Author: Slack, G.
Paper Title Page
WEPWO076 Development of Ultra High Gradient and High Q0 Superconducting Radio Frequency Cavities 2474
 
  • R.L. Geng, W.A. Clemens, J. Follkie, T. Harris, D. Machie, R. Martin, A.D. Palczewski, E. Perry, G. Slack, R.S. Williams
    JLAB, Newport News, Virginia, USA
  • C. Adolphsen, Z. Li
    SLAC, Menlo Park, California, USA
  • J.K. Hao, Y.M. Li, K.X. Liu
    PKU, Beijing, People's Republic of China
  • P. Kushnick
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We re­port on the re­cent progress at Jef­fer­son Lab in de­vel­op­ing ultra high gra­di­ent and high Q0 su­per­con­duct­ing radio fre­quency (SRF) cav­i­ties for fu­ture SRF based ma­chines. A new 1300 MHz 9-cell pro­to­type cav­ity is being fab­ri­cated. This cav­ity has an op­ti­mized shape in terms of the ratio of the peak sur­face field (both mag­netic and elec­tric) to the ac­cel­er­a­tion gra­di­ent, hence the name low sur­face field (LSF) shape. The goal of the ef­fort is to demon­strate an ac­cel­er­a­tion gra­di­ent of 50 MV/m with Q0 of 1010 at 2 K in a 9-cell SRF cav­ity. Fine-grain nio­bium ma­te­r­ial is used. Con­ven­tional form­ing, ma­chin­ing and elec­tron beam weld­ing method are used for cav­ity fab­ri­ca­tion. New tech­niques are adopted to en­sure re­peat­able, ac­cu­rate and in­ex­pen­sive fab­ri­ca­tion of com­po­nents and the full as­sem­bly. The com­pleted cav­ity is to be first me­chan­i­cally pol­ished to a mir­ror-fin­ish, a newly ac­quired in-house ca­pa­bil­ity at JLab, fol­lowed by the proven ILC-style pro­cess­ing recipe es­tab­lished al­ready at JLab. In par­al­lel, new sin­gle-cell cav­i­ties made from large-grain nio­bium ma­te­r­ial are made to fur­ther ad­vance the cav­ity treat­ment and pro­cess­ing pro­ce­dures, aim­ing for the demon­stra­tion of an ac­cel­er­a­tion gra­di­ent of 50 MV/m with Q0 of 2·1010 at 2K.
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