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Title: Design of coupler for the NSLS-II storage ring superconducting RF cavity

Conference ·
OSTI ID:1016651

NSLS-II is a 3GeV, 500mA, high brightness, 1 MW beam power synchrotron facility that is designed with four superconducting cavities working at 499.68 MHz. To operate the cavities in over-damped coupling condition, an External Quality Factor (Qext) of {approx}65000 is required. We have modified the existing coupler for the CESR-B cavity which has a Qext of {approx}200,000 to meet the requirements of NSLS-II. CESR-B cavity has an aperture coupler with a coupler 'tongue' connecting the cavity to the waveguide. We have optimized the length, width and thickness of the 'tongue' as well as the width of the aperture to increase the coupling using the three dimensional electromagnetic field solver, HFSS. Several possible designs will be presented. We have modified the coupler of the CESR-B cavity to be used in the storage ring at the NSLS-II project using HFSS and verified using CST Microwave Studio. Using a combination of increasing the length and width of the coupler tongue and increasing the width of the aperture, the external Q of the cavity coupler was decreased to {approx}65000 as required for the design of the NSLS-II storage ring design.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
Sponsoring Organization:
DOE - OFFICE OF SCIENCE
DOE Contract Number:
DE-AC02-98CH10886
OSTI ID:
1016651
Report Number(s):
BNL-94977-2011-CP; 39KC02000; TRN: US1103094
Resource Relation:
Conference: Particle Accelerator Conference PAC11; New York, NY; 20110328 through 20110401
Country of Publication:
United States
Language:
English