skip to main content


Title: Industrialization of the nitrogen-doping preparation for SRF cavities for LCLS-II

The Linac Coherent Light Source II (LCLS-II) is a new state-of-the-art coherent X-ray source being constructed at SLAC National Accelerator Laboratory. It employs 280 superconducting radio frequency (SRF) cavities in order operate in continuous wave (CW) mode. To reduce the overall cryogenic cost of such a large accelerator, nitrogen-doping of the SRF cavities is being used. Nitrogen-doping has consistently been shown to increase the efficiency of SRF cavities operating in the 2.0 K regime and at medium fields (15–20 MV/m) in vertical cavity tests and horizontal cryomodule tests. While nitrogen-doping’s efficacy for improvement of cavity performance was demonstrated at three independent labs, Fermilab, Jefferson Lab, and Cornell University, transfer of the technology to industry for LCLS-II production was not without challenges. Here in this paper, we present results from the beginning of LCLS-II cavity production. We discuss qualification of the cavity vendors and the first cavities from each vendor. Finally, we demonstrate that nitrogen-doping has been successfully transferred to SRF cavity vendors, resulting in consistent production of cavities with better cryogenic efficiency than has ever been achieved for a large-scale accelerator.
 [1] ;  [2] ;  [1] ;  [3] ;  [3] ;  [2] ;  [2] ;  [2] ;  [3] ;  [2] ;  [3] ;  [2] ;  [1] ;  [2] ;  [2] ;  [2] ;  [3]
  1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
Additional Journal Information:
Journal Volume: 883; Journal Issue: C; Journal ID: ISSN 0168-9002
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
Country of Publication:
United States
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; SRF; Cavity; Accelerator; Niobium; Superconducting; Nitrogen-doping
OSTI Identifier: