Self-pulsing characteristic of hollow cathode discharge at low pressure range in argon

In order to increase the discharge stability and explore the mechanism of self-pulsing in hollow cathode discharge, the self-pulsing phenomenon was investigated in a cylindrical hollow cathode at low pressure in argon. The volt-ampere characteristics, the discharge images, and the time evolution of the current and voltage of self-pulsing were measured under different conditions. The influences of the gas pressure, the discharge current, and the external resistance on the self-pulsing were also studied. Results show that the self-pulsing can be observed in the negative differential resistance region of hollow cathode discharge. The pulse frequency ranges from several kilohertz to tens of kilohertz, and increases with the average current. It is determined mainly by the decay time of the current pulse. The external resistor in series has some influences on the discharge range where the self-pulsing exists. The self-pulsing can be created in a wider average current range as the resistance increasing.