Probe Diagnostics of Plasma Parameters in a Large-Volume Glow Discharge With Coaxial Gridded Hollow Electrodes

Results of the experimental investigation of glow discharge plasma created in a large-volume discharge chamber are presented. The discharge configuration consists of two coaxial gridded electrodes placed in a metallic vacuum chamber. The inner electrode and the chamber housing were grounded while time-varying power up to 2 kV with frequency 20 kHz was applied on the outer electrode. The discharge was created in air at a pressure of 50 Pa and in argon at pressures of 50 and 100 Pa. Measurements of plasma parameters were carried out with a single-probe technique using the commercial Impedans Langmuir Probe system. In order to perform time-resolved measurements, an additional synchronizing device was developed. Variation in time of such plasma parameters as electron temperature, charged particle densities, and electron energy distribution function was obtained during the experiments. It is shown that both electron temperature and density change slightly in time. Obtained results indicate that the plasma created in the considered chamber configuration is similar to the negative glow region of a direct-current glow discharge.