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Title: Film Deposition, Cryogenic RF Testing and Materials Analysis of a Nb/Cu Single Cell SRF Cavity

In this study, we present preliminary results on using a cathodic-arc-discharge Nb plasma ion source to establish a Nb film-coated single-cell Cu cavity for SRF research. The polycrystalline Cu cavity was fabricated and mirror-surface-finished by a centrifugal barrel polishing (CBP) process at Jefferson Lab. Special pre-coating processes were conducted, in order to create a template-layer for follow-on Nb grain thickening. A sequence of cryogenic RF testing demonstrated that the Nb film does show superconductivity. But the quality factor of this Nb/Cu cavity is low as a result of high residual surface resistance. We are conducting a thorough materials characterization to explore if some microstructural defects or hydrogen impurities, led to such a low quality factor.
 [1] ;  [1] ;  [1] ;  [2]
  1. JLAB
  2. Peking
Publication Date:
OSTI Identifier:
Report Number(s):
JLAB-ACC-13-1803; DOE/OR/23177-3231
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: SRF2013, 23-27 Sept 2013. Paris, France
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States