Electron energy distribution functions in He-CO discharge laser mixture: The role of superelastic electronic collisions

Electron energy distribution functions (EDF) in He-CO mixtures have been calculated by solving the Boltzmann equation including superelastic vibrational and electronic collisions. The latter include the metastable states CO(a3Π) and He(3S). The results show that the presence of superelastic electronic collisions strongly affect EDF. In particular small concentrations of He(3S) modify the shape of EDF, by creating different structures. The net result is the dramatic dependence of electronic and ionization rate coefficients on the concentrations of He(3S) and CO(a3Π), while the vibrational rate coefficients are practically unaffected by the presence of these states. (author)