Electron and vibrational kinetics in an N₂-H₂glow discharge with application to surface processes

The electron and vibrational kinetics in an N 2 -H 2 glow discharge have been analysed using a self-consistent theoretical approach valid in the conditions of a low-pressure moderate current, positive column. This model is based on the solutions to the homogeneous Boltzmann equation and the two systems of rate balance equations for the vibrational levels N 2 (X 1 Sigma g + , v) and H 2 (X 1 Sigma g + , v'), which take into account e-V, V-V, and V-T processes for the N 2 -N 2 and H 2 -H 2 systems as well as those involving N 2 -H 2 collisions. The paper presents a large amount of calculated data on the vibrational distribution functions of N 2 (X,v) and H 2 (X,v') molecules, electron energy distribution function, rate of dissociation and electron rate coefficients for excitation. This formulation provides a relationship between the characteristic vibrational temperatures T v (N 2 ) and T v (H 2 ) and a dependence of T v (N 2 ) on the fractional H 2 concentration, which are in satisfactory agreement with measurements by emission spectroscopy and by CARS. The model also predicts the strong decrease of the rate of dissociation of N 2 as it is observed in flowing discharges when a few per cent of H 2 is added to N 2 .