Emittance Measurement with Upgraded RF Gun System at Spring-8

A single cell S-band RFgun has been developed at the SPring-8 since 1996. The minimum normalized beam emittance, measured with double slits´ scanning method in 2002, was 2.3 πmm·mrad at the exit of the gun cavity with charge of 0.1 nC/bunch [1]. In 2004, we installed a following accelerator structure to investigate beam behavior of the whole injector system [2] [3]. In this paper, we report emittance measurement results of upgraded system, using variable quadrupole magnet method. The minimum emittance of 2.0 πmm·mrad with a net charge of 0.14 nC/bunch were able to be measured.