First operation of a thermionic cathode RF gun at NSRRC

A high brightness injector is being constructed for light source R&D at NSRRC. This 150 MeV beam injector consists of a 1.5-cell thermionic cathode RF gun with field ratio adjusted to produce a linear energy chirped electron beam for generation of sub-picoseconds electron pulses at GHz repetition rate by using alpha-magnet as low energy bunch compressor. This short bunch beam is planned to drive an experimental pre-bunched THz FEL in the near future. High power microwave processing of the thermionic cathde RF gun up to ~4 MW cavity forward power has been achieved. The first beam from this gun has been obtained.