Similarity of Gas Percentage and Strength of Magnetic Field on the Electrical Characteristics Control of dc Plasma

Abstract

For nitrogen gas discharge, the control of argon percentage in (Ar-N2) gas mixture and in different magnetic field strengths, both separately in effect were investigated the electrical characteristics of DC plasma at constant low pressure (0.7torr). Under the influence of Ar gas mixture percentage (Ar%) or different magnetized discharges (B+), the plasma parameters were measured such as the discharge current-voltage curves, breakdown voltages, potential distribution, electric field distribution, and the cathode fall thickness (Zc) using the axial potential distribution method, it is noticeable that the breakdown voltages as a function of Ar % were more than those as a function of B+ by 17%, furthermore a reduction of (Zc) about 22% due to the applied B+ more than the case of the applied Ar %. Moreover, the electron energy distribution function (EEDF),electron temperature, and electron density were measured using single Langmuir probe, where electron temperature decreased about 38% for B+ more than Ar%, taking into account, general trend that values of Te and Ne are inversely proportional, where electron density increased about 37% for B+ more than Ar%. Furthermore, a non-Maxwellian EEDF was observed due to two groups of electrons were detected in the case of Ar%, in contrast, a Maxwellian EEDF was found  in the case of B+ due to one group of electrons.