Classical absorption and emission spectroscopy of barrier discharges in N-2/NO and O-2/NOx mixtures

By using emission and classical absorption spectroscopy with a continuum light source we have investigated dielectric barrier discharges in N-2/NO and O-2/NOx mixtures. The concentrations of NO, NO2, NO3, N2O5, and O-3 were measured inside the discharge and in the exhaust. In the discharge space resolved absorption spectroscopy was performed. In discharges with high content of NO or NOx electron impact induced dissociation of NO and NO2 turned out to be important. in discharges in pure nitrogen we found emission from NO and O(S-1). This indicates a surface reaction of atomic nitrogen with chemisorbed oxygen and desorption of atomic oxygen. No indication for the presence of physisorbed NO was detected. A novel method for obtaining the electron distribution function from absolutely measured light intensities was applied and the results compared to solutions of the Boltzmann equation.