Gun breakdown prevention in a system with dense nonrelativistic electron beam focused on a solid target in pulses with millisecond duration

Experiments on formation of a dense nonrelativistic long-pulsed electron beam (20-50 keV, 1-5 A) are presented. As a result of prevention of discharge processes in the high-voltage gap of an electron gun, high energetical parameters of electron beam (pulse duration up to 5 ms and energy density up to 100 kT/cm/sup 2/) had been obtained. A qualitative model of observed phenomena is proposed.