Nanosecond-pulse breakdown of gas-insulated gaps

Breakdown characteristics (50% probability of flashover voltage versus pressure-length characteristics) by impulse voltages with half-peak widths, 30 and 74 ns, respectively, were investigated at uniform field gaps in the atmospheric gases such as air, N2, and O2. Our investigation shows that under impulse voltages with short durations such as 30 and 74 ns, which seem to have an influence on streamer formation, Paschen’s law is valid at gap lengths l=1 and 2 cm, and streamer criteria are satisfied within an electron developing distance, 0.048–0.18 cm, from the cathode.