The mechanism of electrical breakdown of gases, initiated by a large number of electrons

Publisher Website
Google Scholar
Abstract
The mechanism of breakdown in uniform fields was investigated in humid air, dry air, oxygen, hydrogen and nitrogen at atmospheric pressure, using a large number of initial electrons (similar 104) released from the cathode as a delta function at the start of a high-voltage rectangular pulse applied to the discharge gap. The threshold breakdown voltages were about 30% higher than the DC breakdown voltages reported by others. The formative times at threshold and at overvoltages indicated that up to a critical overvoltage, breakdown takes place by the multiple-avalanche Townsend mechanism, due to a photoelectric secondary effect at the cathode. The magnitudes of the critical overvoltages were not significantly less than those with a single initial electron obtained by other workers. For overvoltages higher than the critical, there was a transition region, at the end of which, breakdown transforms to the single-avalanche streamer mechanism.