High Power Coax Window
A superconducting RF (SRF) power coupler capable of handling 500 kW CW RF power is required for present and future storage rings and linacs. There are over 35 coupler designs for SRF cavities ranging in frequency from 325 to 1500 MHz. Coupler windows vary from cylinders to cones to disks, and RF power couplers are limited by the ability of ceramic windows to withstand the stresses due to heating and mechanical flexure. We propose a novel robust co-axial SRF coupler design which uses compressed window technology. This technology will allow the use of highly thermally conductive materials for cryogenic windows. Using compressed window techniques on disk co-axial windows will make significant improvements in the power handling of SRF couplers. We present the bench test results of two window assemblies back to back, as well as individual window VSWR in EIA3.125 coax. A vacuum test assembly was made and the windows baked out at 155C. The processes used to build windows is scalable to larger diameter coax and to higher power levels.