Development of a Superconducting RF 1.5 GHz Landau Cavity for Synchrotron Light Sources

Superconducting radio frequency (SRF) cavities are used to accelerate electron beams worldwide. Brookhaven National Laboratory (BNL) has proposed to build the NSLS­II, a third generation light source, and has identified SRF cavities as the technology of choice. The final machine configuration will require four single-­cell 500 MHz SRF cavities fed by four 300 kW klystrons to compensate beam loss. In addition, two passive two-­cell 1.5 GHz Landau (3rd harmonic) SRF cavities are required to lengthen the bunch, thereby increasing beam lifetime to greater than 3 hours. This project will develop a 1500 MHz SRF Landau cavity. Whereas previously designed cavities used niobium sputtered onto high­ purity copper, this cavity will utilize bulk niobium to enable the stringent specifications and requirements for the NSLS­II ring to be satisfied. Phase I demonstrated technical feasibility by completing the preliminary cavity and cryomodule design. Phase II will finalize the cryomodule design and prototype critical aspects of the system: SRF cavities, power coupler, HOM spectrum, and frequency tuners. Commercial Applications and other Benefits as described by the awardee: The development and demonstration of this new type of superconducting radio frequency Landau cavity should open up many new applications for both scientific and industrial accelerators