Electron Energy Distribution Functions in He-CO DC 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(a³II) 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(a³II), while the vibrational rate coefficients are practically unaffected by the presence of these states.