Coupled electron and excited-state kinetics in a nitrogen afterglow

The coupling between the metastable state N2(A3Σ+u) and the electron energy distribution function (EDF) as well as the vibrational distribution N2(X,v) of the ground state in a nitrogen afterglow has been studied by simultaneously solving the Boltzmann equation for the EDF and the rate equations describing the kinetics of N2(A) and N2(X,v). The results show that in the decaying plasma, the presence of N2(A) strongly affects both the EDF and N2(X,v). In particular, superelastic electronic collisions produce a broad maximum in the EDF which follows the temporal evolution of the N2(A) concentration, while bimolecular reactions involving N2(A) create a N2(X,v) distribution characterized by a plateau which decays with time.