Experimental measurements of the hollow cathode DC glow discharge parameters in Ar and He plasmas

In this article, we focus on some of the fundamental parameters of SS316L hollow cathode glow discharge. Four SS316L samples are placed at different locations on the cathode surface and the current passed through them is measured in Ar and He glow discharge plasmas. The wall current densities of Ar and He are in the range of 8–25 µA cm⁻² and 8–35 µA cm⁻², respectively. Results also show that with decreasing working pressure, the ion flux and current density distribution on the wall surface becomes more uniform. The ion flux of the Ar and He is in the range of 10¹³ to 10¹⁴ $\text{ion}\text{c}{\text{m}}^{-2}$. Total energy losses of Ar and He are measured at the pressure range of 1.4–5.5  ×  10⁻² torr and 3.2–7.1  ×  10⁻¹, respectively. In both Ar and He, total energy losses decreased with increasing pressure. The secondary electron emission coefficients of Ar and He, which are evaluated for the hallow cathode configuration, are about 0.42 and 0.26, respectively, and are higher in comparison with the plate cathode configuration. (paper)