining beam quality, thereby increasing accessibility. Utilizing compact high shunt impedance X-band structures ensures that each RF cycle contains at most a few electrons, preserving beam coherence. CW operation of the RF linac is possible with distributed solid-state architectures* which power each cavity directly with solid-state amplifiers which can now provide up to 100W of power at X-band frequencies. We present a demonstrator design for a prototype low-cost CW RF linac for high-throughput electron diffraction producing 200 keV electrons with a standing-wave architecture where each cell is individually powered by a solid-state transistor. This design also provides an upgrade path for future compact MeV-scale sources on the order of 1 meter in size.
Paper: THPR85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR85
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS01
STAR High-Energy Linac status: complete installation acceptance tests
3718
The installation of the STAR High-Energy Linac, the energy upgrade of the Southern European Thomson Back-Scattering Source for Applied Research (STAR) project at the University of Calabria, was conducted by INFN by the end of 2023. This paper presents the testing procedures aimed at confirming the consistency, completeness, and quality of the STAR accelerator upgrade installation (electron beam energy boost from 65 MeV up to 150 MeV). We illustrate the installation and testing of the electrical, hydraulic and related automation and auxiliary systems. We will discuss the high-power commissioning of the two C-band RF power stations and testing of the low-level C-band RF system and control system configuration based on EPICS. Finally, we will describe the layout and testing of the vacuum system, the characterization and commissioning of the magnets with related power supplies and the assessment of the installed diagnostics devices. The linac commissioning as well as electron beam measurements are planned for Summer 2024, due to pending radioprotection authorizations.
Paper: THPS01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS01
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS02
Upgrade of the SPARC_LAB low level radiofrequency system
3722
SPARC_LAB facility was born in 2004 as an R&D activity to develop a high brightness electron photo-injector dedicated to FEL experiments and exploration of advanced acceleration techniques. The electron source consists in a brazefree 1.6-cell S-band RF gun with a peak electric field of 120 MV/m and a metallic copper photocathode. The gun injects particles into two S-band sections, the initial section acting as an RF compressor using the velocity bunching technique, with built-in solenoid coils that enhance magnetic focusing and control emittance. A subsequent C-band acceleration section acts as a booster to achieve the desired kinetic energy. The Lazio Regional government recently funded the SABINA project for the consolidation of SPARC_LAB facility. The reference and the distribution systems and the Low Level radiofrequency (LLRF) system will also undergo a significant upgrade, involving the replacement of the original analogue S-band and digital C-band radiofrequency systems with commercial, temperature-stabilized, FPGA-controlled LLRF digital systems provided by Instrumentation Technologies in order to improve performance in terms of amplitude, phase resolution, and stability.
Paper: THPS02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS02
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS04
Design and testing of high stability power supply for high energy photon source
3729
The High Energy Photon Source (HEPS) is the fourth-generation synchrotron photon source. Compared with the third-generation synchrotron photon source, the brightness is 100-1000 times higher, and the electron emittance of the storage ring is low to the diffraction limit of light. Through physical calculations, it is required that the stability of the storage ring quadrupole magnet power supply be better than 10ppm, and the accuracy of output current be better than 80ppm. This high demand for technical parameter poses a challenge to the development of high precision and stability power supplies. The main circuit topology of the power supply adopts a phase shifted full bridge soft switching scheme, which avoids interference caused by switching noise and improves power stability and efficiency. The high-precision digital power supply controller based on FPGA improves the sampling speed and control accuracy of the power supply, and the constant temperature control circuit ensures that the output current of the power supply meets the requirements of HEPS for power supply performance. In the batch testing section, a testing facility was built to test the stability, accuracy, repeatability, voltage ripple, and other parameter of high precision and stability power supplies. After a year and a half of testing, the performance tests of 1066 power supplies, including linear accelerators power supplies, booster power supplies, storage rings power supplies, dipole and quadrupole combined power supplies, dipole and quadrupole power supplies, were completed. The results all met and exceeded the design specifications. The HEPS high precision and stability power supply meets the design requirements in terms of current stability, accuracy, repeatability, voltage ripple, and other aspects. The batch test results show that the power supply performance using the full bridge phase shifting soft switching technology combined with high-precision digital controller scheme is excellent, and the power supply consistency is good, providing a guarantee for the successful operation of HEPS in the future.
Paper: THPS04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS04
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS06
Real-time digital controller design based on SoC FPGA for general usage in J-PARC MR magnet power supplies
3735
Nowadays, the real-time control is more and more popular in the particle accelerator field because it is a powerful tool for stable operation and beam loss suppression in the particle accelerator. However, in the Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), real-time control has not been widely used in magnet power supplies yet. Magnet power supplies are very easily affected by disturbances from external factors, such as environmental temperature, device aging, power grid voltage and current fluctuations, and so on. Therefore, it is worth developing a real-time digital controller with general functions for the magnet power supplies to observe and suppress these disturbances. In this paper, we propose the design of a general-purpose intelligence controller for the magnet power supply realized by a System-on-Chip (SoC) Field Programmable Gate Array (FPGA). This digital controller can also be used as a high-resolution data acquisition system, a pattern generator, and a high-precision current control system for magnet power supplies.
Paper: THPS06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS06
About: Received: 12 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPS09
Development of linear power operational amplifier for TPS correction magnet power supply
3742
This paper investigates the design and implementation of a TPS correction magnet power supply using a combination of a linear power operational amplifier (PA05) and a pre-regulator voltage controller. The PA05 linear power operational amplifier features bipolar output, high internal power dissipation, and wide bandwidth. Utilizing a DCCT sensor as a current feedback element integrated with the pre-regulator voltage controller, a closed-loop current modulation circuit is formed, providing the variable voltage required by the linear power operational amplifier. We have successfully developed a prototype of a linear power operational amplifier power supply with a pre-regulator voltage controller for TPS correction magnets through these measures. Design validation is achieved through control loops, resulting in fast and stable output current performance. The output current ripple is maintained below 100 μA, and the rise time during the step response is 75 μs. During the frequency response test using a 0.1 V interference signal, the gain margin remained within -3 dB at an 11.2 kHz bandwidth, and the phase margin was within -45 ° over a range of 5.1 kHz. The long-term stability of the output current is maintained at ten ppm. Finally, a hardware prototype circuit is assembled in the power laboratory with input voltage ranging from ±24 V, an output current of ±20 A, and a maximum rated power of 240 W.
Paper: THPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS09
About: Received: 05 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPS16
Study and simulation of cryogenic photonic-band-gap disk-loaded structure
3761
In order to enhance the accelerating gradient of accelerators, cryogenic accelerating structures have been investigated. Based on material characteristics and technical conditions, a fundamental design has been accomplished. Photonic band-gap (PBG) structures employ a lattice of rods to impede the propagation of RF field through the lattice at specific frequencies while effectively damping higher order modes. The design of the single-cell PBG structure has been refined by altering the shape of the rods surrounding the defect region in order to miti-gate peak surface magnetic field within the structure. The combination of PBG cells and a bi-periodic accelerating structure has resulted in the design of a novel structure. This innovative configuration possesses the advantageous characteristics of a bi-periodic structure while incorporating the additional functionality of a PBG struc-ture to effectively damping higher order modes.
Paper: THPS16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS16
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS35
A novel pulse compressor with dielectric assistance
3813
A compact pulse compressor with dielectric assistance structure is proposed and simulated. The novel pulse compressor adopts a spherical resonant cavity design with dual-mode polarization mode. A dielectric sphere added at the centre of the spherical cavity can reduce the volume and weight of the pulse compressor and improve the unloaded quality factor of the cavity. A C-band compact storage cavity model is designed and simulated on ANSYS HFSS working on 5.712 GHz. The dielectric permittivity of the dielectric sphere is 9, and the dielectric tangent loss is 0.00001. The simulation of the dielectric-assist resonant cavity with an inner diameter of 34 mm indicates an unloaded quality factor about 72000.
Paper: THPS35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS35
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS40
Thermal-fluid analysis and operation of a low power water-cooled tilted beam dump at Facility for Rare Isotope Beams
3823
The Facility for Rare Isotope Beams is a high power heavy ion accelerator completed in April 2022. The FRIB accelerator was commissioned with acceleration of heavy ions to energies above 200 MeV/nucleon (MeV/u) that collide onto a rotating single-disk graphite target. The remaining beam is absorbed by a water-cooled static beam dump that is oriented at a 6 degrees angle with respect to the beam. The beam dump consists of the beam stopper made of machined Aluminum 2219 block, and 3D-printed inlet and outlet parts made of Aluminum 6061 that delivers the cooling water from utilities to the beam stopper and its return. This low power beam dump is designed for up to 10 kW beam power. This paper presents a discussion on the thermal-fluid behavior of the beam dump for various beam species and beam power.
Paper: THPS40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS40
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPS41
Thermal analysis of rotating single slice graphite target system for FRIB
3827
The Facility for Rare Isotope Beams (FRIB) is a high power heavy ion accelerator facility at Michigan State University completed in 2022. Its driver linac is designed to accelerate all stable ions to energies above 200 MeV/u with beam power of up to 400 kW. Currently FRIB is operating at 10 kW delivering various primary beams. The target absorbs roughly 25% of the primary beam power and the rest is dissipated in the beam dump. This paper presents a brief overview of the current production target system and details the thermal analysis ANSYS simulations utilized for temperature and stress prediction. The existing single-slice rotating graphite target can accommodate up to 40 kW for lighter beams, with a planned transition to a multi-slice concept.
Paper: THPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS41
About: Received: 09 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS48
3D integration methodologies of the accelerators at CERN
3845
The 3D design of large accelerators like the Large Hadron Collider (LHC) requires coordination among equipment, services, and infrastructures. As numerous systems are designed, procured, and installed, 3D integration studies are important steps at any stages of a project, starting from the conceptual phase with space reservations, envelopes and interfaces, followed by the technical design phase managing the detailed and simplified 3D models, and finishing by the installation phase with follow-up of discrepancies. While the first phases serve to validate the accelerator configuration and design, the installation phase is followed by a reverse engineering process to verify the ‘as-built’ configuration, representing the final actual setup of the accelerator. At CERN, the 3D integration office for the accelerators assumes responsibility for collecting, aggregating, centralizing, and checking the 3D models provided by CERN design offices such as equipment owners, electrical, civil engineering, metallic structure, transport, handling, cooling, and ventilation services. This office manages 3D space, avoiding mechanical interferences before and during the installation phase. This paper describes the CAD, PDM and PLM methodologies used for 3D integration of the accelerators at CERN, highlighting their critical aspects and specificities.
Paper: THPS48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS48
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS52
PLAN analytics for enhanced understanding of RUN3 and LS3 activities at CERN
3857
Designed as an internal tool at CERN, PLAN has a pivotal role in the centralization and macroscopic aggregation of technical intervention and enhancement activities planned within the accelerator complex. As part of a broader strategy to enhance tool utilization and extract valuable insights, a substantial endeavor during RUN3 aimed to develop and disseminate analytics derived from tool-generated data. These analytics are seamlessly accessible via a FLASK application, crafted primarily using Python and the Bokeh library, JavaScript, HTML, and CSS. Hosted internally at CERN through OpenShift, it is containerized through Docker, and subject to continuous integration via GitLab. These analytics serve versatile purposes, encompassing the quantification of activities, identification of resource constraints across departments and groups, and the provision of insights into various facilities, projects, and more. Moreover, they play an instrumental role in identifying bottlenecks and critical milestones in planning timelines. These analytics are designed to furnish management and other stakeholders with essential insights, ultimately contributing to wide-ranging improvements across CERN.
Paper: THPS52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS52
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS54
Magnetic measurements for Halbach-type permanent quadrupoles using a single-stretched wire system
3864
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.
Paper: THPS54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS54
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS57
Radiation dose simulations for Jefferson Lab’s permanent magnet resiliency LDRD study
3872
In late 2023, Thomas Jefferson National Accelerator Facility (Jefferson Lab) funded a Laboratory Directed Research and Development (LDRD) grant dedicated to investigating the impact of radiation on permanent magnet materials. This research initiative is specifically geared towards assessing materials slated for use in the CEBAF energy upgrade. The experimental approach involves strategically placing permanent magnet samples throughout the accelerator, exposing them to varying radiation doses. The simulation code BDSIM is used to first validate the data and then to simulate the effects on future higher energy passes to study the degradation effects on the permanent magnets. In this paper we present the progress of that work.
Paper: THPS57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS57
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS58
Permanent magnet resiliency in CEBAF’s radiation environment: LDRD grant status and plans
3875
As the FFA@CEBAF energy upgrade study progresses, it is important to investigate the impact of radiation exposure on the permanent magnet materials to be used in the upgraded fixed field alternating gradient (FFA) arcs. To address this, Jefferson Lab has awarded a Laboratory Directed Research and Development (LDRD) grant to study the resiliency of several permanent magnet materials placed in a radiation environment similar to that in which they are expected to operate. Samples of NdFeB and SmCo are to be placed alongside appropriate dosimetry in a variety of radiation environments in the beam enclosure and experimental halls at CEBAF. The magnet degradation will be measured, and extrapolated to the higher energies expected during operations after the energy upgrade. This document will describe the current status of the LDRD study, as well as describe the upcoming plans. It will also direct the readers to other proceedings which further detail the work thus far.
Paper: THPS58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS58
About: Received: 10 May 2024 — Revised: 16 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPS59
Design and instrumentation for permanent magnet samples exposed to a radiation environment
3879
This work is part of a larger program to study the effects of radiation on permanent magnets in an accelerator environment. In order to be sure that the permanent magnet samples are accurately placed, measured, and catalogued we have developed a system of sample racks, holders and measuring apparatuses. We have combined these holders and measurement racks with electronics to allow a single computer to catalogue the position and intensity of the magnet measurements. We outline the design of the apparatus, the collection software, and the methodology we will use to collect the data.
Paper: THPS59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS59
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS60
Bead-pull measurement procedure for AREAL linear accelerator accelerating structure
3882
In this paper, the widely used RF measurement bead-pull technique for the S-band accelerating structure pre-tuning of the AREAL linear accelerator is presented. Bead-pull measurements were conducted before brazing with various group sets of accelerating cells to evaluate the effectiveness of “smart combinations” for AREAL accelerating structures. The “smart combination” technique represents the grouping of cells with corresponding lengths to achieve the same length sets (triplets for 2π/3 mode) as it is possible. Cell lengths were measured in advance based on TM resonance frequencies measurement. This procedure will significantly reduce the tuning routine required after brazing.
Paper: THPS60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS60
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS62
Perspectives and recent achievements on additive manufacturing technologies for accelerators
3890
This paper reports the exploratory studies on advanced accelerator technologies performed within the I.FAST (Innovation Fostering in Accelerator Science and Technology) EU project, and in particular the key results of the additive manufacturing Task 10.2 – “Additive Manufacturing – applications and potential developments” and Task 10.3 – “Repair of damaged accelerator components by AM technologies”. This includes results of two surveys targeted to the accelerator community: a) on current additive manufacturing applications in accelerators and expected new developments, b) on current additive manufacturing repair technologies for accelerator and list of possible applications. The paper is outlining potential additive manufacturing applications in accelerators and overall strategies applicable to accelerator components repairs benefiting from additive manufacturing technology.
Paper: THPS62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS62
About: Received: 18 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS66
Experimental design for validating the feasibility of in-situ plasma cleaning of normal conducting copper cavities
3901
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.
Paper: THPS66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS66
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS69
Mechanical design, structural requirements and optimization of the FCC e+e- interaction region components
3904
This paper describes the mechanical design of the Future Circular Collider e+e- interaction region. The Future Circular Collider, as a forefront particle accelerator project, demands meticulous attention to the mechanical integrity and performance of its components, to the integration of the different systems and to the respect of the spatial constraint. The vacuum chamber design, the support tube and the bellows design are reported, highlighting the solutions adopted. The structural optimization method of the support structure is also presented, as well as the results obtained.
Paper: THPS69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS69
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS70
3D printed beam correctors
3908
Starting from 2018 we have designed and created 3D printed beam correctors using two different types of FDM materials, Ultem and ASA. The design was defined based on the ergonomics of the existing machine parts, avoiding radial and longitudinal mechanical interference, and the magnetic performances to be produced. The size and configuration of the resulting windings influenced the choice of the most suitable FDM material for the purpose. In total we present 3 different prototype models which, in addition to demonstrating the ability to produce the design performances, are currently used on the SPARC-Lab Experiment in our INFN National Laboratories in Frascati.
Paper: THPS70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS70
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
FRXN1
Beam instrumentation for advancing accelerators
3916
Beam instrumentation is of critical importance for the operation and optimization of modern particle accelerators. With advancing accelerator technology and the increasing requirements for higher quality beams, it is an ever-present challenge that beam diagnostics must similarly progress. In this talk the instrumentation considered most impactful for the progress of 4th generation storage ring light sources is presented with reference to possible lessons learned, applicability to other accelerators and potential future directions.
Paper: FRXN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRXN1
About: Received: 17 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
FRXD2
Commissioning of carbon ion treatment accelerator with a superconducting rotating gantry
3921
The world's smallest carbon ion treatment facility has been commissioned at Yamagata University. The treatment system consists of an ECR ion source, a linac cascade of 0.6 MeV/u RFQ and 4 MeV/u IH-DTL, a 430 MeV/u slow extraction synchrotron, and irradiation systems of a fixed horizontal beamline and a compact rotating gantry using superconducting combined function magnets. The size of the building is 45 x 45 m, realized by placing the irradiation rooms not on the same level as the synchrotron, but above it, connected by a vertical beam transport. The most advanced accelerator technology of this machine is to control the beam range up to 300 mm in 0.5 mm steps without any physical block range shifter. To achieve this range step, 600 beam energies were provided in the synchrotron and in the beam transport and tuned to control the beam size in the treatment room. Initial commissioning and daily/monthly quality assurance were carried out by interpolation of beam energy and gantry angle. After tuning the beam size and correcting the beam axis in the treatment rooms, precise dose measurement was performed for clinical irradiation. After the clinical commissioning, the facility started treatment irradiation in February 2021 with a fixed beam port and in March 2022 with a gantry beam port. After March 2023, the gantry angle was operated with a 15-degree step. By November 2023, 1330 patients had been treated.
Paper: FRXD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRXD2
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
FRYD3
Particle colliders: options for the US and internationally
3944
In the US high energy planning process more than 30 colliders were considered. This talk gives an overview of these colliders and emphasized the strength of the various approaches.
Paper: FRYD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRYD3
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024