Extended plateaux in the vibrational and electron distribution functions of O-2/O reacting plasmas in discharge and post-discharge conditions

An accurate state to state model describing the plasma kinetics in reacting oxygen plasma has been built up giving particular attention to vibrational-translational O-O-2 processes, as well as O-O-2(v) dissociation and recombination, direct electron impact dissociation, and resonant electron-vibration (e-V) processes for O-2. Moderate and low pressure situations are investigated for both discharge and post-discharge conditions. In both cases, an important role of three body recombination of O atoms and of multi-quantum e-V processes is observed, the latter being particularly important at low pressure. The interplay of the different processes forms an extended plateaux on the vibrational distribution function (vdf) of O-2 in both discharge and post-discharge conditions. A comparison between our calculated vdf and the corresponding experimental and theoretical results of Annusova et al. shows a good qualitative agreement. Declining plateaux are also observed in the electron energy distribution function. In this case, superelastic electronic collisions involving high lying electronic states of the O atom form important maxima over the declining plateau.