Analysis of the N₂O dissociation in a RF discharge reactor

Abstract

In situ diagnostic measurements and reactor modelling are used to study the N2O dissociation by radio frequency (RF) discharges. Measurements are undertaken at 0.5 and 1 Torr gas pressure with a RF power density varying from 4.2 to 35.7 mW cm-2. The reactor modelling involves an electrical discharge model coupled to hydrodynamic and mass transfer models. Only an electrical discharge model accounting for the negative ion conversion from O- to NO- and the subsequent electron detachment allow a good coherence between the measured and predicted power densities. The electron-N2O dissociation cross sections are first fitted in the present work and then the corresponding dissociation rates, obtained from the electrical model, are used in the mass transfer model which includes eight species (N2O, N2, O2, NO, NO2, N, O(3P) and O(1D)). The corresponding results are in good agreement with the experimental ones related to the production of N2 and O2 and the consumption of N2O. Furthermore, the reactor model results show that N2 and O2 are the most abundant products (>1014 molecules/cm3) at 1 Torr.