New Progress with HF-free Chemical Finishing for Nb SRF Cavities

Conference · Tue Jan 01 04:00:00 EST 2019

DOI:https://doi.org/10.18429/JACoW-LINAC2018-TUPO043· OSTI ID:1542095

Tian, Hui ^[1]; Straka, Bradley J. ^[2]; J., Carroll ^[1]; Reece, Charles E. ^[1]; Hall, T. ^[3]; Radhakrishna, R. ^[3]; Inman, M. ^[3]; Taylor, E. J. ^[3]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Univ. of Tennessee, Knoxville, TN (United States)
3. Faraday Technology, Inc., Englewood, OH, USA

Jefferson Lab has implemented a bipolar pulsed electropolishing system for final chemical processing of niobium SRF cavities. This FARADAYIC bi-polar electropolishing (BPEP) has been applied to single cells, a 7-cell CEBAF C100 cavity, and to 9-cell TESLA-style cavities.* As a mechanistic characterization of the process emerges, the critical role played by the local current density during each cathodic pulse is becoming clear. This influences system and operational parameter refinement. We present current process parameters, removal characterization, and rf performance of the processed cavities. This is the fruit of collaborative work between Jefferson Lab and Faraday Technology, Inc. directed toward the routine commercialization and industrialization of niobium cavity processing. We also present supporting data from controlled-parameter coupon studies.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1542095
• Report Number(s): JLAB-ACC-18-2836; DOE/OR/23177-4574; TUPO043
• Country of Publication: United States
• Language: English