Measurement of beam characteristics for photoelectron beam at Waseda University

The low emittance and short pulse electron beam is expected to be used in a wide field, such as X-ray generation by inverse Compton scattering, pulse radiolysis, etc. The laser driven photocathode rf gun system can produce the low emittance and short pulse electron beam. It is very important for generating the low emittance and short pulse electron beam to measure the beam characteristics such as the bunch length precisely. In this report, the measurement system of the bunch length using frequency analysis for the photoelectron beam generated by the rf gun and results of the preliminary experiment at the KEK-ATF (Accelerator Test Facility) injector linac is described.