SARI-CAS, Pudong, Shanghai, People’s Republic of China
The superconducting radio-frequency electron linear accelerator of the Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) contains 610 1.3 GHz fundamental power couplers which are assembled in 77 superconducting cryomodules used for beam acceleration, and 16 3.9 GHz fundamental power couplers, which are assembled in two third harmonic superconducting cryomodules used for linearizing the longitudinal phase space. The first batch of 26 1.3 GHz coupler prototypes and two 3.9 GHz coupler prototypes have been fabricated from three domestic manufacturers for basic research. Several key manufacturing processes have been developed and qualified, including high residual resistivity ratio (RRR) copper plating, vacuum brazing of ceramic windows, electron beam welding and titanium nitride coating. All the 1.3 GHz coupler prototypes have been power conditioned with 14 kW travelling wave (TW) and 7 kW standing wave (SW) RF in continuous-wave (CW) mode. Even higher power levels have been demonstrated with 20 kW TW and 10 kW SW RF, which indicates their robustness. Both 3.9 GHz coupler prototypes have been power conditioned with 2.2 kW TW and 2 kW SW RF in CW mode.
