Keyword: simulation
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MOPLXGD1 The SuperKEKB Has Broken the World Record of the Luminosity luminosity, injection, impedance, operation 1
 
  • Y. Funakoshi, T. Abe, K. Akai, Y. Arimoto, K. Egawa, S. Enomoto, H. Fukuma, K. Furukawa, N. Iida, H. Ikeda, T. Ishibashi, S.H. Iwabuchi, H. Kaji, T. Kamitani, T. Kawamoto, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, K. Matsuoka, T. Mimashi, G. Mitsuka, F. Miyahara, T. Miyajima, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, K. Nakanishi, H.N. Nakayama, M. Nishiwaki, S. Ogasawara, K. Ohmi, Y. Ohnishi, N. Ohuchi, T. Okada, T. Oki, M.A. Rehman, Y. Seimiya, K. Shibata, Y. Suetsugu, H. Sugimoto, H. Sugimura, M. Tawada, S. Terui, M. Tobiyama, R. Ueki, X. Wang, K. Watanabe, S.I. Yoshimoto, T. Yoshimoto, D. Zhou, X. Zhou, Z.G. Zong
    KEK, Ibaraki, Japan
  • A. Natochii
    University of Hawaii, Honolulu,, USA
  • K. Oide
    CERN, Meyrin, Switzerland
  • R.J. Yang
    CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
  • K. Yoshihara
    Nagoya University, Nagoya, Aichi, Japan
 
  The SuperKEKB broke the world record of the luminosity in June 2020 in the Phase 3 operation. The luminosity has been increasing since then and the present highest luminosity is 4.65 x 1034 cm-2s-1 with βy* of 1 mm. The increase of the luminosity was brought with an application of crab waist, by increasing beam currents and by other improvements in the specific luminosity. In this paper, we describe what we have achieved and what we are struggling with. Finally, we mention a future plan briefly.  
slides icon Slides MOPLXGD1 [6.235 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPLXGD1  
About • Received ※ 10 June 2022 — Accepted ※ 08 July 2022 — Issue date ※ 10 July 2022  
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MOOYSP2 Measurements of Collective Effects Related to Beam Coupling Impedance at SIRIUS impedance, storage-ring, synchrotron, coupling 34
 
  • F.H. de Sá, M.B. Alves, L. Liu
    LNLS, Campinas, Brazil
 
  Sirius is the new storage-ring-based 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS) at the Brazilian Center for Research in Energy and Materials (CNPEM). In ultralow emittance storage rings such as Sirius, the small radius of the vacuum chamber gives rise to strong beam coupling impedances which significantly alter the stored beam dynamics. In this work, we present the single-bunch measurements made so far to characterize such effects and compare the results with those simulated using the impedance budget built during the storage ring design.  
slides icon Slides MOOYSP2 [2.496 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOOYSP2  
About • Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022  
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MOPOST026 Influences of the Energy Jitter to the Performance of the Coherent Electron Cooling electron, experiment, kicker, emittance 115
 
  • G. Wang, V. Litvinenko, J. Ma
    BNL, Upton, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The bandwidth of a coherent electron cooling (CeC) system is typically two to three orders of magnitude higher than the traditional RF based stochastic cooling system, which make it possible to cool the ion bunches with high energy and high intensity. However, for such broad bandwidth, jitters in the energy of the cooling electron bunches present a serious challenge to the performance of the cooling system. In this work, we present analytical as well as simulation studies about the influences of the energy jitter to a CeC system with parameters relevant to the on-going CeC experiment at RHIC.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST026  
About • Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 29 June 2022
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MOPOST027 The Zgoubidoo Python Framework for Ray-Tracing Simulations with Zgoubi: Applications to Fixed-Field Accelerators lattice, closed-orbit, FFAG, focusing 118
 
  • M. Vanwelde, E. Gnacadja, C. Hernalsteens, N. Pauly, E. Ramoisiaux, R. Tesse
    ULB, Bruxelles, Belgium
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
 
  The study of beam dynamics in accelerators featuring main magnets with complex geometries such as Fixed Field Accelerators (FFAs) requires simulation codes allowing step-by-step particle tracking in complex magnetic fields, such as the Zgoubi ray-tracing code. To facilitate the use of Zgoubi and to allow readily processing the resulting tracking data, we developed a modern Python 3 interface, Zgoubidoo, using Zgoubi in the backend. In this work, the key features of Zgoubidoo are illustrated by detailing the main steps to obtain a non-scaling FFA accelerator from a scaling design. The results obtained are in excellent agreement with prior results, including the tune computation and orbit shifts. These results are enhanced by Zgoubidoo beam dynamics analysis and visualization tools, including the placement of lattice elements in a global coordinate system and the computation of linear step-by-step optics. The validation of Zgoubidoo on conventional scaling and non-scaling FFA designs paves the way for future uses in innovative FFA design studies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST027  
About • Received ※ 16 May 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022  
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MOPOST037 Characterisation of Bunch-by-Bunch Tune Shift Effects in the CERN SPS impedance, injection, electron, kicker 148
 
  • I. Mases Solé, H. Bartosik, V. Kain, K. Paraschou, M. Schenk, C. Zannini
    CERN, Meyrin, Switzerland
 
  After the implementation of major upgrades as part of the LHC Injector Upgrade Project (LIU), the Super Proton Synchrotron (SPS) delivers high intensity bunch trains with 25 ns bunch spacing to the Large Hadron Collider (LHC) at CERN. These beams are exposed to several collective effects in the SPS, such as beam coupling impedance, space charge and electron cloud, leading to relatively large bunch-by-bunch coherent and incoherent tune shifts. Tune correction to the nominal values at injection is crucial to ensure beam stability and good beam transmission. During the beam commissioning of the SPS, measurements of the bunch-by-bunch coherent tune shifts have been conducted under different beam conditions, together with appropriate corrections of the average tunes at each injection. In this paper, we describe the methodology that has been developed to acquire bunch-by-bunch position data and to perform online computations of the coherent tune spectra of each bunch using refined Fourier transform analysis. The experimental data are compared to multiparticle tracking simulations using the SPS impedance model, in view of developing an accurate model for tune correction in the SPS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST037  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 19 June 2022
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MOPOST041 Dynamic Aperture Studies for the Transfer Line From FLUTE to cSTART storage-ring, optics, quadrupole, linac 164
 
  • J. Schäfer, B. Härer, A.-S. Müller, A.I. Papash, R. Ruprecht, M. Schuh
    KIT, Karlsruhe, Germany
 
  Funding: J. Schäfer acknowledges the support by the DFG- funded Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology".
The compact STorage ring for Accelerator Research and Technology cSTART project will deliver a new KIT accelerator test facility for the application of novel acceleration techniques and diagnostics. The goal is to demonstrate storing an electron beam of a Laser Plasma Accelerator (LPA) in a compact circular accelerator for the first time. Before installing an LPA, the Far-Infrared Linac and Test Experiment (FLUTE) will serve as a full energy injector for the compact storage ring, providing stable bunches with a length down to a few femtoseconds. The transport of the bunches from FLUTE to the cSTART storage ring requires a transfer line which includes horizontal, vertical and coupled deflections which leads to coupling of the dynamics in the two transverse planes. In order to realize ultra-short bunch lengths at the end of the transport line, it relies on special optics which invokes high and negative dispersion. This contribution presents dynamic aperture studies based on six-dimensional tracking through the lattice of the transfer line.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST041  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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MOPOST042 Using Dynamic Indicators for Probing Single-Particle Stability in Circular Accelerators lattice, alignment, dynamic-aperture, software 168
 
  • C.E. Montanari, A. Bazzani, G. Turchetti
    Bologna University, Bologna, Italy
  • M. Giovannozzi, C.E. Montanari
    CERN, Meyrin, Switzerland
 
  Computing the long-term behaviour of single-particle motion is a numerically intensive process, as it requires a large number of initial conditions to be tracked for a large number of turns to probe their stability. A possibility to reduce the computational resources required is to provide indicators that can efficiently detect chaotic motion, which are considered precursors to unbounded motion. These indicators could allow skilful selection of a set of initial conditions that could then be considered for long-term tracking. The chaotic nature of each orbit can be assessed by using fast-converging dynamic indicators, such as the Fast Lyapunov Indicator (FLI), the Reversibility Error Method (REM), and the Smallest and Global Alignment Index (SALI and GALI). These indicators are widely used in the field of Celestial Mechanics, but not so widespread in Accelerator Physics. They have been applied both to a modulated Hénon map, as a toy model, as well as to realistic lattices of the High-Luminosity LHC. In this paper, we discuss the results of detailed numerical studies, focusing on their performance in detecting chaotic motions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST042  
About • Received ※ 07 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022  
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MOPOST045 A Novel Tool for Beam Dynamics Studies with Hollow Electron Lenses electron, collimation, collider, hadron 176
 
  • P.D. Hermes, R. Bruce, R. De Maria, M. Giovannozzi, G. Iadarola, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  Hollow Electron Lenses (HELs) are crucial components of the CERN LHC High Luminosity Upgrade (HL-LHC), serving the purpose of actively controlling the population of the transverse beam halo to reduce particle losses on the collimation system. Symplectic particle tracking simulations are required to optimize the efficiency and study potentially undesired beam dynamics effects with the HELs. With the relevant time scales in the collider in the order of several minutes, tracking simulations require considerable computing resources. A new tracking tool, Xsuite, developed at CERN since 2021, offers the possibility of performing such tracking simulations using graphics processing units (GPUs), with promising perspectives for the simulation of hadron beam dynamics with HELs. In this contribution, we present the implementation of HEL physics effects in the new tracking framework. We compare the performance with previous tools and show simulation results obtained using known and newly established simulation setups.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST045  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 08 July 2022
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MOPOST047 Determination of the Phase-Space Stability Border with Machine Learning Techniques dynamic-aperture, luminosity, hadron, storage-ring 183
 
  • F.F. Van der Veken, R. Akbari, M.P. Bogaert, E. Fol, M. Giovannozzi, A.L. Lowyck, C.E. Montanari, W. Van Goethem
    CERN, Meyrin, Switzerland
 
  The dynamic aperture (DA) of a hadron accelerator is represented by the volume in phase space that exhibits bounded motion, where we disregard any disconnected parts that could be due to stable islands. To estimate DA in numerical simulations, it is customary to sample a set of initial conditions using a polar grid in the transverse planes, featuring a limited number of angles and using evenly distributed radial amplitudes. This method becomes very CPU intensive when detailed scans in 4D, and even more in higher dimensions, are used to compute the dynamic aperture. In this paper, a new method is presented, in which the border of the phase-space stable region is identified using a machine learning (ML) model. This allows one to optimise the computational time by taking the complex geometry of the phase space into account, using adaptive sampling to increase the density of initial conditions along the border of stability.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST047  
About • Received ※ 06 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022  
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MOPOST049 Electron Cloud Build-Up for the Arc Sextupole Sections of the FCC-ee electron, collider, vacuum, sextupole 191
 
  • J.E. Rocha Muñoz, G.H.I. Maury Cuna
    Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
  • K.B. Cantún-Ávila
    UADY, Mérida, Yucatán, Mexico
  • F. Zimmermann
    CERN, Meyrin, Switzerland
 
  Funding: Consejo Nacional de Ciencia y Tecnología (CONACyT) - México
In particle accelerators that operate with positrons, an electron cloud may occur due to several mechanisms. This work reports preliminary studies on electron cloud build-up for the arc sextupole sections of the positron ring of the FCCe+e using the code PyECLOUD. We compute the electron cloud evolution while varying strategic parameters and consider three simulation scenarios. We report the values of the central density just before the bunch passage, which is related to the single-bunch instability threshold and the electron density threshold for the three scenarios. In addition, we compare the simulated electron distribution across the central circular cross-section for a chamber with and without winglets.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST049  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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MOPOST051 Study of Transverse Resonance Island Buckets at CESR lattice, resonance, sextupole, damping 199
 
  • S. Wang, V. Khachatryan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Work supported by NSF PHYS-1416318 and DMR-1829070.
A 6-GeV lattice with the horizontal tune near a 3rd-order resonance line at 3νx=2 is designed for studying the transverse resonance island buckets (TRIBs) at the Cornell Electron Storage Ring (CESR). The distribution of 76 sextupoles powered individually is optimized to maximize the dynamic aperture and achieve the desired amplitude-dependent tune shift αxx and the resonant driving term h30000, which are necessary conditions to form stable island buckets. The particle tracking simulations are developed to check and confirm the formation of TRIBs at different tunes with clearing kicks in this TRIBs lattice. Finally, the lattice is loaded in CESR and the TRIBs are successfully observed when the horizontal fractional tune is adjusted to 0.665, close to the 3rd-order resonance line. Bunch-by-bunch feedback is also explored to clear the particles in the main bucket and the island buckets, respectively.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST051  
About • Received ※ 20 May 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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MOPOST056 Interplay between Space Charge and Intra-beam Scattering for the CERN Ion Injectors resonance, space-charge, emittance, scattering 214
 
  • M. Zampetakis, F. Antoniou, F. Asvesta, H. Bartosik, Y. Papaphilippou
    CERN, Meyrin, Switzerland
 
  The CERN ion injectors, SPS and LEIR, operate in a strong space charge and intra-beam scattering regime, which can lead to degradation of their beam performance. To optimize machine performance requires thus to study the interplay of these two effects in combined space charge and intrabeam scattering tracking simulations. In this respect, the kinetic theory approach of intra-beam scattering has been implemented in pyORBIT and benchmarked against analytical models. First results of combined space charge and intra-beam scattering simulations for SPS and LEIR are presented in this contribution. The simulation results are compared with observations from beam measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST056  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 07 July 2022
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MOPOPT005 Bunch Measurements with BPM at Low Energy Hadron Accelerators linac, rfq, diagnostics, electron 237
 
  • S.M. Ben Abdillah
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • S. Boussa, A. Gatera, F. Pompon
    SCK•CEN, Mol, Belgium
 
  Beam Position Monitors (BPM) are one of the key diagnostics use in LINACs, BPMs should ensure a continuous monitoring of the beam position and energy. BPMs also give an indication of the beam transverse shape. For electron LINACs, beam longitudinal length is measured with BPMs. However, in hadron LINACs, it is performed with intrusive modules (wire scanners, beam shape monitors) This document relates the measurement of beam longitudinal length with BPMs. It is divided in two parts: first, a theoretical model of the BPM operation and the formulas driving the measurement of beam longitudinal length from BPM output signals. Second, an experimental study run at MYRRHA LINAC facility and showing good agreement between estimated values of beam longitudinal length from Tracewin simulations and BPM measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT005  
About • Received ※ 12 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 27 June 2022
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MOPOPT011 Transverse Excitation and Applications for Beam Control resonance, betatron, extraction, controls 251
 
  • P.J. Niedermayer, R. Singh
    GSI, Darmstadt, Germany
 
  Transverse excitation of stored particle beams is required for a number of applications in accelerators. Using a time-varying, transverse electric field with a dedicated frequency spectrum, the amplitude and coherence of betatron oscillations can be increased in a controlled manner. This allows for determination of the betatron tune from turn-by-turn position measurements, control of transverse beam shapes, as well as extraction of stored beams. For studies of beam excitation, a custom signal generator is being developed. It is based on software-defined radio (SDR) which allows for configurable signal characteristics and tuneable spectra. This approach enables usage for multiple applications in beam diagnostics and control. To determine appropriate excitation spectra, studies of particle dynamics in presence of excitation are being carried out. Nonlinear fields are also incorporated to account for beam extraction conditions, which affects frequency spectra of beam motion due to detuning effects.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT011  
About • Received ※ 30 May 2022 — Accepted ※ 10 June 2022 — Issue date ※ 16 June 2022  
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MOPOPT018 Advancing to a GHz Transition Radiation Monitor for Longitudinal Charge Distribution Measurements vacuum, radiation, target, electron 267
 
  • S. Klaproth, A. Penirschke
    THM, Friedberg, Germany
  • H. De Gersem
    TEMF, TU Darmstadt, Darmstadt, Germany
  • T. Reichert, R. Singh
    GSI, Darmstadt, Germany
 
  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05P21RORB2. Joint Project 05P2021 - R&D Accelerator (DIAGNOSE)
In the past, longitudinal beam profiles have been measured with e.g., Feschenko monitors*, Fast Faraday Cups (FFC)** and field monitors. Feschenko monitors usually examine an average shape over several pulses and FFCs are interceptive devices by design. In this work we want to present the progress in the development of a novel GHz diffraction radiation monitor which shall be able to measure the longitudinal charge distribution of single bunches within Hadron beam LINACS non-destructively. A proof-of-concept measurement has been performed at GSI. We aim for a resolution of 50 to 100ps at beam energies of β=0.05 to 0.74. electronic field simulations were performed using CST Particle Studio to determine an optimal RF-Window, which also suits as vacuum chamber and the beam energy and angular dependencies of the diffraction radiation for different materials were analyzed.
* A. V. Feschenko (2001): Methods and Instrumentation for Bunch Shape Measurements. In Proc. PAC’01, paper ROAB002
** G. Zhu et al (2018): Rev. Sci. Instrum. issn 0034-6748, doi :10.1063/1.5027608
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT018  
About • Received ※ 14 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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MOPOPT019 Wakefield Studies for a Bunch Arrival-Time Monitor Concept with Rod-Shaped Pickups on a Printed Circuit Board for X-Ray Free-Electron Lasers pick-up, FEL, wakefield, electron 271
 
  • B.E.J. Scheible, A. Penirschke
    THM, Friedberg, Germany
  • W. Ackermann, H. De Gersem
    TEMF, TU Darmstadt, Darmstadt, Germany
  • M.K. Czwalinna, H. Schlarb
    DESY, Hamburg, Germany
 
  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under contract No. 05K19RO1.
The European XFEL (EuXFEL) and other notable X-ray Free-Electron Laser facilities rely on an all-optical synchronization system with electro-optical bunch arrival-time monitors (BAM). The current BAMs were benchmarked with a resolution of 3.5 fs for nominal 250 pC bunches at the EuXFEL, including jitter of the optical reference system. The arrival-time jitter could be reduced to about 10 fs with a beam-based feedback system. For future experiments at the EuXFEL the bunch charge will be decreased to a level where the existing system’s accuracy will no longer be sufficient. In simulations a concept based on rod-shaped pickups mounted on a printed circuit board indicated its potential for such low charge applications. For the feasibility of the proposed design, its contribution to the total impedance is essential. In this work the design and an intermediate version are compared to state-of-the-art BAM regarding their wake potential. Furthermore, measures to mitigate wakefields are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT019  
About • Received ※ 08 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 05 July 2022  
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MOPOPT021 5D Tomography of Electron Bunches at ARES electron, emittance, quadrupole, synchrotron 279
 
  • S. Jaster-Merz, R.W. Aßmann, R. Brinkmann, F. Burkart, T. Vinatier
    DESY, Hamburg, Germany
  • R.W. Aßmann
    LNF-INFN, Frascati, Italy
  • S. Jaster-Merz
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  The ARES linear accelerator at DESY aims to deliver stable and well-characterized electron bunches with durations down to the sub-fs level. Such bunches are highly sought after to study the injection into novel high-gradient accelerating structures, test diagnostics devices, or perform autonomous accelerator studies. For such applications, it is advantageous to have a complete and detailed knowledge of the beam properties. Tomographic methods have shown to be a key tool to reconstruct the phase space of beams. Based on these techniques, a novel diagnostics method is being developed to resolve the full 5-dimensional phase space (x,x’,y,y’,z) of bunches including their transverse and longitudinal distributions and correlations. In simulation studies, this method shows an excellent agreement between the reconstructed and the original distribution for all five planes. Here, the 5-dimensional phase space tomography method is presented using a showcase simulation study at ARES.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT021  
About • Received ※ 03 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 07 July 2022  
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MOPOPT029 Longitudinal Phase Space Benchmarking for PITZ Bunch Compressor booster, FEL, laser, experiment 310
 
  • A. Lueangaramwong, Z. Aboulbanine, G.D. Adhikari, N. Aftab, P. Boonpornprasert, G.Z. Georgiev, J. Good, M. Groß, C. Koschitzki, M. Krasilnikov, X.-K. Li, O. Lishilin, D. Melkumyan, H.J. Qian, G. Shu, F. Stephan, G. Vashchenko, T. Weilbach
    DESY Zeuthen, Zeuthen, Germany
  • N. Chaisueb
    Chiang Mai University, Chiang Mai, Thailand
 
  The longitudinal phase space characteristics of space-charge dominated electron beams are keys to achieving bunch compression for the accelerator-based THz source at the Photo Injector Test facility at DESY in Zeuthen (PITZ). Such a THz source is proposed as a prototype for an accelerator-based THz source for pump-probe experiments at the European XFEL. A start-to-end simulation has suggested the settings of the phase of booster linear accelerator manipulating longitudinal beam characteristics to optimize the performance of the THz FEL. Although beam diagnostics after compression at PITZ are limited, the longitudinal beam characteristics as a function of the booster phase have been measured and compared with the corresponding simulations. The benchmark involves measurements of longitudinal phase space distribution for bunch charges up to 2 nC. The measurement technique assigned uses 50-um slits to achieve higher momentum and time resolution (1.8 keV/c and 0.5 ps, respectively).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT029  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOPT032 Improvement of Matching Circuit for J-PARC Main Ring Injection Kicker Magnet kicker, operation, injection, impedance 316
 
  • T. Sugimoto, K. Ishii, S. Iwata, H. Matsumoto, T. Shibata
    KEK, Ibaraki, Japan
 
  In this paper, present status of improvements of the impedance matching circuit for the J-PARC main ring injection kicker magnet to achieve 1.3MW beam operation planed after 2022 is described. In order to reduce the temperature-rise of resistors under the higher repetition rate pulse excitation, number of paralleled resistors was doubled and volume of each resistor was enlarged 2.6 times. Ceramic-made beads with diameter of 3 mm were filled in the cylinder of the resistor to increase the heat conductivity. An aluminum-made water-cooled heat sink was attached to the resistors directly and an air-cooling fan was mounted to the side of the box containing the resistors. All resistors and their support structure have been replaced in March 2022. Temperature-rise of resistors during continuous pulse excitation was measured by commercial thermo camera and compared with numerical calculations. In addition, predictions about the beam induced heating of the resistors are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT032  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 26 June 2022
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MOPOPT034 Surrogate-Based Bayesian Inference of Transverse Beam Distribution for Non-Stationary Accelerator Systems controls, experiment, beam-transport, framework 324
 
  • H. Fujii, N. Fukunishi
    RIKEN Nishina Center, Wako, Japan
  • M. Yamakita
    Tokyo Tech, Tokyo, Japan
 
  Constraints on the beam diagnostics available in real-time and time-varying beam source conditions make it difficult to provide users with high-quality beams for long periods without interrupting experiments. Although surrogate model-based inference is useful for inferring the unmeasurable, the system states can be incorrectly inferred due to manufacturing errors and neglected higher-order effects when creating the surrogate model. In this paper, we propose to adaptively assimilate the surrogate model for reconstructing the transverse beam distribution with uncertainty and underspecification using a sequential Monte Carlo from the measurements of quadrant beam loss monitors. The proposed method enables sample-efficient and training-free inference and control of the time-varying transverse beam distribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT034  
About • Received ※ 19 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOPT041 Artificial Intelligence-Assisted Beam Distribution Imaging Using a Single Multimode Fiber at CERN network, experiment, coupling, detector 339
 
  • G. Trad, S. Burger
    CERN, Meyrin, Switzerland
 
  In the framework of developing radiation tolerant imaging detectors for transverse beam diagnostics, the use of machine learning powered imaging using optical fibers is explored for the first time at CERN. This paper presents the pioneering work of using neural networks to reconstruct the scintillating screen beam image transported from a harsh radioactive environment over a single, large-core, multimode, optical fiber. Profiting from generative modeling used in image-to-image translation, conditional adversarial networks have been trained to translate the output plane of the fiber, imaged on a CMOS camera, into the beam image imprinted on the scintillating screen. Theoretical aspects, covering the development of the dataset via geometric optics simulations, modeling the image propagation in a simplified model of an optical fiber, and its use for training the network are discussed. Finally, the experimental setups, both in the laboratory and at the CLEAR facility at CERN, used to validate the technique and evaluate its potential are highlighted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT041  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
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MOPOPT047 Experimental Demonstration of Machine Learning Application in LHC Optics Commissioning optics, quadrupole, MMI, diagnostics 359
 
  • E. Fol, F.S. Carlier, J. Dilly, M. Hofer, J. Keintzel, M. Le Garrec, E.H. Maclean, T.H.B. Persson, F. Soubelet, R. Tomás García, A. Wegscheider
    CERN, Meyrin, Switzerland
  • J.F. Cardona
    UNAL, Bogota D.C, Colombia
 
  Recently, we conducted successful studies on the suitability of machine learning (ML) methods for optics measurements and corrections, incorporating novel ML-based methods for local optics corrections and reconstruction of optics functions. After performing extensive verifications on simulations and past measurement data, the newly developed techniques became operational in the LHC commissioning 2022. We present the experimental results obtained with the ML-based methods and discuss future improvements. Besides, we also report on improving the Beam Position Monitor (BPM) diagnostics with the help of the anomaly detection technique capable to identify malfunctioning BPMs along with their possible fault causes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT047  
About • Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022  
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MOPOPT050 Systematic Study of Electron Beam Measuring Systems at the PBP-CMU Electron Linac Laboratory electron, emittance, quadrupole, linac 371
 
  • K. Techakaew, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
 
  The linear accelerator system at the PBP-CMU Electron Linac Laboratory (PCELL) is used to produce electron beam with suitable properties for generating coherent teragertz (THz) radiation and mid-infrared free-electron laser (MIR FEL). Optimization of machine parameters to produce short electron bunches with low energy spread and low transverse emittance was focused in this study. We conducted ASTRA simulations including three-dimentional (3D) space charge algorithm and 3D field distributions for radio-frequency (RF) electron gun and all magnets to develop measuring systems. Electron beam energy and energy spread were investigated downstream the RF gun and the RF linac using an alpha magnet and a dipole spectrometer, respectively. The transverse beam emittance was studied using the quadrupole scan technique. By filtering proper portion of electrons before entering the linac, the beam with average energy of 20 MeV and energy spread of 0.1-1% can be achieved for a bunch charge of 100 pC. The systematic error is less than 10% for measuring average energy and energy spread while it is less than 31% for measuring transverse emittance when placing the screen of at least 1.0 m behind the scanning quadrupole magnet. The results of this study were used to develop the measuring setups in our system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT050  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 13 June 2022
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MOPOPT055 A Gas Jet Beam Profile Monitor for Beam Halo Measurement experiment, electron, background, diagnostics 389
 
  • O. Stringer, N. Kumar, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
  • N. Kumar, C.P. Welsch, H.D. Zhang
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft Institute core grant No. ST/G008248/1.
The gas jet beam profile monitor is a non-invasive beam monitor that is currently being commissioned at Cockcroft Institute. It utilises a supersonic gas curtain which transverses the beam at an angle of 45 degrees and measures beam-induced ionisation interactions of the gas to produce a 2D transverse beam profile image. This paper builds upon previously used single-slit skimmers and improves their ability to form the gas jet into a desired distribution for imaging beam halo. A skimmer device removes off-momentum gas particles and forms the jet into a dense thin curtain, suitable for transverse imaging of the beam. The use of a novel double-slit skimmer is shown to provide a mask-like void of gas over the beam core, increasing the relative intensity of the halo interactions for measurement. Such a non-invasive monitor would be beneficial to storage rings by providing real time beam characteristic measurements without affecting the beam. More specifically, beam halo behaviour is a key characteristic associated with beam losses within storage rings.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT055  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 26 June 2022
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MOPOPT056 Commissioning of a Gas Jet Beam Profile Monitor for EBTS and LHC electron, photon, vacuum, MMI 393
 
  • H.D. Zhang, N. Kumar, A. Salehilashkajani, O. Sedláček, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M. Ady, T. Lefèvre, S. Mazzoni, I. Papazoglou, A. Rossi, G. Schneider, O. Sedláček, K. Sidorowski, R. Veness
    CERN, Meyrin, Switzerland
  • P. Forck, S. Udrea
    GSI, Darmstadt, Germany
  • N. Kumar, A. Salehilashkajani, O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work is supported by the HL-LHC-UK II project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1.
A gas jet beam profile monitor was designed for measuring the electron beam at the electron beam test stand (EBTS) for the Hollow electron lens (HEL) and the proton beam in the large hadron collider (LHC). It is partially installed in the LHC during the second long shutdown. The current monitor is tailored to the accelerator environment including vacuum, geometry, and magnetic field for both the EBTS and the LHC. It features a compact design, a higher gas jet density, and a wider curtain size for a better integration time and a larger detecting range. In this contribution, the commissioning of this monitor at the Cockcroft Institute will be discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT056  
About • Received ※ 08 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022  
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MOPOPT063 Reconstruction of Beam Parameters from Betatron Radiation Using Maximum Likelihood Estimation and Machine Learning radiation, betatron, diagnostics, beam-diagnostic 407
 
  • S. Zhang, G. Andonian, C.E. Hansel, P. Manwani, B. Naranjo, M.H. Oruganti, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • Ö. Apsimon, C.P. Welsch, M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: US Department of Energy, Division of High Energy Physics, Contract No. DE-SC0009914 STFC Liver-pool Centre for Doctoral Training on Data Intensive Science, grant agreement ST/P006752/1
Betatron radiation that arises during plasma wakefield acceleration can be measured by a UCLA-built Compton spectrometer, which records the energy and angular position of incoming photons. Because information about the properties of the beam is encoded in the betatron radiation, measurements of the radiation can be used to reconstruct beam parameters. One method of extracting information about beam parameters from measurements of radiation is maximum likelihood estimation (MLE), a statistical technique which is used to determine unknown parameters from a distribution of observed data. In addition, machine learning methods, which are increasingly being implemented for different fields of beam diagnostics, can also be applied. We assess the ability of both MLE and other machine learning methods to accurately extract beam parameters from measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT063  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 26 June 2022
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MOPOPT066 Gas Sheet Diagnostics Using Particle in Cell Code electron, diagnostics, plasma, experiment 410
 
  • M. Yadav, P. Manwani, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Santa Monica, California, USA
  • Ö. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • N.M. Cook, A. Diaw, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • N.P. Norvell
    UCSC, Santa Cruz, California, USA
 
  Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1 and DE-SC0019717.
When intense particle beam propagates in dense plasma or gas, ionization can yield valuable information on the drive beam properties. Impact ionization and tunnel ionization are the two ionization regimes that must be accounted for varying beam properties. Due to these ionization mechanisms, new plasma electrons are generated causing different instabilities, dependent on the dominant ionization process considered. In order to accomplish the ambitious experimental goals of sophisticated beam diagnostics using ionization imaging, careful studies on the different ionization regimes, and the cross-over periods, required. Here we will discuss the impact ionization using fully parallel PIC code OSIRIS. We focus on understanding the gas sheet ionization diagnostics for characterizing high intensity charged particle beams. We study the interaction of neutral gas with an electron beam and varying density. We will also investigate the principle of detecting photon emission, rather than direct primary ion imaging, from the ionization induced in the interaction between the gas jet and charged particle beams.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT066  
About • Received ※ 07 June 2022 — Revised ※ 19 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 26 June 2022
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MOPOPT067 Electron Beam Phase Space Reconstruction From a Gas Sheet Diagnostic electron, diagnostics, network, experiment 414
 
  • N.M. Cook, A. Diaw, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • G. Andonian
    RadiaBeam, Santa Monica, California, USA
  • N.P. Norvell
    UCSC, Santa Cruz, California, USA
  • M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0019717.
Next generation particle accelerators craft increasingly high brightness beams to achieve physics goals for applications ranging from colliders to free electron lasers to studies of nonperturbative QED. Such rigorous requirements on total charge and shape introduce diagnostic challenges for effectively measuring bunch parameters prior to or at interaction points. We report on the simulation and training of a non-destructive beam diagnostic capable of characterizing high intensity charged particle beams. The diagnostic consists of a tailored neutral gas curtain, electrostatic microscope, and high sensitivity camera. An incident electron beam ionizes the gas curtain, while the electrostatic microscope transports generated ions to an imaging screen. Simulations of the ionization and transport process are performed using the Warp code. Then, a neural network is trained to provide accurate estimates of the initial electron beam parameters. We present initial results for a range of beam and gas curtain parameters and comment on extensibility to other beam intensity regimes.

 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT067  
About • Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 10 July 2022  
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MOPOTK001 The Influence of Solenoid Field on Off-Axis Travelling Beam in AREAL Accelerator solenoid, laser, alignment, experiment 422
 
  • H. Davtyan
    CANDLE, Yerevan, Armenia
  • G.A. Amatuni, A.A. Asoyan, A. Grigoryan, M.G. Yazichyan
    CANDLE SRI, Yerevan, Armenia
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  A wide range of experiments are being held at AREAL accelerator in the fields of materials science and life sci-ence by generating ultra-short 5 MeV electron beams. Beam parameter formation and stability preservation during the experiments are one of the key tasks of stable operation of the accelerator. Laser spot displacement on the photocathode could be one of the beam parameter distortion sources, which causes off-axis bunch travel also through the solenoid. The influences of laser spot horizontal displacement and the solenoid horizontal misalignment on the beam position at the experiment location are investigated separately via computer simulations. Using a laser spot mover and solenoid movers, an experiment has been carried out to compare simulation results with experiment.
*davtyan@asls.candle.am
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK001  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
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MOPOTK003 Absorbed Dose Characteristics for Irradiation Experiments at AREAL 5 MeV Electron Linac electron, experiment, radiation, gun 429
 
  • V.G. Khachatryan, Z. Amirkhanyan, H. Davtyan, A. Grigoryan, B. Grigoryan, M. Ivanyan, V.H. Petrosyan, A. Vardanyan, A.S. Yeremyan
    CANDLE SRI, Yerevan, Armenia
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  Existing electron photogun facility at the CANDLE SRI currently can provide electron beam with the energy up to 5 MeV. The beam is being used as an irradiation source in the number of material science and life science experiments. Performed beam particle tracking simulations along with intensive application of the beam diagnostic instruments (bending magnet, YAG stations, Faraday cups) allow control of the experimental samples’ irradiation parameters, particularly exposure times for given dose as well as absorbed dose spatial distribution. Direct application of the electron beam for the irradiation experiments allows achievement of high absorbed dose. For the calculation of the irradiation parameters of the experimental samples’ particle transport simulation results should be combined with the beam current measurements by Faraday Cup (FC). Dose measurements and the comparison with numerical simulations using various initial parameters (Transverse size, divergence and energy spread) permit to pin down their actual values.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK003  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
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MOPOTK004 Status of the Soleil Upgrade Lattice Robustness Studies lattice, injection, MMI, optics 433
 
  • O.R. Blanco-García
    INFN/LNF, Frascati, Italy
  • D. Amorim, A. Loulergue, L.S. Nadolski, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
  • M.A. Deniaud
    JAI, Egham, Surrey, United Kingdom
 
  The SOLEIL synchrotron has entered its Technical Design Report (TDR) phase for the upgrade of its storage ring to a fourth generation synchrotron light source. Verification of the equipment specifications (alignment, magnets, power supplies, BPMs), and the methodology for optics corrections are critical in order to ensure the feasibility of rapid commissioning restoring full performance for daily operations. The end-to-end simulation, from beam threading in the first turns to beam storage and stacking, should be handled with a comprehensive model close to the actual commissioning procedure, taking into account all practical steps. During 2021 and 2022, the CDR lattice has undergone significant modifications in response to additional constraints. In this paper, we present an update of the robustness studies for the TDR baseline lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK004  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 05 July 2022
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MOPOTK011 Generalisation and Longitudinal Extension of the Genetic Lattice Construction (GLC) Algorithm quadrupole, lattice, beam-transport, space-charge 453
 
  • S. Reimann, M. Droba, O. Meusel, H. Podlech
    IAP, Frankfurt am Main, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
  • S. Reimann
    GSI, Darmstadt, Germany
 
  The GLC algorithm allows the construction of efficient transfer lines with defined imaging properties using a minimum number of quadrupole elements. This work describes a generalization of this algorithm to make it applicable to the use of arbitrary beam optical elements. This includes an extension to longitudinal phase space.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK011  
About • Received ※ 18 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK013 Machine Learning Based Surrogate Model Construction for Optics Matching at the European XFEL optics, quadrupole, electron, FEL 461
 
  • Z.H. Zhu, Y. Chen, W. Qin, M. Scholz, S. Tomin
    DESY, Hamburg, Germany
 
  Beam optics matching is a daily routine in the operation of an X-ray free-electron laser facility. Usually, linear optics is employed to conduct the beam matching in the control room. However, the collective effects like space charge dominate the electron bunch in the low-energy region which decreases the accuracy of the existing tool. Therefore, we proposed a scheme to construct a surrogate model with nonlinear optics and collective effects to speed up the optics matching in the European XFEL injector section. This model also facilitates further research on beam dynamics for the space-charge dominated beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK013  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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MOPOTK022 A Design Study of Injector System for Synchrotron Light Source linac, electron, gun, cavity 485
 
  • C. Kim, E.-S. Kim, C.S. Park
    KUS, Sejong, Republic of Korea
 
  This work presents a design study of a 200 MeV electron linear accelerator consisting of an electron gun, bunchers, and accelerator structures. We aimed to design the linac with low emittance and low energy spread. A coasting beam from a thermionic electron gun is bunched using a series of buncher cavities: sub-harmonic buncher (SHB), a pre-buncher (PB), and a Buncher. The bunched beam is then accelerated up to 200 MeV with 4 cascaded accelerating structures. The SHB was designed with one-cell standing wave structure for improving the bunching efficiency. The two types of the 500 MHz SHB were considered: elliptical and coupled-cavity linac types. We also investigated constant-gradient and constant-impedance types of 3 GHz multi-cell traveling wave resonators for following buncher cavities and accelerating structures. Depending on the type, geometries of each traveling wave structure (TWS) cavity were determined, and then the electromagnetic fields were calculated. RF powers and phases of each cavity along this linac system were optimized using beam dynamics simulation. Furthermore, the beam distributions in the transverse direction are adjusted using solenoid magnets in the lowenergy section as well as quad triplets in the high-energy section.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK022  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022
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MOPOTK028 Zero Dispersion Optics to Improve Horizontal Emittance Measurements at the CERN Proton Synchrotron optics, emittance, quadrupole, space-charge 503
 
  • W. Van Goethem, F. Antoniou, F. Asvesta, H. Bartosik, A. Huschauer
    CERN, Meyrin, Switzerland
 
  In modern particle accelerators, the horizontal dispersion function is forced to zero at locations with instrumentation measuring the transverse beam distribution, in order to remove the dispersive contribution to the horizontal beam size. The design of the CERN Proton Synchrotron did not foresee such a zero-dispersion insertion, making it challenging to get a good precision on the beam size measurements. In this contribution, we present a new optics configuration, which allows to reach zero horizontal dispersion at the locations of different beam size measurement locations. This can be achieved by powering a set of trim quadrupoles, the so-called Low Energy Quadrupoles (LEQ). We investigate how the resulting optics perturbation affects beam parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK028  
About • Received ※ 07 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 08 July 2022
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MOPOTK030 Beam Optics Modelling Through Fringe Fields During Injection and Extraction at the CERN Proton Synchrotron extraction, injection, focusing, proton 511
 
  • E.P. Johnson, M.G. Atanasov, Y. Dutheil, M.A. Fraser, E. Oponowicz
    CERN, Meyrin, Switzerland
 
  As the beam is injected and extracted from the CERN Proton Synchrotron, it passes through the fringing magnetic fields of the main bending units (MUs). In this study, tracking simulations using field maps created from a 3D magnetic model of the MUs are compared to beam based measurements made through the fast injection and slow extraction regions. The behaviour of the fringe field is characterised and its implementation in the MAD-X model of the machine is described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK030  
About • Received ※ 03 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 12 June 2022
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MOPOTK036 Studies of the Vertical Excursion Fixed Field Alternating Gradient Accelerator lattice, closed-orbit, quadrupole, optics 535
 
  • M.E. Topp-Mugglestone, S.L. Sheehy
    JAI, Oxford, United Kingdom
  • J.-B. Lagrange, S. Machida
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  The Vertical Excursion Fixed Field Alternating Gradient Accelerator (VFFA) concept offers a number of advantages over existing accelerator archetypes, as discussed in previous works. However, the VFFA has nonplanar orbits by design and unavoidable transverse coupling. Hence, current understanding of the dynamics of this machine is limited; this paper presents some in-depth study of its behaviour using a combination of analytical and numerical techniques.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK036  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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MOPOTK039 Iron Yoke Effects in Quadrupole Magnets for High Rigidity Isotope Beams quadrupole, sextupole, dipole, superconducting-magnet 546
 
  • D.B. Greene, Y. Choi, J. DeKamp, P.N. Ostroumov, M. Portillo, J.D. Wenstrom, T. Xu
    FRIB, East Lansing, Michigan, USA
  • S.L. Manikonda
    AML, Melbourne, Florida, USA
 
  Iron-dominated superconducting magnets are one of the most popular and most used design choices for superconducting magnetic quadrupoles for accelerator systems. While the iron yoke and pole tips are economic and effective in shaping the field, the large amount of iron also leads to certain drawbacks, namely, unwanted harmonics from the sextupole correctors nested inside of the quadrupole. Additional problems include the nonlinear field profile present in the high-field regime engendered by the presence of steel, and the mechanical and cryogenic design challenges of the entire iron yoke being part of the cold mass. The presented work discusses these effects and challenges by comparing an iron-dominated quadrupole model to an equivalent coil-dominated quadrupole model. The comparison of their respective magnetic harmonics, integrated strength, multipole effects, and mechanical challenges demonstrates that the coil-dominated design is a more favorable choice for select accelerator systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK039  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 03 July 2022
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MOPOTK041 Magnetic Field Noise Search Using Turn-by-Turn Data at CESR kicker, power-supply, electron, synchrotron 553
 
  • V. Khachatryan, J. Barley, M.H. Berry, A.T. Chapelain, D.L. Rubin, J.P. Shanks, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: The authors thank NSF PHYS-1416318 and DMR-1829070.
A method for searching for magnetic field noise has been developed using the CESR beam turn-by-turn data. The technique is tested using Monte-Carlo samples and turn-by-turn real data with induced noise in one of the CESR magnets. We estimate the analysis sensitivity for the noise sources slower than 4 kHz (or 100 CESR-turns) with the current CESR BPM system on the level of 1 microradian or 0.2 Gs×m field integral. In this work we report the observed noise sources and the improvements achieved by applying this technique. Long-term, several hours, beam stability analysis is also performed using the same method.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK041  
About • Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022  
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MOPOTK043 Wakefield Effects Evaluation on Nanometer Small Beam at KEK-ATF wakefield, vacuum, alignment, cavity 556
 
  • Y. Abe, K. Kubo, T. Okugi, N. Terunuma
    Sokendai, Ibaraki, Japan
  • K. Kubo, T. Okugi, N. Terunuma
    KEK, Ibaraki, Japan
 
  Funding: This work was supported by JST, the establishment of university fellowships towards the creation of science technology innovation, Grant Number JPMJFS2136. This work was also supported by JST SPRING, Grant Number SDP221102.
Accelerator Test Facility (ATF) is R&D facility to evaluate final focus technology for small beam required by ILC. The final focus beamline(ATF2) sets the goal to achieve 37 nm vertical beam size and 41 nm beam size had been demonstrated. Moreover, a significant intensity dependence on a nanometer beam size was observed and several studies of the wakefield had been conducted [*,**,***]. ATF2 is a proper beamline for wakefield studies with low emittance beam and nanometer resolution cavity BPMs and a nanometer beam size monitor. The simulation results were qualitatively cross-checked with experimental results and showed that the effects of some vacuum components and BPMs were significant. Further analysis of the wakefield will be done for flexible components (e.g. bellows). An upgrade of the ATF2 beamline is proposed by including minimization of the wakefield sources, to establish technologies for stable nanometer beam.
*J.Snuverink et al., PHYS. REV.ACCEL. BEAMS19, 091002.
**T.Okugi et al., PASJ16, FRPI023, 2019.
***P.Korysko et al., PHYS. REV.ACCEL. BEAMS23, 121004.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK043  
About • Received ※ 20 May 2022 — Revised ※ 16 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 05 July 2022
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MOPOTK051 Modeling a Nb3Sn Cryounit in GPT at UITF cavity, SRF, gun, electron 576
 
  • S. Pokharel, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • A.S. Hofler, G.A. Krafft
    JLab, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Nb3Sn is a prospective material for future superconducting RF (SRF) accelerator cavities. The material can achieve higher quality factors, higher temperature operation and potentially higher accelerating gradients (Eacc 96 MV/m) compared to conventional niobium. In this work, we performed modeling of the Upgraded Injector Test Facility (UITF) at Jefferson Lab utilizing newly constructed Nb3Sn cavities. We studied the effects of the buncher cavity and varied the gun voltages from 200-500 keV. We have calibrated and optimized the SRF cavity gradients and phases for the Nb3Sn five-cell cavities energy gains with the framework of General Particle Tracer (GPT). Our calculations show the beam goes cleanly through the unit. There is full energy gain out of the second SRF cavity but not from the first SRF cavity due to non-relativistic phase shifts.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK051  
About • Received ※ 20 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 19 June 2022
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MOPOTK052 CEBAF Injector Model for KL Beam Conditions laser, experiment, gun, cathode 580
 
  • S. Pokharel, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • M.W. Bruker, J.M. Grames, A.S. Hofler, R. Kazimi, G.A. Krafft, S. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
The Jefferson Lab KL experiment will run at the Continuous Electron Beam Accelerator Facility with a much lower bunch repetition rate (7.80 or 15.59 MHz) than nominally used (249.5 or 499 MHz). While the proposed average current of 2.5 - 5.0 muA is relatively low compared to the maximum CEBAF current of approximately 180 muA, the corresponding bunch charge is atypically high for CEBAF injector operation. In this work, we investigated the evolution and transmission of low-rep-rate, high-bunch-charge (0.32 to 0.64 pC) beams through the CEBAF injector. Using the commercial software General Particle Tracer, we have simulated and analyzed the beam characteristics for both values of bunch charge. We performed these simulations with the existing injector using a 130 kV gun voltage. We have calculated and measured the transmission as a function of the photocathode laser spot size and pulse length. We report on the findings of these simulations and optimum parameters for operating the experiment.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK052  
About • Received ※ 07 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 26 June 2022  
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MOPOTK054 Review of Alignment and Stability Tolerances for Advanced Light Sources alignment, SRF, storage-ring, synchrotron 588
 
  • A. Khan, S.K. Sharma, V.V. Smaluk
    BNL, Upton, New York, USA
 
  Alignment and mechanical-stability specifications are essential to the performance of low-emittance storage rings. Beam dynamics simulations are usually performed to establish these specifications. However, the simulation procedures and the input parameters related to magnet positions are not well established which leads to differences in the final specifications. In this paper we discuss important parameters of the mechanical/structural systems of the storage ring that impact on the alignment and stability specification. Following a detailed review of the specifications and simulation procedures adopted at several facilities we propose a procedure to be used for a low-emittance upgrade of NSLS-II.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK054  
About • Received ※ 18 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 07 July 2022
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MOPOTK059 Implementation of the Vico-Greengard-Ferrando Poisson Solver in Synergia2 space-charge, site, beam-beam-effects, framework 600
 
  • C.S. Park
    KUS, Sejong, Republic of Korea
 
  Computation of space charge fields in accelerator simulations is one of the most challenging tasks. The algorithm proposed by Hockney and Eastwood is the fastest method for numerically solving Poisson equations with open boundaries and has been implemented in various accelerator simulation codes. Recently, Vico-Greengard-Ferrando proposed a new hybrid fast algorithm for computing volume potentials. The new algorithm is promising higher accuracy and faster error convergence than that of Hockney-Eastwood. This study presents the implementation of the Vico-Greengard-Ferrando solver in Synergia and shows a comparison of results with these Poisson solvers.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK059  
About • Received ※ 10 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 29 June 2022
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MOPOTK062 Numerical Calibration of the Bead-Pull Setup for Beam Coupling Impedance Evaluation cavity, impedance, coupling, experiment 607
 
  • D.M.F. El Dali, E. Métral, C. Zannini
    CERN, Meyrin, Switzerland
  • G. De Michele, S. Fanella
    AVO-ADAM, Meyrin, Switzerland
 
  The bead-pull method is a commonly used electromagnetic field measurement technique exploited to tune a radiofrequency cavity to achieve design specifications. The frequency of a resonant cavity is perturbed by inserting a metallic or dielectric bead. For a given electromagnetic field, the amplitude of the perturbation depends only on the geometry of the perturbing object. Therefore, the calibration of the bead can be done in different resonant structures without loss of generality. In this paper, a method to perform an accurate calibration of the bead with electromagnetic simulations is proposed. Compared to the common practice of measuring a reference cavity, the flexibility given by the simulation method to study different bead shapes and sizes could be advantageous to optimize the measurement setup. A calibrated bead-pull setup allows to quantify the electric field and, therefore, the shunt impedance of the resonant modes of the cavity. As experimental benchmark, the beam coupling impedance measured with the calibrated bead-pull setup is compared with electromagnetic simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK062  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 20 June 2022
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MOPOTK065 Minimising Transverse Multipoles in Accelerating RF Cavities via Azimuthally Modulated Designs cavity, multipole, GUI, coupling 610
 
  • L.M. Wroe
    JAI, Oxford, United Kingdom
  • R. Apsimon
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • M. Dosanjh
    CERN, Meyrin, Switzerland
  • S.L. Sheehy
    The University of Melbourne, Melbourne, Victoria, Australia
 
  In this paper, we build upon previous work of designing RF structures that support modes with tailored multipolar fields by applying the concept to negate the transverse multipoles in accelerating RF cavities caused by the incorporation of waveguide slots and tuning deformations. We outline a systematic method for designing structures that minimise these transverse multipoles and present analysis of simulations of two different minimisation designs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK065  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 06 July 2022
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MOPOMS005 Start-to-End Simulations of a THz-Driven ICS Source electron, linac, gun, photon 631
 
  • M. Fakhari, Y.-K. Kan
    DESY, Hamburg, Germany
  • F.X. Kärtner
    The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
  • F.X. Kärtner
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • N.H. Matlis, M. Vahdani
    CFEL, Hamburg, Germany
  • M. Vahdani
    University of Hamburg, Hamburg, Germany
 
  We present start-to-end simulations for a fully THz-driven table-top X-ray source. A dielectric-loaded metallic cavity operating at its Higher Order Mode accelerates 1 PC photo emitted electron bunch up to 430 keV kinetic energy. The output beam of the gun is injected into a dielectric-loaded waveguide where phase velocity of the traveling wave is adjusted in such a way that electrons see an accelerating field all the way along the tube resulting to an 18.5-MeV output beam which is then transported to an inverse Compton scattering (ICS) stage. The injection phase of the electrons can be tuned to introduce a negative energy chirp to the electron bunch leading to a ballistic bunch compression after the linac. In addition, a set of permanent magnet quadrupoles is designed to focus the beam at the ICS interaction point where the electron beam scatters off a 250-mJ, 0.5ps, 1-µm laser beam and generates an X-ray beam with 2.6x107 photons per shot containing photon energies 2keV< Eph <8keV in a beam with 50 mrad half opening angle. The required terahertz waves to power the gun and linac are 550-ps pulses at 300 GHz containing 5 mJ and 23 mJ energies respectively with 1 kHz repetition rate.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS005  
About • Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022  
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MOPOMS008 Diagnosis of Transverse Emittance in Laser-Driven Ion Beam laser, emittance, target, proton 637
 
  • T. Miyatake, I. Takemoto, Y. Watanabe
    Kyushu University, Interdisciplinary Graduate School of Engineering Sciences, Kasuga-Shi, Japan
  • T.-H. Dinh, M. Kando, S. Kojima, K. Kondo, K. Kondo, M. Nishikino, M. Nishiuchi, H. Sakaki
    National Institutes for Quantum Science and Technology, Kyoto, Japan
 
  Funding: This work was supported by JST-MIRAI R&D Program No. JPMJMI17A1. This work was supported by JSPS KAKENHI Grant Number JP21J22132.
Ion beam produced in laser-driven ion acceleration by ultra-intense lasers has characteristics of high peak cur-rent and low emittance. These characteristics become an advantage to operate the request for the beam applica-tion. Therefore, we study how to control the parameters with the laser-plasma interaction. Here, we used 2D Particle-in-Cell code to simulate the laser-driven ion acceleration and investigated the results in terms of transverse emittance, beam current, and brightness. The laser spot size and target thickness were changed in the simulation. And, these qualitative results show that interaction target thickness is a major factor in controlling beam characteristics.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS008  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 18 June 2022
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MOPOMS012 Simulation Studies of Drive Beam Instability in a Dielectric Wakefield Accelerator wakefield, GUI, focusing, quadrupole 645
 
  • W.H. Tan, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • A. Huebl, R. Jambunathan, R. Lehé, A. Myers, T. Rheaume, J.-L. Vay, W. Zhang
    LBNL, Berkeley, USA
  • P. Piot
    ANL, Lemont, Illinois, USA
 
  Funding: This work is supported by the US DOE award DE-SC0018656 with NIU and DE-AC02-06CH11357 with ANL. This work used resources from NERSC, supported by DOE contract DE-AC02-05CH11231. This research used WarpX, which is supported by the US DOE Exascale Computing Project. Primary WarpX contributors are with LBNL, LLNL, CEA-LIDYL, SLAC, DESY, CERN, and Modern Electron.
Beam-driven collinear wakefield acceleration using structure wakefield accelerators promises a high gradient acceleration within a smaller physical footprint. Sustainable extraction of energy from the drive beam relies on precise understanding of its long term dynamics and the possible onset or mitigation of the beam instability. The advance of computational power and tools makes it possible to model the full physics of beam-driven wakefield acceleration. Here we report on the long-term beam dynamics studies of a drive beam considering the example of a dielectric waveguide using high fidelity particle-in-cell simulations performed with WarpX.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS012  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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MOPOMS015 Temporal and Spatial Characterization of Ultrafast Terahertz Near-Fields for Particle Acceleration acceleration, electron, radiation, laser 656
 
  • A.E. Gabriel, M.C. Hoffmann, E.A. Nanni, M.A.K. Othman
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515.
We have measured the THz near-field in order to inform the design of improved THz-frequency accelerating structures. THz-frequency accelerating structures could provide the accelerating gradients needed for next generation particle accelerators with compact, GV/m-scale devices. 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 significant losses during transport of THz radiation from the generating nonlinear crystal to the acceleration structure. In addition, the spectral properties of high-field THz sources make it difficult to couple THz radiation into accelerating structures. A better understanding of the THz near-field source properties is necessary for the optimization of THz transport and coupling. We have developed a technique for detailed measurement of the THz near-fields and used it to reconstruct the full temporal 3D THz near-field close to the LN emission face. Analysis of the results from this measurement will inform designs of novel structures for use in THz particle acceleration.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS015  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOMS017 Beam Transport Simulations Through Final Focus High Energy Transport Lines with Implemented Gabor Lenses focusing, electron, target, proton 663
 
  • A. Sherjan, M. Droba, O. Meusel, S. Reimann, K.I. Thoma
    IAP, Frankfurt am Main, Germany
  • S. Reimann
    GSI, Darmstadt, Germany
 
  First investigations on Gabor Lens GL2000 at Goethe University have shown that it is possible to confine a 2m long stable Electron Plasma Column and to apply it as a hadron beam focusing device. With this knowledge theoretical implementations of GLs in final focus and transfer lines have started. The focusing with GLs is a weak but smooth focusing in radial direction. The GL is a suitable and inexpensive choice in addition to the existing focusing elements eg. magnetic quadrupoles. The device helps to improve beam quality and minimize losses over long distances. The investigation of relativistic hadron beams in GeV range using the example of the proposed NA61/SHINE VLE-beamline at CERN is carried out and will be presented. Thin-matrix simulations with a generated distribution as well as field map simulations with generated and realistic distributions (Geant4) at 1 - 6 GeV/c have been analysed and compared. In addition, the H4-beamline at North Area (CERN) is proposed to implement GLs for experimental tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS017  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 14 June 2022
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MOPOMS020 Dark Current Studies for a High Gradient SW C-Band RF Gun gun, cathode, solenoid, electron 675
 
  • F. Cardelli, D. Alesini, L. Faillace, A. Giribono, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • G. Di Raddo
    LNF-INFN, Frascati, Italy
  • T.G. Lucas
    PSI, Villigen PSI, Switzerland
 
  It is now well-established that for the generation of very high brightness beams, required for fourth generation light sources, it is highly advantageous to use injectors based on Radiofrequency photo-guns with very high peak electric fields on the cathode (>120 MV/m). This very high surface electric field leads to the generation of undesirable electrons due to the field emission effect. The emitted electrons can be captured and propagate along the Linac forming a dark current beam, leading to background radiation that can damage the instrumentation and radioactivate components. Consequently, it is important that the emission of these electrons, and their subsequent transportation, is carefully evaluated. Recently, in the framework of the I-FAST project, a high gradient, standing wave, C-band (5712 MHz) RF photogun has been designed and will be realized soon. In this paper, the results of dark current studies and simulations are illustrated. The transport efficiency and the spectrum of the dark current have been evaluated by Particle-In-Cell simulations for different cathode peak field values considering also the effect of the focusing solenoid on the dark current beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS020  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 30 June 2022
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MOPOMS023 Start-to-End Beam-Dynamics Simulations of a Compact C-Band Electron Beam Source for High Spectral Brilliance Applications electron, FEL, laser, photon 687
 
  • L. Faillace, M. Behtouei, B. Spataro, C. Vaccarezza
    LNF-INFN, Frascati, Italy
  • R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh
    RadiaBeam, Santa Monica, California, USA
  • F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • D.L. Bruhwiler
    RadiaSoft LLC, Boulder, Colorado, USA
  • O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams
    UCLA, Los Angeles, USA
  • A. Giribono
    INFN/LNF, Frascati, Italy
  • S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Funding: This work is partially supported by DARPA under the Contract No. HR001120C0072, by DOE Contract DE-SC0009914, DOE Contract DE-SC0020409, and by the National Science Foundation Grant No. PHY-1549132.
Proposals for new linear accelerator-based facilities are flourishing world-wide with the aim of high spectral brilliance radiation sources. Most of these accelerators are based on electron beams, with a variety of applications in industry, research and medicine such as colliders, free-electron lasers, wake-field accelerators, coherent THz and inverse Compton scattering X/’ sources as well as high-resolution diagnostics tools in biomedical science. In order to obtain high-quality electron beams in a small footprint, we present the optimization design of a C-band linear accelerator machine. Driven by a novel compact C-band hybrid photoinjector, it will yield ultra-short electron bunches of few 100’s pC directly from injection with ultra-low emittance, fraction of mm-mrad, and a few hundred fs length simultaneously, therefore satisfying full 6D emittance compensation. The normal-conducting linacs are based on a novel high-efficiency design with gradients up to 50 MV/m. The beam maximum energy can be easily adjusted in the mid-GeV’s range. In this paper, we discuss the start-to-end beam-dynamics simulations in details.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS023  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOMS029 HPC Modeling of a High-Gradient C-Band Linac for Hard X-Ray Free-Electron Lasers cavity, electron, FEL, linac 703
 
  • T.B. Bolin, S. Biedron
    UNM-ECE, Albuquerque, USA
  • S. Sosa
    ODU, Norfolk, Virginia, USA
 
  The production of soft to hard x-rays (up to 25 keV) at XFEL (x-ray free-electron laser) facilities has enabled new developments in a broad range of disciplines. Great potential exists for new scientific discovery at higher energies (42+ keV) such as envisioned at MaRIE (Matter-Radiation Interactions in Extremes) at Los Alamos National Laboratory. These instruments can require a large amount of real estate, which quickly escalates costs: The driver of the FEL is typically an electron beam linear accelerator (LINAC) and the need for higher beam energies capable of generating these X-rays can dictate that the linac becomes longer. State of art accelerating technology is required to reduce the linac length by reducing the size of the cavities, providing for compact, high-frequency, high acceleration gradients. Here, we describe using the Argonne Leadership Computing Facility (ALCF) to facilitate our investigations into design concepts for future XFEL high-gradient LINAC’s in the C-band (~4-8 GHz). We investigate two different traveling wave (TW) geometries optimized for high-gradient operation as modeled at the ALCF using VSim software.*
* https://www.txcorp.com
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS029  
About • Received ※ 03 July 2022 — Accepted ※ 04 July 2022 — Issue date ※ 08 July 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS033 Emittance Measurements of Nanoblade-Enhanced High Field Cathode cathode, electron, emittance, laser 709
 
  • G.E. Lawler, N. Majernik, J.I. Mann, N.E. Montanez, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • V.S. Yu
    RadiaBeam, Santa Monica, California, USA
 
  Funding: This work was supported by the Center for Bright Beams, National Science Foundation Grant No. PHY-1549132.
High brightness cathodes are increasingly a focus for accelerator applications ranging from free electron lasers to ultrafast electron diffraction. There is further an increasing interest in fabrication and control of cathode surface to better control the emission characteristics and improve beam brightness. One method which we can consider is based on well-known silicon nanofabrication techniques which we use to create patterned cathode surfaces. The sharp edges produced lead to field emission increases and high brightness emission. We have demonstrated that a beam can be successfully extracted with a low emittance and we have reconstructed a portion of the energy spectrum. Due to the simplicity of extended geometries in nanofabrication our beam uniquely possesses a high aspect ratio in its transverse cross section. We can begin to consider modifications for emittance exchange beamlines and having shown the patterning principle is sound we can consider additional patterns such as hollow beams. Future work will continue to characterize the produced beam and the addition of fabrication steps to remove one of the blades in the double blade geometry in order to more accurately characterize the emission.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS033  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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MOPOMS036 Simulations of Laser Field Emission from Nanostructures with Image Charge Trapping and Band Structure Transitions electron, laser, vacuum, photon 717
 
  • B. Wang, G.E. Lawler, J.I. Mann, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • T. Arias, J.K. Nangoi
    Cornell University, Ithaca, New York, USA
  • S.S. Karkare
    Arizona State University, Tempe, USA
 
  Funding: National Science Foundation Grant No. PHY-1549132
Laser-induced field emission from nanostructures as a means to create high brightness electron beams has been a continually growing topic of study. Experiments using nanoblade emitters have achieved peak fields upwards of 40 GV/m, begging further investigation in this extreme regime. A recent paper has provided analytical reductions of the common semi-infinite Jellium system for pulsed incident lasers. We utilize these results as well as similar previous results to further understand the physics underlying electron rescattering-type emissions. We progress in numerically evaluating the analytical solution to attempt to more efficiently generate spectra for this system. Additionally, we use the full 1-D time-dependent Schrödinger equation with a Hartree potential and a dispersion-relation transition from material to vacuum to study the same system. We determine what importance the inclusion of the material band structure may have on emissions using this computationally challenging approach.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS036  
About • Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 01 July 2022
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MOPOMS040 Radiation Shielding Design for the X-Band Laboratory for Radio-Frequency Test Facility - X-Lab - at the University of Melbourne radiation, electron, controls, operation 724
 
  • M. Volpi, R.P. Rassool, S.L. Sheehy, G. Taylor, S.D. Williams
    The University of Melbourne, Melbourne, Victoria, Australia
  • D. Banon-Caballero
    IFIC, Valencia, Spain
  • M. Boronat, N. Catalán Lasheras
    CERN, Meyrin, Switzerland
  • R.T. Dowd
    AS - ANSTO, Clayton, Australia
  • S.L. Sheehy
    ANSTO, Kirrawee DC New South Wales, Australia
 
  Here we report radiation dose estimates calculated for the X-band Laboratory for Accelerators and Beams (X-LAB) under construction at the University of Melbourne (UoM). The lab will host a CERN X-band test stand containing two 12 GHz 6 MW klystron amplifiers. By power combination through hybrid couplers and the use of pulse compressors, up to 50 MW of peak power can be sent to any of to either of the two test slots at pulse repetition rates up to 400 Hz. The test stand is dedicated to RF conditioning and testing CLIC’s high gradient accelerating structures beyond 100 MV/m. This paper also gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at X-LAB, radiation fields at high-energy accelerators, and the radiation monitoring system used at X-LAB. The bunker design to achieve a dose rate less than annual dose limit of 1 mSv is also shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS040  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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MOPOMS041 Concrete Shielding Activation for Proton Therapy Systems Using BDSIM and FISPACT-II proton, shielding, neutron, septum 728
 
  • E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde
    ULB, Bruxelles, Belgium
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
  • F. Stichelbaut
    IBA, Louvain-la-Neuve, Belgium
 
  Proton therapy systems are used worldwide for patient treatment and fundamental research. The generation of secondary particles when the beam interacts with the beamline elements is a well-known issue. In particular, the energy degrader is the dominant source of secondary radiation. This poses new challenges for the concrete shielding of compact systems and beamline elements activation computation. We use a novel methodology to seamlessly simulate all the processes relevant to the activation evaluation. A realistic model of the system is developed using Beam Delivery Simulation (BDSIM), a Geant4-based particle tracking code that allows a single model to simulate primary and secondary particle tracking and all particle-matter interactions. The secondary particle fluxes extracted from the simulations are provided as input to FISPACT-II to compute the activation by solving the rate equations. This approach is applied to the Ion Beam Applications (IBA) Proteus®ONE (P1) system and the shielding of the proton therapy research centre of Charleroi, Belgium. Proton loss distributions are used to model the production of secondary neutrals inside the accelerator structure. Two models for the distribution of proton losses are compared for the computation of the clearance index at specific locations of the design. Results show that the variation in the accelerator loss models can be characterised as a systematic error.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS041  
About • Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS042 Comparison Between Run 2 TID Measurements and FLUKA Simulations in the CERN LHC Tunnel of the Atlas Insertion Region radiation, operation, experiment, luminosity 732
 
  • D. Prelipcean, K. Biłko, F. Cerutti, A. Ciccotelli, D. Di Francesca, R. García Alía, B. Humann, G. Lerner, D. Ricci, M. Sabaté-Gilarte
    CERN, Meyrin, Switzerland
  • B. Humann
    TU Vienna, Wien, Austria
 
  In this paper we present a systematic benchmark between the simulated and the measured data for the radiation monitors useful for Radiation to Electronics (R2E) studies at the Large Hadron Collider (LHC) at CERN. For this purpose, the radiation levels in the main LHC tunnel on the right side of the Interaction Point 1 (ATLAS detector) are simulated using the FLUKA Monte Carlo code and compared against Total Ionising Dose (TID) measurements performed with the Beam Loss Monitoring (BLM) system, and 180 m of Distributed Optical Fibre Radiation Sensor (DOFRS). Considering the complexity and the scale of the simulations as well as the variety of the LHC operational parameters, we find a generally good agreement between measured and simulated radiation levels, typically within a factor of 2 or better.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS042  
About • Received ※ 08 June 2022 — Revised ※ 23 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 09 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS046 Reliability Analysis of the HL-LHC Energy Extraction System extraction, target, operation, monitoring 747
 
  • M.R. Blaszkiewicz, A. Apollonio, T. Cartier-Michaud, B.I. Panev, M. Pojer, D. Wollmann
    CERN, Meyrin, Switzerland
 
  The energy extraction systems for the protection of the new HL-LHC superconducting magnet circuits are based on vacuum breakers. This technology allows to significantly reduce the switch opening time and increases the overall system reliability with reduced maintenance needs. This paper presents the results of detailed reliability studies performed on these new energy extraction systems. The study quantifies the risk of a failure which prevents correct protection of a magnet circuit and identifies the most critical components of the system. For this, the model considers factors such as block or component level failure probabilities, different maintenance strategies and repair procedures. The reliability simulations have been performed with AvailSim4, a novel Monte Carlo code for availability and reliability simulations. The results are compared with the system reliability requirements and provides insights into the most critical components.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS046  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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TUPOST005 RF Voltage Calibration Using Phase Space Tomography in the CERN SPS cavity, synchrotron, alignment, collective-effects 841
 
  • D. Quartullo, S.C.P. Albright, H. Damerau, A. Lasheen, G. Papotti, C. Zisou
    CERN, Meyrin, Switzerland
 
  Voltage calibration using longitudinal phase-space tomography is a purely beam-based technique to determine the effective RF voltage experienced by a bunch. It was applied in the SPS, separately to each of its six accelerating travelling wave structures. A low spread in voltage errors was obtained by carefully optimizing the number of acquired bunch profiles. The technique moreover provided the relative phases of the cavities, which allowed their alignment to be checked. Pairs of cavities were measured as well to validate the consistency of the single-cavity voltages. The beam measurements were repeated after several months to confirm the reproducibility of the results. Longitudinal beam dynamics simulations, including the full SPS impedance model, were performed as a benchmark. The aim was to verify that the effect of the cable transfer-function on the bunch profiles can be neglected, as well as collective effects and small errors in the accelerator parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST005  
About • Received ※ 30 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 25 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST027 Machine Learning-Based Tuning of Control Parameters for LLRF System of Superconducting Cavities cavity, controls, LLRF, SRF 915
 
  • J.A. Diaz Cruz, S. Biedron
    UNM-ECE, Albuquerque, USA
  • J.A. Diaz Cruz
    SLAC, Menlo Park, California, USA
  • R. Pirayesh
    UNM-ME, Albuquerque, New Mexico, USA
  • S. Sosa
    ODU, Norfolk, Virginia, USA
 
  The multiple systems involved in the operation of particle accelerators use diverse control systems to reach the desired operating point for the machine. Each system needs to tune several control parameters to achieve the required performance. Traditional Low-Level RF (LLRF) systems are implemented as proportional-integral feedback loops, whose gains need to be optimized. In this paper, we explore Machine Learning (ML) as a tool to improve a traditional LLRF controller by tuning its gains using a Neural Network (NN). We present the data production scheme and a control parameter optimization using a NN. The NN training is performed using the THETA supercomputer.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST027  
About • Received ※ 14 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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TUPOST031 Online Optimization of the Transfer Line from UNILAC towards SIS18 at GSI Using a Genetic Autotune Algorithm experiment, injection, lattice, controls 922
 
  • S. Reimann
    GSI, Darmstadt, Germany
  • S. Reimann
    IAP, Frankfurt am Main, Germany
 
  Due to the complexity of GSI’s accelerator facilities and it’s upcoming expansion FAIR, various methods for optimizing accelerator settings are currently being studied to increase efficiency and to minimize the need for manual intervention. Besides a necessary improvement of the accelerator models, a better reproducibility of settings and the development of feedback systems, also heuristic methods are in the focus of the investigation. This work presents the results, recently achieved in optimizing the transfer line from UNILAC to SIS18 using the Autotune algorithm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST031  
About • Received ※ 18 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST042 Towards the Automatic Setup of Longitudinal Emittance Blow-Up in the CERN SPS controls, emittance, target, interface 949
 
  • N. Bruchon, I. Karpov, N. Madysa, G. Papotti, D. Quartullo, C. Zisou
    CERN, Meyrin, Switzerland
  • C. Zisou
    AUTH, Thessaloniki, Greece
 
  Controlled longitudinal emittance blow-up in the CERN SPS is necessary to stabilize high-intensity beams for the High-Luminosity LHC (HL-LHC) by increasing the synchrotron frequency spread. The process consists of injecting bandwidth-limited noise into the main RF phase loop to diffuse particles in the core of the bunch. The setting up of the noise parameters, such as frequency band and amplitude, is a non-trivial and time-consuming procedure that has been performed manually so far. In this preliminary study, several optimization methods are investigated to set up the noise parameters automatically. We apply the CERN Common Optimization Interfaces as a generic framework for the optimization algorithm. Single-bunch profiles generated with the BLonD simulation code have been used to investigate the optimization algorithms offline. Furthermore, analysis has been carried out on measured bunch profiles in the SPS to define the problem constraints and properly formulate the objective function.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST042  
About • Received ※ 31 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
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TUPOST044 Fortune Telling or Physics Prediction? Deep Learning for On-Line Kicker Temperature Forecasting kicker, operation, injection, network 957
 
  • F.M. Velotti, M.J. Barnes, B. Goddard, I. Revuelta
    CERN, Meyrin, Switzerland
 
  The injection kicker system MKP of the Super Proton Synchrotron SPS at CERN is composed of 4 kicker tanks. The MKP-L tank provides additional kick needed to inject 26 GeV Large Hadron Collider LHC 25 ns type beams. This device has been a limiting factor for operation with high intensity, due to the magnet’s broadband beam coupling impedance and consequent beam induced heating. To optimise the usage of the SPS and avoid idle (kicker cooling) time, studies were conducted to develop a recurrent deep learning model that could predict the measured temperature evolution of the MKP-L, using the beam conditions and temperature history as input. In a second stage, the ferrite temperature is also estimated putting together the external temperature predictions from accurate thermo-mechanical simulations of the kicker magnet. In this paper, the methodology is described and details of the neural network architecture used, together with the implementation of an ad-hoc loss function, are given. The results applied to the SPS 2021 operational data are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST044  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
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TUPOST048 Development of a Virtual Diagnostic for Estimating Key Beam Descriptors diagnostics, MEBT, real-time, controls 969
 
  • K.R.L. Baker, I.D. Finch, S.R. Lawrie, A.A. Saoulis
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • S. Basak, J. Cha, J. Thiyagalingam
    STFC/RAL/SCD, Didcot, United Kingdom
 
  Funding: Science and Technology Facilities Council (STFC), U.K. Research and Innovation (UKRI)
Real-time beam descriptive data such as emittance, envelope and loss, are central to accelerator operations, including online diagnostics, maintenance and beam quality control. However, these cannot always be obtained without disrupting user runs. Physics-based simulations, such as particle tracking codes, can be leveraged to provide estimates of these beam descriptors. However, such simulation-based methods are computationally intensive requiring access to high performance computing facilities, and hence, they are often non-realistic for real-time purposes. The proposed work explores the feasibility of using machine learning to replace these simulations with fast-executing inference models based on surrogate modelling. The approach is intended to provide the operators with estimates of key beam properties in real time. Bayesian optimisation is used to generate a synthetic dataset to ensure the input space is efficiently sampled and representative of operating conditions. This is used to train a surrogate model to predict beam envelope, emittance and loss. The methodology is applied to the ISIS MEBT as a case study to evaluate the performance of the surrogate model.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST048  
About • Received ※ 01 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 02 July 2022
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TUPOST049 Simulation Study for an Inverse Designed Narrowband THz Radiator for Ultrarelativistic Electrons radiation, electron, experiment, photon 973
 
  • G. Yadav, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • T. Feurer
    Universität Bern, Institute of Applied Physics, Bern, Switzerland
  • U. Haeusler, A. Kirchner
    FAU, Erlangen, Germany
  • B. Hermann, R. Ischebeck
    PSI, Villigen PSI, Switzerland
  • P. Hommelhoff
    University of Erlangen-Nuremberg, Erlangen, Germany
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  THz radiation has many applications, including medical physics, pump-probe experiments, communications, and security systems. Dielectric grating structures can be used to generate cost-effective and beam synchronous THz radiation based on the Smith Purcell effect. We present a 3-D finite difference time domain (FDTD) simulation study for the THz radiation emitted from an inverse designed grating structure after a 3 GeV electron bunch traverses through it. Our farfield simulation results show a narrowband emission spectrum centred around 881 um, close to the designed value of 900 um. The grating structure was experimentally tested at the SwissFEL facility, and our simulated spectrum shows good agreement with the observed one.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST049  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 12 June 2022
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TUPOST050 Liverpool Centre for Doctoral Training for Innovation in Data Intensive Science cathode, experiment, electron, network 976
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This new Center for Doctoral Training has received funding from the UK’s Science and Technology Facilities Council.
The Liverpool center for doctoral training for innovation in data intensive science (LIV. INNO) is an inclusive hub for training three cohorts of students in data intensive science. Starting in October 2022, each year will train about 12 PhD students in applying data skills to address cutting edge research challenges across astrophysics, nuclear, theoretical and particle physics, as well as accelerator science. This framework is expected to provide an ideal basis for driving science and innovation, as well as boosting the employability of the LIV. INNO PhD students. This contribution gives examples of the accelerator science R&D projects in the center. It includes details about research into the optimization of 3D imaging techniques and the characterization of photocathodes for accelerator applications.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST050  
About • Received ※ 05 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST051 Using Data Intensive Science for Accelerator Optimization plasma, experiment, electron, radiation 980
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work was supported by STFC under grant agreement ST/P006752/1.
Particle accelerators and light sources are some of the largest, most data intensive, and most complex scientific systems. The connections and relations between machine subsystems are complicated and often nonlinear with system dynamics involving large parameter spaces that evolve over multiple relevant time scales and accelerator systems. In 2017, the Liverpool Centre for Doctoral Training in Data Intensive Science (LIV. DAT) was established. With almost 40 PhD students, the centre is now established as an international hub for training PhD students in data intensive science. This contribution presents results from studies carried out in LIV. DAT into novel high gradient accelerators with a focus on the data science techniques that were used. This includes studies into inverse-designed narrowband THz radiators for ultra-relativistic electrons, simulation of the transverse asymmetry and inhomogeneity on seeded self-modulation of beams in plasma, as well as studies into the physical aspects of collinear laser injection in Trojan Horse laser plasma experiments.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST051  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 05 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST053 Beam Tuning at the FRIB Front End Using Machine Learning operation, rfq, controls, status 983
 
  • K. Hwang, K. Fukushima, T. Maruta, S. Nash, P.N. Ostroumov, A.S. Plastun, T. Zhang, Q. Zhao
    FRIB, East Lansing, Michigan, USA
 
  The Facility for Rare Isotope Beams (FRIB) at Michigan State University produced and identified the first rare isotopes demonstrating the key performance parameter and completion of the project. An important next step toward FRIB user operation includes fast tuning of the Front End (FE) decision parameters to maintain optimal beam optics. The FE consists of the ion source, charge selection system, LEBT, RFQ, and MEBT. The strong coupling of many ion source parameters, strong space-charge effects in multi-component ion beams, and a not well-known neutralization factor in the beamline from the ion source to the charge selection system make the FE modeling difficult. In this paper, we present our first effort toward the Machine Learning (ML) application for automatic control of the beam exiting the FE.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST053  
About • Received ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST059 PyEmittance: A General Python Package for Particle Beam Emittance Measurements with Adaptive Quadrupole Scans emittance, quadrupole, software, experiment 1003
 
  • S.A. Miskovich, A.L. Edelen, C.E. Mayes
    SLAC, Menlo Park, California, USA
 
  The emittance of a particle beam is a critically important parameter for many particle accelerator applications. Its measurements guide the initial tuning of an accelerator and are typically done using quadrupole or wire scans. Quadrupole scans are time-intensive, and it can be difficult to determine scan values that provide a good emittance measurement. To address this issue, we describe an adaptive quadrupole scan method that automates the determination of the scan range. With a given initial set of scanning values, our method adapts the range to capture the waist of the beam, and returns the Twiss parameters and a measure of the beam matching at the measurement screen. With the added capability to repeat beam size measurements when needed, this method provides a reliable measurement of the emittance even with sub-optimal initial conditions. To efficiently integrate these measurements into Python-based machine learning optimizations, the method was developed into a Python package, PyEmittance, at the SLAC National Accelerator Laboratory. We present the experimental tests of PyEmittance as performed at the Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Test (FACET-II).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST059  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT011 Start To End Simulation Study For Oscillator-Amplifier Free-Electron Laser electron, radiation, FEL, cavity 1022
 
  • H. Sun, Z.H. Zhu
    SINAP, Shanghai, People’s Republic of China
  • C. Feng, B. Liu
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
  • Z.H. Zhu
    DESY, Hamburg, Germany
 
  External seeding techniques like high-gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) have been proposed and proven to be able to generate fully coherent radiation in the EUV and X-ray range. A big challenge is to combine the advantages of seeding schemes with high repetition rates. Recently, for seeding at a high repetition rate, an optical resonator scheme has been introduced to recirculate the radiation in the modulator to seed the high repetition rate electron bunches. Earlier studies have shown that a resonator-like modulator combined with an amplifier in high gain harmonic generation (HGHG) configuration can be used to generate radiation whose wavelength can reach the water window region. This scheme overcomes the limitation of requiring high repetition rate seed laser systems. In this contribution, we present start-to-end simulation results of a seeded oscillator-amplifier FEL scheme.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT011  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT017 Start-to-end Simulations for Bunch Compressor and THz SASE FEL at PITZ FEL, booster, experiment, undulator 1037
 
  • A. Lueangaramwong, P. Boonpornprasert, M. Krasilnikov, X.-K. Li, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
 
  The magnetic bunch compressor was designed as part of a THz accelerator source being developed at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a prototype for pump-probe experiments at the European XFEL. As an electron bunch is compressed to achieve higher bunch currents for the THz source, the beam dynamics in the bunch compressor was studied by numerical simulations. A start-to-end simulation optimizer including coherent synchrotron radiation (CSR) effects has been developed by combining the use of ASTRA, OCELOT, and GENESIS to support the design of the THz source prototype. In this paper we present simulation results to explore the possibility of improving the performance of the THz FEL at PITZ by using the developed bunch compressor.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT017  
About • Received ※ 18 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 13 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT018 Fermi 2.0 Future Upgrade Strategy FEL, electron, laser, bunching 1041
 
  • L. Giannessi, E. Allaria, L. Badano, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, M. Coreno, M.B. Danailov, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, M. Ferianis, G. Gaio, F. Gelmetti, G. Kurdi, M. Lonza, M. Malvestuto, M. Manfredda, C. Masciovecchio, I. Nikolov, G. Penco, K.C. Prince, E. Principi, P. Rebernik Ribič, C. Scafuri, N. Shafqat, P. Sigalotti, A. Simoncig, F. Sottocorona, S. Spampinati, C. Spezzani, L. Sturari, M. Trovò, M. Veronese, R. Visintini, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • M. Coreno
    CNR-ISM, Trieste, Italy
  • G. Penn
    LBNL, Berkeley, California, USA
  • G. Perosa
    Università degli Studi di Trieste, Trieste, Italy
  • T. Tanaka
    RIKEN SPring-8 Center, Hyogo, Japan
 
  FERMI is studying a series of developments to keep the facility in a world-leading position on the base of the requests coming from the user community, the Scientific Advisory Council and the Machine Advisory Committee. The ultimate goal of the development plan consists in doubling the photon energy range and reducing the pulse duration below the characteristic lifetime of the atomic core levels located in the energy range of the source. One of the most promising approaches is the echo-enabled harmonic generation (EEHG) scheme, relying on two external lasers to precisely control the spectro-temporal properties of the FEL pulse. The implementation of EEHG in the double-stage harmonic cascade presently in use on FEL-2, would allow harmonics as high as 120 enabling to generate coherent pulses down to 2 nm starting from UV lasers. An upgrade of FERMI aimed at reaching the oxygen K-edge requires a profound modification of the FEL configurations and of the main components of the machine, including the linac and the undulator lines. The main aspects of the upgrade strategy will be discussed in this presentation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT018  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 07 July 2022
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TUPOPT019 FERMI FEL-1 Upgrade to EEHG FEL, laser, electron, free-electron-laser 1044
 
  • C. Spezzani, E. Allaria, L. Badano, D. Castronovo, P. Cinquegrana, M.B. Danailov, R. De Monte, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, M. Ferianis, G. Gaio, F. Gelmetti, L. Giannessi, G. Kurdi, M. Lonza, C. Masciovecchio, I. Nikolov, G. Penco, P. Rebernik Ribič, C. Scafuri, N. Shafqat, P. Sigalotti, F. Sottocorona, S. Spampinati, L. Sturari, M. Trovò, M. Veronese, R. Visintini
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • G. Perosa
    Università degli Studi di Trieste, Trieste, Italy
 
  The Fermi free-electron laser (FEL) facility is operating since 2010 providing the user community with ultrashort pulses in the VUV- XUV range. Using the High Gain Harmonic Generation (HGHG) setup, nearly transform-limited pulses with gigawatt peak power are made available. Furthermore, several multicolor and coherent control schemes are possible and highly required from the user community. To meet the request of extending the spectral range over the whole water window, an upgrade strategy of the FERMI facility has recently initiated. During the first phase of the upgrade, the single cascade FEL-1 will be adapted to operate either in Echo Enabled Harmonic Generation (EEHG) or in HGHG. Required modifications can be achieved with limited impact on FERMI operations and will improve FEL-1’s spectral range, spectral quality and flexibility. The second phase includes modification of the FEL-2 setup and will benefit from the experience gained with phase 1. The two phases will proceed in parallel to the linac upgrade aiming at extending the beam energy to 1.8 GeV. We report here details on the upgrade of the FEL-1 foreseen to provide light to users in the new configuration by spring 2023.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT019  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 29 June 2022
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TUPOPT027 Numerical Simulation of a Superradiant THz Source at the PITZ Facility electron, radiation, FEL, undulator 1063
 
  • N. Chaisueb, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
  • P. Boonpornprasert, M. Krasilnikov, X.-K. Li, A. Lueangaramwong
    DESY Zeuthen, Zeuthen, Germany
  • S. Rimjaem
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  An accelerator-based THz source is under development at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). The facility can produce high brightness electron beams with high charge and small emittance. Currently, a study on development of a tunable high-power THz SASE FEL for supporting THz-pump, X-ray-probe experiments at the European XFEL is underway. An LCLS-I undulator, a magnetic chicane bunch compressor, and THz pulse diagnostics have been installed downstream the previously existing setup of the PITZ beamline. Additional to the SASE FEL, a possibility to generate superradiant THz undulator radiation from short electron bunches is under investigation, which is the focus in this study. Numerical simulations of the superradiant THz radiation by using sub-picosecond electron bunches with energy of 6 - 22 MeV and bunch charge up to 2 nC produced from the PITZ accelerator are performed. The results show that the radiation with a spectral range of 0.5 to 9 THz and a pulse energy in the order of sub-uJ can be obtained. The results from this study can be used as a benchmark for the future development.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT027  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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TUPOPT028 THz Undulator Radiation Based on Super-Radiant Technique at Chiang Mai University undulator, radiation, electron, software 1067
 
  • E. Kongmon
    IST, Chiang Mai, Thailand
  • N. Chaisueb, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
  • S. Rimjaem
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  A linear accelerator system at the PBP-CMU Electron Linac Laboratory is used as an electron source for generating coherent THz radiation and MIR-FEL. To achieve high power THz radiation, the super-radiant technique using pre-bunched electrons and undulator magnet is utilized. In this study, we investigate the generation of such radiation with comparable properties as the FEL. The beamline composes of a 180-degree magnetic bunch compressor, a 2 m-electromagnet undulator, quadrupole magnets and diagnostic devices. This work includes the undulator design and investigation on properties of electron beam and THz radiation. Based-on the results of beam dynamic study, the optimized electron beams have an energy in a range of 10-16 MeV, a bunch charge of 100 pC, and a bunch length of 300 fs. The radiation with frequency covering from 0.5 to 3 THz yields a peak power of 5.21 MW at 1.15 THz. This information was used as an initial parameter for undulator design by using the CST-EM Studio software. It has 19.5 periods with a period length of 100 mm. The design results show that the maximum magnetic field is 0.2317 T. The results of this study are used as the guideline for construction of the undulator and the THz-FEL beamline.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT028  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 27 June 2022
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TUPOPT030 Design and Simulation of the MIR-FEL Generation System at Chiang Mai University FEL, electron, cavity, undulator 1074
 
  • S. Sukara, K. Kongmali, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
  • H. Ohgaki
    Kyoto University, Kyoto, Japan
 
  At the PBP-CMU Electron Linac Laboratory, the system to generate MIR-FEL using the electron linac has been developed. In this contribution, the design and simulation results of the MIR-FEL generation system are presented. The system is designed as the oscillator-FEL type consisting of two mirrors and a 1.6-m permanent planar undulator. The middle of the undulator is determined as the laser beam waist position. Both two mirrors are the concave gold-coated copper mirrors placing upstream and downstream the optical cavity, which has a total length of 5.41 m. The FEL is designed to coupling out at a hole with diameter of 2 mm on the upstream mirror. The optical cavity is optimized to obtain high FEL gain and high FEL power using GENESIS 1.3 simulation code. The electron beam with energy of 25 MeV is used in the consideration. As a result, the MIR-FEL with central wavelength of 13.01 ’m is obtained. The optimum upstream and downstream mirror curvatures are 3.091 m and 2.612 m, respectively, which give the Rayleigh length of 0.631 m. This optical cavity yields the power coupling ratio of 1:1000 and the FEL gain of up to 40%. The extracted MIR-FEL peak power in 100 kW scale is obtained at the coupling hole. The construction of the practical MIR-FEL system is conducted based on the results from this study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT030  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT034 Modelling of X-Ray Volume Excitation of the XLO Gain Medium Using Flash laser, plasma, electron, target 1081
 
  • P. Manwani, N. Majernik, B. Naranjo, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • E.C. Galtier, A. Halavanau, C. Pellegrini
    SLAC, Menlo Park, California, USA
 
  Funding: This work was performed with the support of the US Department of Energy under Contract No. DE-AC02-76SF00515 and DESC0009914.
Plasma dynamics and crater formation of laser excited volumes in solids is a complex process due to thermalization, shockwave formation, varying absorption mechanisms, and a wide range of relevant physics timescales. The properties and interaction of such laser-matter systems can be modeled using an equation of state and opacity based multi-temperature treatment of plasma using a radiation hydrodynamics code. Here, we use FLASH, an adaptive mesh radiation-hydrodynamics code, to simulate the plasma expansion following after the initial energy deposition and thermalization of the column, to benchmark the results of experiments undertaken at UCLA on optical laser ablation. These computational results help develop a quantitative understanding of the material excitation process and enable the optimization of the gain medium delivery system for the x-ray laser oscillator project *.
* Halavanau, Aliaksei, et al. "Population Inversion X-Ray Laser Oscillator." Proceedings of the National Academy of Sciences, vol. 117, no. 27, 2020, pp. 15511-15516.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT034  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 24 June 2022
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TUPOPT057 Using Surrogate Models to Assist Accelerator Tuning at ISIS synchrotron, controls, operation, injection 1133
 
  • A.A. Saoulis, K.R.L. Baker, H.V. Cavanagh, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • S. Basak, J. Cha, J. Thiyagalingam
    STFC/RAL/SCD, Didcot, United Kingdom
 
  Funding: STFC and UKRI
High intensity hadron accelerator performance is often dominated by the need to minimise and control beam losses. Operator efforts to tune the machine during live operation are often restricted to local parameter space searches, while existing physics-based simulations are generally too computationally expensive to aid tuning in real-time. To this end, Machine Learning-based surrogate models can be trained on data produced by physics-based simulations, and serve to produce fast, accurate predictions of key beam properties, such as beam phase and bunch shape over time. These models can be used as a virtual diagnostic tool to explore the parameter space of the accelerator in real-time, without making changes on the live machine. At the ISIS Neutron and Muon source, major beam losses in the synchrotron are caused by injection and longitudinal trapping processes, as well as high intensity effects. This paper describes the training and inference performance of a neural network surrogate model of the longitudinal beam dynamics in the ISIS synchrotron, from injection at 70 MeV to 800 MeV extraction, and evaluates the model’s ability to assist accelerator tuning.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT057  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT070 Surrogate Modelling of the FLUTE Low-Energy Section network, gun, electron, controls 1182
 
  • C. Xu, E. Bründermann, A.-S. Müller, A. Santamaria Garcia, J. Schäfer
    KIT, Karlsruhe, Germany
 
  Funding: Supported by the Helmholtz Association (Autonomous Accelerator, ZT-I-PF-5-6) and the DFG-funded Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology".
Numerical beam dynamics simulations are essential tools in the study and design of particle accelerators, but they can be prohibitively slow for online prediction during operation or for systematic evaluations of new parameter settings. Machine learning-based surrogate models of the accelerator provide much faster predictions of the beam properties and can serve as a virtual diagnostic or to augment data for reinforcement learning training. In this paper, we present the first results on training a surrogate model for the low-energy section at the Ferninfrarot Linac- und Test-Experiment (FLUTE).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT070  
About • Received ※ 30 May 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022  
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TUPOTK005 Mitigation of Parasitic Losses in the Quadrupole Resonator Enabling Direct Measurements of Low Residual Resistances of SRF Samples niobium, quadrupole, SRF, cavity 1196
 
  • S. Keckert, R. Kleindienst, J. Knobloch, F. Kramer, O. Kugeler, D.B. Tikhonov
    HZB, Berlin, Germany
  • W. Ackermann, H. De Gersem
    TEMF, TU Darmstadt, Darmstadt, Germany
  • X. Jiang, A.O. Sezgin, M. Vogel
    University Siegen, Siegen, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
  • M. Wenskat
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  The quadrupole resonator (QPR) is a dedicated sample-test cavity for the RF characterization of superconducting samples in a wide temperature, RF field and frequency range. Its main purpose are high resolution measurements of the surface resistance with direct access to the residual resistance thanks to the low frequency of the first operating quadrupole mode. Besides the well-known high resolution of the QPR, a bias of measurement data towards higher values has been observed, especially at higher harmonic quadrupole modes. Numerical studies show that this can be explained by parasitic RF losses on the adapter flange used to mount samples into the QPR. Coating several micrometer of niobium on those surfaces of the stainless steel flange that are exposed to the RF fields significantly reduced this bias, enabling a direct measurement of a residual resistance smaller than 5 nano-Ohm at 2 K and 413 MHz.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK005  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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TUPOTK008 Cavity Designs for the Ch3 to Ch11 and Bellow Tuner Investigation of the Superconducting Heavy Ion Accelerator Heliac cavity, SRF, heavy-ion, niobium 1204
 
  • T. Conrad, M. Busch, H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, F.D. Dziuba, V. Gettmann, T. Kürzeder, S. Lauber, J. List, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth, M. Basten, F.D. Dziuba, M. Heilmann, A. Rubin, A. Schnase, S. Yaramyshev
    GSI, Darmstadt, Germany
 
  New CH-DTL cavities designs of the planned Helmholtz Linear Accelerator (HELIAC) are developed in collaboration of HIM, GSI and IAP Frankfurt. The linac, operated in cw-mode with a final energy of 7.3 MeV/u, is intended for various experiments, in particular with heavy ions at energies close to the Coulomb barrier for research on SHE. Twelve sc CH cavities are foreseen, divided into four different cryostats. Each cavity will be equipped with dynamic bellow tuner. After successful beam tests with CH0, CH3 to CH11 are being designed. Based on the experience gained so far, optimization will be made, which will lead to both an increase in performance in terms of reducing the peak fields limiting superconductivity and a reduction in manufacturing costs and time. In order to optimize manufacturing, attention was paid to design many parts of the cavity, such as lids, spokes, tuner and helium shell, with the same geometrical dimensions. In addition, a tuner test rig was developed, which will be used to investigate the mechanical properties of the bellow tuner. For this purpose, different simulations were made in order to realize conditions as close as possible to reality in the test rig.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK008  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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TUPOTK009 Development of Superconducting CH Cavity Preparation at IAP cavity, coupling, ECR, vacuum 1208
 
  • P. Müller, H. Podlech
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth, M. Basten, V. Gettmann, T. Kürzeder, M. Miski-Oglu
    GSI, Darmstadt, Germany
 
  Funding: HIC for FAIR, BMBF Contr. No. 05P21RFRB2 and HFHF
Goethe University (GU), Gesellschaft für Schwerionenforschung (GSI) and Helmholtz Institut Mainz (HIM) work in collaboration on the Helmholtz Linear Accelerator (HELIAC). A new superconducting (sc) continous wave (cw) high intensity heavy ion linear accelerator (Linac) will provide ion beams with maximum duty factor up to beam energies of 7.3 MeV/u. The acceleration voltage will be provided by sc Crossbar-H-mode (CH) cavities, developed of Institute for Applied Physics (IAP) at GU. Cavity preparation is researched and optimized towards widely used elliptical multicell cavities. A standardized preparation protocol for CH cavities is researched in collaboration between GU, GSI and HIM on a 360 MHz 19 gap CH prototype. Baseline measurements and a 120°C 48 hour bake produced higher maximum gradient, higher intrinsic quality factor and a shorter cavity conditioning phase. As a critical preparation step, High Pressure Rinsing (HPR) with ultra pure water will be performed at HIM and is currently in preparation. HPR cycles are currently tested on a CH dummy with a new nozzle layout that is optimized towards CH cavity geometry.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK009  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 02 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOTK024 Multipacting Simulation on Half-Wave Resonator for 200 MeV Energy Upgrade of Komac Proton Linac cavity, multipactoring, electron, linac 1255
 
  • J.J. Dang, H.S. Kim, H.-J. Kwon, S. Lee
    KOMAC, KAERI, Gyeongju, Republic of Korea
 
  Funding: This work was supported through KOMAC operation fund of KAERI by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (KAERI-524320-22).
A superconducting linac is developed at KOrea Multi-purpose Accelerator Complex (KOMAC) for proton beam energy upgrade from 100 MeV to 200 MeV. The SRF linac consists of thirty-six half-wave resonator (HWR) cavities. 350 MHz, β = 0.56 HWR is designed to provide 3.6 MV accelerating voltage. After a fundamental RF design study, an analysis on a multipacting (MP) of HWR is carried out. The MP simulation for the HWR is performed by using CST Particle Studio. To understand a feature of the MP occurrence in the HWR, a particle-in-cell simulation is conducted while changing various conditions such as an RF amplitude, an RF phase, and an emission surface.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK024  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 04 July 2022
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TUPOTK034 Evaluating the Effects of Nitrogen Doping and Oxygen Doping on SRF Cavity Performance cavity, SRF, niobium, ECR 1287
 
  • H. Hu, Y.K. Kim
    University of Chicago, Chicago, Illinois, USA
  • D. Bafia
    Fermilab, Batavia, Illinois, USA
 
  Superconducting radiofrequency (SRF) cavities are resonators with extremely low surface resistance that enable accelerating cavities to have extremely high quality factors (Q0). High Q0 decreases the capital required to keep the accelerators cold by reducing power loss. The performance of SRF cavities is largely governed by the surface composition of the first §I{100}{nm} of the cavity surface. Impurities such as oxygen and nitrogen have been observed to yield high Q0, but their precise roles are still being studied. Here, we compare the performance of cavities doped with nitrogen and oxygen in terms of surface composition and heating behavior with field. A simulation of the diffusion of oxygen into the bulk of the cavity was built using COMSOL Multiphysics software. Simulated results were compared to the actual surface composition of the cavities as determined from secondary ion mass spectrometry analysis. Understanding how these impurities affects performance allows us to have further insight into the underlying mechanisms that enable these surface treatments to yield high Q0.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK034  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 30 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOTK038 Next Generation SRF Cavities at Cornell University cavity, SRF, radio-frequency, accelerating-gradient 1303
 
  • N.M. Verboncoeur, M. Liepe, R.D. Porter, L. Shpani
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Our goal is to develop new materials and protocols for the growth and preparation of thin-film and layered superconductors for next generation SRF cavities with higher performance for future accelerators. We are working primarily with Nb3Sn to achieve this goal, as well as other materials which aim to optimize the RF field penetration layer of the cavity. This contribution gives a general update on our most recent cavity test results. A deeper insight into RF loss distribution and dynamics during cavity testing is gained using a new global high-speed temperature mapping system (T-Map).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK038  
About • Received ※ 11 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 22 June 2022
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TUPOTK040 Design of the Electron Ion Collider Electron Storage Ring SRF Cavity cavity, HOM, impedance, operation 1307
 
  • J. Guo, E. Daly, J. Henry, J. Matalevich, G.-T. Park, R.A. Rimmer, H. Wang, S. Wang
    JLab, Newport News, Virginia, USA
  • D. Holmes, K.S. Smith, W. Xu, A. Zaltsman
    BNL, Upton, New York, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
The Electron Ion Collider (EIC) under construction at Brookhaven National Laboratory is a high luminosity collider as the next major research facility for the nuclear physics community. Among the numerous RF subsystems in the EIC, the electron storage ring (ESR) fundamental RF cavities system is one of the most challenging. This system will handle a high beam current of up to 2.5 A and replenish up to 10 MW of beam power losses from synchrotron radiation and HOM. Variable coupling is required in the cavities due to the wide range of required total RF voltage and beam current combinations. In this paper, we will present the status of the design and future plans.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK040  
About • Received ※ 16 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 28 June 2022
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TUPOTK051 Design Studies on a High-Power Wide-Band RF Combiner for Consolidation of the Driver Amplifier of the J-PARC RCS synchrotron, proton, controls, acceleration 1333
 
  • H. Okita, K. Hara, K. Hasegawa, M. Nomura, T. Shimada, F. Tamura, M. Yamamoto
    KEK/JAEA, Ibaraki-Ken, Japan
  • C. Ohmori, Y. Sugiyama, M. Yoshii
    KEK, Ibaraki, Japan
  • M.M. Paoluzzi
    CERN, Meyrin, Switzerland
 
  A power upgrade of the existing 8 kW solid-state driver amplifier is required for the acceleration of high intensity proton beams in the J-PARC 3 GeV rapid cycling synchrotron (RCS). The development of a 25 kW amplifier with gallium nitride (GaN) HEMTs and based on 6.4 kW modules is ongoing. The combiner is a key component to achieve such a high output power over the wide bandwidth required for multi-harmonic rf operation. This paper presents a preliminary design of the combiner. The circuit simulation setup and results, including the realistic magnetic core characteristics and frequency response of the cables are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK051  
About • Received ※ 18 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 14 June 2022
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TUPOTK053 Design Progress of High Efficiency Klystron for CEPC LINAC klystron, cavity, gun, linac 1339
 
  • Z.D. Zhang, Y.L. Chi, D. Dong, M. Iqbal, G. Pei, S.C. Wang, O. Xiao, S. Zhang, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
  • S. Zhang, Z.D. Zhang
    UCAS, Beijing, People’s Republic of China
 
  The injector linear accelerator (LINAC) for the CEPC requires a higher efficiency klystron with 80MW output power than S band 65MW pulsed klys-tron currently operating in LINAC of BEPCII to reduce energy consumption and cost. The efficiency is ex-pected to improve from the currently observed 42% to more than 55% and output power will be improved from 65MW to more than 80MW with same operation voltage. In this paper, BAC bunching method is ap-plied for klystron efficiency improvement. The optimi-zation of the gun and solenoid parameters is complet-ed with 2-D code DGUN and then 3-D code CST. The preliminary design of the cavity parameters is also completed in 1-D disk model based AJDISK code and then further checked by 2-D code EMSYS. Finally, new klystron prototype will be fabricated in Chinese com-pany after design parameters are determined.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK053  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
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TUPOTK058 Development and Testing of High Power CW 1497 MHz Magnetron cathode, cavity, electron, power-supply 1351
 
  • M. Popovic, M.A. Cummings, A. Dudas, R.P. Johnson, R.R. Lentz, M.L. Neubauer, T. Wynn
    Muons, Inc, Illinois, USA
  • T. Blassick, J.K. Wessel
    Richardson Electronics Ltd, Lafox, Illinois, USA
  • K. Jordan, R.A. Rimmer, H. Wang
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by DOE NP STTR grant DE-SC0013203
We have designed, built, and tested a new magnetron tube that generates RF power at 1497 MHz. In the tests so far, the tube has produced CW 9 kW RF power, where the measured power is limited by the test equipment. The final goal is to use it to power superconducting (SC) cavities.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK058  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 06 July 2022
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TUPOTK060 Simulations of Miscut Effects on the Efficiency of a Crystal Collimation System collimation, proton, collider, hadron 1358
 
  • M. D’Andrea, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  Funding: Research supported by the HL-LHC project.
The concept of crystal collimation relies on the use of bent crystals which can coherently deflect high-energy halo particles at angles orders of magnitude larger than what is obtained from scattering with conventional materials. Crystal collimation is studied to further improve the collimation efficiency at the High Luminosity Large Hadron Collider (HL-LHC). In order to reproduce the main experimental results of crystal collimation tests and to predict the performance of such a system, a simulation routine capable of modeling interactions of beam particles with crystal collimators was developed and recently integrated into the latest release of the single-particle tracking code SixTrack. A new treatment of the miscut angle, i.e. the angle between crystalline planes and crystal edges, was implemented to study the effects of this manufacturing imperfection on the efficiency of a crystal collimation system. In this paper, the updated miscut angle model is described and simulation results on the cleaning efficiency are presented, using configurations tested during Run 2 of the LHC as a case study.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK060  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 04 July 2022
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TUPOTK064 HL-LHC Crab Cavity HOM Couplers: Challenges and Results HOM, cavity, impedance, cryomodule 1374
 
  • J.A. Mitchell, R. Calaga, E. Montesinos
    CERN, Meyrin, Switzerland
 
  To compensate for the detrimental effect of the crossing angle on luminosity production in the High Luminosity Large Hadron Collider’s (HL-LHC) interaction regions, superconducting crab cavities (vertical and horizontal) will be installed at the two interaction regions of the ATLAS and CMS experiments. Both cavity designs use multiple Higher Order Mode (HOM) couplers to reduce beam instabilities and heat loads caused by the very high proton current in the HL-LHC. The conceptual RF designs of the HOM couplers are firstly presented, evaluating HOM damping requirements, fundamental mode rejection and dynamic heat load constraints. A special focus is given to the coupler’s characteristic impedance (Z0), to improve the robustness during transport and operation. Following this, RF measurements of the HOM couplers before installation, installed on the superconducting cavities and with a circulating proton beam are detailed, analysing deviations from the simulated cases.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK064  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022
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TUPOMS008 Lifetime Correction Using Fast-Off-Energy Response Matrix Measurements sextupole, optics, lattice, operation 1409
 
  • S.M. Liuzzo, N. Carmignani, L.R. Carver, L. Hoummi, T.P. Perron, B. Roche, S.M. White
    ESRF, Grenoble, France
 
  Following the measurements done at MAX-IV * we try to exploit for the ESRF-EBS Storage Ring (SR) off-energy response matrix measurement for the optimization of Touschek lifetime. The measurements performed with fast AC steerers on- and off-energy are analyzed and fitted producing an effective model including quadrupole and sextupole errors. Several alternatives to extrapolate sextupoles strengths for correction are compared in terms of lifetime. For the time being none of the corrections could produce better lifetime than the existing empirically optimized set of sextupoles.
*D.Olsson et al., Nonlinear optics from off-energy closed orbits, 10.1103/PhysRevAccelBeams.23.102803
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS008  
About • Received ※ 19 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
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TUPOMS016 A Pipeline for Orchestrating Machine Learning and Controls Applications software, controls, operation, framework 1439
 
  • I.V. Agapov, M. Böse, L. Malina
    DESY, Hamburg, Germany
 
  Machine learning and artificial intelligence are becoming widespread paradigms in control of complex processes. Operation of accelerator facilities is not an exception, with a number of advances having happened over the last years. In the domain of intelligent control of accelerator facilities, the research has mostly been focused on feasibility demonstration of ML-based agents, or application of ML-based agents to a well-defined problem such as parameter tuning. The main challenge on the way to a more holistic AI-based operation, in our opinion, is of engineering nature and is related to the need of significant reduction of the amount of human intervention. The areas where such intervention is still significant are: training and tuning of ML models; scheduling and orchestrating of multiple intelligent agents; data stream handling; configuration management; and software testing and verification requiring advanced simulation environment. We have developed a software framework which attempts to address all these issues. The design and implementation of this system will be presented, together with application examples for the PETRA III storage ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS016  
About • Received ※ 09 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOMS018 Error Analysis and Commissioning Simulation for the PETRA-IV Storage Ring lattice, MMI, optics, storage-ring 1442
 
  • T. Hellert, I.V. Agapov, S.A. Antipov, R. Bartolini, R. Brinkmann, Y.-C. Chae, D. Einfeld, M.A. Jebramcik, J. Keil
    DESY, Hamburg, Germany
 
  The upgrade of the PETRA-III storage ring into a diffraction limited synchrotron radiation source is nearing the end of its detailed technical design phase. We present a preliminary commissioning simulation for PETRA-IV demonstrating that the final corrected machines meet the performance design goals.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS018  
About • Received ※ 10 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 15 June 2022
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TUPOMS022 Cooling Challenges in a NEG-Coated Vacuum Chamber of a Light Source vacuum, radiation, software, synchrotron 1456
 
  • S. Talebi Motlagh, A. Danaeifard, J. Rahighi, F. Saeidi
    ILSF, Tehran, Iran
  • F. Zamani
    University of Kashan, Kashan, Iran
 
  In a light Source, unused synchrotron radiation is being distributed along the walls of the chambers. Due to the small conductance of the chambers, vacuum pumping is based on the distributed concept, and then non-evaporable getter (NEG) coating is extensively used. The vacuum chambers are made of copper alloys tube, and cooling circuits are welded to the chamber to remove the heat load from the radiation generated. Filler metal is used to create a brazed joint between the water cooling pipe and the vacuum chamber body. The thermal conductivity of the fillers is less than the vacuum chamber body. Moreover, the water velocity in the cooling pipe must be taken into account in thermal calculations. In this paper, we study and investigate the effects of the filler metal and the cooling water velocity in cooling the chambers.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS022  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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TUPOMS024 Sensitivity of EEHG Simulations to Dynamic Beam Parameters electron, FEL, radiation, laser 1463
 
  • D. Samoilenko, W. Hillert, F. Pannek
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Ackermann, E. Ferrari, N.S. Mirian, P. Niknejadi, G. Paraskaki, L. Schaper
    DESY, Hamburg, Germany
  • F. Curbis, M.A. Pop, S. Werin
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  Currently, the Free electron laser user facility FLASH at DESY is undergoing a significant upgrade involving the complete transformation of one of its beamlines to allow external seeding. With the Echo-Enabled Harmonic Generation (EEHG) seeding method, we aim for the generation of fully coherent XUV and soft X-ray pulses at wavelengths down to 4 nm. The generated FEL radiation is sensitive to various electron beam properties, e.g., its energy profile imprinted either deliberately or by collective effects such as Coherent Synchrotron Radiation (CSR). In dedicated particle tracking simulations, one usually makes certain assumptions concerning the beam properties and the collective effects to simplify implementation and analysis. Here, we estimate the influence of some of the common assumptions made in EEHG simulations on the properties of the output FEL radiation, using the example of FLASH and its proposed seeding beamline. We conclude that the inherent properties of the FLASH1 beam, namely the negatively chirped energy profile, has dominant effect on the spectral intensity profile of the radiators output compare to that of the CSR induced chirp.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS024  
About • Received ※ 20 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 29 June 2022
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TUPOMS028 3HC - Third Harmonic Normal Conducting Active Cavity Collaboration Between HZB, DESY and ALBA cavity, HOM, impedance, storage-ring 1471
 
  • F. Pérez, J.R. Ocampo, A. Salom, P. Solans
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • W. Anders, V. Dürr, T. Loewner, A.N. Matveenko, M. Ries, L. Shi, Y. Tamashevich, A.V. Tsakanian
    HZB, Berlin, Germany
  • M. Ebert, R. Onken
    DESY, Hamburg, Germany
  • P. Hülsmann
    GSI, Darmstadt, Germany
  • W.F.O. Müller
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  Funding: Co-funded by the European Regional Development Fund (ERDF)
A collaboration agreement between the HZB, DESY and ALBA institutions was signed on 2021 in order to test the 3rd harmonic normal conducting, HOM damped, active cavity designed and prototyped by ALBA*. The test will involve low power characterization of the fundamental mode, bead pull measurements to fully determine the HOM characteristics, a full high power conditioning to validate the power capability of the cavity, and finally, the installation of the cavity in the BESSY II storage ring in order to test the cavity in real conditions with beam. In this paper the low power, bead pull and conditioning results will be presented. The cavity has been installed at BESSY II on May 2022 to be tested after the summer shutdown.
* Prototype fabrication of an active normal conducting third harmonic cavity for the ALBA Storage Ring. J.Ocampo et al. , IPAC 2022 proceedings.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS028  
About • Received ※ 06 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 02 July 2022
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TUPOMS031 Fill Pattern for Reducing Transient Beam Loading and Ion-Trapping in the Diamond-II Storage Ring cavity, storage-ring, beam-loading, emittance 1483
 
  • T. Olsson, H.C. Chao
    DLS, Oxfordshire, United Kingdom
 
  The Diamond-II upgrade will replace the existing Diamond storage ring with a multibend achromat lattice providing higher brightness to the users by reducing the emittance and increasing the beam energy. The new storage ring will require a harmonic cavity that lengthens the bunches to increase the Touschek lifetime as well as mitigate instabilities and suppress the emittance blow up from intrabeam scattering. It is expected that the ring will have to operate with gaps in the fill pattern for ion-clearing, but that will lead to transient beam loading resulting in reduced bunch lengthening. The length and occurrence of the gaps therefore have to be determined as a trade-off between the requirements for transient beam loading and ion-trapping. This paper presents simulations of both effects for the Diamond-II storage ring to find an optimal fill pattern.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS031  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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TUPOMS036 Commissioning of the Lower Emittance Lattice at SPEAR3 lattice, emittance, septum, operation 1502
 
  • K. Tian, W.J. Corbett, S.M. Gierman, X. Huang, J. Kim, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek, M. Song, Z. Zhang
    SLAC, Menlo Park, California, USA
 
  SPEAR3, commissioned in 2004, is a third generation light source at the SLAC National Accelerator Laboratory. The low emittance lattice with an emittance of 10 nm had been operated for over a decade until the recent commission of the new lower emittance lattice with 7 nm emittance. The new lattice, based on the same double-bend achromat lattice, has pushed toward the design limit of such type of lattice in SPEAR3. In this paper, we will elaborate our commissioning experience for the new lattice in SPEAR3.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS036  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022
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TUPOMS037 RCDS-S: An Optimization Method to Compensate Accelerator Performance Drifts kicker, experiment, operation, storage-ring 1506
 
  • Z. Zhang, X. Huang, M. Song
    SLAC, Menlo Park, California, USA
 
  We propose an optimization algorithm, Safe Robust Conjugate Direction Search (RCDS-S), which can perform accelerator tuning while keeping the machine performance within a designated safe envelope. The algorithm builds probability models of the objective function using Lipschitz continuity of the function as well as characteristics of the drifts and applies to the selection of trial solutions to ensure the machine operates safely during tuning. The algorithm can run during normal user operation constantly, or periodically, to compensate for the performance drifts. Simulation and online tests have been done to validate the performance of the algorithm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS037  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 30 June 2022 — Issue date ※ 30 June 2022
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TUPOMS042 Cavity R&D for HBS Accelerator cavity, neutron, brilliance, proton 1520
 
  • N.F. Petry, K. Kümpel, S. Lamprecht, O. Meusel, H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
 
  The demand for neutrons of various types for research is growing day by day worldwide. To meet the growing demand the Jülich High Brilliance Neutron Source (HBS) is in development. It is based on a high power linear proton accelerator with an end energy of 70 MeV and a proton beam current of 100 mA. After the injector and the MEBT is the main part of the accelerator, which consists of about 36 CH-type cavities. The design of the CH-type cavities will be optimized in terms of required power, required cooling and reliability and the recent results will be presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS042  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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TUPOMS043 High Power Tests of a New 4-Rod RFQ with Focus on its Mechanical Vibrations rfq, laser, experiment, operation 1523
 
  • S.R. Wagner, D. Koser, K. Kümpel, H. Podlech
    IAP, Frankfurt am Main, Germany
  • K.B. Bahrke-Rein
    TU Darmstadt, Darmstadt, Germany
  • M. Basten
    GSI, Darmstadt, Germany
  • M. Basten
    HIM, Mainz, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
 
  Because of strong mechanical vibrations of the electrodes and its sensitivity to changes of thermal load, the operational stability of the existing 4-rod RFQ at the High Charge State Injector (HLI) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, could not be ensured for all planned operating states. To resolve this issue and ensure stable injection into the HLI, a new RFQ-prototype, optimized in terms of vibration suppression and cooling efficiency, was designed at the Institute of Applied Physics (IAP) of Goethe University Frankfurt. To test the performance of this prototype and demonstrate the operational stability in terms of mechanical vibration as well as thermal load, high power tests with more than 25’kW/m were performed at GSI. After initial conditioning, detailed vibrational measurements during high power RF operation using a laser Doppler vibrometer were performed, which were then compared to previously conducted simulations using ANSYS. Ultimately, the ability for stable operation up to high power levels with an efficient vibration suppression and moderate heating have clearly been demonstrated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS043  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOMS051 Prototype Fabrication of an Active Normal Conducting Third Harmonic Cavity for the ALBA Storage Ring cavity, HOM, GUI, storage-ring 1542
 
  • J.R. Ocampo, J.M. Álvarez, B. Bravo, F. Pérez, A. Salom, P. Solans
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Funding: Co-funded by the European Regional Development Fund (ERDF)
ALBA has designed a normal conducting active 1.5 GHz HOM damped cavity for the active third harmonic RF system for the ALBA Storage Ring (SR), which also will serve for the upgraded ALBA II. The third harmonic cavity at ALBA will be used to increase the bunch length in order to improve the beam lifetime and increase the beam stability thresholds. A prototype has been constructed by the company AVS in collaboration with VITZRO. This paper presents the design of the cavity, the constructed prototype, the Acceptance Tests measurements, and the future plans.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS051  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 30 June 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOMS053 Start-to-End Simulations of the LCLS-II HE Free Electron Laser electron, FEL, undulator, photon 1549
 
  • D.B. Cesar, G. Marcus, H.-D. Nuhn, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: This work is supported in part by DOE Contract No. DE-AC02-76SF00515
In this proceeding we present start-to-end simulations of the LCLS-II-HE free electron laser. The HE project will extend the LCLS-II superconducting radio-frequency (SRF) linac from 4 GeV to 8 GeV in order to produce hard x-rays from the eponymous hard x-ray undulators (26 mm period). At the same time, soft x-ray performance is preserved (and extended into the tender regime) by using longer period undulators (56 mm period) than were originally built for LCLS-II (39 mm period). Here we use high-fidelity numerical particle simulations to study the performance of several SASE beamline configurations, and compare the resulting x-ray energy, power, duration, and transverse properties. Using the LCLS-II normal-conducting gun, we find that the x-ray pulse energy drops off rapidly above ~15 keV, while using the lower emittance beam from a proposed SRF gun, we improve the cutoff to ~20 keV.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS053  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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WEOXSP2 All Optical Chartacterization of a Dual Grating Accelerator Structure laser, electron, controls, acceleration 1602
 
  • S.A. Crisp, P. Musumeci, A. Ody
    UCLA, Los Angeles, USA
 
  Funding: ACHIP grant from the Gordon and Betty Moore Foundation (GBMF4744) U.S. Department of Energy grant DE-AC02-76SF00515 National Science Foundation Graduate Research Fellowship Program Grant DGE1650604.
We present progress and an experimental plan for multi-MeV relativistic energy gain in a dielectric laser-driven accelerator (DLA). Using a 780 nm, 100 fs pulse-front-tilted laser, we achieve interaction with 6 MeV electrons over a 4 mm long structure with 800 nm period. To compensate for resonant defocusing effects, the laser pulse is imprinted with a phase mask, applied by a Spatial Light Modulator, which uses alternating phase focusing (APF) to achieve stable beam transport. The DLA is mechanically mounted with a variable sized gap (600-1200 nm) in order to maximize transmission while maintaining high gradient within the channel. The combination of high interaction length and use of APF confines and accelerates the electrons by up to 3.5 MeV.
 
slides icon Slides WEOXSP2 [1.603 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOXSP2  
About • Received ※ 08 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022  
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WEOXSP3 mm-Wave Structure Development for High Gradient Acceleration cavity, coupling, GUI, distributed 1606
 
  • E.J.C. Snively, A.E. Gabriel, E.A. Nanni, M.A.K. Othman, A.V. Sy
    SLAC, Menlo Park, California, USA
  • A.E. Gabriel
    UCSC, Santa Cruz, California, USA
 
  Funding: This work is supported by U.S. Department of Energy Contract No. DE-AC02-76SF00515, SLAC LDRD project 21-014 and Internal Agency Agreement 21-0007-IA (MIPR HR0011150657).
We report on the design of mm-wave accelerator structures operating near 100 GHz. Simulations of the cavity geometry and RF coupling are performed in ANSYS-HFSS and using SLAC’s parallel electromagnetic code suite ACE3P. We present experimental results for structures fabricated from copper, niobium, and copper plated with NbTiNi. We report on techniques for tuning these high frequency structures, as well as preliminary brazing results. A mm-wave accelerator cavity enables not only a high achievable gradient due to higher breakdown thresholds, but also reduced fill times which decrease pulsed heating and allow for higher repetition rates. We discuss the potential advantages and challenges for applications requiring ultra-compact structures.
 
slides icon Slides WEOXSP3 [1.800 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOXSP3  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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WEOZGD1 Design of an LPA-Based First-Stage Injector for a Synchrotron Light Source electron, plasma, laser, beam-loading 1639
 
  • X.Y. Shi, H.S. Xu
    IHEP, Beijing, People’s Republic of China
 
  Study of plasma-based acceleration has been a frontier of accelerator community for decades. The beam performance obtained from a laser-plasma based accelerator (LPA) becomes higher and higher. Nowadays, a combination of LPAs and the conventional RF accelerators is a trend. One of the interesting directions to go is to replace a LINAC by an LPA as the first-stage injector of a synchrotron light source. In this paper, we present a physical design of a 500 MeV LPA-based first-stage injector for a synchrotron light source.  
slides icon Slides WEOZGD1 [8.971 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZGD1  
About • Received ※ 15 June 2022 — Revised ※ 22 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 04 July 2022
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WEIZSP2 Trapping of Neutral Molecules by the Electromagnetic Beam Field dipole, vacuum, electron, alignment 1649
 
  • G. Franchetti
    GSI, Darmstadt, Germany
  • F. Zimmermann
    CERN, Meyrin, Switzerland
 
  Neutral uncharged molecules are affected by the electromagnetic field of a charged particle beam if they carry either an electric or a magnetic dipole moment. The residual gas in an accelerator beam pipe consists of such molecules. In this paper we study their dynamics. Under a few approximations, whose validity we explore and justify, we derive the equations of motion of neutral molecules and their invariants, determine the conditions for these neutral molecules to become trapped in the field of the beams as function of beam-pipe temperature, and compute the resulting enhancement of molecule density in the vicinity of the beam. We demonstrate that large agglomerates of molecules, "flakes," are much more likely to be pulled into the beam than single molecules, and suggest that this phenomenon might help explain some beam observations at the Large Hadron Collider.  
slides icon Slides WEIZSP2 [6.142 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEIZSP2  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 22 June 2022
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WEOZSP1 Longitudinal Bunch Shaping Using an X-Band Transverse Deflecting Cavity Powered by Wakefield Power Extractor at Argonne Wakefield Accelerator Facility wakefield, electron, quadrupole, acceleration 1655
 
  • S.Y. Kim, G. Chen, D.S. Doran, W. Liu, J.G. Power, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • A. Bibian, C.-J. Jing, E.W. Knight, S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  • P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: This project is supported under DoE SBIR Phase I Grant No. DE-SC0021733. This work is also supported by Department of Energy, Office of Science, under contract No. DEAC02-06CH11357.
Longitudinal bunch shaping using transverse deflecting cavities (TDC) was recently proposed*. This configuration is well suited for shaping the current profile of high-charge bunches since it does not use dipole magnets, and therefore, is not prone to deleterious effects arising from coherent synchrotron radiation. An intercepting mask located downstream of the first TDC, which introduce a spatiotemporal correlation, transversely shape the beam. Downstream of the second TDC, upon removal of the cross-plane correlation, the bunch is temporally shaped. In this paper, we investigate longitudinal bunch shaping with an X-band TDC powered by an X-band, short-pulse wakefield Power Extraction and Transfer Structure (PETS), where the wakefield from the drive beam propagating through the PETS is the power source. We describe the RF designs of the X-band TDC and the configuration of the overall shaping system. Finally, we explore via beam-dynamics simulations the performances of the proposed shaper and its possible application to various bunch shapes relevant to beam-driven acceleration and coherent radiation generation.
*Gwanghui Ha et al., Phys. Rev. Accel. Beams 23, 072803, 2020
 
slides icon Slides WEOZSP1 [6.235 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP1  
About • Received ※ 14 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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WEOZSP2 Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance emittance, impedance, experiment, octupole 1659
 
  • N. Triantafyllou, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • F. Antoniou, H. Bartosik, P. Baudrenghien, X. Buffat, R. Calaga, Y. Papaphilippou
    CERN, Meyrin, Switzerland
  • T. Mastoridis
    CalPoly, San Luis Obispo, California, USA
 
  Crab Cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to minimize the luminosity reduction caused by the crossing angle. Two superconducting crab cavities were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to test their operation in a proton machine for the first time. An important point to consider is the increase in transverse emittance induced by noise in the Low-Level RF (LLRF) system. During the first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in 2021, are discussed.  
slides icon Slides WEOZSP2 [2.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP2  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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WEOZSP3 Measurements of Radiation Fields From a Ceramic Break radiation, impedance, injection, synchrotron 1663
 
  • Y. Shobuda, S. Hatakeyama, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Toyama
    KEK, Tokai, Ibaraki, Japan
 
  Ceramic breaks are used in synchrotrons for many purposes. For example, they are inserted between the Multi-Wire Profile Monitor (MWPM) on the injection line at the Rapid Cycling Synchrotron (RCS) in J-PARC to completely prevent the wall currents accompanying beams from affecting the MWPM. On the other hand, from the viewpoint of suppressing beam impedances and the radiation fields from the ceramic breaks, it would be preferable that the inner surface of the ceramic break is coated with Titanium Nitride (TiN), or covered over capacitors. In this report, we measure the radiation fields from the ceramic break with and without capacitors as well as the beam profile and investigate the effect of the ceramic breaks on the measurements.  
slides icon Slides WEOZSP3 [35.441 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP3  
About • Received ※ 12 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 05 July 2022
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WEOZSP4 Full Coupling Studies at ALBA coupling, emittance, lattice, operation 1667
 
  • Z. Martí, G. Benedetti, M. Carlà, U. Iriso, L. Torino
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  As other low emittance machine upgrades ALBA-II proposal considers operating in full coupling. In such configuration the horizontal emittance is further reduced while the lifetime is increased at the price of working close to equal fractional tunes. This mode of operation has not been adopted by any existing light source to date, and it presents a few disadvantages, like the optics degradation, injection efficiency reduction and beam size stability. In this paper the above mentioned difficulties are studied for the present ALBA storage ring in full coupling conditions.  
slides icon Slides WEOZSP4 [1.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP4  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022
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WEPOST007 Centre-of-Mass Energy in FCC-ee collider, radiation, polarization, cavity 1683
 
  • J. Keintzel, R. Tomás García, F. Zimmermann
    CERN, Meyrin, Switzerland
  • A.P. Blondel
    DPNC, Genève, Switzerland
  • D.N. Shatilov
    BINP SB RAS, Novosibirsk, Russia
 
  The Future Circular electron-positron Collider (FCC-ee) is designed for high precision particle physics experiments. This demands a precise knowledge of the beam energies, obtained by resonant depolarization, and from which the center-of-mass energy and possible boosts at all interaction points are then determined. At the highest beam energy mode of 182.5 GeV, the energy loss due to synchrotron radiation is about 10 GeV per revolution. Hence, not only the location of the RF cavities, but also a precise control of the optics and understanding of beam dynamics, are crucial. In the studies presented here, different possible locations of the RF-cavities are considered, when calculating the beam energies over the machine circumference, including energy losses from crossing angles, a non-homogeneous dipole distribution, and an estimate of the beamstrahlung effect at the collision point.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST007  
About • Received ※ 08 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 27 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST013 Exploitation of Crystal Shadowing via Multi-Crystal Array, Optimisers and Reinforcement Learning operation, extraction, septum, proton 1707
 
  • F.M. Velotti, M. Di Castro, L.S. Esposito, M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, E. Matheson
    CERN, Meyrin, Switzerland
 
  The CERN Super Proton Synchrotron (SPS) routinely delivers proton and heavy ion beams to the North experimental Area (NA) in the form of 4.8 s spills. To produce such a long flux of particles, resonant third integer slow extraction is used, which, by design, foresees primary beam lost on the electrostatic septum wires to separate circulating from extracted beam. Shadowing with thin bent crystal has been proposed and successfully tested in the SPS, as detailed in *. In 2021, a thin crystal was used for physics production showing results compatible with what measured during early testing. In this paper, the results from the 2021 physics run are presented also comparing particle losses at extraction with previous operational years. The setting up of the crystal using numerical optimisers is detailed, with possible implementation of reinforcement learning (RL) agents to improve the setting up time. Finally, the full exploitation of crystal shadowing via multi-array crystals is discussed, together with the performance reach in the SPS.
F.Velotti, et. al, "Septum shadowing by means of a bent crystal to reduce slow extraction beam loss", Phys. Rev. Accel. Beams 22, 093502 - Published 27 September 2019
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST013  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
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WEPOST015 Implementation of a Tune Sweep Slow Extraction with Constant Optics at MedAustron extraction, betatron, operation, optics 1715
 
  • P.A. Arrutia Sota, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • A. De Franco
    QST Rokkasho, Aomori, Japan
  • F. Kuehteubl, M.T.F. Pivi, D.A. Prokopovich
    EBG MedAustron, Wr. Neustadt, Austria
 
  Conventional slow extraction driven by a tune sweep perturbs the optics and changes the presentation of the beam separatrix to the extraction septum during the spill. The constant optics slow extraction (COSE) technique, recently developed and deployed operationally at the CERN Super Proton Synchrotron to reduce beam loss on the extraction septum, was implemented at MedAustron to facilitate extraction with a tune sweep of operational beam quality. COSE fixes the optics of the extracted beam by scaling all machine settings with the beam rigidity following the extracted beam’s momentum. In this contribution the implementation of the COSE extraction technique is described before it is compared to the conventional tune sweep and operational betatron core driven cases using both simulations and recent measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST015  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
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WEPOST016 Development of Collimation Simulations for the FCC-ee collimation, radiation, framework, coupling 1718
 
  • A. Abramov, R. Bruce, M. Hofer, G. Iadarola, S. Redaelli
    CERN, Meyrin, Switzerland
  • F.S. Carlier, T. Pieloni, M. Rakic
    EPFL, Lausanne, Switzerland
  • L.J. Nevay
    JAI, Egham, Surrey, United Kingdom
  • S.M. White
    ESRF, Grenoble, France
 
  A collimation system is under study for the FCC-ee to protect the machine from the multi-MJ electron and positron beams and limit the backgrounds to the detectors. One of the key aspects of the collimation system design is the setup of simulation studies combining particle tracking and scattering in the collimators. The tracking must include effects important for electron beam single-particle dynamics in the FCC-ee, such as synchrotron radiation. For collimation, an aperture model and particle-matter interactions for electrons are required. There are currently no established simulation frameworks that include all the required features. The latest developments of an integrated framework for multi-turn collimation studies in the FCC-ee are presented. The framework is based on an interface between tracking codes, pyAT and Xtrack, and a particle-matter interaction code, BDSIM, based on Geant4. Promising alternative simulation codes and frameworks are also discussed. The challenges are outlined, and the first results are presented, including preliminary loss maps for the FCC-ee.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST016  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022
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WEPOST018 Power Deposition Studies for Crystal-Based Heavy Ion Collimation in the LHC collimation, heavy-ion, operation, hadron 1726
 
  • J.B. Potoine, R. Bruce, R. Cai, L.S. Esposito, P.D. Hermes, A. Lechner, S. Redaelli, A. Waets
    CERN, Meyrin, Switzerland
  • F. Wrobel
    IES, Montpellier, France
 
  The LHC heavy-ion program with 208Pb82+ beams is foreseen to benefit from a significant intensity upgrade in 2022. A performance limitation may arise from ion fragments scattered out of the collimators in the betatron cleaning insertion, which risk quenching superconducting magnets during periods of short beam lifetime. In order to mitigate this risk, an alternative collimation technique, relying on bent crystals as primary collimators, will be used in future heavy-ion runs. In this paper, we study the power deposition in superconducting magnets by means of FLUKA shower simulations, comparing the standard collimation system against the crystal-based one. The studies focus on the dispersion suppressor regions downstream of the betatron cleaning insertion, where the ion fragment losses are the highest. Based on these studies, we quantify the expected quench margin expected in future runs with 208Pb82+ beams.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST018  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 03 July 2022
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WEPOST019 Benchmarks of Energy Deposition Studies for Heavy-Ion Collimation Losses at the LHC collimation, heavy-ion, operation, betatron 1730
 
  • J.B. Potoine, R. Bruce, R. Cai, P.D. Hermes, A. Lechner, S. Redaelli, A. Waets
    CERN, Meyrin, Switzerland
  • F. Wrobel
    IES, Montpellier, France
 
  During some periods in its second physics run (2015-2018), the LHC has been operated with 208Pb82+ ion beams at an energy of 6.37 ZTeV. The LHC is equipped with a betatron collimation system, which intercepts the transverse beam halo and protects sensitive equipment such as superconducting magnets against beam losses. However, hadronic fragmentation and electromagnetic dissociation of heavy ions in collimators generate off-rigidity particles, which can be lost in the downstream dispersion suppressor, putting the magnets at risk to quench. An accurate modelling of the beam-induced energy deposition in the collimation system and superconducting magnets is important for quantifying possible performance limitations arising from magnet quenches. In this paper, we compare FLUKA shower simulations against beam loss monitor measurements recorded during the 2018 208Pb82+ run. In particular, we investigate fast beam loss events, which lead to recurring beam aborts in 2018 operation. Based on these studies, we assess the ability of the simulation model to reproduce the observed loss patterns in the collimation region and dispersion suppressor.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST019  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 23 June 2022
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WEPOST021 Theoretical Study of Laser Energy Absorption Towards Energetic Proton and Electron Sources laser, target, electron, proton 1737
 
  • I.M. Vladisavlevici, E. d’Humières
    CELIA, Talence, France
  • D. Vizman
    West University of Timisoara, Timisoara, Romania
 
  Funding: This work was supported by Romanian National Authority for Scientific Research PN 75/2018, Agence Nationale de la Recherche project ANR-17-CE30-0026-Pinnacle, WUT - JINR collaboration project 05-6-1119-2014/2023 (2/2019; 86/2020; 103/2021) and Erasmus+ Student grant (2018/2019; 2019/2020; 2020/2021).
Our main goal is to describe and model the energy transfer from laser to particles, from the transparent to less transparent regime of laser-plasma interaction in the ultra-high intensity regime, and using the results obtained to optimize laser ion acceleration. We investigate the case of an ultra high intensity (1022 W/cm2) ultra short (20 fs) laser pulse interacting with a near-critical density plasma made of electrons and protons of density 5 nc (where nc = 1.1·1021 cm-3 is the critical density for a laser wavelength of 1 µm). Through 2D particle-in-cell (PIC) simulations, we study the optimal target thickness for the maximum conversion efficiency of the laser energy to particles. Theoretical modelling of the predominant laser-plasma interaction mechanisms predicts the particle energy and conversion efficiency optimization. Our studies led to an optimization of the target thickness for maximizing electron and proton acceleration.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST021  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 08 July 2022
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WEPOST026 Conceptual Design of the FCC-ee Beam Dumping System radiation, operation, extraction, dumping 1753
 
  • A.M. Krainer, P. Andreu Muñoz, W. Bartmann, M. Calviani, Y. Dutheil, A. Lechner, F.-X. Nuiry, A. Perillo-Marcone
    CERN, Meyrin, Switzerland
  • R.L. Ramjiawan
    JAI, Oxford, United Kingdom
 
  The Future Circular electron-positron Collider (FCC-ee) will have stored beam energies of up to 20 MJ. This is a factor 100 higher than any current or past lepton collider. A safe and reliable disposal of the beam onto a beam dump block is therefore critical for operation. To ensure the survival of the dump core blocks, transversal dilution of the beam is necessary. To reduce the complexity of the system and guarantee high availability, an optimized, semi-passive beam dumping system has been designed. The main dump absorber design has been optimized following recent studies for high energy dump block materials for the LHC High Luminosity upgrade. First simulations regarding the radiation environment of the dumping system have been carried out, allowing the definition of preliminary constraints for the integration with respect to radiation sensitive equipment. The performance of the system has been evaluated using Monte-Carlo simulations as well as thermomechanical Finite-Element-Analysis to investigate potential material failure and assess safety margins. An experiment at the CERN HiRadMat facility has been carried out and preliminary results show good agreement with simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST026  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST030 Multitask Optimization of Laser-Plasma Accelerators Using Simulation Codes with Different Fidelities plasma, laser, wakefield, acceleration 1761
 
  • Á. Ferran Pousa, M. Kirchen, A. Martinez de la Ossa, M. Thévenet
    DESY, Hamburg, Germany
  • S.T.P. Hudson, J.M. Larson
    ANL, Lemont, Illinois, USA
  • A. Huebl, R. Lehé, J.-L. Vay
    LBNL, Berkeley, USA
  • S. Jalas
    University of Hamburg, Hamburg, Germany
 
  When designing a laser-plasma acceleration experiment, one commonly explores the parameter space (plasma density, laser intensity, focal position, etc.) with simulations in order to find an optimal configuration that, for example, minimizes the energy spread or emittance of the accelerated beam. However, laser-plasma acceleration is typically modeled with full particle-in-cell (PIC) codes, which can be computationally expensive. Various reduced models can approximate beam behavior at a much lower computational cost. Although such models do not capture the full physics, they could still suggest promising sets of parameters to be simulated with a full PIC code and thereby speed up the overall design optimization. In this work we automate such a workflow with a Bayesian multitask algorithm, where each task has a different fidelity. This algorithm learns from past simulation results from both full PIC codes and reduced PIC codes and dynamically chooses the next parameters to be simulated. We illustrate this workflow with a proof-of-concept optimization using the Wake-T and FBPIC codes. The libEnsemble library is used to orchestrate this workflow on a modern GPU-accelerated high-performance computing system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST030  
About • Received ※ 08 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 14 June 2022  
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WEPOST043 An Effective-Density Model for Accelerating Fields in Laser-Graphene Interactions laser, plasma, target, electron 1795
 
  • C. Bonțoiu, O. Apsimon, E. Kukstas, C.P. Welsch, M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
  • A. Bonatto
    Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
  • J. Resta-López
    ICMUV, Paterna, Spain
  • G.X. Xia
    UMAN, Manchester, United Kingdom
 
  Funding: This work was supported by STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT)
With the advancement of high-power UV laser technology, the use of nanostructures for particle acceleration attracts renewed interest due to its possibility of achieving TV/m accelerating gradients in solid state plasmas. Electron acceleration in ionized materials such as carbon nanotubes and graphene is currently considered as a potential alternative to the usual laser wakefield acceleration (LWFA) schemes. An evaluation of the suitability of a graphene target for LWFA can be carried out using an effective density model, thus replacing the need to model each layer. We present a 2D evaluation of the longitudinal electric field driven by a short UV laser pulse in a multi-layer graphene structure, showing that longitudinal fields of ~5 TV/m are achievable.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST043  
About • Received ※ 20 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST046 Beam Matching in an Elliptical Plasma Blowout Driven by Highly Asymmetric Flat Beams plasma, emittance, wakefield, focusing 1802
 
  • P. Manwani, H.S. Ancelin, G. Andonian, N. Majernik, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Marina del Rey, California, USA
  • G. Ha, J.G. Power
    ANL, Lemont, Illinois, USA
  • M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
  • M. Yadav
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was performed with the support of the US Department of Energy under Contract No. DE-SC0017648 and DESC0009914.
Particle beams with highly asymmetric emittance ratios, or flat beams, are employed at accelerator facilities such as the AWA and foreseen at FACET-II. Flat beams have been used to drive wakefields in dielectric structures and are an ideal candidate for high-gradient wakefields in plasmas. The high aspect ratio produces a blowout region that is elliptical in cross section and this asymmetry in the ion column structure creates asymmetric focusing in the two transverse planes. The ellipticity of the plasma blowout decreases as the normalized peak current increases, and gradually approaches an axisymmetric column. An appropriate matching condition for the beam envelope inside the elliptical blowout is introduced. Simulations are performed to investigate the ellipticity of the resultant wakefield based on the initial drive beam parameters, and are compared to analytical calculations. The parameter space for two cases at the AWA and FACET facilities, with requirements for plasma profile and achievable fields, is presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST046  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022
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WEPOST048 Excitation of Very High Gradient Plasma Wakefields From Nanometer Scale Beams plasma, wakefield, focusing, quadrupole 1806
 
  • P. Manwani, H.S. Ancelin, G. Andonian, D.R. Chow, N. Majernik, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Marina del Rey, California, USA
  • R. Robles
    SLAC, Menlo Park, California, USA
  • M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
  • M. Yadav
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was performed with the support of the US Department of Energy under Contract No. DESC0009914.
The plasma based terawatt attosecond project at SLAC, termed PAX, offers near mega-Ampere beams that could be used to demonstrate plasma wakefield acceleration at very high gradients (TV/m). The beam has a large aspect ratio which allows it to be used at high densities since the longitudinal beam size is lower than the plasma skin depth. This beam can be focused using a permanent magnitude quadrupole (PMQ) triplet to further reduce its transverse size. Since the beam is extremely short compared to the plasma skin depth, it behaves like a delta-function perturbation to the plasma. This reduces the expected focusing effect of the ion column and simulations show that only the tail of the beam is notably focused and decelerated. This scenario is investigated with attendant experimental considerations discussed. The creation of the witness beam by the deceleration of the tail of the beam is also discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST048  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 29 June 2022
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WEPOPT008 Supervised Machine Learning for Local Coupling Sources Detection in the LHC coupling, quadrupole, network, optics 1842
 
  • F. Soubelet, T.H.B. Persson, R. Tomás García
    CERN, Meyrin, Switzerland
  • Ö. Apsimon, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This research is supported by the LIV. DAT Center for Doctoral Training, STFC and the European Organization for Nuclear Research
Local interaction region (IR) linear coupling in the LHC has been shown to have a negative impact on beam size and luminosity, making its accurate correction for Run 3 and beyond a necessity. In view of determining corrections, supervised machine learning has been applied to the detection of linear coupling sources, showing promising results in simulations. An evaluation of different applied models is given, followed by the presentation of further possible application concepts for linear coupling corrections using machine learning.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT008  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022
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WEPOPT010 Progress on Action Phase Jump for LHC Local Optics Correction optics, quadrupole, operation, interaction-region 1850
 
  • J.F. Cardona, Y. Rodriguez Garcia
    UNAL, Bogota D.C, Colombia
  • H. García Morales, M. Hofer, E.H. Maclean, T.H.B. Persson, R. Tomás García
    CERN, Meyrin, Switzerland
  • Y. Rodriguez Garcia
    UAN, Bogotá D.C., Colombia
 
  The correction of the local optics at the Interaction Regions of the LHC is crucial to ensure a good performance of the machine. This is even more important for the future LHC upgrade, HL-LHC, where the optics is more sensitive to magnetic errors. For that reason, it is important to explore alternative techniques for local optics corrections. In this paper, we evaluate the performance of the Action Phase Jump method for optics correction in the LHC and the HL-LHC and explore ways to integrate this technique in regular operations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT010  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022
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WEPOPT012 MAD-X for Future Accelerators coupling, optics, closed-orbit, GUI 1858
 
  • T.H.B. Persson, H. Burkhardt, R. De Maria, L. Deniau, E.J. Høydalsvik, A. Latina, P.K. Skowroński, R. Tomás García, L. van Riesen-Haupt
    CERN, Meyrin, Switzerland
 
  The development of MAD-X was started more than 20 years ago and it still remains the main tool for single particle dynamics for both optics design, error studies as well as for operational model-based software at CERN. In this article, we outline some of the recent development of MAD-X and plans for the future. In particular, we focus on the development of the twiss module used to calculate optics functions in MAD-X which is based on first and second order matrices. These have traditionally been calculated as an expansion around the ideal orbit. In this paper, we describe explicitly how an expansion around the closed orbit can be employed instead, in order to get more precise results. We also describe the latest development of the beam-beam long range wire compensator in MAD-X, an element that has been implemented using the aforementioned approach.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT012  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 01 July 2022
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WEPOPT013 Effect of a Spurious CLIQ Firing on the Circulating Beam in HL-LHC beam-losses, luminosity, collimation, collider 1862
 
  • C. Hernalsteens, B. Lindström, E. Ravaioli, O.K. Tuormaa, M. Villén Basco, C. Wiesner, D. Wollmann
    CERN, Meyrin, Switzerland
 
  The High Luminosity LHC (HL-LHC) will reach a nominal, levelled luminosity of §I{5e34}{\per\cm\square\per\second} and a stored energy of nearly §I{700}{MJ} in each of the two proton beams. The new large-aperture final focusing Nb3Sn quadrupole magnets in IR1 and IR5, which are essential to achieve the luminosity target, will be protected using the novel Coupling Loss Induced Quench (CLIQ) system. A spurious discharge of a CLIQ unit will impact the circulating beam through higher order multipolar field components that develop rapidly over a few turns. This paper reports on dedicated beam tracking studies performed to evaluate the criticality of this failure on the HL-LHC beam. Simulations for different machine and optics configurations show that the beam losses reach a critical level after only five machine turns following the spurious CLIQ trigger, which is much faster than assumed in previous simulations that did not consider the higher order multipolar fields. Machine protection requirements using a dedicated interlock to mitigate this failure are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT013  
About • Received ※ 08 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 01 July 2022  
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WEPOPT014 The Effect of a Partially Depleted Halo on the Criticality and Detectability of Fast Failures in the HL-LHC beam-losses, luminosity, collider, dipole 1866
 
  • C. Hernalsteens, C. Lannoy, O.K. Tuormaa, M. Villén Basco, C. Wiesner, D. Wollmann
    CERN, Meyrin, Switzerland
 
  In the High Luminosity LHC (HL-LHC) era, the bunch intensity will be increased to νm{2.2e11} protons, which is almost twice the nominal LHC intensity. The stored energy in each of the two beams will increase to §I{674}{MJ}. The HL-LHC will feature beams whose transverse halos are partially depleted by means of a hollow electron lens. The reduced stored energy in the beam tails will significantly change the development of losses caused by failures. This paper reports on beam tracking simulations evaluating the effect of a partially depleted halo on the criticality and detection of failures originating from the superconducting magnet protection systems. In addition, the effect of the transverse damper operating as a coherent excitation system leading to orbit excursions on a beam with a partially depleted halo is discussed. The results in terms of time-dependent beam losses are presented. The margins between the failure onset, its detection, and the time to reach critical loss levels, are discussed. The results are extrapolated to failure cases of different origins that induce similar beam loss dynamics.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT014  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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WEPOPT015 Study of Hydrodynamic-Tunnelling Effects Induced by High-Energy Proton Beams in Graphite target, proton, coupling, hadron 1870
 
  • C. Wiesner, F. Carra, J. Don, I. Kolthoff, A. Lechner, S.R. Rasile, D. Wollmann
    CERN, Meyrin, Switzerland
 
  The design and assessment of machine-protection systems for existing and future high-energy accelerators comprises the study of accidental beam impact on machine elements. In case of a direct impact of a large number of high-energy particle bunches in one location, the damage range in the material is significantly increased due to an effect known as hydrodynamic tunnelling. The effect is caused by the beam-induced reduction of the material density along the beam trajectory, which allows subsequent bunches to penetrate deeper into the target. The assessment of the damage range requires the sequential coupling of an energy-deposition code, like FLUKA, and a hydrodynamic code, like Autodyn. The paper presents the simulations performed for the impact of the nominal LHC beam at 7 TeV on a graphite target. It describes the optimisation of the simulation setup and the required coupling workflow. The resulting energy deposition and the evolution of the target density are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT015  
About • Received ※ 20 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
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WEPOPT019 RHIC Blue Snake Blues polarization, closed-orbit, operation, optics 1881
 
  • F. Méot, E.C. Aschenauer, H. Huang, A. Marusic, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, V. Schoefer
    BNL, Upton, New York, USA
 
  Funding: Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Two helical full snakes are used in both Blue and Yellow rings of RHIC collider, in order to preserve beam polarization during acceleration to collision energy and polarization lifetime at store. A snake in RHIC is comprised of four 2.4m long modules, powered by pair. During the startup of RHIC Run 22 in December 2021, two successive power dips have caused the 9 o’clock RHIC BlBrookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.ue ring snake to loose two of its four modules. In spite of this regrettable loss, it has been possible to maintain near 180deg snake precession, by proper powering of the remaining two modules, as well as, by re-tuning the 3 o’clock sister snake, vertical spin precession axis around the ring and spin tune 1/2. Determining these new settings, in order to salvage polarization with the handicapped Blue snake pair, has required series of numerical simulations, a brief overview is given here.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT019  
About • Received ※ 03 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 07 July 2022
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WEPOPT028 Design Update on the HSR Injection Kicker for the EIC impedance, kicker, injection, coupling 1904
 
  • M.P. Sangroula, C.J. Liaw, C. Liu, J. Sandberg, N. Tsoupas, B.P. Xiao
    BNL, Upton, New York, USA
  • X. Sun
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The Electron-Ion Collider (EIC), the next-generation nuclear science facility, is under the design at the Brookhaven National Laboratory. The present RHIC rings will be reconfigured as the Hadron Storage Ring (HSR) for the EIC. Design of a stripline injection kicker for the HSR for beams with the rigidity of  ∼  81   T-m poses some technical challenges due to the expected shorter bunch spacing, heating due to higher peak current and the larger number of bunches, and the required higher pulsed voltage. Recently, we updated its mechanical design to optimize the characteristic and beam coupling impedances. In addition, we incorporated the impedance tuning capability by introducing the kicker aperture adjustment mechanism. Finally, we incorporated high voltage FID feedthroughs (FC26) to this kicker. This paper reports the design and optimization updates of the HSR injection kicker including the impedance tuning capability, optimization of both the characteristic and the beam coupling impedances, and finally the incorporation of a high voltage feedthrough design.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT028  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 26 June 2022
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WEPOPT036 Dependence of Beam Size Growth on Macro-Particle’s Initial Actions in Strong-Strong Beam-Beam Simulation for the Electron-Ion Collider electron, proton, emittance, collider 1924
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, J. Kewisch, H. Lovelace III, C. Montag, S. Peggs, V. Ptitsyn, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
  • B.R. Gamage, H. Huang, E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177.
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with design luminosities up to 1×1034cm-2s-1 in the center mass energy range of 20-140 GeV. We simulated the planned electron-proton collision of flat beams with Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than that from weak-strong simulation. To understand the numerical noises further, we calculate the beam size growth rate of macro-particles as function of their initial longitudinal and transverse actions. This method is applied to both strong-strong and weak-strong simulations. The purpose of this study is to identify which group of macro-particles contributes most of the artificial emittance growth in strong-strong beam-beam simulation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT036  
About • Received ※ 22 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 22 June 2022
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WEPOPT037 Dynamic Aperture Evaluation for EIC Hadron Storage Ring with Crab Cavities and IR Nonlinear Magnetic Field Errors dynamic-aperture, electron, proton, cavity 1927
 
  • Y. Luo, J.S. Berg, W. Fischer, X. Gu, H. Lovelace III, C. Montag, S. Peggs, V. Ptitsyn, H. Witte, D. Xu
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  • T. Satogata
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177.
The electron ion collider (EIC) presently under construction at Brookhaven National Laboratory will collider polarized high energy electron beams with hadron beams with luminosities up to 1034 cm-2s-1 in the center mass energy range of 20-140 GeV. In this article, we evaluate the dynamic aperture of the Hadron Storage Ring (HSR) with symplectic element-by-element tracking. Crab cavities, nonlinear magnetic field errors, and weak-strong beam-beam interaction are included. We compared the dynamic aperture from head-on collision to crossing-angle collision and found the reason for the dynamic aperture drop. We also studied the field error tolerances for IR magnets and for some particular magnets.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT037  
About • Received ※ 22 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
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WEPOPT038 Summary of Numerical Noise Studies for Electron-Ion Collider Strong-Strong Beam-Beam Simulation electron, proton, emittance, collider 1931
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, J. Kewisch, H. Lovelace III, C. Montag, S. Peggs, V. Ptitsyn, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
  • B.R. Gamage, H. Huang, E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams, reaching luminosities up to 1×1034cm-2s-1 in center mass energy range of 20-140 GeV. We studied the planned electron-proton collisions using a Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than in weak-strong simulation. To understand the numerical noise and its impact on strong-strong simulation results, we carried out extensive studies to identify all possible causes for artificial emittance growth and quantify their contributions. In this article, we summarize our study activities and findings. This work will help us better understand the simulated emittance growth and the limits of the PIC based strong-strong beam-beam simulation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT038  
About • Received ※ 19 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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WEPOPT039 Fine Decoupling Test and Simulation Study to Maintain a Large Transverse Emittance Ratio in Hadron Storage Rings emittance, coupling, experiment, proton 1935
 
  • Y. Luo, I. Blackler, M. Blaskiewicz, W. Fischer, A. Marusic, C. Montag, T.C. Shrey, D. Xu
    BNL, Upton, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
I In previous and existing hadron storage rings, the horizontal and vertical emittances are normally the same or very close. For the Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC), the design proton transverse emittance ratio is 10:1. To maintain this large emittance ratio, we need to have an online fine decoupling system to prevent transverse emittance exchange. For this purpose, we carried out fine decoupling experiments in the Relativistic Heavy Ion Collider (RHIC) and reviewed its previous operational data. Analytical prediction and numerical simulation are preformed to estimate how small the global coupling coefficient should be to maintain a 10:1 emittance ratio.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT039  
About • Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT040 Numerical Noise Error of Particle-In-Cell Poisson Solver for a Flat Gaussian Bunch proton, electron, emittance, collider 1939
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • H. Huang, E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177.
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collider polarized high energy electron beams with hadron beams with luminosity up to 1×1034cm-2s-1 in the center mass energy range of 20-140 GeV. We simulated the planned electron-proton collision of flat beams with Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than that from weak-strong simulation. To better understand the emittance growth rate from the strong-strong simulation, we compare the beam-beam kicks between the PIC method and the analytical calculation and calculate the RMS variation in beam-beam kicks among 1000 sets of random Gaussian particle distributions. The impacts of macro-particle number, grid number, and bunch flatness are also studied.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT040  
About • Received ※ 23 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT041 Strong-Strong Simulations of Coherent Beam-Beam Effects in the EIC electron, proton, luminosity, resonance 1942
 
  • J. Qiang
    LBNL, Berkeley, California, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo, C. Montag, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
 
  The high luminosity electron ion collider (EIC) will provide great opportunities in nuclear physics study and is under active design. The coherent effects due to the beam-beam interaction of two colliding beams can cause beam size blow-up and degrade the luminosity in the EIC. In this paper, we report on the study of coherent beam-beam effects in the EIC design using self-consistent strong-strong simulations. These simulations show the coherent dipole and quadrupole mode instabilities in the tune working point scan and bunch intensity scan.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT041  
About • Received ※ 18 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 23 June 2022
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WEPOPT044 Electron-Ion Collider Design Status electron, hadron, storage-ring, collider 1954
 
  • C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, X. Gu, R.C. Gupta, Y. Hao, C. Hetzel, D. Holmes, H. Huang, J.P. Jamilkowski, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, G.J. Mahler, D. Marx, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, M.P. Sangroula, S. Seletskiy, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, D. Xu, W. Xu, A. Zaltsman
    BNL, Upton, New York, USA
  • S.V. Benson, B.R. Gamage, J.M. Grames, T.J. Michalski, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer
    JLab, Newport News, Virginia, USA
  • A. Blednykh, D.M. Gassner, B. Podobedov, S. Verdú-Andrés
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  • Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan
    SLAC, Menlo Park, California, USA
  • E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois, USA
  • G.H. Hoffstaetter, D. Sagan, J.E. Unger
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • F. Lin, V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • M.G. Signorelli
    Cornell University, Ithaca, New York, USA
 
  Funding: Work supported under Contract No. DE-SC0012704, Contract No. DE-AC05-06OR23177, Contract No. DE-AC05-00OR22725, and Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy.
The Electron-Ion Collider (EIC) is being designed for construction at Brookhaven National Laboratory. Activities have been focused on beam-beam simulations, polarization studies, and beam dynamics, as well as on maturing the layout and lattice design of the constituent accelerators and the interaction region. The latest design advances will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT044  
About • Received ※ 03 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022
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WEPOPT045 Transverse Electron Beam Tails and Beam Lifetime in the EIC Electron Storage Ring electron, proton, vacuum, storage-ring 1958
 
  • C. Montag
    BNL, Upton, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704.
While for most storage ring design activities it is sufficient to assume a Gaussian distribution of the beam particles, a more detailed prediction of the population in the transverse tails is necessary to predict the beam lifetime in a given aperture. Dominant processes that result in non-Gaussian distributions are the beam-beam interaction in a collider as well as beam-gas scattering. Simulations to determine the required apertures and vacuum levels in the EIC electron storage ring will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT045  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 28 June 2022 — Issue date ※ 05 July 2022
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WEPOPT046 Preparation of a Prototype Plasma Lens as an Optical Matching Device for the ILC e+ Source plasma, positron, focusing, optical-matching 1961
 
  • M. Formela, N. Hamann, G.A. Moortgat-Pick
    University of Hamburg, Hamburg, Germany
  • K. Flöttmann, G. Loisch, G.A. Moortgat-Pick
    DESY, Hamburg, Germany
 
  In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to the potential advantages in compactness and beam dynamics compared to conventional focusing elements. One potential application is the optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures. A collaboration between University Hamburg and DESY Hamburg has been established to develop a prototype design for this application. Here, we discuss beam dynamics simulation results, preliminary parameters of the lens prototype, and the current status of the prototype design.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT046  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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WEPOPT049 Beam-Beam Interaction for Tilted Storage Rings cavity, electron, collider, storage-ring 1968
 
  • D. Xu, D. Holmes, C. Montag, F.J. Willeke
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  In the Electron-Ion Collider (EIC) design, to avoid vertical orbit bumps in the Electron Storage Ring (ESR) at some crossing points with Hadron Storage Ring (HSR) to preserve the electron polarization, we plan to tilt the ESR plane by 200 ’rad with an axis connecting IP6 and IP8. In this article, we study the beam-beam interaction when two rings are not in the same plane. The Lorentz boost formula is derived and the required vertical crabbing strength is calculated to compensate the dynamic effect The strong-strong simulations are performed to validate the theory.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT049  
About • Received ※ 16 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
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WEPOPT050 Detector Solenoid Compensation in the EIC Electron Storage Ring cavity, solenoid, detector, collider 1972
 
  • D. Xu
    BNL, Upton, New York, USA
  • Y. Luo
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
 
  The Electron Ion Collider (EIC) uses crab cavities to restore the geometrical luminosity loss. Due to the space limitation, the detector solenoid cannot be compensated locally. This paper presents the lattice design to compensate the detector solenoid without interfering the crab cavities. The skew quadrupoles are employed to avoid additional crab cavities. The correction scheme is checked by beam-beam simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT050  
About • Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 28 June 2022
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WEPOPT058 A Response Matrix Approach to Skew-Sextupole Correction in the LHC at Injection coupling, sextupole, injection, resonance 1987
 
  • E. Waagaard
    Uppsala University, Uppsala, Sweden
  • E.H. Maclean
    CERN, Meyrin, Switzerland
 
  To date, no dedicated attempt has been made to correct skew-sextupole resonances in the LHC at injection. Recently this topic has gained interest however, following the investigation for the emittance growth generation during the LHC energy ramp, due to third order islands. The LHC is equipped with skew-sextupole correctors in the experimental insertions (MCSSX), intended for local compensation at top energy, and with several families of skew sextupole magnets in the arcs (MSS), which are intended for chromatic coupling compensation at top energy but are not optimally placed for resonance compensation. Simulation studies were performed in MAD-X and PTC to assess whether the MSS and MCSSX correctors could be used to compensate skew-sextupole RDTs in the LHC at injection via a response matrix approach, based on measured values at the LHC BPMs. It was found that compensation was viable, but at the cost of significantly increased corrector strength compared to chromatic coupling compensation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT058  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 23 June 2022
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WEPOPT059 Corrections of Systematic Normal Decapole Field Errors in the HL-LHC Separation/Recombination Dipoles target, resonance, dynamic-aperture, dipole 1991
 
  • J. Dilly, M. Giovannozzi, R. Tomás García, F.F. Van der Veken
    CERN, Meyrin, Switzerland
 
  Funding: This work has been supported by the HiLumi Project and been sponsored by the Wolfgang Gentner Programme of the German Federal Ministry of Education and Re-search.
Magnetic measurements revealed that the normal decapole (b5) errors of the recombination dipoles (D2) could have a systematic component of up to 11 units. Based on previous studies, it was predicted that the current corrections would not be able to compensate this, thereby leading to a degradation of the dynamic aperture by about 0.5 - 1 ’. On the other hand, the separation dipole D1 is expected to have a systematic b5 component of 6-7 units and its contribution to the resonance driving terms will partly compensate the effect of D2, due to the opposite field strength of the main component. Simulations were performed with the HL-LHC V1.4 lattice to test these concerns and to verify the compensation assumption. In addition, various normal decapole resonance driving terms were examined for correction, the results of which are presented in this contribution.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT059  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022
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WEPOPT060 Controlling Landau Damping via Feed-Down From High-Order Correctors in the LHC and HL-LHC optics, target, MMI, controls 1995
 
  • J. Dilly, E.H. Maclean, R. Tomás García
    CERN, Meyrin, Switzerland
 
  Funding: This work has been supported by the HiLumi Project and been sponsored by the Wolfgang Gentner Programme of the German Federal Ministry of Education and Re-search.
Amplitude detuning measurements in the LHC have shown that a significant amount of detuning is generated in Beam 1 via feed-down from decapole and dodecapole field errors in the triplets of the experiment insertion regions, while in Beam 2 this detuning is negligible. In this study, we investigate the cause of this behavior and we attempt to find corrections that use the feed-down from the nonlinear correctors in the insertion region for amplitude detuning.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT060  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
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WEPOPT062 Optimisation of the FCC-ee Positron Source Using a HTS Solenoid Matching Device positron, solenoid, target, linac 2003
 
  • Y. Zhao, S. Döbert, A. Latina, S. Ogur
    CERN, Meyrin, Switzerland
  • B. Auchmann, P. Craievich, J. Kosse, R. Zennaro
    PSI, Villigen PSI, Switzerland
  • I. Chaikovska, R. Chehab
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • M. Duda
    IFJ-PAN, Kraków, Poland
  • P.V. Martyshkin
    BINP SB RAS, Novosibirsk, Russia
 
  In this paper, we present the simulation and optimisation of the FCC-ee positron source, where a high-temperature superconducting (HTS) solenoid is used as the matching device to collect positrons from the target. The "conventional" target scheme is used which simply consists of amorphous tungsten. The target is placed inside the bore of the HTS solenoid to improve the accepted positron yield at the entrance of the damping ring and the location of the target is optimised. The latest recommended baseline beam parameters are used and presented. An optimisation of the ideal positron yield using the analytic SC solenoid on-axis field is also performed and shows that the design of the HTS solenoid is optimal as far as the accepted positron yield is concerned.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT062  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
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WEPOPT064 Simulations and Measurements of Luminosity at SuperKEKB luminosity, resonance, experiment, impedance 2011
 
  • D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi
    KEK, Ibaraki, Japan
  • Y. Zhang
    IHEP, Beijing, People’s Republic of China
 
  The interplay of beam-beam interaction, machine imperfections, and beam coupling impedance makes it difficult to predict the luminosity performance of SuperKEKB. Since 2020, the crab waist scheme was introduced to SuperKEKB to suppress beam-beam resonances. The coherent beam-beam head-tail instability and beam-beam driven synchro-betatron resonances due to large crossing angle can drive horizontal blowup, which cannot be suppressed by crab waist. The longitudinal impedance modulates the synchrotron motion and therefore affects beam-beam instability. In this paper, we compare simulations and measurements of luminosity and discuss the challenges and direction toward developing a predictable luminosity simulation model for SuperKEKB.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT064  
About • Received ※ 13 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 30 June 2022
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WEPOTK005 Electromagnetic Analysis of a Circular Storage Ring for Quantum Computing Using Vsim controls, laser, storage-ring, electromagnetic-fields 2034
 
  • S.I. Sosa Guitron, S. Biedron, T.B. Bolin
    UNM-ECE, Albuquerque, USA
  • S. Biedron
    UNM-ME, Albuquerque, New Mexico, USA
  • K.A. Brown
    BNL, Upton, New York, USA
  • B. Huang
    SBU, Stony Brook, USA
 
  We discuss design considerations for a circular ion trap based on electromagnetic and particle beam simulations. This is a circular radiofrequency quadrupole (rfq) being designed for quantum information applications. The circular rfq should have good electromagnetic properties to accumulate and store the beam for prolonged times, while providing apertures for laser cooling and lower voltage electrodes to provide control over the beam. We use the electromagnetic and particle-in-cell software VSim, which uses finite difference time-domain and particle-in-cell methods, together with high performance computing tools.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK005  
About • Received ※ 30 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 30 June 2022 — Issue date ※ 08 July 2022
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WEPOTK006 Proton Beamline Simulations for the High Intensity Muon Beamline at PSI target, proton, optics, cyclotron 2036
 
  • M. Haj Tahar, D.C. Kiselev, A. Knecht, D. Laube, D. Reggiani, J. Snuverink, V. Talanov
    PSI, Villigen PSI, Switzerland
 
  The High Intensity Proton Accelerator (HIPA) cyclotron at the Paul Scherrer Institut (PSI) delivers 590 MeV CW proton beam with a maximum power of 1.42 MW. After extraction, the beam is transferred in a 120 m long channel towards two target stations (TgM and TgE) before depositing its remaining power at the spallation target SINQ for neutron production. As part of the High Intensity Muon Beamline (HIMB) feasibility study, which belongs to the IMPACT (Isotope and Muon Production using Advanced Cyclotron and Target technologies) initiative, the first of these targets will be replaced with a thicker one and its geometry opti- mized thereby specifically boosting the emission of surface muons. In order to assess the impact of the changes on the proton beamline, BDSIM/GEANT4 simulations were performed with the realistic technical design of the target insert, the collimation system was redesigned and the power depositions were benchmarked with MCNP6. In this paper, we discuss the major changes and challenges for HIMB as well as the key considerations in redesigning the optics of the high power beam in the vicinity of the target stations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK006  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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WEPOTK013 Direct Impedance Measurement of the CERN PS Booster Finemet Cavities impedance, cavity, booster, proton 2064
 
  • S.C.P. Albright, M.E. Angoletta, D. Barrientos, A. Findlay, M. Jaussi, J.C. Molendijk
    CERN, Meyrin, Switzerland
 
  Over CERN’s Long Shutdown 2, the conventional ferrite-loaded cavities of the PS Booster were replaced with wide-band Finemet-loaded cavities. The Finemet cavities bring many operational advantages, but also represent a significant broadband impedance source. The impedance is mitigated by servo loops, which suppress the induced voltage, reducing the impedance as seen by the beam. Accurately including the impedance of the cavity and the effect of the servoloops in longitudinal tracking simulations is essential to predict the performance with beam. This paper discusses the results of a measurement campaign, which is intended to give a direct measurement of the cavity impedance. Using the detected voltage and the measured beam profile, the cavity impedance can be inferred and used to improve beam dynamics modelling.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK013  
About • Received ※ 26 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022
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WEPOTK017 An Efficient H-/ D- Extraction in Neutral Beam Injection (NBI) Ion Sources extraction, plasma, electron, ion-source 2078
 
  • V. Variale
    INFN-Bari, Bari, Italy
  • M. Cavenago
    INFN/LNL, Legnaro (PD), Italy
 
  Funding: INFN, DTT
The negative ion source development has reached performances very close to those required by the ITER project; see for example the test facility ELISE results*. A main residual problem seems to be the great amount of co-extracted electrons in the top part of the source. The introduction of a magnetic filter to remove the electrons from the extraction zone of the source causes ExB particle drifts (or shifts) which move both ions and electrons towards the top (or bottom depending on the B direction); in the top part the electron concentration and extracted current increase and that limits the extracted ion amount. In this contribution, as a possible solution, the application of a Planar Ion Funnel (PIF) extraction electric field configuration** on the source exit is proposed. The electric field line shape of PIF configuration, not only should break the perpendicularity between the magnetic filter B and the extraction electric field E in such a way to prevents the ExB particle drifts, but also should give a more efficient field shape for the H-/D- extraction. Preliminary simulations of D- and e- trajectories are presented to confirm the efficiency of the PIF system.
* B. Heinemann et al., Fusion Engineering and design (2021).
** A. Chaudhary et al., Rev. Sci. 85, 105101 (2014).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK017  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 22 June 2022
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WEPOTK018 Simulation of Heavy-Ion Beam Losses with Crystal Collimation* collimation, proton, heavy-ion, coupling 2082
 
  • R. Cai, R. Bruce, R. Bruce, M. D’Andrea, L.S. Esposito, P.D. Hermes, A. Lechner, A. Lechner, D. Mirarchi, J.B. Potoine, S. Redaelli, F. Salvat Pujol, J. Schoofs
    CERN, Meyrin, Switzerland
  • J.B. Potoine
    IES, Montpellier, France
  • M. Seidel
    PSI, Villigen PSI, Switzerland
 
  With the higher stored energy envisioned for future heavy-ion runs in the LHC and the challenging fragmentation aspect of heavy-ion beams due to interaction with collimator material, the need arises for even more performing collimation systems. One promising solution is crystal channeling, which is used in the HL-LHC baseline and starts with Run III for heavy-ion collimation. To investigate an optimal configuration for the collimation system, a well-tested simulation setup is required. This work shows the simulations of channeling and other coherent effects in the SixTrack-FLUKA Coupling simulation framework and compares simulated loss patterns with data from previous beam tests.
*Research supported by the HL’LHC project
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK018  
About • Received ※ 07 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 15 June 2022  
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WEPOTK022 Horizontal Beam Response at Extraction Conditions at the Heidelberg Ion-Beam Therapy Centre extraction, resonance, sextupole, pick-up 2096
 
  • E.C. Cortés García, E. Feldmeier, Th. Haberer
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion-Beam Therapy Centre’s synchrotron makes use of the sextupole driven RF-KO method near the third-order resonance in order to slowly extract the beam that is delivered to the patients. The horizontal beam response of a coasting beam was studied experimentally and with simulations at extraction conditions in order to deduce regions of interest for an optimal excitation signal spectrum. Two narrow frequency regions were found were the beam reacts coherently. With these information an RF signal was proposed for the resonant slow extraction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK022  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 03 July 2022
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WEPOTK028 Implementation of RF Channeling at the CERN PS for Spill Quality Improvements flattop, cavity, extraction, resonance 2114
 
  • P.A. Arrutia Sota, H. Damerau, M.A. Fraser, M. Vadai, F.M. Velotti
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
 
  Resonant slow extraction from synchrotrons aims at providing constant intensity spills over timescales much longer than the revolution period of the machine. However, the extracted intensity is undesirably modulated by noise on the machine’s power converters with a frequency range of between 50 Hz and a few kHz. The impact of power converter noise can be suppressed by exploiting a Radio Frequency (RF) technique known as empty bucket channelling, which increases the speed at which particles cross the tune resonance boundary. In this contribution the implementation of empty bucket channelling in the CERN Proton Synchrotron (PS) is described via simulation and measurement. The technique was tested with both a resonant RF cavity and an inductive Finemet cavity, which can produce non-sinusoidal waveforms, to significantly reduce the low frequency noise observed on the extracted spill.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK028  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022
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WEPOTK029 Advances in Low Energy Antimatter Beam Generation and Manipulation proton, antiproton, experiment, electron 2118
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 721559.
The Accelerators Validating Antimatter physics (AVA) project has enabled an interdisciplinary and cross-sector R&D program on low energy antimatter research. The network comprises 13 universities, 9 national and inter-national research centers and 13 partners from industry. Between 2016 and 2021, AVA has successfully trained 16 early-stage researchers that were based at universities, research centers and companies across Europe where they carried out cutting edge research into low energy antimat-ter physics and related technologies. This contribution presents several research highlights that originated within or on the basis of AVA: Results from studies into carbon nano-tubes as field emitters for cold electron beams with supe-rior beam quality, the design of a low energy negative ion injection beamline for experiments with antiprotonic atoms, and studies into realistic simulations of antiproton deceleration in foil degraders.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK029  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 27 June 2022
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WEPOTK030 Modelling Growth and Asymmetry in Seeded Self-Modulation of Elliptical Beams in Plasma plasma, wakefield, proton, acceleration 2122
 
  • A. Perera, O. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • Ö. Apsimon, A. Perera, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was supported by STFC UK grant ST/P006752/1. The Authors are grateful for computing time provided by the STFC Scientific Computing Department’s SCARF cluster.
The seeded self-modulation (SSM) of long particle bunches for the generation of gigavolts-per-meter wakefields that can accelerate witness electron beams was first shown using the Super Proton Synchrotron beam as a driver by the AWAKE experiment. The stability of the produced microbunch trains over tens or hundreds of meters is crucial for extrapolating this scheme as proposed for use in several high energy plasma-based linear colliders. However, aside from the competing hosing instability, which has been shown to be suppressible by SSM when that process saturates, few works have examined other effects of transverse asymmetry in this process. Here, we use analytical modelling and 3D particle-in-cell simulations with QuickPIC to characterise the impact on the SSM growth process due to transverse asymmetry in the beam. A metric is constructed for asymmetry in simulation results, showing that the initial azimuthal complexity changes only slightly during SSM growth. Further, we show quantitative agreement between simulations and analytical predictions for the scaling of the reduction SSM growth rate with unequal aspect ratio of the initial beam profile. These results serve to inform planning and tolerances for both AWAKE and other SSM-based novel acceleration methods in the future.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK030  
About • Received ※ 09 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
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WEPOTK032 Fast Electromagnetic Models of Existing Beamline Simulations quadrupole, focusing, experiment, proton 2130
 
  • S. Padden, E. Kukstas, P. Pusa, V. Rodin, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • S. Padden, V. Rodin, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The AD-ELENA complex decelerates antiprotons to ener- gies of 100 keV before transport to experiments through elec- trostatic transfer lines. Transfer line optics are traditionally designed from a lattice based approach and are unaffected by external effects. Presented is a method of rapidly proto- typing MAD-X simulations into G4Beamline models which propagate particles via electromagnetic fields rather than idealised optical lattice parameters. The transfer line to the ALPHA experiment is simulated in this approach. Due to the presence of fringe fields disagreement is found between the two models. Using an error minimisation technique, revised quadrupole strengths are found which improve agreement by 30% without any manual adjustment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK032  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022
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WEPOTK036 Progress on Electron Beam Optimization for FLASH Radiotherapy Experiment at Chiang Mai University electron, experiment, radiation, linac 2146
 
  • K. Kongmali, P. Apiwattanakul, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • P. Apiwattanakul, N. Kangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • P. Lithanatudom
    IST, Chiang Mai, Thailand
 
  At present, one of diseases that kills many people worldwide is cancer. The FLASH radiotherapy (RT) is a promising cancer treatment under study. It involves the fast delivery of RT at much higher dose rates than those currently used in clinical practice. The very short time of exposure leads to the destruction of the cancer cells, while the nearby normal cells are less damaged as compared with conventional RT. This work focuses on study of FLASH-RT experiment using electron beams produced from the accelerator system at the PBP-CMU Electron Linac Laboratory. The structure and properties of our electron pulses with microbunches in picosecond time scale and macropulses in microsecond time scale match well to FLASH-RT requirement. To optimize the condition for experiment, the electron beam simulations are performed by varying energy, charge and bunch length. The 25 MeV electrons energy before hitting the window for 50 and 100 pC bunch length have a bunch length of 1.16 and 1.97 ps. The transverse rms beam sizes of 50 pC and 100 pC bunch charges have the differences between ASTRA and GEANT4 from 7.90 % to 34.0 %. The optimized electron beam properties from this study will be used as the guideline for further simulation and experiment preparation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK036  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 22 June 2022
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WEPOTK040 Spin-Tracking Simulations in a COSY Model Using Bmad resonance, dipole, polarization, experiment 2158
 
  • M. Vitz
    FZJ, Jülich, Germany
 
  The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole Moment) of elementary charged particles. A permanent EDM of a subatomic particle violates time reversal and parity symmetry at the same time and would be, with the currently achievable experimental accuracy, an indication for further CP violation than established in the Standard Model. The JEDI-Collaboration (Jülich Electric Dipole moment Investigations) in Jülich has performed a direct EDM measurement for deuterons with the so called precurser experiments at the storage ring COSY (COoler SYnchrotron). In order to understand the measured data and to disentangle an EDM signal from systematic effects, spin tracking simulations in an accurate simulation model of COSY are needed. Therefore a model of COSY was implemented using the software library Bmad. Systematic effects were considered by including element misalignments, effective dipole shortening and steerer kicks. These effects rotate the invariant spin axis additional to the EDM and have to be analyzed and understood. The most recent spin tracking results as well as the methods to find the invariant spin axis will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK040  
About • Received ※ 02 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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WEPOTK052 Beam Coupling Impedance Study and Its Database of Siam Photon Source Storage Ring impedance, storage-ring, vacuum, wakefield 2177
 
  • N. Juntong, T. Chanwattana, S. Jummunt, K. Kittimanapun, T. Phimsen, W. Promdee, T. Pulampong
    SLRI, Nakhon Ratchasima, Thailand
 
  Since the Siam Photon Source (SPS) had an electron beam energy upgraded from 1.0 GeV to 1.2 GeV in 2005, the storage ring impedance measurements were done once in 2007. Two insertion magnet devices have been installed in the SPS storage ring during June to August 2013. There are several vacuum components added to the storage ring; these affect the ring impedance. Quantitative understanding of instabilities requires detailed knowledge of the impedance of the ring. For this purpose, the development of an impedance database is a necessity, where the wake potentials of each vacuum component are kept and maintained in a standard format. The self-describing data sets (SDDS) file format will be utilized to record components wake potentials. The wake potentials of each vacuum component can be obtained from a particle tracking simulation; a CST particle studio program will be used in the simulation process. The wake potentials can also be included in a beam dynamic tracking program such as ELEGANT to observe beam behaviors with these instabilities and find a curing means. The study results will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK052  
About • Received ※ 19 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 25 June 2022
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WEPOTK053 Simulation of Bunch Formation for the Mu2e Experiment proton, impedance, experiment, dipole 2180
 
  • K.P. Harrig, E. Prebys
    UCD, Davis, California, USA
  • V.P. Nagaslaev, S.J. Werkema
    Fermilab, Batavia, Illinois, USA
 
  Funding: Grant DE-SC0019254, The U.S. Department of Energy, Office of Science and Fermi Research Alliance, LLC Contract No. DE-AC02-07CH11359
The Fermilab Recycler is an 8 GeV storage ring composed of permanent magnets that was crucial to the success of the Fermilab Tevatron Collider program. It is currently being used to slip-stack protons for the high energy neutrino program and to re-bunch protons for use in the Muon g-2 and Mu2e experiments. For the latter applications, the Recycler re-bunches each 1.6 µs "batch" from the Fermilab Booster into four 2.5 MHz bunches. For the Mu2e experiment, it is crucial that beam more than 125 ns from the nominal bunch center be suppressed by at least a factor of 1E-5. While bunch formation is currently in operation for the g-2 experiment, this out of time requirement has not been met, and the reason is not understood. This work presents a simulation of bunch formation in the Recycler, in an effort to understand the reason for this excessive out of time beam and to search for a way to reduce it.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK053  
About • Received ※ 30 May 2022 — Revised ※ 16 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 11 July 2022
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WEPOTK054 Experimental Verification of DARHT Axis 1 Injector PIC Simulations cathode, emittance, solenoid, experiment 2183
 
  • A.F. Press, M.A. Jaworski, D.C. Moir, S. Szustkowski
    LANL, Los Alamos, New Mexico, USA
 
  Validated particle in cell (PIC) simulations of the DARHT Axis 1 injector have the potential to reduce accelerator downtime, assist experimental data analysis and improve accelerator tunes. To realize these benefits, the simulations must be validated with experimental results. In this work, the particle in cell code Chicago is used to simulate the injector region of the dual-axis radiographic hydrodynamic test facility (DARHT) first axis. These simulations are validated against experiment using measured anode-cathode voltage, beam current at three positions, optical transition radiation and previously calculated emittance. Since all of these measurements contain some variation, the respective simulation parameters are varied to understand their effect. The resulting simulated beam current distributions can then be compared to the measured 2RMS radius. This resulted in a reasonably well validated simulation model. Some inconstancy between simulated and measured results still exists, which future work will address.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK054  
About • Received ※ 06 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 05 July 2022
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WEPOTK055 Beam Lifetime Measurements in Sirius Storage Ring vacuum, storage-ring, scattering, synchrotron 2186
 
  • M.B. Alves, L. Liu, X.R. Resende, F.H. de Sá
    LNLS, Campinas, Brazil
 
  SIRIUS is the new storage ring-based 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS) at the Brazilian Center for Research in Energy and Materials (CNPEM). In ultralow emittance storage rings such as SIRIUS, the dominant contribution to the beam lifetime is due to large angle scattering between electrons within the same bunch, namely the Touschek effect. We used the strategy of storing two bunches simultaneously with different currents to measure their Touschek lifetime independently of other contributions, such as gas scattering. The measurements were carried out in different conditions of bunch current and RF voltage to compare the experimental results with those expected from theory and simulations for SIRIUS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK055  
About • Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022  
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WEPOTK058 Experimental Study of the Transverse Mode Coupling Instability with Space-Charge at the CERN SPS space-charge, emittance, experiment, lattice 2193
 
  • X. Buffat, H. Bartosik
    CERN, Meyrin, Switzerland
 
  Past studies on the Transverse Mode Coupling Instability (TMCI) suggested that it can be suppressed in the presence of space-charge forces. Recent developments in this field show that for higher strength, space-charge forces leads to other types of instabilities. We investigate the characteristics of these instabilities by means of stability threshold measurements at the CERN SPS for various intensities, longitudinal and transverse emittances. These observations are compared to numerical tracking simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK058  
About • Received ※ 03 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022  
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WEPOTK063 A Wireless Method to Obtain the Impedance From Scattering Parameters impedance, coupling, scattering, GUI 2213
 
  • C. Antuono, M. Migliorati, E. Métral, C. Zannini
    CERN, Meyrin, Switzerland
  • M. Migliorati, A. Mostacci
    LNF-INFN, Frascati, Italy
  • A. Mostacci
    Sapienza University of Rome, Rome, Italy
 
  The coaxial wire method is a common and appreciated choice to assess the beam coupling impedance of an accelerator element from scattering parameters. Nevertheless, the results obtained from wire measurements could be inaccurate due to the presence of the stretched conductive wire that artificially creates the conditions for the propagation of a Transverse ElectroMagnetic (TEM) mode. The aim of this work is to establish a solid technique to obtain the beam coupling impedance from electromagnetic simulations, without modifications of the device under test. In this framework, we identified a new relation to get the resistive wall beam coupling impedance of a circular chamber directly from the scattering parameters and demonstrated that it reduces to the exact theoretical expression. Furthermore, a possible generalization of the method to arbitrary cross section geometries has been studied and validated with numerical simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK063  
About • Received ※ 07 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 20 June 2022  
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WEPOTK064 Generating Sub-Femtosecond Electron Beams at Plasma Wakefield Accelerators plasma, emittance, electron, wakefield 2217
 
  • R. Robles, C. Emma, R.M. Hessami, K. Larsen, A. Marinelli
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00515 and by the DOE, Laboratory Directed Research and Development program at SLAC, under contract DE-AC02-76SF00515.
The Plasma-driven Attosecond X-ray source (PAX) project at FACET-II aims to produce attosecond EUV/soft x-ray pulses with milijoule-scale pulse energy via nearly coherent emission from pre-bunched electron beams. In the baseline approach*, a beam is generated using the density downramp injection scheme with a percent-per-micron chirp and 1e-4 scale slice energy spread. Subsequent compression yields a current spike of just 100 as duration which can emit 10 nm light nearly coherently due to its strong pre-bunching. In this work, we report simulation studies of a scheme to generate similarly short beams without relying on plasma injection. Instead, we utilize a high-charge beam generated at an RF photocathode, with its tail acting as the witness bunch for the wake. The witness develops a percent-per-micron chirp in the plasma which is then compressible downstream. The final bunch length demonstrated here is as short as 100 nm, and is limited primarily by emittance effects. The configurations studied in this work are available for experimental testing at existing PWFA facilities such as FACET-II.
*APL Photonics 6, 076107 (2021)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK064  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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WEPOTK065 Revisiting Intrabeam Scattering for Laminar Beams space-charge, electron, scattering, emittance 2221
 
  • R. Robles, Z. Huang, A. Marinelli
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00515
Intrabeam scattering (IBS) is becoming an increasingly important effect in the design of high-brightness linear electron accelerators due to the ever-increasing transverse brightness of beams produced from radiofrequency photoinjectors. The existing theory describing the energy spread growth rate due to IBS was derived in the context of circular machines where the beam particles are frequently and randomly colliding, and therefore should only be applied to non-laminar, emittance dominated flow. This is not the case in the injector portion of a linear accelerator, where the beam is space-charge dominated and the flow is laminar. The different nature of the microscopic motion in the two cases demands a reevaluation of the applicability of IBS theory to the photoinjector. In this work, we present a simple analytic model for energy spread growth during perfectly laminar flow and show that it matches well to point-to-point multiparticle simulations. In this way we demonstrate that stochastic energy spread growth in laminar beams is more attributable to the initial random placement of the particles in the bunch rather than the traditional temperature rearrangement mechanism of IBS.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK065  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 08 July 2022
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WEPOMS003 Beam Dynamics with a Superconducting Harmonic Cavity for the SOLEIL Upgrade cavity, synchrotron, SRF, operation 2229
 
  • A. Gamelin, W. Foosang, P. Marchand, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
  • N. Yamamoto
    KEK, Ibaraki, Japan
 
  In 4th generation low emittance synchrotron light sources, harmonic cavities are critical components needed to reach the required performance. However, RF systems with harmonic cavities can be limited by their own set of instabilities. An instability dominated by the coupled-bunch mode l=1 can prevent the RF system from reaching the flat potential condition, hence limiting the maximum bunch lengthening. Here we report how this instability impacts the performance of 3rd and 4th harmonic superconducting cavities for the SOLEIL Upgrade.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS003  
About • Received ※ 08 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 26 June 2022  
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WEPOMS004 Investigation of RF Heating for the Multipole Injection Kicker Installed at SOLEIL impedance, injection, kicker, operation 2233
 
  • A. Gamelin, P. Alexandre, R. Ben El Fekih, J. Da Silva Castro, M. El Ajjouri, A. Letresor, L.S. Nadolski, R. Ollier, T.S. Thoraud
    SOLEIL, Gif-sur-Yvette, France
  • M. Sacko, S. Taurines
    Avantis Concept, SAINT-CERE, France
 
  During the commissioning of the new Multipole Injection Kicker (MIK) pulsed magnet at SOLEIL synchrotron, an anomalously high heating of the MIK chamber and flanges was found. To better manage the heat load, fans directed toward the MIK were added to improve the air-cooling flow. This allowed the nominal current to be reached in all operation modes while keeping reasonable temperatures on the MIK. Post-installation investigations subsequently showed that the initial estimate of the maximal heat load was in agreement with the measured temperature in several operation modes both with and without the additional fans. In this article, we present the complete study, starting from the impedance calculation to thermal simulations, and comparison with the measured data with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS004  
About • Received ※ 18 May 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022  
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WEPOMS005 Simulations of the Micro-Bunching Instability for SOLEIL and KARA Using Two Different VFP Solver Codes synchrotron, bunching, radiation, storage-ring 2237
 
  • M. Brosi, A.-S. Müller, P. Schreiber
    KIT, Karlsruhe, Germany
  • S. Bielawski, C. Evain, E. Roussel, C. Szwaj
    PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
 
  Funding: M.B. acknowledges the funding by the Helmholtz Association in the frame of the Helmholtz doctoral prize. The project has been supported by the ANR-DFG ULTRASYNC project. PhLAM acknowledges support from the CPER Photonics for Society, and the CEMPI LABEX.
The longitudinal dynamics of a bunched electron beam is an important aspect in the study of existing and the development of new electron storage rings. The dynamics depend on different beam parameters as well as on the interaction of the beam with its surroundings. A well established method for calculating the resulting dynamics is to numerically solve the Vlasov-Fokker-Planck equation. Depending on the chosen parameters and the considered wakefields and impedances, different effects can be studied. One common application is the investigation of the longitudinal micro-wave and micro-bunching instabilities. The latter occurs for short electron bunches due to self-interaction with their own emitted coherent synchrotron radiation (CSR). In this contribution, two different VFP solvers are used to simulate the longitudinal dynamics with a focus on the micro-bunching instability at the Soleil synchrotron and the KIT storage ring KARA (Karlsruhe Research Accelerator).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS005  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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WEPOMS006 Simulation of the Effect of Corrugated Structures on the Longitudinal Beam Dynamics at KARA impedance, resonance, bunching, radiation 2241
 
  • S. Maier, M. Brosi, A. Mochihashi, A.-S. Müller, M.J. Nasse, P. Schreiber, M. Schwarz
    KIT, Karlsruhe, Germany
 
  Funding: Supported by the DFG project 431704792 in the ANR-DFG collaboration project ULTRASYNC. S. M. acknowledge the support by the Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology" (KSETA).
Two parallel corrugated plates will be installed at the KIT storage ring KARA (KArlsruhe Research Accelerator). This impedance manipulation structure will be used to study and eventually control the beam dynamics and the emitted coherent synchrotron radiation (CSR). In this contribution, we present the results obtained with the Vlasov-Fokker-Planck solver Inovesa showing the impedance impact of different corrugated structures on the bunch and its emitted CSR power.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS006  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 02 July 2022
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WEPOMS009 Simulation Studies of Longitudinal Stability for High-Intensity LHC-Type Beams in the CERN SPS emittance, controls, impedance, injection 2249
 
  • D. Quartullo, L. Intelisano, I. Karpov, G. Papotti
    CERN, Meyrin, Switzerland
 
  Beams in the SPS for the High Luminosity LHC (HL-LHC) must be stabilized in the longitudinal plane up to an intensity of 2.4·1011 protons per bunch. The fourth harmonic RF system increases Landau damping, and controlled longitudinal emittance blow-up is applied to cope with coupled-bunch instabilities along the ramp and at flat-top. Longitudinal multi-bunch beam dynamics simulations of the SPS cycle were performed starting from realistic bunch distributions, as injected from the PS. The full SPS impedance model was included, as well as the effect of low-level RF (LLRF) feedback for beam-loading compensation. A realistic model of the beam-based LLRF loops was used for the particle tracking studies. Controlled longitudinal emittance blow-up was included by generating bandwidth-limited RF phase noise and by injecting it into the beam phase-loop input, exactly as in hardware. Due to the stringent constraints on particle losses and extracted bunch lengths, particular attention was paid to monitoring these parameters in the simulations, and to determining the best configuration for a stable acceleration of the beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS009  
About • Received ※ 30 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 02 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS010 Studies of Transverse Coupled-Bunch Instabilities from Resistive-Wall and Cavity Higher Order Modes for Diamond-II impedance, cavity, HOM, storage-ring 2253
 
  • S.W. Wang, H.C. Chao, R.T. Fielder, I.P.S. Martin, T. Olsson
    DLS, Oxfordshire, United Kingdom
 
  The transverse coupled-bunch instabilities from resistive-wall impedance and main cavity higher order modes (HOMs) are studied for the Diamond-II storage ring. The growth rates of all the coupled-bunch modes are calculated using both the results from tracking simulations and analytic formula, which show a good consistency. The instability threshold from the resistive-wall impedance is estimated and verified by simulation. The impact of the main cavity HOMs is studied in a similar way, and the results show instabilities from HOMs are much smaller than that from resistive-wall impedance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS010  
About • Received ※ 06 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 05 July 2022  
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WEPOMS013 Neural Network Solver for Coherent Synchrotron Radiation Wakefield Calculations in Accelerator-Based Charged Particle Beams radiation, wakefield, synchrotron, synchrotron-radiation 2261
 
  • A.L. Edelen, C. Emma, C.E. Mayes, R.J. Roussel
    SLAC, Menlo Park, California, USA
 
  Particle accelerators support a wide array of scientific, industrial, and medical applications. To meet the needs of these applications, accelerator physicists rely heavily on detailed simulations of the complicated particle beam dynamics through the accelerator. One of the most computationally expensive and difficult-to-model effects is the impact of Coherent Synchrotron Radiation (CSR). CSR is one of the major drivers of growth in the beam emittance, which is a key metric of beam quality that is critical in many applications. The CSR wakefield is very computationally intensive to compute with traditional electromagnetic solvers, and this is a major limitation in accurately simulating accelerators. Here, we demonstrate a new approach for the CSR wakefield computation using a neural network solver structured in a way that is readily generalizable to new setups. We validate its performance by adding it to a standard beam tracking test problem and show a ten-fold speedup along with high accuracy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS013  
About • Received ※ 10 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS021 Entropy Production and Emittance Growth Due to the Imperfection in Long Periodical Acceleration Chains emittance, acceleration, focusing, space-charge 2286
 
  • M. Droba, O. Meusel, H. Podlech, S. Reimann
    IAP, Frankfurt am Main, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
  • S. Reimann
    GSI, Darmstadt, Germany
 
  Contemporary design of efficient linear accelerator is based on ideal periodical structures with an optimi-sation for perfect periodicity. However, practical reali-sation involves random errors in the structure (e.g. position of elements, off-sets, non-linearity of the fields etc.) which make prediction of emittance growth difficult. Error studies helps to understand critical points, but they are normally used at the end of the design process. The concept of beam entropy in very simple approximation (assumption of Ornstein-Uhlenbeck model) is used to evaluate emittance growth in perfect periodical chains. The analysis will be performed and differences in modern designs on some examples discussed. Focus will be laid on linac designs with short acceleration structures (RF-phase settings versus position error) and external transversal focusing magnets.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS021  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 23 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS022 Detailed Analysis of Transverse Emittance of the FLUTE Electron Bunch emittance, laser, electron, quadrupole 2289
 
  • T. Schmelzer, E. Bründermann, A.-S. Müller, M.J. Nasse, R. Ruprecht, J. Schäfer, M. Schuh, N.J. Smale, P. Wesolowski
    KIT, Karlsruhe, Germany
 
  The compact and versatile linear accelerator-based test facility FLUTE (Ferninfrarot Linac- Und Test-Experiment) is operated at KIT. Its primary goal is to serve as a platform for a variety of accelerator R\&D studies like the generation of strong ultra-short terahertz pulses. The amplitude of the generated coherent THz pulses is proportional to the square number of particles in the bunch. With the transverse emittance a measure for the transverse particle density can be determined. It is therefore a vital parameter in the optimization for operation. In a systematic study, the transverse emittance of the electron beam was measured in the FLUTE injector. A detailed analysis considers different influences such as the bunch charge and compares this with particle tracking simulations carried out with ASTRA. In this contribution, the key findings of this analysis are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS022  
About • Received ※ 08 June 2022 — Revised ※ 23 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 28 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS023 Optimization Studies of Simulated THz Radiation at FLUTE electron, radiation, linac, synchrotron 2292
 
  • C. Xu, E. Bründermann, A.-S. Müller, A. Santamaria Garcia, J. Schäfer, M. Schwarz
    KIT, Karlsruhe, Germany
 
  Funding: Supported by the Helmholtz Association (Autonomous Accelerator, ZT-I-PF-5-6) and the DFG-funded Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology".
The linac-based test facility FLUTE (Ferninfrarot Linac Und Test Experiment) at KIT will be used to study novel accelerator technology and provide intense THz pulses. In this paper, we present start-to-end simulation studies of FLUTE with different bunch charges. We employ a parallel Bayesian optimization algorithm for different bunch charges of FLUTE to find optimized accelerator settings for the generation of intense THz radiation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS023  
About • Received ※ 20 May 2022 — Accepted ※ 21 June 2022 — Issue date ※ 10 July 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS032 Simulations of Coherent Electron Cooling with Orbit Deviation electron, plasma, kicker, hadron 2319
 
  • J. Ma, V. Litvinenko, G. Wang
    BNL, Upton, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Coherent electron cooling (CeC) is a novel technique for rapidly cooling high-energy, high-intensity hadron beam. Plasma cascade amplifier (PCA) has been proposed for the CeC experiment in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Cooling performance of PCA based CeC has been predicted in 3D start-to-end CeC simulations using code SPACE. The dependence of the PCA gain and the cooling rate on the electron beam’s orbit deviation has been explored in the simulation studies.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS032  
About • Received ※ 16 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS033 CETA-A Code Package Being Developed for Collective Effect Analysis and Simulation in Electron Storage Rings cavity, impedance, storage-ring, collective-effects 2323
 
  • C. Li, Y.-C. Chae
    DESY, Hamburg, Germany
 
  The code Collective Effect Tool Analysis (CETA) is under development to study the collective effects in the electron storage ring. With the impedance either generated by itself or imported from an external file, CETA can calculate the loss and kick factors, the longitudinal equilibrium bunch length from a Haissinski solver, and the head-tail mode frequency shift from a Vlasov solver. Meanwhile, the code CETASim, which can track particles to study coupled-bunch instabilities caused by long-range wakefield, ion effects, transient beam loading effect, bunch-by-bunch feedback, etc., is also under development. In this paper, we describe the code status and give several simulation results from CETA and CETASim to show how these codes work.
This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 871072
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS033  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 05 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS036 Accelerating Linear Beam Dynamics Simulations for Machine Learning Applications space-charge, controls, GPU, experiment 2330
 
  • O. Stein, I.V. Agapov, A. Eichler, J. Kaiser
    DESY, Hamburg, Germany
 
  Machine learning has proven to be a powerful tool with many applications in the field of accelerator physics. Training machine learning models is a highly iterative process that requires large numbers of samples. However, beam time is often limited and many of the available simulation frameworks are not optimized for fast computation. As a result, training complex models can be infeasible. In this contribution, we introduce Cheetah, a linear beam dynamics framework optimized for fast computations. We show that Cheetah outperforms existing simulation codes in terms of speed and furthermore demonstrate the application of Cheetah to a reinforcement-learning problem as well as the successful transfer of the Cheetah-trained model to the real world. We anticipate that Cheetah will allow for faster development of more capable machine learning solutions in the field, one day enabling the development of autonomous accelerators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS036  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS037 Microbunching Studies for the FLASH2020+ Upgrade Using a Semi-Lagrangian Vlasov Solver bunching, laser, FEL, electron 2334
 
  • Ph. Amstutz, M. Vogt
    DESY, Hamburg, Germany
 
  Precise understanding of the microbunching instability is mandatory for the successful implementation of a compression strategy for advanced FEL operation modes such as the EEHG seeding scheme, which a key ingredient of the FLASH2020+ upgrade project. Simulating these effects using particle-tracking codes can be quite computationally intensive as an increasingly large number of particles is needed to adequately capture the dynamics occurring at small length scales and reduce artifacts from numerical shot-noise. For design studies as well as dedicated analysis of the microbunching instability semi-Lagrangian codes can have desirable advantages over particle-tracking codes, in particular due to their inherently reduced noise levels. However, rectangular high-resolution grids easily become computationally expensive. To this end we developed SelaV1D, a one dimensional semi-Lagrangian Vlasov solver, which employs tree-based domain decomposition to allow for the simulation of entire exotic phase-space densities as they occur at FELs. In this contribution we present results of microbunching studies conducted for the FLASH2020+ upgrade using SelaV1D.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS037  
About • Received ※ 06 June 2022 — Revised ※ 29 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 09 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS039 Analysis of Xcos Simulation Model for Intensity at Third and Fifth Harmonics Undulator Radiation undulator, radiation, electron, FEL 2338
 
  • H. Jeevakhan
    NITTTR, Bhopal, India
  • K. Kushwaha, M. Syed
    RGPV, Bhopal, India
  • G. Mishra
    Devi Ahilya University, Indore, India
 
  Xcos simulation model is analysed for the intensity of planar undulator radiation at the third and fifth harmonics. The Xcos model is designed by using the numerical approach. The results obtained from the simulation model are compared with the analytical method. The model can also be utilized for observing the effect of energy spread on radiation by numerical approach. An algorithm for analysing the effect of energy spread is also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS039  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 19 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS043 UFO, a GPU Code Tailored Toward MBA Lattice Optimization GPU, lattice, electron, optics 2346
 
  • M. Carlà, M. Canals
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  The complexity of multi-bend achromatic optics is such that computational tools performance has become a dominant factor in the design process a last generation synchrotron light source. To relieve the problem a new code (UFO) tailored toward performance was developed to assist the design of the ALBA-II optics. Two main strategies contribute to the performance of UFO: the execution flow follows a data parallel paradigm, well suited for GPU execution; the use of a just-in-time compiler allows to simplify the computation whenever the lattice allows for it. At the core of UFO lies a parallel tracking routine structured for parallel simulation of optics which differs in some parameters, such as magnet strength or alignment, but retains the same element order, reflecting the scenario found in optimization processes, or when dealing with magnetic or alignment errors. Such an approach allows to take advantage of GPUs which yield the best performance when running thousands of parallel threads. Moreover UFO is not limited to tracking. A few modules that rely on the same tracking routine allow for the fast computation of dynamic and momentum aperture, closed orbit and linear optics.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS043  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 21 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS046 Machine Learning-Based Modeling of Muon Beam Ionization Cooling emittance, target, lattice, collider 2354
 
  • E. Fol, D. Schulte
    CERN, Meyrin, Switzerland
  • C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  Surrogate modeling can lead to significant improvements of beam dynamics simulations in terms of computational time and resources. Application of supervised machine learning, using collected simulation data allows to build surrogate models which can estimate beam parameters evolution based on the provided cooling channel design. The created models help to understand the correlations between different lattice components and the importance of specific beam properties for the cooling performance. We present the application of surrogate modeling to enhance final muon cooling design studies, demonstrating the potential of such approach to be integrated into the design and optimization of other components of future colliders.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS046  
About • Received ※ 07 June 2022 — Revised ※ 28 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 05 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS047 Automated Design and Optimization of the Final Cooling for a Muon Collider emittance, collider, solenoid, optics 2358
 
  • E. Fol, D. Schulte, B. Stechauner
    CERN, Meyrin, Switzerland
  • C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Schieck
    HEPHY, Wien, Austria
 
  The desired beam emittance for a Muon collider is several orders of magnitude less than the one of the muon beams produced at the front-end target. Ionization cooling has been demonstrated as a suitable technique for the reduction of the muon beam emittance. Final cooling, as one of the most critical stages of the muon collider complex, necessitates careful design and optimization in order to control the beam dynamics and ensure efficient emittance reduction. We present an optimization framework based on ICool simulation code and application of different optimization algorithms, to automatize the choice of optimal initial muon beam parameters and simultaneous tuning of numerous final cooling components.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS047  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS048 A Flexible Online Optimizer for SPS injection, booster, emittance, storage-ring 2362
 
  • T. Pulampong, N. Suradet
    SLRI, Nakhon Ratchasima, Thailand
 
  Siam Photon Source (SPS) machine in Thailand has been operating for more than two decades with limited diagnostic systems. It is very challenging to efficiently tune and operate the machine. With online optimization, only variables and objectives are required to tune for better solutions. It this work, a flexible optimizer was developed. Objectives and variables can be freely defined based on available hardware in the form of Process Variables (PVs). Several multi-objective and Robust Conjugated Direction Search (RCDS) algorithms are provided. The online optimizer was tested on the SPS machine to improved the injection efficiency. Due to its flexibility, the optimizer can also be used for other systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS048  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 19 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS049 ESS RFQ Electromagnetic Simulations Using CST Studio Suite rfq, cavity, radio-frequency-quadrupole, radio-frequency 2365
 
  • E. Trachanas, A. Bignami, N. Gazis, B. Jones, R. Zeng
    ESS, Lund, Sweden
  • G. Fikioris, E.N. Gazis, A. Kladas
    National Technical University of Athens, Zografou, Greece
  • P. Hamel, O. Piquet
    CEA-IRFU, Gif-sur-Yvette, France
 
  The Radio Frequency Quadrupole (RFQ) of the European Spallation Source (ESS), operates at 352.21 MHz with an RF pulse length of 3.2 ms and repetition rate of 14 Hz. The RFQ focuses, bunches and accelerates the 62.5 mA proton beam from 75 keV up to 3.6 MeV. In an effort to study and compare the results from 3D electromagnetic codes, different models of the RFQ were simulated with CST Studio suite. This paper presents the selection of optimal parameters for simulation of the RFQ cavity voltage and comparison of the results with the RFQ design code Toutatis.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS049  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS053 Using Taylor Maps with Synchrotron Radiation Effects Included radiation, ion-effects, synchrotron, factory 2376
 
  • D. Sagan, G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • P. Nishikawa
    KEK, Ibaraki, Japan
 
  Funding: DOE
Routinely, particle tracking in accelerators is done either by tracking element-by-element which is slow, or by using a transfer map that does not take into account radiation effects. However, there is a fairly straight forward way for constructing Taylor maps that do have radiation effects included. This paper shows how, by partial map inversion, non-symplectic effects due to the finite truncation of the Taylor series can be eliminated. This enables tracking simulations to use maps of lower order than what would otherwise be necessary leading to a speedup of the simulation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS053  
About • Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 08 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOMS055 Cathode Space Charge in Bmad space-charge, cathode, controls, gun 2380
 
  • N. Wang
    Cornell University, Ithaca, New York, USA
  • J.A. Crittenden, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • C.E. Mayes
    SLAC, Menlo Park, California, USA
 
  Funding: This project was supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
We present an implementation of charged particle tracking with the cathode space charge effect included which is now openly available in the Bmad toolkit for charged particle simulations. Adaptive step size control is incorporated to improve the computational efficiency. We demonstrate its capability with a simulation of a DC gun and compare it with the well-established space charge code Impact-T.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS055  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 05 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOXGD2 Electron Cooling Experiment for Proton Beams with Intense Space-Charge in IOTA electron, space-charge, proton, emittance 2395
 
  • N. Banerjee, J.A. Brandt
    Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
  • M.K. Bossard, Y.K. Kim
    University of Chicago, Chicago, Illinois, USA
  • B.L. Cathey, S. Nagaitsev, G. Stancari
    Fermilab, Batavia, Illinois, USA
 
  Funding: Fermi Research Alliance, LLC under Contract No.~DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics and also the University of Chicago.
Electron cooling as a method of creating intense ion beams has a practical upper limit when it comes to the peak phase space density of ion beams which can be achieved in practice. We describe a new experiment to study electron cooling of 2.5 MeV protons at the intensity limit using the Integrable Optics Test Accelerator (IOTA), which is a storage ring dedicated to beam physics research at Fermilab. This system will enable the study of magnetized electron cooling of a proton beam with transverse incoherent tune shifts approaching -0.5 due to the presence of intense space-charge forces. We present an overview of the hardware design, simulations and specific experiments planned for this project.
 
slides icon Slides THOXGD2 [2.775 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOXGD2  
About • Received ※ 13 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOXSP3 Path to High Repetition Rate Seeding: Combining High Gain Harmonic Generation with an Optical Klystron FEL, electron, laser, klystron 2411
 
  • G. Paraskaki, E. Ferrari, L. Schaper, E. Schneidmiller
    DESY, Hamburg, Germany
  • E. Allaria
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  External seeding in combination with harmonic generation has become a hot topic in the field of high gain free-electron lasers (FELs) since it allows delivery of superior FEL radiation characterized by, for example, full coherence and unprecedented shot-to-shot stability. At low repetition rate machines operating at few 10 Hz, novel experiments have been realized already, however, at superconducting machines, current laser technology does not support exploiting the full repetition rate available. One way to overcome this problem is to reduce the requirements in seed laser power: here, an optical klystron based high gain harmonic generation (HGHG) setup is proposed to reduce the laser peak power requirements by orders of magnitude, enabling operation at drastically increased repetition rates. We report simulation results based on the seeded beamline concept of the FLASH2020+ project. Among other topics, the effect of a linear electron beam energy chirp on this setup will be discussed.  
slides icon Slides THOXSP3 [1.502 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOXSP3  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOYSP1 Construction and Measurement of a Tuneable Permanent Magnet Quadrupole for Diamond Light Source permanent-magnet, quadrupole, radiation, HOM 2424
 
  • A.R. Bainbridge, B.J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.G. Hinton, N. Krumpa
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • I.P.S. Martin, W. Tizzano
    DLS, Oxfordshire, United Kingdom
 
  Permanent magnets (PMs) are becoming an attractive proposition as a green and efficient replacement for electromagnets in particle accelerators. The Zero-Power Tuneable Optics (ZEPTO) collaboration between STFC and CERN has demonstrated that traditional limitations of PM technology, such as the ability to change the flux density in the magnet aperture, can be overcome. Moving PM blocks relative to fixed steel structures that define the field, the strength may be changed while suitable field homogeneity is maintained. A new ZEPTO variant has been developed in conjunction with Diamond Light Source (DLS) to demonstrate the technology on a real accelerator. This magnet features a number of crucial design innovations over previous generations of ZEPTO magnets that improve the convenience and versatility of PM systems and demonstrate that they can be deployed in many situations. We present the construction and measurement results of this new magnet and outline the planned data collection whilst installed on DLS. We analyse its performance relative to design and discuss the new features with focus on the real-world implications of PM technology for current and future accelerators.  
slides icon Slides THOYSP1 [3.675 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOYSP1  
About • Received ※ 30 May 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOST006 Simulations of the Suitability of a DC Electron Photogun and S-Band Accelerating Structure as Input to an X-Band Linac gun, emittance, electron, acceleration 2445
 
  • S.D. Williams, R.P. Rassool, S.L. Sheehy, G. Taylor, M. Volpi
    The University of Melbourne, Melbourne, Victoria, Australia
  • R. Auchettl, R.T. Dowd
    AS - ANSTO, Clayton, Australia
 
  Work has been underway for some time to design a compact electron beamline utilising X-band linear accelerating structures in the new Melbourne X-band Laboratory for Accelerators and Beams (X-LAB). The original design utilised an S-band RF photogun as an input to a pair of high gradient X-band linear accelerating structures, but we have been motivated to investigate an alternative starting section to allow for initial testing. This will utilise a DC photogun and S-band accelerating structure similar to those used at the Australian Synchrotron. Simulation results incorporating space charge of a beamline composed of a DC photogun, S-band accelerating structures, and two high gradient X-band structures will be presented. These simulation results will be optimised for minimum emittance at the end of the beamline.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST006  
About • Received ※ 20 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOST009 Simulation Study of a Bunch Compressor for an Accelerator-Based THz Source at the European XFEL FEL, electron, undulator, radiation 2454
 
  • P. Boonpornprasert, G.Z. Georgiev, M. Krasilnikov, X.-K. Li, A. Lueangaramwong
    DESY Zeuthen, Zeuthen, Germany
 
  The European XFEL has planned to perform pump-probe experiments using its X-ray pulses and THz pulses. A promising concept to provide the THz pulses with a pulse repetition rate identical to that of the X-ray pulses is to generate them using an accelerator-based THz source. The THz source requires a bunch compressor in order to manipulate the longitudinal phase space of the electron bunch to match with various options of THz radiation generation. This paper presents and discusses simulation study of the bunch compressor for the THz source.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST009  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
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THPOST016 Development Progress of HEPS LINAC linac, MMI, emittance, LLRF 2472
 
  • C. Meng, N. Gan, D.Y. He, X. He, Y. Jiao, J.Y. Li, J.D. Liu, Y.M. Peng, H. Shi, G. Shu, S.C. Wang, O. Xiao, J.R. Zhang, Z.D. Zhang, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
  • X.H. Lu, X.J. Nie
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  The High Energy Photon Source (HEPS) is a synchrotron radiation source of ultrahigh brightness and under construction in China. Its accelerator system is comprised of a 6-GeV storage ring, a full energy booster, a 500-MeV Linac and three transfer lines. The Linac is a S-band normal conducting electron linear accelerator with available bunch charge up to 10 nC. The Linac installation has been finished at the end of May this year. The system joint debugging and device conditioning of the accelerating units, the power supplies, et al., are in progress. The beam commissioning will start in September 2022. This paper presents the status of the HEPS Linac and detailed introduction of the beam commissioning simulations and preparations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST016  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
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THPOST017 Physical Design of a 10 MeV High Scanning Frequency Irradiation Electron Linear Accelerator electron, radiation, gun, kicker 2476
 
  • S. Zhang, Z.D. Zhang
    UCAS, Beijing, People’s Republic of China
  • Y.L. Chi, M. Iqbal, J.R. Zhang, S. Zhang, Z.D. Zhang, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
 
  A compact 10 MeV irradiation S-band electron linear accelerator has been proposed to carry out the electron radiation effect test of materials and devices. The Linac includes a standing wave pre-buncher, a traveling wave bunching accelerating structure. The traveling wave accelerating structure uses a 5MW klystron as RF source and provides electron beam energy 3.5-10MeV and average current 0.01-1mA. The required irradiation scanning frequency is very high, up to 100Hz and irradiation area is large (200mm×200mm). To meet the requirements, a novel beam scanning system, including one kicker for horizontal scanning and one magnet for vertical scanning, have been proposed. This paper presents the physical design of the 10MeV electron Linac and beam dynamics simulation results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST017  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 14 June 2022
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THPOST021 Beam Dynamics Simulations of Linear Accelerator for Natural Rubber Vulcanization at Chiang Mai University electron, linac, gun, cathode 2491
 
  • J. Saisut, S. Rimjaem, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The Linear accelerator system for natural rubber vulcanization has been developed at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The main components of the accelerator system consist of a DC electron gun with a thermionic cathode, an RF linear accelerator, an RF system, a control system, and an irradiation system. The electron beam properties for natural rubber vulcanization are predicted from the beam dynamics simulation starting from a cathode to the titanium exit window. The electron beam generation and the particle in cell simulation inside the DC electron gun are performed using CST Studio Suit software. The electron distribution at the gun exit from the CST output is covered to be an input distribution of the ASTRA beam dynamics simulation program. The electron beam enters linac and is accelerated by RF filed inside the linac. The ASTRA simulation code is used to track electron trajectories including the space-charge interaction and the simulation starts from linac entrance to the exit windows. The electron beam properties for various conditions are evaluated and will be used for further simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST021  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 03 July 2022
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THPOST026 Design of the Magnetic Shield for VSR DEMO cavity, shielding, SRF, GUI 2501
 
  • H.-W. Glock, P. Anumula, F. Glöckner, J. Knobloch, F. Pflocksch, A. Vélez
    HZB, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
  • A. Vélez
    Technical University Dortmund, Dortmund, Germany
 
  Funding: Work supported by grants of the Helmholtz Association
The VSR DEMO module, recently under development at HZB, will house two 4-cell 1.5 GHz superconducting RF cavities with a particularly powerful HOM damping scheme based on five waveguide HOM absorbers per cavity. A magnetic shield made of high-permeable material is needed around the cavities in order to prevent the ambient magnetic field exceeding very few µT thereby causing considerable unwanted RF losses. The shield needs to accommodate the waveguides, the fundamental power coupler, two beam pipes, two He feed / return lines, the tuner and the support structures, whilst being manufacturable and mountable. The paper discusses those difficulties and presents the matured magnetic shield design. Numerical simulations are used to evaluate the efficacy of the shield.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST026  
About • Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 22 June 2022
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THPOST034 Development of Magnetic Harmonics Measurement System for Small Aperture Magnets quadrupole, permanent-magnet, multipole, data-analysis 2517
 
  • J.M. Hwang, J. Bahng
    Korea University Sejong Campus, Sejong, Republic of Korea
  • E.-S. Kim
    KUS, Sejong, Republic of Korea
 
  Storage ring has been improved to achieve high brightness of x-ray light source by making beam size and beam emittance smaller and enlarging the beam intensity. To achieve requirements such as a small beam emittance, the magnets need to have a larger magnetic field gradient and complex function with small aperture size. Since the complex structure and small beam size accompany with large errors in beam dynamics by high order field distortion of the magnets, it is important to measure the harmonics of the magnet in order to measure and improve it. Traditional field measurement methods such as hall probe and rotating loop have difficulty in measuring the harmonics of a magnet with a small aperture due to restrictions that physical size of the hall sensor and loop-card respectively. We developed Single Stretched Wire (SSW) method for the magnetic field measurement method on a small aperture magnet, in particular harmonics of the magnet. The system consists of a thin wire, accurate actuator system, and voltmeter. We describe the development of the SSW system and the result of the performance test by using our system in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST034  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 02 July 2022
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THPOPT001 Online Optimization of the ESRF-EBS Storage Ring Lifetime sextupole, octupole, SRF, lattice 2552
 
  • N. Carmignani, L.R. Carver, L. Hoummi, S.M. Liuzzo, T.P. Perron, P. Raimondi, S.M. White
    ESRF, Grenoble, France
 
  In the first year of operation of the EBS storage ring, online nonlinear dynamics optimisations were performed to increase the Touschek lifetime. Several sextupole, octupole and skew quadrupole knobs have been studied in simulations and tested in the machine. A fast optimisation procedure has been defined and it is followed at each machine restart. The knobs and the optimisation procedure are described in the paper. As a result, up to 41 h Touschek lifetime in nominal multi-bunch mode have been achieved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT001  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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THPOPT002 Beam Power Deposition on the Cryogenic Permanent Magnet Undulator SRF, cryogenics, undulator, impedance 2556
 
  • L.R. Carver, C. Benabderrahmane, P. Brumund, N. Carmignani, J. Chavanne, G. Le Bec, R. Versteegen, S.M. White
    ESRF, Grenoble, France
 
  X-rays with high brilliance and low phase errors are generated in the Cryogenic Permanent Magnet Undulator (CPMU) currently in use at the ESRF. In the event of a failure of the cryogenic cooling the beam will continue to deposit power into the module, even when the undulator jaws are fully opened. This could lead to unacceptably high heating of the magnet blocks which could cause their demagnetisation. Impedance simulations were performed using IW2D and CST to compute the power deposited by the beam in both the closed and open jaw settings. This was followed by thermal simulations to compute the expected temperature rise. These results will help advise the operational procedure in the event of a cooling failure.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT002  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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THPOPT004 Design of a Compact 180-Degree Single-Shot Energy Spectrometer Based on a Halbach Dipole Magnet electron, dipole, vacuum, detector 2564
 
  • R. Bazrafshan, T. Rohwer
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • M. Fakhari, N.H. Matlis
    CFEL, Hamburg, Germany
  • F.X. Kaernter
    DESY, Hamburg, Germany
 
  In the AXSIS project at DESY, we develop compact THz accelerating structures for a table-top x-ray source. Acceleration is achieved by passing the electron beam through a dielectric-loaded waveguide powered by multi-cycle THz radiation. The final electron energy strongly depends on THz-power injected into the LINAC and timing. Thus in first experiments we expect large energy fluctuations and a large range of energies to cover. We designed an electron energy spectrometer for a wide range of final energies covering 5 to 20 MeV in a single-shot. Here, we present the design of an energy spectrometer which uses a compact dipole magnet based on the Halbach array concept to deflect the electron beam through a 180° path intercepted by a Fiber Optic Scintillator (FOS) mounted inside the vacuum perpendicular to the beam. The 180-degree bending geometry provides the possibility of having the focus point of all energies at the same distance from the magnet edge which makes the design simpler and more compact. It also removes the necessity of installing a safety dipole at the end of the accelerator. A slit system at the spectrometer entrance increases resolution to better than 0.2%.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT004  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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THPOPT007 High Bunch Charges in the Second Injection Beamline of MESA electron, dipole, operation, acceleration 2574
 
  • A.A. Kalamaiko, K. Aulenbacher, M.A. Dehn, S. Friederich, C.P. Stoll
    KPH, Mainz, Germany
 
  MESA (Mainz Energy-recovering Superconducting Accelerator) is an accelerator with two laser-driven electron sources (polarized and unpolarized) operating at 100 kV which is under construction at the Johannes Gutenberg University in Mainz. The unpolarized electron source MIST (MESA Injector Source Two) allows to produce high charged electron bunches with charge up to 7.7 pC. This source and a Mott polarimeter will be arranged on the same height above the MESA injector main beamline. A parallel shifting beamline was developed which allows to transport high charged beam from the source MIST to the main MESA beamline. Moreover, the designed beamline allows to transport beam from the electron source STEAM to the Mott polarimeter. This report is dedicated to the design of the separation beamline which transports and compresses highly charged electron bunches from the electron source MIST to the first acceleration section of MESA.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT007  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 23 June 2022
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THPOPT014 Simulation and Optimization of SPS-II Linac linac, synchrotron, emittance, storage-ring 2590
 
  • T. Chanwattana, S. Chunjarean, N. Juntong, S. Klinkhieo, P. Sudmuang
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
 
  Siam Photon Source II (SPS-II), the new 3-GeV synchrotron light source project in Thailand, has been designed based on an accelerator system consisting of a 150-MeV injector linac, a full-energy booster synchrotron and a storage ring based on a Double Triple Bend Achromat (DTBA) lattice. A turn-key linac system has been used in an injection system of many synchrotron facilities, and thus it is considered for the SPS-II project. Preliminary beam dynamics simulation and optimization of the SPS-II linac are necessary for investigating achievable beam parameters which can be used for study of beam injection through a transfer line to the booster. Multi-objective optimization algorithm (MOGA) has been used in design and optimization of many accelerators including a linac system for synchrotron light sources, similar to the SPS-II linac. In this paper, results of beam dynamics simulation and MOGA optimization of the SPS-II linac are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT014  
About • Received ※ 19 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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THPOPT024 MIST - The MESA-Injector Source Two cathode, electron, booster, laser 2624
 
  • M.A. Dehn, P.S. Plattner
    IKP, Mainz, Germany
  • K. Aulenbacher
    HIM, Mainz, Germany
  • K. Aulenbacher
    GSI, Darmstadt, Germany
  • K. Aulenbacher
    KPH, Mainz, Germany
 
  Funding: Work supported by the German science ministry BMBF through Verbundforschung
The new accelerator MESA (Mainz Energy Recovering Superconducting Accelerator) will provide an average CW electron beam current of up to 10 mA. Operating at 1.3 GHz, this corresponds to a bunch charge of 7.7 pC. The new DC photoemission source MIST is optimized for these requirements. A challenge is heating of the photocathode at high laser power. By a suitable mechanical construction and the use of specific materials, the heat can be dissipated during operation. Options for further improvements are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT024  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT040 Injection Using a Non-Linear Kicker at the ESRF injection, kicker, SRF, emittance 2679
 
  • S.M. White, T.P. Perron
    ESRF, Grenoble, France
 
  The ESRF injection consists in a standard four kickers bump off-axis injection. Although this scheme is very robust and reliable it is known to disturb users during injections and may represent a severe limitation in case frequent injections are required. The non-linear kicker injection scheme provides a possible solution to this problem by acting only on the injected beam. This paper reports on the potential integration of a non-linear kicker injection scheme at the ESRF. A layout and specifications for the kicker are proposed and simulations are provided to evaluate the performance and limitations of such scheme.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT040  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT045 OPAL Simulations of the MESA Injection System solenoid, electron, quadrupole, experiment 2697
 
  • S. Friederich
    IKP, Mainz, Germany
  • K. Aulenbacher
    HIM, Mainz, Germany
  • K. Aulenbacher
    GSI, Darmstadt, Germany
  • K. Aulenbacher, C.P. Stoll
    KPH, Mainz, Germany
 
  Funding: This work is supported by the DFG excellence initiative PRISMA+.
The MESA injection system will produce the spin-polarized electron beam for the upcoming accelerator MESA in Germany. The photoemission electron source (STEAM) will deliver 150 uA of spin-polarized electrons from GaAs-based photocathodes for the P2 experiment. Afterwards the low-energy beam transportation system (MELBA) can rotate the spin using two Wien filters and a solenoid for polarization measurements and to compensate for the spin precession in MESA. A chopper and buncher system prepares the phase space for the first acceleration in the normal-conducting pre-booster MAMBO. First OPAL simulation results of MELBA were presented at IPAC’21. Meanwhile these simulations have been extended by a 270-degree-bending alpha magnet as well as the electrostatic and magnetostatic fieldmaps of the Wien filters. Furthermore the fieldmaps of the 4 modules of the pre-accelerator MAMBO have been implemented. Hence, the complete MESA injection system could be simulated in OPAL and the results will be shown.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT045  
About • Received ※ 30 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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THPOPT053 Goubau-Line Set Up for Bench Testing Impedance of IVU32 Components impedance, undulator, cavity, vacuum 2719
 
  • P.I. Volz, A. Meseck
    HZB, Berlin, Germany
  • A. Meseck
    KPH, Mainz, Germany
 
  The worldwide first in-vacuum elliptical undulator, IVUE32, is being developed at Helmholtz-Zentrum Berlin. The 2.5 m long device with a period length of 3.2 cm and a minimum gap of about 7 mm is to be installed in the BESSY II storage ring. It will deliver radiation in the soft X-ray range to several beamlines. The proximity of the undulator structure to the electron beam makes the device susceptible to wakefield effects which can influence beam stability. A complete understanding of its impedance characteristics is required prior to installation and operation, as unforeseen heating of components could have catastrophic consequences. To understand and measure the IVU’s impedance characteristics a Goubau-Line test stand is being designed. A Goubau-line is a single wire transmission line for high frequency surface waves with a transverse electric field resembling that of a charged particle beam out to a certain radial distance. A concept optimized for bench testing IVUE32-components will be discussed, microwave simulations will be presented together with first measurements from a test stand prototype.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT053  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOPT060 Tolerance Study on the Geometrical Errors for a Planar Superconducting Undulator undulator, FEL, MMI, FEM 2734
 
  • V. Grattoni, S. Casalbuoni, B. Marchetti
    EuXFEL, Schenefeld, Germany
 
  At the European XFEL, a superconducting afterburner is considered for the SASE2 hard X-ray beamline. It will consist of six undulator modules. Within each module, two superconducting undulators (SCU) 2 m long are present. Such an afterburner will enable photon energies above 30 keV. A high field quality of the SCU is crucial to guarantee the quality of the electron beam trajectory, which is directly related to the spectral quality of the emitted free-electron laser (FEL) radiation. Therefore, the effects of the SCU’s mechanical imperfections on the resultant magnetic field have to be carefully characterized. In this contribution, we present possible mechanical errors affecting the undulator structure, and we perform an analytical study aimed at determining the tolerances on these errors for our SCUs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT060  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 27 June 2022
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THPOPT063 Design of Scilab Xcos Simulation Model for Pulsed Wire Method Data Analyses undulator, electron, experiment, radiation 2741
 
  • H. Jeevakhan
    NITTTR, Bhopal, India
  • S.M. Khan, G. Mishra
    Devi Ahilya University, Indore, India
 
  Pulsed wire method (PWM)is used for undulator characterisation. Scilab Xcos simulation model is designed for the analyses of data obtained by PWM. The data obtained from PWM is given as input to the model and its output gives the magnetic field of the undulator. Scilab Xcos model can also be utilized for determining the phase error of the undulator.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT063  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 09 July 2022
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THPOPT066 Helical Wiggler Design for Optical Stochastic Cooling at CESR wiggler, electron, storage-ring, permanent-magnet 2751
 
  • V. Khachatryan, M.B. Andorf, I.V. Bazarov, J.A. Crittenden, S.J. Levenson, J.M. Maxson, D.L. Rubin, J.P. Shanks, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • W.F. Bergan
    BNL, Upton, New York, USA
 
  Funding: The authors thank the Center for Bright Beams, NSF award PHY-1549132; W.F.B. was supported by the NSF Graduate Research Fellowship Program under grant number DGE-1650441.
A helical wiggler with parameter kund=4.35 has been designed for the Optical Stochastic Cooling (OSC) experiment in the Cornell Electron Storage Ring (CESR). We consider four Halbach arrays, which dimensions are optimized to get the required helical field profile, as well as, to get the best Dynamic Aperture (DA) in simulations. The end poles are designed with different dimensions to minimize the first and second field integrals to avoid the need of additional correctors for the beam orbit. The design is adopted to minimize the risks for the magnet blocks demagnetization. To quantify the tolerances, we simulated the effects of different types of geometrical and magnetic field errors on the OSC damping rates. In addition, to understand the challenges for the construction, as well as, to validate the model field calculations, we prototyped a small two period version. The prototype field is compared to the model, and the results are presented in this work.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT066  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 14 June 2022
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THPOTK003 Optimization of Mass Resolution Parameters Combined with Ion Cooler Performance rfq, emittance, ion-source, experiment 2770
 
  • M. Cavenago, C. Baltador, L. Bellan, M. Comunian, E. Fagotti, A. Galatà, M. Maggiore, A. Pisent, C.R. Roncolato, M. Rossignoli, A. Ruzzon
    INFN/LNL, Legnaro (PD), Italy
  • G. Maero, M. Romé
    Universita’ degli Studi di Milano e INFN, Milano, Italy
  • V. Variale
    INFN-Bari, Bari, Italy
 
  High mass resolution spectrometers (HRMS) for separation of exotic ion species in nuclear physics experiment request a low emittance and small energy spread (with D E the peak-to-peak value, and sE the rms value) of the input beam, so that ion cooler devices, as a Radio Frequency Quadrupole Coolers (RFQC), are typically envisioned. The SPES (Selective Production of Exotic Species) project at LNL requests M/(D M) about 20000, rms normalized emittance in the order of 2 nm, and for 160 keV ions, spread sE about 1 eV. Typical limits of RFQC[*] and HRMS[**] performances are discussed, and relevant formulas are implemented in easy reference tools. The necessary collisional data are reviewed, in particular for Cs+ against He gas, whose pressure ranges from 2 to 9 Pa; status of Milan test bench is briefly updated. Practical consideration on gas pumping, voltage stability and magnet design are also included.
[*] Cavenago et al. Optimization of ion transport in a combined RFQ Cooler …, in ICIS 2021 (in press)
[**] M. Comunian et al. p. 3252 in proceedings IPAC2018 doi:10.18429/JACoW-IPAC2018-THPAK021
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK003  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK010 Development of a Short Period Superconducting Helical Undulator undulator, electron, FEL, photon 2788
 
  • A.G. Hinton
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • J. Boehm, L. Cooper, B. Green, T. Hayler, P. Jeffery, C.P. Macwaters, B.J.S. Matthews
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • S. Milward
    DLS, Oxfordshire, United Kingdom
  • B.J.A. Shepherd, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Superconducting technology provides the possibility to develop short period, small bore undulators that can generate much larger magnetic fields than alternative technologies. This may allow an XFEL with optimised superconducting undulators to cover a broader range of wavelengths than traditional undulators. At STFC, we have undertaken work to design and build a prototype superconducting helical undulator module with parameters suitable for use on a future XFEL facility. This work includes the design of an undulator with 13 mm period and 5 mm magnetic gap, as well as the supporting cryogenic and vacuum systems required for operation. We present here the updated design of the superconducting helical undulator that represents the results of prototyping work. Improved methods for manufacturing the undulator former and winding the superconducting wire have been developed. The measured mechanical tolerances and the impact on the field quality will be presented. The fields produced by prototype undulators will soon be measured using a Hall probe system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK010  
About • Received ※ 06 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022  
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THPOTK014 100 keV Electron Source Design for the New 3 GeV Synchrotron Facility in Thailand gun, cathode, electron, focusing 2800
 
  • N. Juntong, S. Bootiew, T. Chanwattana, Ch. Dhammatong, S. Jummunt, K. Kittimanapun, W. Phacheerak
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
 
  The Synchrotron Light Research Institute (SLRI) is developing a new synchrotron light source with an electron beam energy of 3 GeV. The DC thermionic electron gun was chosen because it is simple and less cost. The design process is well known. The operation is more stable compared to the RF gun. The cathode Y-646B was considered because it had already been used at the old synchrotron machine and the possibility of sharing the stock outweighs other disadvantages. Moreover, it is used in many synchrotron facilities, so it is easy to find references. The present of the focusing electrode was discussed. The focusing electrode will increase the complexity of the gun, but it is necessary to get a high-quality beam from the gun. The designed electron gun can produce 1.1 A beams current with the normalized emittance of 0.910 Pi·mm·mrad, which satisfied the requirement of the linac injector. The design and study results will be discussed in this report.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK014  
About • Received ※ 20 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 29 June 2022  
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THPOTK015 Solid-State Pulsed Power Supply for a 100 keV Electron Source of the New Synchrotron Facility in Thailand electron, gun, high-voltage, power-supply 2803
 
  • W. Phacheerak, S. Bootiew, T. Chanwattana, Ch. Dhammatong, N. Juntong, K. Kittimanapun
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
 
  The new synchrotron light source project in Thailand will utilize a thermionic DC electron gun. The maximum operation of the gun is 100 keV, which requires a pulsed power supply of 100kV. The present synchrotron machine uses a conventional design of the gun power supply. To improve the high voltage pulsed quality, the solid-state design of the gun power supply is utilized. The output pulse width can be adjusted easily and the droop is less compared to the conventional design. The designed output of 100 kV amplitude with 5 µs pulsed width can be achieved with this design. It also produces a less droop of 1.8%. The design process and results will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK015  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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THPOTK032 A Vacuum System for the Milliampere Booster cavity, vacuum, linac, experiment 2833
 
  • R.G. Heine, C.L. Lorey
    KPH, Mainz, Germany
 
  The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently designed and built at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO relies on normal conducting technolgy. The MAMBO RF cavities are bi-periodic pi/2 structures that are about 2m long, each. In this paper we present the results of Molflow+ simulations of several setups of the vacuum system for MAMBO that differ in number of pumps, pumping speed and diameter of the pumping ports that are connected to the DN40 beam pipe.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK032  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 24 June 2022
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THPOTK043 Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet impedance, injection, kicker, coupling 2868
 
  • M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velotti, C. Zannini
    CERN, Meyrin, Switzerland
 
  The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam induced power deposition was considered an issue. These magnets are very lossy from a beam impedance perspective: this is expected to be an issue during SPS operation with the higher intensity beams needed for HL-LHC. A design, with serigraphy applied to an alumina carrier, has been developed to significantly reduce the broadband beam coupling impedance and hence mitigate the heating issues. During high voltage pulse testing there were electrical discharges associated with the serigraphy. Detailed mathematical models have been developed to aid in understanding the transiently induced voltages and to reduce the magnitude and duration of electric field. In this paper, we discuss the solutions implemented to mitigate the electrical discharges while maintaining an adequately low beam-coupling impedance. In addition, the results of high voltage tests are reported. The alumina substrate has a high secondary electron yield and thus electron-cloud could be an issue, with SPS beam, if mitigating measures were not taken: this paper also discusses the measures implemented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK049 Irradiation of Low-Z Carbon-Based Materials with 440 GeV/c Proton Beam for High Energy & Intensity Beam Absorbers: The CERN HiRadMat-56-HED Experiment target, experiment, proton, operation 2883
 
  • P. Andreu Muñoz, M. Calviani, N. Charitonidis, A. Cherif, E.M. Farina, A.M. Krainer, A. Lechner, J. Maestre, F.-X. Nuiry, R. Seidenbinder, C. Torregrosa
    CERN, Meyrin, Switzerland
  • P. Simon
    TU Darmstadt, Darmstadt, Germany
 
  The beam stored energy and the peak intensity of CERN Large Hadron Collider (LHC) will grow in the next few years. The former will increase from the 320 MJ values of Run2 (2015-2018) to almost 540 MJ during Run3 (2022 onwards) and 680 MJ during the HL-LHC era putting stringent requirements on beam intercepting devices, such as absorbers and dumps. The HiRadMat-56-HED (High-Energy Dumps) experiment performed in Autumn 2021 executed at CERN HiRadMat facility employed the Super Proton Synchrotron accelerator (SPS) 440 GeV/c proton beam to impact different low-density carbon-based materials targets to assess their performance to these higher energy beam conditions. The study focused on advanced grades of graphitic materials, including isostatic graphite, carbon-fiber reinforced carbon and carbon-SiC materials in addition to flexible expanded graphite. Some of them specifically tailored in collaboration with industry to very specific properties. The objectives of this experiment are: (i) to assess the performance of existing and potentially suitable advanced materials for the currently operating LHC beam dumps and (ii) to study alternative materials for the HL-LHC main dump or for the Future Circular Collider dump systems. The contribution will detail the R&D phase during design, the execution of the experiment, the pre-irradiation tests as well as the first post irradiation examination of the target materials. Lessons learnt and impact on operational devices will also be drawn.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK049  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK050 CFD Studies of the Convective Heat Transfer Coefficients and Pressure Drops in Geometries Applied to Water Cooling Channels of the Crotch Absorbers of ALBA Synchrotron Light Source experiment, synchrotron, GUI, storage-ring 2887
 
  • S. Grozavu, G.A. Raush
    ESEIAAT, Terrassa, Spain
  • J.J. Casas, C. Colldelram, M. Quispe
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Currently, the storage ring vacuum chambers of ALBA are protected by 156 crotch absorbers made of copper and Glidcop. After more than 10 years of operation as a third-generation light source, the ALBA II project arose, aiming to transform this infrastructure into a fourth-generation synchrotron. This introduces new challenges in terms of the thermal and mechanical design of the future absorbers. The absorbers’ cooling channels consist of a set of 8-mm-diameter holes parallel to each other and drilled into the body of the absorbers. In each hole, there is a 6x1 mm stainless steel concentric inner tube coiled in spiral wires, whose aim is to enhance the heat transfer. The convective heat transfer coefficients used for the original design of the absorbers come from experimental correlations from the literature, and are applied as a global value for the whole system. In this work, Heat Transfer-Computational Fluid Dynamics (HT-CFD) studies of the convective heat transfer coefficients and pressure gradients in three different cooling channel geometries are carried out, aiming at leading the way of designing the cooling systems toward the CFD simulations rather than applying global experimental values. This information will be useful for the sizing of the new absorbers for the ALBA II project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK050  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK054 Proposal of a VHEE Linac for FLASH Radiotherapy linac, electron, cavity, gun 2903
 
  • L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, A. De Gregorio, L. Ficcadenti, D. Francescone, G. Franciosini, M. Migliorati, A. Mostacci, L. Palumbo, V. Patera, A. Sarti
    Sapienza University of Rome, Rome, Italy
  • D. Alesini, A. Gallo, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • M. Behtouei, L. Faillace, B. Spataro
    LNF-INFN, Frascati, Italy
  • M.G. Bisogni, F. Di Martino, J.H. Pensavalle
    INFN-Pisa, Pisa, Italy
  • G.A.P. Cirrone, G. Cuttone, G. Torrisi
    INFN/LNS, Catania, Italy
  • V. Favaudon, A. Patriarca
    Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
  • S. Heinrich
    Institut Curie, Centre de Recherche, Orsay, France
 
  Translation of electron FLASH radiotherapy in clinical practice requires the use of high energy accelerators to treat deep tumours and Very High Electron Energy (VHEE) could represent a valid technique to achieve this goal. In this sce- nario, a VHEE FLASH linac is under study at the University La Sapienza of Rome (Italy) in collaboration with the Italian Institute for Nuclear Research (INFN) and the Curie Insti- tute (France). Here we present the preliminary results of a compact C-band system aiming to reach an high accelerating gradient and an high pulse current necessary to deliver high dose per pulse and ultra-high dose rate required for FLASH effect. We propose a system composed of a low energy high current injector linac followed by a modular section of high accelerating gradient structures. CST code is used to define the required LINAC’s RF parameters and beam dynamics simulations are performed using T-Step, ASTRA and GPT tracking codes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK054  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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THPOTK062 Thermal Modeling and Benchmarking of Crystalline Laser Amplifiers laser, experiment, software, ECR 2921
 
  • D.T. Abell, D.L. Bruhwiler, P. Moeller, R. Nagler, B. Nash, I.V. Pogorelov
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
Ti:sapphire crystals constitute the lasing medium of a class of lasers valued for their wide tunability and ultra-short, ultra-high intensity pulses. When operated at high power and high repetition rate (1kHz), such lasers experience multiple effects that can degrade performance. In particular, thermal gradients induce a spatial variation in the index of refraction, hence thermal lensing*. Using the open-source finite-element code FEniCS***, we solve the relevant partial differential equations to obtain a quantitative measure of the disruptive effects of thermal gradients on beam quality. We present thermal simulations of a pump laser illuminating a Ti:sapphire crystal. From these simulations we identify the radial variation in the refractive index, and hence the extent of thermal lensing. In addition, we present analytic models used to estimate the effect of thermal gradients on beam quality. This work generalizes to other types of crystal amplifiers.
* S. Cho, et al., Appl. Phys. Express, 11:092701, 2018.
** M. Born & E. Wolf, Principles of Optics, Cambridge Univ. Press, 1980.
*** The FEniCS computing platform, https://fenicsproject.org
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK062  
About • Received ※ 13 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK063 Open Source Software to Simulate Ti:Sapphire Amplifiers laser, optics, photon, experiment 2925
 
  • D.L. Bruhwiler, D.T. Abell, B. Nash
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
The design of next-generation PW-scale fs laser systems, including scaling to kHz rates and development of new laser gain media for efficiency, will require parallel multiphysics simulations with realistic errors and nonlinear optimization. There is currently a lack of broadly available modeling software that self-consistently captures the required physics of gain, thermal loading and lensing, spectral shaping, and other effects required to quantitatively design such lasers.* We present initial work towards an integrated multiphysics capability for modeling pulse amplification in Ti:Sa lasers. All components of the software suite are open source. The Synchrotron Radiation Workshop (SRW)** is being used for physical optics, together with Python utilities. The simulations are being validated against experiments.
* R. Falcone et al., Brightest Light Initiative Workshop Report (2019).
** https://github.com/ochubar/srw
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK063  
About • Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS003 Upgrade of a Proton Therapy Eye Treatment Nozzle Using a Cylindrical Beam Stopping Device for Enhanced Dose Rate Performances scattering, proton, radiation, ECR 2937
 
  • E. Gnacadja, C. Hernalsteens, N. Pauly, E. Ramoisiaux, R. Tesse, M. Vanwelde
    ULB, Bruxelles, Belgium
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
 
  Proton therapy is a well established treatment method for ocular cancerous diseases. General-purpose multi-room systems which comprise eye-treatment beamlines must be thoroughly optimized to achieve the performances of fully dedicated systems in terms of depth-dose distal fall-off, lateral penumbra, and dose rate. For eye-treatment beamlines, the dose rate is one of the most critical clinical performances, as it directly defines the delivery time of a given treatment session. This delivery time must be kept as low as possible to reduce uncertainties due to undesired patient movement. We propose an alternative design of the Ion Beam Applications (IBA) Proteus Plus (P+) eye treatment beamline, which combines a beam-stopping device with the already existing scattering features of the beamline. The design is modelled with Beam Delivery SIMulation (BDSIM), a Geant4-based particle tracking and beam-matter interactions Monte-Carlo code, to demonstrate that it increases the maximum achievable dose rate by up to a factor §I{3} compared to the baseline configuration. An in-depth study of the system is performed and the resulting dosimetric properties are discussed in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS003  
About • Received ※ 20 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS004 Achromatic Gantry Design Using Fixed-Field Spiral Combined-Function Magnets proton, FFAG, lattice, emittance 2941
 
  • R. Tesse, E. Gnacadja, C. Hernalsteens, N. Pauly, E. Ramoisiaux, M. Vanwelde
    ULB, Bruxelles, Belgium
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
 
  Arc-therapy and flash therapy are promising proton therapy treatment modalities as they enable further sparing of the healthy tissues surrounding the tumor site. They impose strong constraints on the beam delivery system and rotating gantry structure, in particular in providing high dose rate and fast energy scanning. Fixed-field achromatic transport lattices potentially satisfy both constraints in allowing instant energy modulation and sufficient transmission efficiency while providing a compact footprint. The presented design study uses fixed-field magnets with spiral edges respecting the FFA scaling law. The cell structure and the layout are studied in simulation and integrated in a compact gantry. Results and further optimizations are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS004  
About • Received ※ 20 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 11 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS008 Physics Design of Electron Flash Radiation Therapy Bemaline at PITZ electron, radiation, quadrupole, booster 2954
 
  • X.-K. Li, Z. Aboulbanine, Z. Amirkhanyan, M. Groß, M. Krasilnikov, A. Lueangaramwong, R. Niemczyk, A. Oppelt, S. Philipp, H.J. Qian, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
  • G. Loisch, F. Obier, M. Schmitz
    DESY, Hamburg, Germany
 
  The Photo Injector Test facility at DESY in Zeuthen (PITZ) is preparing an R&D platform for electron FLASH radiotherapy, very high energy electron (VHEE) radiotherapy and radiation biology based on its unique beam parameters: ps scale bunches with up to 5 nC bunch charge at MHz bunch repetition rate in bunch trains of up to 1 ms in length repeating at 10 Hz. This platform is called FLASHlab@PITZ. The PITZ beam is routinely accelerated to 22 MeV, with a possible upgrade to 250 MeV for VHEE radiotherapy in the future. The 22 MeV beam will be used for dosimetry experiments and studying biological effects in thin samples in the next years. A new beamline to extract and match the beam to the experimental station is under physics design. The main features include: an achromatic dogleg to extract the beam from the PITZ beamline; a sweeper to scan the beam across the sample within 1 ms for tumor painting studies; and an imaging system to keep the beam size small at the sample after scattering in the exit window while maintaining the scan range of the sweeper. In this paper, the beam dynamics with bunch charges from 10 pC to 5 nC in and the preparation of the new beamline will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS008  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS010 Heating and Beam Impact of High Intensity Exit Windows for FLASHlab@PITZ electron, radiation, scattering, Windows 2958
 
  • Z. Amirkhanyan
    CANDLE SRI, Yerevan, Armenia
  • Z. Aboulbanine, M. Groß, M. Krasilnikov, T. Kuhl, X.-K. Li, R. Niemczyk, A. Oppelt, S. Philipp, H.J. Qian, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
  • M. Schmitz
    DESY, Hamburg, Germany
 
  The high-brightness electron beam at the Photo Injector Test facility at DESY in Zeuthen (PITZ) is being prepared for use in dosimetry experiments and for the study of biological effects in thin samples. This is part of the preparations for FLASHlab@PITZ which is going to be an R&D platform for FLASH and VHEE radiation therapy and radiation biology. These studies require precise information on the electron beam parameters downstream of the exit window, such as the scattering angle and the energy spectrum of the particles as well as the thermal load on the exit window. A Titanium window is compared with a DESY Graphite window design. Heat deposition in the window by a single 22MeV / 1nC electron bunch of various size, its scattering and energy spectrum due to passage through the window are calculated by means of the Monte Carlo program FLUKA. Time resolved temperature profiles, as generated by the passage of 1ms long electron pulse trains with up to 4500 single pulses, each of them between 0.1 and 60ps long, are calculated with a self-written FEM code.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS010  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 30 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS023 Design of the 590 MeV Proton Beamline for the Proposed TATTOOS Isotope Production Target at PSI proton, target, neutron, site 3000
 
  • M. Hartmann, D.C. Kiselev, D. Reggiani, M. Seidel, J. Snuverink, H. Zhang
    PSI, Villigen PSI, Switzerland
 
  IMPACT (Isotope and Muon Production with Advanced Cyclotron and Target Technologies) is a proposed initiative envisaged for the high-intensity proton accelerator facility (HIPA) at the Paul Scherrer Institute (PSI). As part of IMPACT, a radioisotope target station, TATTOOS (Targeted Alpha Tumour Therapy and Other Oncological Solutions) will allow the production of terbium radionuclides for therapeutic and diagnostic purposes. The proposed TATTOOS beamline and target will be located near the UCN (Ultra Cold Neutron source) target area, branching off from the main UCN beamline. In particular, the beamline is intended to operate at a beam intensity of 100 µA, requiring a continuous splitting of the main beam via an electrostatic splitter. Realistic beam loss simulations to verify safe operation have been performed and optimised using Beam Delivery Simulation (BDSIM), a Geant4 based tool enabling the simulation of beam transportation through magnets and particle passage through the accelerator. In this study, beam profiles, beam transmission and power deposits are generated and studied.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS023  
About • Received ※ 18 May 2022 — Revised ※ 31 May 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS026 Monte Carlo Simulation of Electron Beam in Phantom Water for Radiotherapy Application electron, radiation, photon, linac 3011
 
  • P. Apiwattanakul, C. Phueng-ngern, S. Rimjaem, J. Saisut
    Chiang Mai University, Chiang Mai, Thailand
  • P. Lithanatudom
    IST, Chiang Mai, Thailand
  • P. Nimmanpipug, S. Rimjaem, J. Saisut
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  Radiotherapy (RT) is an effective treatment that can control the growth of cancer cells. There is a hypothesis suggests that secondary electrons with an energy of a few eV produced from RT play an important role on cancer’s DNA strand break. In this study, the Monte Carlo simulation of electron beam irradiation in phantom water is performed to investigate the production of low-energy electrons. Electron beams produced from an radio-frequency linear accelerator (RF linac) are used in this study. The accelerator can generate the electron beam with adjustable energy of up to 4 MeV and adjustable repetition rate of up to 200 Hz. With these properties, the electron dose can be varied. We used ASTRA software to simulate the electron beam dynamics in the accelerator and GEANT4 toolkit for studying interactions of electrons in water. The energy of electrons decreases from MeV scale to keV-eV scale as they travel in the water. From simulations, the dose distribution and depth in phantom water were obtained for the electron dose of 1, 3, 5, 10, 25, and 50 Gy. Further study on effect of low-energy electron beam with these dose values on cancer DNAs will be performed with GEANT4-DNA simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS026  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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THPOMS028 Performance Study of the NIMMS Superconducting Compact Synchrotron for Ion Therapy with Strongly Curved Magnets multipole, lattice, synchrotron, quadrupole 3014
 
  • H.X.Q. Norman, R.B. Appleby
    UMAN, Manchester, United Kingdom
  • E. Benedetto
    SEEIIST, Geneva, Switzerland
  • M. Karppinen
    CERN, Meyrin, Switzerland
  • H.L. Owen
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • H.L. Owen
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • S.L. Sheehy
    The University of Melbourne, Melbourne, Victoria, Australia
 
  Delivery of heavy ion therapy currently utilises normal conducting synchrotrons. For the future generation of clini- cal facilities, the accelerator footprint must be reduced while adopting beam intensities above 1 × 1010 particles per spill for more efficient, effective treatment. The Next Ion Medical Machine Study (NIMMS) is investigating the feasibility of a compact (27 m circumference) superconducting synchrotron, based on 90° alternating-gradient, canted-cosine-theta mag- nets to meet these criteria. The understanding of the impact of the higher order multipole fields of these magnets on the beam dynamics of the ring is crucial for optimisation of the design and to assess its performance for treatment. We analyse the electromagnetic model of a curved superconducting magnet to extract its non-linear components. Preliminary as- sessment is performed using MADX/PTC. Further scope, involving cross-referencing with other particle tracking codes, is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS028  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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THPOMS033 Design and Optimisation of a Stationary Chest Tomosynthesis System with Multiple Flat Panel Field Emitter Arrays: Monte Carlo Simulations and Computer Aided Designs photon, target, electron, diagnostics 3034
 
  • T.G. Primidis, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • T.G. Primidis, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • T.G. Primidis
    King’s College London, London, United Kingdom
  • V. Soloviev, S.G. Wells
    Adaptix Ltd, Oxford, United Kingdom
 
  Funding: Funded by the Accelerators for Security, Healthcare and Environment Centre for Doctoral Training of the United Kingdom Research and Innovation, Science and Technology Facilities Council, ST/R002142/1
Digital tomosynthesis (DT) allows 3D imaging by using a ~30° range of projections instead of a full circle as in computed tomography (CT). Patient doses can be ~10 times lower than CT and similar to 2D radiography but diagnostic ability is significantly better than 2D radiography and can approach that of CT. Moreover, cold-cathode field emission technology allows the integration of 10s of X-ray sources into source arrays that are smaller and lighter than conventional X-ray tubes. The distributed source positions avoid the need for source movements and Adaptix Ltd has demonstrated stationary 3D imaging with this technology in dentistry, orthopaedics, veterinary medicine and non-destructive testing. In this work we present Monte Carlo simulations of an upgrade to the Adaptix technology to specifications suited for chest DT and we show computer aided designs for a system with various populations of these source arrays. We conclude that stationary arrays of cold-cathode X-ray sources could replace movable X-ray tubes for 3D imaging and different arrangements of many such arrays could be used to tailor the X-ray fields to different patient size and diagnostic objective.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS033  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022
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THPOMS041 Design and Parameterization of Electron Beam Irradiation System for Natural Rubber Vulcanization experiment, electron, radiation, linac 3061
 
  • P. Wongkummoon
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • N. Kangrang, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • M.W. Rhodes
    IST, Chiang Mai, Thailand
 
  Electron beam irradiation is a process to modify or improve the properties of materials with less chemical residue. In natural rubber vulcanization, a proper electron absorbed dose is about 50-150 kGy. In this study, the experimental station is designed to investigate the deposition of the electron beam in natural rubber. Electron beams generated from an RF linac are used in this study. This accelerator can generate the beam with energies in the range of 1-4 MeV and an adjustable repetition rate of up to 200 Hz. We can optimize these parameters to maximize the throughput and uniformity of electron dose in the vulcanization. The simulation results from GEANT4 were used to narrow down the appropriate parameters in the experiment. In the early stage of the study, water was used as a sample instead of natural rubber. The dose distribution was obtained by placing a B3 film dosimeter under a water chamber. The water depth was varied from 0.5 to 2.0 cm. The simulation results provide the dose distribution to compare with the experimental results. In a further study, the beam irradiation in natural rubber with these optimal parameters and vulcanization tests will be performed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS041  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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THPOMS042 Development of a Cyclotron Based External Beam Irradiation System for Elemental Analysis proton, radiation, target, cyclotron 3064
 
  • P. Thongjerm, A. Ngamlamiad, W. Pornroongruengchok, K. Tangpong, S. Wonglee
    Thailand Institute of Nuclear Technology, Nakhon Nayok, Thailand
 
  We present the studies carried out at the cyclotron facility at Thailand Institute of Nuclear Technology (TINT, Nakhon Nayok, Thailand). The cyclotron accelerates up to 30 MeV proton with a maximum beam current of 200 µA. Proton beam is transported to three target halls, including the R&D vault. Particularly, the R&D beamline consists of a five-port switching magnet allowing further extension for multidisciplinary research and experiments. The first station of the research vault is dedicated to non-destructive and multi-elemental analysis using proton-induced x-ray (PIXE) and proton-induced gamma (PIGE) techniques. For this purpose, the beam is extracted through an exit foil to the air. The beam size is then shaped by a set of collimators before reaching a sample. However, the range of the protons in air and the attenuation of x-rays may deteriorate. Therefore, the external irradiation system, including exit foil, collimator and detector arrangement, is evaluated in Geant4 to optimise the proton beam quality and improve detection efficiency. A detailed description of the simulation and results are discussed in this work.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS042  
About • Received ※ 16 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 23 June 2022
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THPOMS046 Generation of Flat-Laser Compton Scattering Gamma-ray Beam in UVSOR undulator, electron, laser, experiment 3070
 
  • H. Ohgaki, K. Ali, T. Kii, H. Zen
    Kyoto University, Kyoto, Japan
  • M. Fujimoto, Y. Taira
    UVSOR, Okazaki, Japan
  • T. Hayakawa, T. Shizuma
    QST, Tokai, Japan
 
  Funding: This work is supported by JSPS KAKENHI Grant Number 21H01859. A part of this work was performed at the BL1U of UVSOR, IMS, Okazaki (IMS program 21-603).
Flat energy distribution Laser Compton scattering (F-LCS) gamma-ray beam, which has a flat distribution in the energy spectrum and the spatial distribution with a small beam size, has been developed to study an isotope selective CT Imaging application at the beamline BL1U in UVSOR. We have successfully demonstrated a three-dimensional (3D) isotope-selective CT image by using a conventional LCS gamma-ray beam[1]. However, the conventional LCS beam with a small beam size whose energy spread is narrow can’t excite a few isotopes at the same time. Therefore, we proposed the F-LCS gamma-ray beam by using the Apple-II undulator installed in BL1U in UVSOR to excite a circular motion of the electron beam. An EGS5 simulation shows that a weak magnetic field (K=0.2) can generate an F-LCS beam. The demonstration experiments have been carried out in UVSOR and the spectra of generated LCS beam with different K-values of the undulator were measured. As a result, the measured spectra agreed with the EGS5 simulation. The principle of F-LCS generation and experimental results, including the effect on the stored electron beam, will be presented at the conference.
[1] K. Ali, et. al., "Three-dimensional nondestructive isotope-selective tomographic imaging of 208Pb distribution via nuclear resonance fluorescence". Appl. Sci. 2021, 11, 3415.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS046  
About • Received ※ 02 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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THPOMS053 Proton Beam Irradiation System for Space Part Test proton, radiation, target, vacuum 3093
 
  • H.-J. Kwon, J.J. Dang, W.-H. Jung, H.S. Kim, K.Y. Kim, K.R. Kim, S. Lee, Y.G. Song, S.P. Yun
    KOMAC, KAERI, Gyeongju, Republic of Korea
 
  Funding: This work is supported by the Nuclear Research and Development Program (2021M2D1A1045615) through the National Research Foundation of Korea.
A proton beam irradiation system for space part test has been developed at Korea Multi-purpose Accelerator Complex (KOMAC) based on 100 MeV proton linac. It consists of a thermal vacuum chamber, a beam diagnostic system and a control system in the low flux beam target room. The thermal vacuum chamber accommodates the capacity for proton beam irradiation in addition to temperature control in vacuum condition. The beam diagnostic system is newly installed to measure the lower dose rate than existing one. In this paper, the proton beam irradiation system for space part test including a thermal vacuum chamber, newly installed beam diagnostic system is presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS053  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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