Keyword: simulation
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SUPCAV006 Cavity Designs for the CH3 to CH11 of the Superconducting Heavy Ion Accelerator HELIAC cavity, heavy-ion, linac, solenoid 15
 
  • T. Conrad, M. Busch, H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher, J. List
    IKP, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, M. Basten, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth, M. Heilmann, A. Rubin, A. Schnase, S. Yaramyshev
    GSI, Darmstadt, Germany
  • S. Lauber
    KPH, Mainz, Germany
 
  Funding: BMBF
In collaboration of GSI, HIM and IAP Frankfurt, the superconducting linear accelerator HELIAC is being built at GSI. The cw-mode operated linac with a final energy of 7.3 MeV/u at a mass-to-charge ratio of A/q=6 and a frequency of 216.816 MHz is intended for various experiments, especially with heavy ions at energies close to the Coulomb barrier for the research of SHE. The planned linac consists of 4 cryostats, 4 superconducting bunchers, 4 solenoids and 12 superconducting CH-cavities. After successful beam tests with CH0 and high frequency tests with CH1 and CH2, CH3 to CH11 will be designed. Based on previous experience and successful test results, individual optimizations of the cavity design will be performed. Attention has been paid to reducing production costs by designing as many components as possible, such as spokes or the tank caps with the same geometries. Despite this cost reduction, it was possible to improve the theoretical performance in the simulations. In addition, a test bench is being developed which will be used for the first-time investigation of the mechanical stability, possible material fatigue and the durability of the dynamic bellows tuners.
 
poster icon Poster SUPCAV006 [1.495 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV006  
About • Received ※ 21 June 2021 — Accepted ※ 21 October 2021 — Issue date ※ 12 November 2021  
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SUPCAV013 Multipacting Analysis of the Quadripolar Resonator (QPR) at HZB multipactoring, electron, quadrupole, operation 42
 
  • S. Bira, D. Longuevergne
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • Y. Kalboussi
    CEA-IRFU, Gif-sur-Yvette, France
  • S. Keckert, J. Knobloch, O. Kugeler
    HZB, Berlin, Germany
  • Th. Proslier
    CEA-DRF-IRFU, France
 
  Multipacting (MP) is a resonating electron discharge, often plaguing radio-frequency (RF) structures, produced by the synchronization of emitted electrons with the RF fields and the electron multiplication at the impact point with the surface structure. The electron multiplication can take place only if the secondary emission yield (SEY, i.e. the number of electrons emitted due to the impact of one incoming electron), , is higher than 1. The SEY value depends strongly on the material and the surface contamination. Multipacting simulations are crucial in high-frenquency (HF) vacuum structures to localize and potentially improve the geometry. In this work, multipacting simulations were carried out on the geometry of the Quadrupole Resonator (QPR) in operation at HZB using the Spark 3D module in Microwave Studio suite (CST). These simulations helped to understand a particular behavior observed during the QPR tests, and furthermore made it possible to suggest enhancement ways in order to limit this phenomenon and facilitate its operation.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV013  
About • Received ※ 09 July 2021 — Revised ※ 09 July 2021 — Accepted ※ 09 April 2022 — Issue date ※ 07 May 2022
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SUPCAV014 Design and Simulation of 500 MHz Single Cell Superconducting Cavity cavity, superconducting-cavity, HOM, ECR 46
 
  • Y.B. Sun, W. Ma
    Sun Yat-sen University, Zhuhai, Guangdong, People’s Republic of China
  • G.M. Liu
    SSRF, Shanghai, People’s Republic of China
  • L. Lu, L. Yang, Z. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  Funding: Work supported by Shenzhen Development and Reform Commis-sion
The Shenzhen Industrial Synchrotron Radiation Light Source is a fourth-generation medium-energy light source with a 3GeV storage ring electron energy and an emit-tance less than 100 pm·rad. In order to ensure the long-term stable and efficient operation of the light source, a new type of 500 MHz single-cell superconducting cavity was designed in this study to be used as a pre-research superconducting cavity for the Light Source. The 500 MHz superconducting cavity has a large beam aperture and low high order modes (HOMs) impedance, which can be used in accelerators with larger currents. In this design, we simply adopted the same design scheme as the KEKB-type and CESR-type superconducting cavity. Using CST electromagnetic field simulation software to calculate and simulate the characteristics of the cavity, the results show that the designed 500 MHz single-cell cavity can meet the requirements of a high acceleration gradient, a high r/Q value, and a low peak surface field.
 
poster icon Poster SUPCAV014 [0.425 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV014  
About • Received ※ 21 June 2021 — Revised ※ 07 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 05 May 2022
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SUPFDV003 Effect of Mean Free Path on Nonlinear Losses of Trapped Vortices Driven by a RF Field Field cavity, ECR, linear-dynamics, radio-frequency 67
 
  • M.R.P. Walive Pathiranage, A.V. Gurevich
    ODU, Norfolk, Virginia, USA
 
  Funding: This work was supported by NSF under Grants PHY 100614-010 and PHY 1734075, and by DOE under Grant DE-SC 100387-020.
We report extensive numerical simulations on nonlinear dynamics of a trapped elastic vortex under rf field, and its dependence on electron mean free path li. Our calculations of the field-dependent residual surface resistance Ri(H) take into account the vortex line tension, the linear Bardeen-Stephen viscous drag and random distributions of pinning centers. We showed that Ri(H) decreases significantly at small fields as the material gets dirtier while showing field independent behavior at higher fields for clean and dirty limit. At low frequencies Ri(H) increases smoothly with the field amplitude at small H and levels off at higher fields. The mean free path dependency of viscosity and pinning strength can result in a nonmonotonic mean free path dependence of Ri, which decreases with li at higher fields and weak pinning strength.
 
poster icon Poster SUPFDV003 [1.344 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV003  
About • Received ※ 20 June 2021 — Accepted ※ 19 December 2021 — Issue date ※ 09 April 2022  
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MOPCAV014 The Development of a Prototype Fundamental Power Coupler for CiADS and HIAF Half Wave Resonators cavity, operation, linac, coupling 295
 
  • T.C. Jiang, F. Bai, Y. He, Z.Q. Lin, Y.Q. Wan, R.X. Wang, Z.J. Wang, M. Xu, S.H. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  More than 100 Half-wave resonators (HWR) will be adopted for China Initiative Accelerator Driven Sys-tem (CiADS) and High Intensity heavy-ion Accelerator Facility (HIAF) at IMP. Each HWR cavity equips with one variable coupling, dual-warm-ceramic fundamen-tal power coupler (FPC). The FPC should be able to transmit up to 30 kW in CW mode. This paper will give an overview of the RF design of the 162.5 MHz CW power coupler. The coupler employs two warm ceram-ics in a 50 Ω coaxial line to ensure operation relia-bility. The results of thermal and thermomechanical will also be reported. Two prototype couplers have been fabricated and the RF measurements with low RF power were carried out.  
poster icon Poster MOPCAV014 [1.128 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV014  
About • Received ※ 21 June 2021 — Accepted ※ 01 April 2022 — Issue date ※ 07 April 2022  
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MOPFDV003 Measuring Flux Trapping Using Flat Samples cavity, experiment, controls, HOM 326
 
  • F. Kramer, S. Keckert, J. Knobloch, O. Kugeler
    HZB, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
 
  With modern superconducting cavities flux trapping is a limiting factor for the achievable quality factor. Flux trapping is influenced by various parameters such as geometry, material, and cooldown dynamics. At SRF2019 we presented data showing the magnetic field surrounding a cavity. We now present supplemental simulations for this data focusing on geometric effects. As these simulations are inconclusive, we have designed a new setup to measure trapped flux in superconducting samples which is presented as well. The advantages compared to a cavity test are the simpler sample geometry, and quicker sample production, as well as shorter measurement times. With this setup we hope to identify fundamental mechanisms of flux trapping, including geometry effects, different materials, and different treatments. First results are presented along with the setup itself.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPFDV003  
About • Received ※ 21 June 2021 — Accepted ※ 03 April 2022 — Issue date ※ 02 May 2022  
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TUPFDV002 SIMS Sample Holder and Grain Orientation Effects niobium, experiment, cavity, SRF 401
 
  • J.W. Angle, M.J. Kelley
    Virginia Polytechnic Institute and State University, Blacksburg, USA
  • M.J. Kelley, E.M. Lechner, A.D. Palczewski, C.E. Reece
    JLab, Newport News, Virginia, USA
  • F.A. Stevie
    NCSU AIF, Raleigh, North Carolina, USA
 
  SIMS analyses for ’N-doped’ materials are becoming increasingly important. A major hurdle to acquiring quantitative SIMS results for these materials is the uncertainty of instrument calibration due to changes in sample height either from sample topography or from the sample holder itself. The CAMECA sample holder design allows for many types of samples to be analyzed. However, the cost is that the holder faceplate can bend, introducing uncertainty into the SIMS results. Here we designed and created an improved sample holder which is reinforced to prevent faceplate deflection and thereby reduce uncertainty. Simulations show that the new design significantly reduces deflection from 10 µm to 5 nm. Measurements show a reduction of calibration (RSF) uncertainty from this source from 4.1% to 0.95%. Grain orientation has long been suspected to affect RSF determination as well. A bicrystal implant standard consisting of [111] and [001] grains were repeatedly rotated 15° in between analyses. It was observed that 20% of the analyses performed on [111] grains exhibited anomalously high RSF values likely due to the changing of the grain normal with respect to the primary Cs+ beam.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFDV002  
About • Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 05 January 2022
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TUPFDV006 Dynamics of One-Side Multipactor on Dielectrics electron, multipactoring, space-charge, resonance 411
 
  • G.V. Romanov
    Fermilab, Batavia, Illinois, USA
 
  Breakdown of dielectric RF windows is an important issue for particle accelerators and high-power RF sources. One of the generally considered reasons for the RF windows failure is the multipactor effect on dielectric surface. The multipactor may be responsible for excessive heating of dielectric and discharge of charges that accumulated in ceramic due to secondary emission. In this study the comprehensive self-consistent PIC simulations with space charge effect were performed in order to better understand the dynamic of one-side multipactor development and floating potential on dielectric induced by the emission. The important correlations between the multipactor parameters at saturation and the secondary emission properties of dielectric and the applied RF field parameters were found and are reported in the paper.  
poster icon Poster TUPFDV006 [0.849 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFDV006  
About • Received ※ 17 June 2021 — Revised ※ 12 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 06 October 2021
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TUPCAV002 HOM Excitation in Spoke Resonator for SRF Studies cavity, HOM, coupling, multipactoring 435
 
  • D. Longuevergne, N. Bippus, F. Chatelet, V. Delpech, N. Hu, C. Joly, T. Pépin-Donat, F. Rabehasy, L. Renard
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • M. Baudrier
    CEA-DRF-IRFU, France
  • E. Cenni, L. Maurice
    CEA-IRFU, Gif-sur-Yvette, France
 
  The excitation of Higher Order Modes (HOM) or Lower Order Modes (LOM) has been performed for years on multi-cell superconducting accelerating cavities as a mean to coarsely locate a quench, a defective area or ignite a plasma for surface cleaning. Moreover, such multi-mode testing is very useful to understand more accurately the frequency dependence of the surface resistance in a wide range of surface magnetic fields (0<B<150mT). In that sense, several type of dedicated non-accelerating resonators like Quadrupole Resonator (QPR), Half- or Quarter- Wave resonators have been built to specifically study new superconducting materials or new surface or heat treatments. What is proposed in this paper is to perform such multi-mode analysis (352 MHz, 720 MHz and 1300 MHz) in an existing accelerating cavity, in particular a Spoke Resonator. Baseline results will be presented and perspectives of such technique will be discussed.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV002  
About • Received ※ 22 June 2021 — Revised ※ 19 July 2021 — Accepted ※ 23 August 2021 — Issue date ※ 15 April 2022
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TUPCAV014 Design of a Third Harmonic Cavity With Low R/Q for the ESR in BNL EIC cavity, HOM, multipactoring, electron 469
 
  • B.P. Xiao
    BNL, Upton, New York, USA
 
  Funding: The work is supported by by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
For the electron Storage Ring (ESR) of Brookhaven National Lab Electron Ion Collider (BNL EIC), beam loading is a great concern due to the high beam current together with abortion gap, especially for harmonic cavities due to higher operational frequency. There were attempts to use feedback/feedforward control, using multiple cavities with counter-phasing. A straightforward way to lower beam loading effect is to design a cavity with low R/Q. In this paper, we show such a design for the 3rd harmonic cavity for BNL EIC ESR.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV014  
About • Received ※ 22 June 2021 — Revised ※ 12 November 2021 — Accepted ※ 11 February 2022 — Issue date ※ 22 February 2022
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TUPCAV015 Performance of a Low Frequency QWR-Based SRF Gun cavity, electron, experiment, multipactoring 472
 
  • G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T.B. Petersen, T. Reid
    ANL, Lemont, Illinois, USA
  • X. Lu, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
Superconducting radio-frequency (SRF) electron guns are generally considered to be an effective way of producing beams with high brightness and high repetition rates (or continuous wave). In this work, the 199.6 MHz quarter wave resonator (QWR)-based Wisconsin Free Electron Laser (WiFEL) superconducting electron gun was recently refurbished and tested at Argonne (ANL). The field performance of the e-gun was fully characterized. During this time, multipacting (MP) conditioning was performed for over 20 hours to overcome the hard MP barrier observed in the accelerating voltage range of 8 to 40 kV; the presence of multipacting is expected to operationally important for future e-guns. Here we simulated and studied the effect using CST* Microwave Studio and Particle Studio and compare with the measured data.
* CST Studio Suite, version 2020, https://www.cst.com.
 
poster icon Poster TUPCAV015 [4.874 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV015  
About • Received ※ 21 June 2021 — Revised ※ 20 December 2021 — Accepted ※ 22 February 2022 — Issue date ※ 23 March 2022
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TUPTEV018 Status of RF Power Coupler for HWR in RISP cryomodule, cavity, vacuum, status 531
 
  • S. Lee, M. Lee, Y.U. Sohn
    IBS, Daejeon, Republic of Korea
  • Y.U. Sohn
    PAL, Pohang, Republic of Korea
 
  Funding: This work was supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science and ICT and NRF of Korea 2013M7A1A1075764.
A heavy-ion accelerator facility is under construction for Rare Isotope Science Project(RISP) in Korea. Four types of super conducting cavities, QWR, HWR, SSR1, and SSR2 are developed to accelerate the ion beams. The QWR cryomodule is already installed in the tunnel. The HWR cryomodule is transport to the tunnel. Here, the status of HWR RF power coupler is presented. After the fabrication, the coupler is test with high power RF. The some of the test results are described.
 
poster icon Poster TUPTEV018 [1.740 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV018  
About • Received ※ 21 June 2021 — Revised ※ 09 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 29 April 2022
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WEPFAV005 Design Optimization of the 166-MHz and 500-MHz Fundamental Power Couplers for Superconducting RF Cavities at High Energy Photon Source cavity, multipactoring, cryogenics, photon 544
 
  • T.M. Huang, Z.Z. Chang, L. Guo, H.Y. Lin, Q. Ma, W.M. Pan, P. Zhang, X.Y. Zhang
    IHEP, Beijing, People’s Republic of China
 
  Funding: Supported in part by High Energy Photon Source, a major national science and technology infrastructure in China, and in part by the National Natural Science Foundation of China under Grant 12075263.
Five 166-MHz quarter-wave ß=1 cavities have been chosen for the fundamental srf system while two 500-MHz single-cell elliptical cavities for the third-harmonic system for High Energy Photon Source (HEPS). Each cavity will be equipped with one fundamental power coupler (FPC) capable of delivering 250-kW continuous-wave rf power. For the 166-MHz FPC, two prototypes were developed and excellent performances were demonstrated in the high-power operations. However, the inner air part was observed to be warmer than predictions. Therefore, an innovative cooling scheme was adopted. In addition, the Nb extension tube has been elongated to solve the overheating in the cavity-coupler interface region. Concerning the 500-MHz FPC, several improvements were proposed. First, a doorknob adopting WR1800 instead of WR1500 waveguide was chosen to better match the operating frequency; Second, the window position was optimized to ensure multipacting-free on the window; Third, the cryogenic heat load was estimated carefully to obtain an optimum helium gas cooling. The main parameters and the design optimizations of the 166-MHz and 500-MHz FPCs are presented in this paper.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPFAV005  
About • Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 20 January 2022  
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WEPCAV002 Improvement of Chemical Etching Capabilities (BCP) for SRF Spoke Resonators at IJCLab cavity, SRF, HOM, niobium 590
 
  • J. Demercastel-Soulier, P. Duchesne, D. Longuevergne, G. Olry, T. Pépin-Donat, F. Rabehasy, D. Reynet, S. Roset, L.M. Vogt
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
 
  Buffered chemical polishing (BPC) is the reference surface polishing adopted for ESS and MYRRHA SRF spoke resonators at IJCLab. This chemical treatment, in addition to improving the RF performance, fits into the frequency adjustment strategy of the jacketed cavity during its preparation phase. In the framework of the collaboration with Fermilab for PIP-II project, IJCLab has developed a new setup to perform rotational BCP. The implementation of a rotation during chemical etching improves significantly the homogeneity and quality of surface polishing. In this paper, we present the numerical analysis based on a fluid dynamics model. The goal is to estimate the acid flow characteristics inside the cavity, determine the influence of several parameters as mass flow rate and rotation speed and propose the best configuration for the new experimental setup  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV002  
About • Received ※ 23 June 2021 — Revised ※ 18 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 14 January 2022
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WEPCAV006 650 MHz Elliptical Cavities in IMP for CiADS Project cavity, niobium, linac, proton 594
 
  • Y.L. Huang, H. Guo, Y. He, C.L. Li, T. Liu, R.X. Wang, Z.J. Wang, M. Xu, Z.Q. Yang, S.X. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  Funding: Large Research Infrastructures "China initiative Accelerator Driven System"(Grant No.2017-000052-75-01-000590 ) and National Natural Science Foundation of China (Grant NO. 11805249)
650MHz multi-cell superconducting elliptical cavities with optimum beta equal to 0.62 and 0.82 were adopted in the driver linac of Chinese initiative Accelerator Driven Subcritical System (CiADS) to accelerate the 10 mA proton beam from 175 MeV up to 500 MeV, with the possibility to upgrade the energy to 1 GeV and higher. Mechanical design and optimization of the niobium cavity-titanium helium vessel assembly will be summarized in this paper. Vertical test results of three single cell prototype cavities will also be discussed, with comparisons with the simulation values.
*Work supported by Large Research Infrastructures "China initiative Accelerator Driven System’(Grant No.2017-000052-75-01-000590 ) and National Natural Science Foundation of China (Grant NO. 11805249)
 
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DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV006  
About • Received ※ 21 June 2021 — Revised ※ 10 December 2021 — Accepted ※ 05 February 2022 — Issue date ※ 07 April 2022
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WEPCAV008 A Fast Mechanical Tuner for SRF Cavities cavity, SRF, controls, acceleration 600
 
  • S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  • V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
 
  There is a particular need for fast tuners and phase shifters for advanced superconducting accelerator RF systems. The tuners based on ferrite, ferroelectric and piezo materials are commonly used. However, those methods suffer from one or another issue of high power loss, slow response, and narrow tuning range. We propose a robust, fast (up to ~5 MHz/sec), high efficient mechanical tuner for SRF cavities operating at the frequency 50 MHz. We develop an external mechanical tuner that is strongly coupled to the cavity. The tuner design represents a trade-off of high efficiency (low RF losses and low heat flux) and frequency tunability range. Our approach solves this trade-off issue. We propose RF design which exploits two coupled resonators so that a main high-field cavity is controlled with a small tunable resonator with a flexible metallic wall operating in a relatively low RF field. Simulations, carried out for a 7.5 MV/m 50 MHz SRF Quarter Wave Resonator (QWR), show that frequency tunability at level 10-3 is obtainable.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV008  
About • Received ※ 17 June 2021 — Revised ※ 06 August 2021 — Accepted ※ 22 November 2021 — Issue date ※ 04 February 2022
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WEPTEV002 High Power Coupler Devepment for EIC multipactoring, SRF, cavity, detector 632
 
  • W. Xu, Z.A. Conway, J.M. Fite, D. Holmes, K.S. Smith, A. Zaltsman
    BNL, Upton, New York, USA
 
  Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The future EIC Electron storage ring at BNL needs to compensate up to 10 MW synchrotron loss with RF systems. The RF system relies on 34 fundamental power couplers to deliver RF power from power sources at room temperature to 17 SRF cavities at 2 K. Each power coupler will operate with 400 kW forward power, with full reflection for ~10% of time. We are developing two 1 MW coaxial FPCs at BNL, one with a BeO window and the other with an Al2O3 window. This paper will briefly summarize test results of high power test on the BeO window FPC , and then describe the development status of the Al2O3 window FPC.
 
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DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPTEV002  
About • Received ※ 25 June 2021 — Revised ※ 28 January 2022 — Accepted ※ 05 April 2022 — Issue date ※ 12 May 2022
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WEPTEV016 Field Emission Studies During ESS Cryomodule Tests at CEA Saclay cavity, cryomodule, electron, detector 677
 
  • E. Cenni
    CEA-IRFU, Gif-sur-Yvette, France
  • M. Baudrier, G. Devanz, L. Maurice, O. Piquet
    CEA-DRF-IRFU, France
 
  For the development of efficient superconducting cavi-ties, field emission is an important parasitic phenomena to monitor. A diagnostic system composed of Geiger-Mueller (G-M) probes, NaI(Tl) scintillators are placed in the cryomodule test stand. Collected data is analysed and confronted to particle tracking simulation and electro magnetic shower code. With such systematic analysis we aim to identify the most probable field emission location and hence help to improve clean procedures during as-sembly and operation.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPTEV016  
About • Received ※ 21 June 2021 — Revised ※ 22 September 2021 — Accepted ※ 18 December 2021 — Issue date ※ 17 May 2022
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THPFDV001 Status of the New Quadrupole Resonator for SRF R&D quadrupole, SRF, cavity, operation 751
 
  • R. Monroy-Villa, W. Hillert, M. Wenskat
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Gorgi Zadeh, P. Putek
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  • M. Lemke, R. Monroy-Villa, D. Reschke, M. Röhling, J.H. Thie
    DESY, Hamburg, Germany
 
  A basic understanding of the properties of SRF samples under surface treatments would aid in the development of consistent theories. To study the RF properties of such samples under realistic superconducting-cavity-like conditions, a test device called Quadrupole Resonator (QPR) was fabricated. In this publication we report the status of the QPR at Universität Hamburg in collaboration with DESY. Our device is based on the QPRs operated at CERN and at HZB, and its design will allow for testing samples at temperatures between 2 K and 8 K, under magnetic fields up to 120 mT and with operating frequencies of 433 MHz, 866 MHz and 1300 MHz. Fabrication tolerance studies on the electromagnetic field distributions and simulations of the static detuning of the device, together with the commissioning report and the ongoing surface treatment, will be presented.  
poster icon Poster THPFDV001 [1.074 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPFDV001  
About • Received ※ 27 June 2021 — Revised ※ 23 August 2021 — Accepted ※ 23 August 2021 — Issue date ※ 29 April 2022
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THPCAV001 Modal Analysis and Vibration Test of Single Spoke Resonator Type{}-1 (SSR1) for RAON cavity, FEM, SRF, experiment 776
 
  • M.O. Hyun, Y.W. Jo, H.C. Jung, Y. Kim, M. Lee
    IBS, Daejeon, Republic of Korea
 
  Funding: This paper was supported by the Rare Isotope Science Project (RISP), which is funded by the Ministry of Science and ICT (MSIT) and National Research Foundation (NRF) of the Republic of Korea.
Rare Isotope Science Project (RISP) is developing the single spoke resonator type-1 (SSR1) and type-2 (SSR2) for making superconducting linear accelerator 2 (SCL2). For optimizing of SSR1 and SSR2, we should research every aspects of superconducting cavity including RF performances and mechanical properties. This paper explains about modal analysis of SSR1 using FEM (finite element method) applying material properties of RRR300 niobium for bare cavity and STS316L for liquid helium jacket. Also, this paper shows the vibration test results with modal analysis.
 
poster icon Poster THPCAV001 [1.641 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV001  
About • Received ※ 22 June 2021 — Accepted ※ 06 September 2021 — Issue date ※ 15 May 2022  
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THPCAV005 Status of the INFN-LASA Contribution to the PIP-II Linac cavity, SRF, linac, experiment 787
 
  • R. Paparella, M. Bertucci, M. Bonezzi, A. Bosotti, D. Cardelli, A. D’Ambros, A.T. Grimaldi, P. Michelato, L. Monaco, D. Sertore
    INFN/LASA, Segrate (MI), Italy
  • C. Pagani
    Università degli Studi di Milano & INFN, Segrate, Italy
 
  The international effort for the PIP-II project at Fermilab has been joined by INFN with its planned contribution to the PIP-II proton linac in the low-beta section. INFN-LASA is finalizing its commitment to deliver in kind the full set of the LB650 cavities, 36 plus spares resonators with 5-cell cavities at 650 MHz and geometrical beta 0.61. All cavities, designed by INFN-LASA, will be produced and surface treated in industry to reach the unprecedented performances required by PIP-II, qualified through vertical cold test at state-of-the art infrastructures and delivered as ready for the linac at the string assembly site. The status of INFN contribution to PIP-II, the development of infrastructures and prototypes as well as the ongoing activities toward the start of series production are summarized in this paper.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV005  
About • Received ※ 21 June 2021 — Accepted ※ 09 October 2021 — Issue date ※ 08 May 2022  
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THPCAV009 Statistical Modeling of Peak Accelerating Gradients in LCLS-II and LCLS-II-HE cavity, cryomodule, multipactoring, accelerating-gradient 804
 
  • J.T. Maniscalco, S. Aderhold, J.D. Fuerst, D. Gonnella
    SLAC, Menlo Park, California, USA
  • T.T. Arkan, M. Checchin, J.A. Kaluzny, S. Posen
    Fermilab, Batavia, Illinois, USA
  • J. Hogan, A.D. Palczewski, C.E. Reece, K.M. Wilson
    JLab, Newport News, Virginia, USA
 
  In this report, we study the vertical test gradient performance and the gradient degradation between vertical test and cryomodule test for the 1.3 GHz LCLS-II cavities. We develop a model of peak gradient statistics, and use our understanding of the LCLS-II results and the changes implemented for LCLS-II-HE to estimate the expected gradient statistics for the new machine. Finally, we lay out a plan to ensure that the LCLS-II-HE cryomodule gradient specifications are met while minimizing cavity disqualification by introducing a variable acceptance threshold for the accelerating gradient.  
poster icon Poster THPCAV009 [1.311 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV009  
About • Received ※ 21 June 2021 — Revised ※ 14 September 2021 — Accepted ※ 02 November 2021 — Issue date ※ 23 November 2021
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