Influence of a voltage pulse rise time and pressure of air and nitrogen on the parameters of runaway electron beams

The generation of runaway electron beams with different high-voltage generators has been studied. The current of runaway electron beams generated during breakdown in air and nitrogen at a pressure range of 25–100 kPa was measured. It has been shown the conditions for electron runaway are easily realized at voltage pulse rise time of up to 200 ns. It has been found that to measure electron beam current at minimum voltages (tens of kilovolts) and a long rise time of the voltage pulse, anodes from a grid with a small cell size should be used. It follows from this work and the results of our previous studies that the generation of a runaway electron initiates the formation of a streamer, the development of which leads to an initial drop in the voltage across the gap.