On the coupling of electron and vibrational energy distributions in H2, N2, and CO post discharges

Abstract

A coupled solution of the Boltzmann equation, of the vibrational master equation, and of the plasma chemistry describing the dissociation process has been performed in H2 post discharges in the μs and ms regimes. The results in H2 show that the superelastic vibrational gain tends to compensate both the inelastic and elastic (including rotational) energy losses, thereby yielding a quasistationary situation characterized by an electron ‘‘temperature’’ smaller than the vibrational temperature θ1(Te<θ1). Results for N2 and CO show that the correlation Te∼θ1 does exist only at moderate θ1 values, when the vibrational distribution is mainly concentrated on the first vibrational levels. At higher θ1 values, Te>θ1 in N2 and CO as a result of the deviation of the actual vibrational distributions of these species from the Boltzmann one.