PERFORMANCE OF THE ENERGY COMPRESSION SYSTEM AT THE SPRING-8 LINAC

GeV electron beams of the SPring-8 linac are injected into the 8-GeV booster synchrotron ring and the 1.5-GeV storage ring "NewSUBARU". The beam injection into the NewSUBARU was made by one shot every few minutes. The beam energy stability in the linac had to be kept at less than ±0.3%, which is as much as the beam energy acceptance for the NewSUBARU. The energy spread due to the beam loading had to be reduced to increase the beam injection current. For this purpose, an energy compression system (ECS) was installed in the downstream of the linac in 2000. The ECS resulted in beam energy stability of 0.01% rms and reduced energy spread, which consequently realized high current beam injection. This paper describes the RF system of the ECS and the results of beam tests with the ECS.