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Title: Investigation of differential surface removal due to electropolishing at JLab

Conference ·
OSTI ID:1223453
 [1];  [1];  [1]
  1. Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

Surface chemistry carried out for Superconducting Radio Frequency (SRF) cavities such as Buffered Chemical Polishing (BCP) and Electropolishing (EP) aims to uniformly remove the internal surface of a cavity along the entire structure and within each cell from equator to iris in order to obtain an equally etched surface. A uniform removal, however, is not readily achievable due to the complex fluid flow and varying temperatures of the acid mixture, which can lead to differential etching. This needs to be considered when envisaging a certain surface damage removal throughout the interior. The process-specific differential etching influences the target frequency set at the manufacturing stage as well as the field flatness and length of the as-built cavity. We report on analyses of JLab's present EP system using experimental data for six nine-cell cavities that have been processed recently in the frame of the LCLS-II high-Q development plan. In conjunction with numerical simulations, the differential etching and the impact on field flatness is assessed.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP)
DOE Contract Number:
AC05-06OR23177
OSTI ID:
1223453
Report Number(s):
JLAB-ACC-15-2070; DOE/OR/23177-3434; TRN: US1601429
Resource Relation:
Conference: IPAC 2015, Richmond, VA (United States), 3-8 May 2015
Country of Publication:
United States
Language:
English