Characteristic Study of an Atmospheric-Pressure Radio-Frequency Capacitive Argon/Nitrogen Plasma Discharge

A developed atmospheric-pressure capacitive discharge source driven by radio-frequency power supply at 13.56 MHz is capable of producing a homogeneous and cold glow discharge in N₂/Ar. The measurements of its electrical parameters are made systematically with respect to the nitrogen component when diluted into argon plasma discharge at various concentration ratio, and the variation tendencies of the atomic nitrogen and the N₂(C³Π_u) states with the concentration ratio of nitrogen to argon are investigated by means of optical emission spectroscopy. It is shown that although the admixture of nitrogen into argon plasma changes the electric characteristics greatly, the vibrational distribution function alters slightly at the same mixture ratio, and the production of N-atom is proportional to the nitrogen component.