Pulse-periodic gas discharge in atmospheric pressure helium with nanosecond excitation fronts

Abstract

The characteristics of barrier gas discharge in helium at atmospheric pressure are investigated when excited by pulses with voltage rise fronts of 3–10 ns and a pulse repetition rate of 5–100 kHz. The volumetric mode of the pulse current up to 80 A with a peak power of up to 1.5 MW and a specific power supply of an average power of up to 250 W cm−3 is realized. An increase in the steepness of the excitation pulses has little effect on the discharge current value but allows to maintain the volumetric nature of the current flow to the higher operating voltages. It is demonstrated that the maximum discharge current is restricted by an increase in ionization with an increase in the electron current from the cathode due to the ion–electron emission and charging of the dielectric surface, which increases the floating potential of the cathode surface relative to plasma.