Abstract
Effects of admixing argon to air DB discharge, at atmospheric pressure, on the electrical and optical emission characteristics have been studied. Optical emission spectroscopy is used to investigate the effect of argon admixing on the emission intensity of the nitrogen second positive systems (300-450 nm) and its relative population of N-2(C-3 Pi(u),v') state. Also the vibrational temperature of the nitrogen second positive systems has been calculated for the sequence Delta v = -2, that follows Boltzmann's distribution. It was found that the vibrational temperature of second positive system can be raised significantly from 0.31 to 0.35 eV in air dielectric barrier discharge (DBD) plasma at discharge current 0.5 mA with admixing of Ar gas at flow rate of 3 L/min. Admixing of argon to air DB discharge also enhances the discharge current, the electron density and the consumed power. Mechanisms of excitation and ionization processes of nitrogen molecules in this mixture have been studied. Processes which are responsible for the enhancement of the population density of N-2(C-3 Pi(u),v') and its vibrational temperature have been reported.