Experimental investigation and numerical simulation of the energy distribution of positive ions in the negative glow of an oxygen discharge

Abstract

Using a two-electrode probe, we measured the energy distribution functions of positive ions in the cathode regions of an oxygen glow discharge. The ion distribution functions have two maxima, the magnitude and position of which depend on the gas pressure and the voltage applied to the probe. The proposed approximation of the observed distribution functions is based on the assumption that two groups of ions exist with different mean energies and well described experimental curves. We numerically simulated the measuring process and found an approach for reproducing the ion energy distribution in the plasma unperturbed by the probe.