ELECTRON AND VIBRATIONAL KINETICS IN AN N2-H2 GLOW-DISCHARGE WITH APPLICATION TO SURFACE PROCESSES

The electron and vibrational kinetics in an N2-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 N2(X1SIGMA(g)+, v) and H-2(X1SIGMA(g)+, v'), which take into account e-V, V-V, and V-T processes for the N2-N2 and H-2-H-2 systems as well as those involving N2-H-2 collisions. This paper presents a large amount of calculated data on the vibrational distribution functions ot N2(X, v) and H2(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)(N2) and T(v)(H2) and a dependence of T(v)(N2) 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 N2 as it is observed in flowing discharges when a few per cent of H-2 is added to N2.