High Power Co-Axial SRF Coupler

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 will always be 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. In Phase II a complete RF coupler assembly will be built and tested at high power. A compressed co-axial window will be designed and fabricated using materials with high thermal conductivity. The mechanical designs will fit into standard-sized ConFlat® flanges for ease of assembly. Low power tests will confirm the broadband match characteristics of the microwave design. Commercial Applications and Other Benefits as described by the awardee. Compressed co-axial window technology in standard ConFlat® flange dimensions have a wide range of applications in scientific and commercial vacuum systems for feed-throughs of various designs for high voltage as well as microwave energy. This technology is needed for current and future synchrotron radiation light source, free electron laser, and spallation neutron source user facilities