Streak Investigations of the Initial Phase of a Subnanosecond Pulsed Electrical Breakdown in Gas Gaps

Abstract – Streak investigations of the glow, which accompanies the breakdown of highly overvoltaged gas gaps by voltage pulses having the rise time of 1 ns or shorter, is performed. The gap flashover is followed by ionization wave processes starting in the gas volume and playing the decisive role at the first phase of the breakdown. The dynamics of the ionization waves in the interelectrode gap is calcu-lated in a one-dimensional approximation. A uni-form distribution of the initial electrons over the volume of the gas gap is taken as the initial condi-tion. The calculation results are in qualitative agreement with the relevant experimental data. It can be stated therefore that the breakdown can be initiated from the volume of the gas rather than from the surface of the electrodes. 1