The parameters of a plasma flow of a vacuum dielectric flashover

Recently [1] it was revealed that vacuum flashover is source of multiple charged accelerated ions. In [1] high voltage short duration generator RADAN 150 [2] with fixed pulse parameters (150kV, 4ns) was used. The mechanism of formation and acceleration of multiple ionized plasma flow remains unclear. This paper is devoted to obtain dependence of flashover plasma parameters on pulse amplitude and duration. Two type of generators were used. 1. The pulse cable generator with durations of pulse 5ns, 35ns, 50ns and 100ns. 2. RADAN generator with 150kV pulse amplitude and 5ns duration. High pressure polyethylene was used as dielectric. The discharge electrodes was made of copper. Cathode was a copper wire 1mm or 4mm diameter placed in the center. Anode ring was 4mm or 25mm diameter. Anode - cathode gap was 1mm for cable generator or 1cm for RADAN. The results of experiments shows, that there is no considerable dependence of ion energy on a pulse amplitude and straight one on a ion charge. Time of ion charge composition formation is about 5ns.