Optimization of a GHz UV Laser System for a High Gradient X-band PWT

A Plane Wave Transformer (PWT) is being designed to produce 25 MeV electron bunches of extremely high brightness using a 20 MW of X-band klystron. The PWT average brightness can be further increased by filling multiple rf buckets in the accelerating cavity during an individual klystron pulse. A diode laser in a short optical cavity is modulated with external fields and modelocked using a fast saturable absorber to produce sub-picosecond pulses which then seed a CPA system. A fiber switch is used to select a GHz pulse train which is subsequently amplified and converted to UV. Temporal pulse shaping is used to optimize the photocathode laser and minimize the PWT emittance.