An Extremely High Power, Field Coupled, Low Loss RF Transmission Line for SRF Cavities

73155-Superconducting particle accelerators require high power radio frequency (RF) couplers, which have high capital and operational costs. The operational costs include power dissipation at cryogenic temperatures and operational down time. New coupler designs are needed that reduce these costs for particle accelerators that require even higher RF power than now available. This project will design a very high power field coupled, non-contacting RF transmission line for Superconducting Radio Frequency (SRF) cavities. The design will be applicable to both coaxial and waveguide couplers. In Phase I, the design and analysis for both coaxial and waveguide couplers were completed. Analysis included RF, cryogenic, and multipacting performance. Modeling results of both couplers resulted in exceptional performance. Phase II will complete the final anyalysis of the waveguide coupler and develop a detailed engineering package that includes all drawings and fabrication processes required to build the couplers. Two couplers and a high power test stand will be built and integrated. High power testing of the assembly will be conducted with traveling and standing wave RF power at 700 MHz. Commercial Applications and Other Benefits as described by awardee: Particle accelerators are an integral part of basic research in high-energy, nuclear, and health sciences, and are also used in military and industrial applications. Reduced capital and operating costs for SRF-cavity RF coupling would extend the application of SRF accelerators by providing more cost effective, robust solutions in all these areas.