Q0 Improvement of Large-Grain Multi-Cell Cavities by Using JLab's Standard ILC EP Processing
- Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
- IHIP, Peking University, Beijing (China)
As reported previously at the Berlin workshop, applying the JLab standard ILC electropolishing (EP) recipe on previously buffered chemical polishing (BCP) etched fine-grain multi-cell cavities results in improvement both in gradient and Q{sub 0}. We recently had the opportunity to experiment with two 1300 MHz 9-cell large-gain niobium cavities manufactured by JLab and Peking University. Both cavities were initially BCP etched and further processed by using JLab's standard ILC EP recipe. Due to fabrication defects, these two cavities only reached a gradient in the range of 20-30 MV/m. Interestingly both cavities demonstrated significant Q{sub 0} improvement in the gradient range of 15-20 MV/m. At 2K, a Q{sub 0} value of 2E10 is achieved at 20 MV/m. At a reduced temperature of 1.8K, a Q{sub 0} value of 3E10 is achieved at 20 MV/m. These results suggest that a possible path for obtaining higher Q{sub 0} in the medium gradient range is to use the large-grain material for cavity fabrication and EP and low temperature bake for cavity processing.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1057884
- Report Number(s):
- JLAB-ACC-11-1461; DOE/OR/23177-2425; TRN: US1300369
- Resource Relation:
- Conference: SRF 2011 (RF Superconductivity), Chicago, IL (United States), 25-29 Jul 2011
- Country of Publication:
- United States
- Language:
- English
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