Development of a Tunable 28 MHz Superconducting RF Cavity for RHIC

The 28 MHz accelerating cavities for Brookhaven¿s Relativistic Heavy Ion Collider (RHIC) are based on copper structures and high power tetrodes. In order to improve performance and reliability, and significantly reduce maintenance, this project will investigate replacing the existing 28 MHz accelerating cavity system with superconducting RF structures driven by solid state amplifiers. Phase I will develop the system design for the superconducting accelerating structure and cryomodule design, as well as the solid state amplifier with input coupler. Phase II would finalize the cryomodule design and develop prototypes for critical aspects of the system, such as the SRF cavities, power coupler, HOM spectrum, and frequency tuners. Commercial Applications and other Benefits as described by the awardee Upgrading to a tunable 28 MHz superconducting RF system would allow one SRF cavity to replace two copper cavities, thereby reducing the number of cavities or maintaining the second cavity as a spare. Also, the smaller SRF cavity would have reduced electrical and RF power requirements, due to lower losses of the superconducting material and the use of a solid state power amplifier.