Evolution of subnanosecond pulsed electric breakdown of gas gaps for uniform gas preionization

Initiation and evolution of breakdown of gas gaps by surge voltage pulses with a rise time of ≤1 ns are investigated experimentally and theoretically. The propagation of ionization waves for a uniform initial electron distribution in the gap is analyzed. The results of calculation are in qualitative agreement with the experiment. It is shown that the evolution of ionization waves leads to electric field redistribution in the discharge gap, and a region of an enhanced field with the strength sufficient for initiating emission processes and generation of a short fast electron beam in the cathode region is formed at the cathode for a very short time (up to 100 ps).