Development of Breakdown in Air in a Strongly Nonuniform Field of a Nanosecond Pulse

Resumo

The results of precision measurements of the rate of breakdown development in air at atmospheric pressure in the tip–plane electrode system are presented. It is shown that breakdown begins when the threshold voltage U_thr is reached. The higher its value is, the larger is the radius of the tip electrode; a breakdown development rate of 6.2 mm/ns is practically independent of the radius of the tip electrode and is the same for pulses with peak voltages of 25–30 kV. Visualization of the discharge structure with an aluminum film 4 nm thick showed the presence of a large number of microchannels with sizes ranging from 5 to 20 μm.