V-T Process in Nitrogen Ground State Post-Discharge Kinetics

The post-discharge kinetics is a very complex problem. Various radiative and non-radiative processes lead during the post-discharge period to the establishing of thermodynamic equilibrium. Generally, all these processes are vibrationally specific. A special interest deals with the processes of metastables. In presented numeric model of nitrogen plasma, the vibrational distribution function (VDF) is studied in time. About 90 % of total energy in active plasma is dissipated into vibrational levels of the ground state and this energy is transformed to the electron excitation, ionization, dissociation and other processes during the afterglow. More or less all post-discharge kinetics thus starts in the ground electronic state where vibrational-translational (V-T) and vibrational-vibrational (V-V) energy transfers play the major role. Thus both these processes are necessary to know for the calculation of VDF in time. The first step of our calculation is the simulation of V-T process for the collision of N2 molecule with vibrationally specific N2(X, v) molecule. Subsequently, probabilities of the V-T transfer are calculated from the SSH theory at particular discharge conditions. Finally, the time evolution of VDF is calculated from the obtained transfer probabilities and initial concentrations in active discharge.