Development of on-demand beam route and parameter switching system for SACLA to achieve both flexible X-ray free-electron laser operation and SPring-8 injection

We have developed an on-demand beam route and parameter switching system for SACLA in order to realize a wide variety of operation patterns for XFEL beamlines and to inject electron beams to the SPring-8 storage ring in parallel with the XFEL operation. The beam route information is distributed every 60 pps (pulses per second) beam shot from a MicroTCA.4-based master trigger unit via a high-speed reflective memory network. Each accelerator unit receives the beam route at a 60 pps repetition rate, turns on or off the accelerator unit, and sets the acceleration RF phase, etc. The kicker magnet power supply to switch the beam route is also controlled according to the beam route. We tested the on-demand switching system at a test bench and the SACLA linac. The beam route and parameters were appropriately controlled with a negligible failure rate of less than 2.5 x 10^-8 /shot/unit and the XFEL performance was not degraded. This system was also utilized for the beam injection test from SACLA to SPring-8 with an additional function to precisely synchronize SACLA to a desired SPring-8 beam bucket. The injected beam from SACLA was properly captured by the SPring-8 storage ring with a sufficient injection efficiency of more than 90%. (author)