Dependence of Voltage-Current Characteristics of High-Current Nitrogen Glow Discharge on Gap Length and Gas Pressure

Abstract

Voltage-current characteristics and plasma parameters of high-current nitrogen glow discharge for various gap lengths and gas pressures are described in this article. The transient glow discharge was produced with high-current larger than 100 A by static breakdown in nitrogen gas. Damping resistor was used to control the glow discharge current and was altered in order to obtain the voltage-current characteristics. The voltage-current characteristics of the normal glow phase and the abnormal glow phase were obtained in a wide current range from 50 mA to 100 A. The experimental results show that the current at phase transition of a normal to abnormal glow increases with increasing the gas pressure. The current at the phase transition is independent of the gap length. The electron density and temperature in positive column of the glow discharge were estimated using the voltage-current characteristics. The electron density and temperature increased with increasing the glow current and these values were 1010-1012 cm-3 and a few eV, respectively. The number densities of ions, metastable molecules and atomic radical particles in plasma were also estimated based on the each voltage-current characteristics. Metastable molecules density was 2-3 orders higher than electron density. Especially, the N2(A) metastable molecule density was 3 orders higher than the other metastable molecule densities.