Review of Advanced Laser Technologies for Photocathode High-Brightness Guns

Tuesday 14 Jul 2009, 11:30 → 12:30 Europe/Rome

Franco Tazzioli Room (Bldg. 2) (Laboratori Nazionali di Frascati, Via Enrico Fermi 40, Frascati)

ABSTRACT

I developed an adaptive 3-D pulse shaping UV-laser system as an ideal light source for yearlong stable generation of a low-emittance electron beam. In its current form, the UV-laser's pulse-energy stability has been improved to 0.7~1.4% at the third-harmonic generation (263 nm). Such improvement reflects an ability to stabilize the laser system in a humidity-controlled clean room. In addition, the ideal spatial and temporal profiles of a shot-by-shot single UV-laser pulse are essential to suppress emittance growth in an RF gun. I applied a deformable mirror that automatically shapes the spatial UV-laser profile with a feedback routine, based on a genetic algorithm, and a pulse stacking system consisting of three birefringence Alpha-BBO crystal rods for temporal shaping at the same time. The 3D shape of the laser pulse is spatially top-hat (flattop) and temporally a square stacked chirped pulse. Utilizing the coherency of laser, I propose a laser-induced Schottky-effect-gated photocathode gun using Z-polarization of the laser source.