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

Brookhaven National Laboratory (BNL) has proposed building the NSLS¬II, a third generation light source, and has identified superconducting radio frequency (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. Also, two passive, two-¬cell, 1.5 GHz Landau (3rd harmonic) SRF cavities will be required to lengthen the bunch, thereby increasing the beam lifetime. This project will develop a 1.5 GHz Landau SRF cavity system. The cavity will use bulk niobium, which is capable of higher gradients with lower cryogenic losses. Also, the cavity will have improved HOM damping by providing additional HOM couplers, and ferrite absorbers on the beam tube. Phase I will develop the accelerating structure and cryomodule design based on systems-efficiency technology, beam dynamics simulations, and higher order mode (HOM) analysis. Phase II would finalize the cryomodule design and develop prototypes for critical aspects of the system, such as the SRF cavities, HOM couplers, and frequency tuners. Commercial Applications and other Benefits as described by the awardee: In addition to providing BNL with the required 1.5 GHz SRF system, the technology should have application to other light sources. To date, no US vendor has been capable of delivering SRF systems for synchrotron light sources.