Nitrous oxide production-loss balance in non-thermal high pressure N$_{2}$/O$_{2}$ plasmas and correlation with acetaldehyde removal

Various nitrogen oxides and ozone molecules are produced in high pressure non-equilibrium plasmas in N$_{2}$/O$_{2}$ mixtures. Amongst these compounds, the production-loss balance of N$_{2}$O involves excited states of atomic and molecular oxygen and nitrogen, in particular metastables which play important role in the conversion of hydrocarbons and VOCs. The measure of the N$_{2}$O density should help in the understanding of the excited states kinetics if measurements can be compared to predictions of a self-consistent modelling of the discharge and plasma reactivity. This is the case for the photo-triggered discharge which allows to create a transient homogeneous plasma. The present work deals with the N2O kinetic processes studied with the help of model predictions compared to the measure of the molecule density by laser absorption spectroscopy in the infrared (QCL). Main parameters are the O$_{2}$ percentage in the mixture (at 460 mbars) and the specific deposited energy. Results are discussed with respect to the existing literature on the N$_{2}$O kinetic. The effect of addition of a small amount of acetaldehyde (less than 0.5 {\%}) to the N$_{2}$/O$_{2}$ mixture is examined in order to get information about the role of N$_{2}$ and O metastable states in the removal of the pollutant molecule.