Author: Reid, T.
Paper Title Page
SUPCAV018 First N-Doping and Mid-T Baking of Medium-ß 644 MHz 5-Cell Elliptical Superconducting RF Cavities for Michigan State University’s Facility for Rare Isotope Beams 53
 
  • K.E. McGee, S.H. Kim, P.N. Ostroumov, A. Taylor
    FRIB, East Lansing, Michigan, USA
  • G.V. Eremeev, M. Martinello, A.V. Netepenko
    Fermilab, Batavia, Illinois, USA
  • M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by the 2020 US DoE, Office of Science Graduate Student Research award (SCGSR), and US DoE, Office of Science, High Energy Physics under Cooperative Agreement award number DE-SC0018362
Two hadron linacs currently under development in the US, the PIP-II linac at Fermi National Accelerator Laboratory (FNAL) and the upgrade for Michigan State University’s Facility For Rare Isotope Beams (FRIB), will employ 650 and 644 MHz ß-0.6 elliptical superconducting cavities respectively to meet their design energy requirements. The desired CW operation modes of these two linacs sets Q-factor requirements well above any previously achieved for cavities at this operating frequency and velocity, driving the need to explore new high-Q treatments. The N-doping technique developed at FNAL and employed at an industrial scale to the LCLS-II cryomodules is a strong candidate for high-Q treatments, but work is needed to refine the treatment to the lower operating frequency and velocity regime. We present the first results of the first N-doping tests and a "mid-T" bake test in the FRIB 644 MHz 5-cell elliptical cavities.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-SUPCAV018  
About • Received ※ 23 June 2021 — Revised ※ 16 November 2021 — Accepted ※ 08 May 2022 — Issue date ※ 08 May 2022
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TUPCAV005 Toward Qualifications of HB and LB 650MHz Cavities for the Prototype Cryomodules for the PIP-II Project 448
 
  • M. Martinello, D.J. Bice, C. Boffo, S.K. Chandrasekaran, G.V. Eremeev, F. Furuta, T.N. Khabiboulline, K.E. McGee, A.V. Netepenko, J.P. Ozelis, A.I. Sukhanov, G. Wu
    Fermilab, Batavia, Illinois, USA
  • M. Bagre, V. Jain, A. Puntambekar, S. Raghvendra, P. Shrivastava
    RRCAT, Indore (M.P.), India
  • M. Bertucci, A. Bosotti, C. Pagani, R. Paparella
    INFN/LASA, Segrate (MI), Italy
  • P. Bhattacharyya, S. Ghosh, S. Ghosh, A. Mandal, S. Seth, S. Som
    VECC, Kolkata, India
  • M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
  • S.H. Kim, K.E. McGee, P.N. Ostroumov
    FRIB, East Lansing, Michigan, USA
  • K.K. Mistri, P.N. Prakash
    IUAC, New Delhi, India
 
  High-beta (HB) and low-beta (LB) 650 MHz cryomodules are key components of the Proton Improvement Plan II (PIP-II) project. In this contribution we present the results of several 5-cell HB650 cavities that have been processed and tested with the purpose of qualifying them for the prototype cryomodule assembly, which will take place later this year. We also present the first results obtained in LB650 single-cell cavities process optimization. Taking advantage of their very similar geometry, we are also analyzing the effect of different surface treatments in FRIB’s 5-cell medium-beta 644MHz cavities. Cavities processed with N-doping and mid-T baking showed very promising results in term of both Q-factors and accelerating gradient for these low-beta structures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-TUPCAV005  
About • Received ※ 01 July 2021 — Accepted ※ 02 November 2021 — Issue date; ※ 16 May 2022  
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TUPCAV015 Performance of a Low Frequency QWR-Based SRF Gun 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 [4.870 MB]  
DOI • reference for this paper ※ https://doi.org/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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WEPCAV015 Refurbishment and Testing of the WiFEL E-Gun at Argonne 627
 
  • T.B. Petersen, G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T. Reid
    ANL, Lemont, Illinois, USA
  • P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  We report on the refurbishment and testing of the Wisconsin Free Electron Laser (WiFEL) superconducting radiofrequency electron gun with application as an electron injector for DOE accelerators and as a possible future stand-alone tool for electron microscopy. Initial testing at ANL showed the cavity had a very low quality factor, ~107, later determined to be due to contamination some-time since the initial assembly. Following ultrasonic cleaning, high-pressure water rinsing, reassembly, and cold testing, the e-gun has largely recovered with Q~109 and surface electric fields ~15 MV/m. We intend that WiFEL be available as a testbed for future high brightness sources and, in particular, for testing an SRF gun photocathode loader design; an essential, and as yet, not sufficiently proven technology. We report here on many operationally important properties of a quarter-wave SRF cavity for application as an e-gun, including microphonics, pressure sensitivity, and mechanical tuning. New electromagnetic simulations show that the WiFEL cavity shape and design can be optimized in several respects.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-WEPCAV015  
About • Received ※ 21 June 2021 — Revised ※ 23 October 2021 — Accepted ※ 07 April 2022 — Issue date ※ 07 April 2022
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