Optical and Electrical Characteristics of AC Glow-Discharge Plasma in

This paper considers the optical and electrical characterization of an ac glow-discharge plasma in the abnormal glow mode used for optical emission spectroscopy. The total discharge current and applied voltage are measured using conventional techniques. The electrical characteristics of the planer-cathode glow discharge confirmed that the plasma is operating at an abnormal discharge mode characterized by the increases in the operating voltage as the current was raised under given pressure. Optical emission spectroscopy was used to determine the main emission lines of the glow-discharge plasma of N₂O at pressures between 0.5 and 4.0 torr. It shows that the discharge emission range is mainly within 300-400 nm. The emission lines correspond to NO, O₂, and O₂ ⁺ are the dominant lines in the glow-discharge plasma in this paper. Intensity of the emission lines show linear increase with the discharge current up to 0.4 A followed by saturation at higher currents. No emission lines were observed in this paper corresponding to atomic oxygen or nitrogen