EXPERIMENTAL-STUDY ON THE PRODUCTION OF HIGH-DENSITY ELECTRON BUNCHES FROM A GAAS PHOTOCATHODE

In order to obtain a high charge, low emittance electron source, useful for FEL electron injector and for e+ e- collider experiments, we performed a test experiment on a gallium arsenide photocathode, activated by negative electron affinity technique and illuminated with a 10 ns long laser pulse of 532 nm wavelength. We measured a maximum charge delivered, at relatively low potentials, of about 18 nC/bunch. The mean lifetime is greater than 60 h.