Cut disk structure type RF-deflector for slice emittance measurement for RF-gun at SuperKEKB

We report on development of a high power and compact deflecting system with a cut disk structure type RF-deflector of a standing wave tube with multiple cells. This deflector, operated in a HEM11 mode, will be used to measure the slice emittance of the beam in the pre-injector part of the injector linac system for the SuperKEKB project at KEK. The data obtained for the slice emittance of the beam will be used to diagnose and correct the time structure of the laser light pulses that drive the high current, low emittance photocathode RF electron gun.