Investigation of the Propagation of Intense Charged Particle Beams into Vacuum

Abstract : Laser-controlled beamfront accelerator experiments achieved gradients of up to 40 MV/m and proton acceleration to 18 MeV over 40 cm with a beam energy of 900 keV. Beamfront electric field degradiation requirements beam energy to be increased as the gradient is increased. An experiment with a beam energy of 1.5 MeV achieved a 60 MV/m gradient in a 100 cm distance, matching theoretical models. Experiments with psuedospark discharges achieved electron beams of 25 KV, 1000 A/sq. cm., 10 ns with 10(11) A/(m-rad)sq brightness. Theory indicates densities greater than 10(3) A/sq. cm. and brightness greater than 10(11) A/(m- rad)sq are achievable. (jhd)