A. Garscadden et R. Nagpal, NONEQUILIBRIUM ELECTRONIC AND VIBRATIONAL KINETICS IN H-2-N-2 AND H-2DISCHARGES, Plasma sources science & technology, 4(2), 1995, pp. 268-280
In the first section of this paper, the results from a systematic theo
retical study describing the electron kinetics and the heavy particle
kinetics of H-2 in glow discharges through H-2-N-2 mixtures are presen
ted. The results show that the collisional interactions between the vi
bronic states of H-2, N-2 are highly nonlinear, and that they strongly
affect the dissociation, ionization, gas heating, discharge impedance
and power loading. It is shown that at low discharge currents (< 80 m
A), medium gas pressures (> 1 Torr), and approximate to 10-80%H-2-N-2
gas mixture composition, quenching of the excited electronic states of
N-2 by H-2 is the dominant dissociation channel of H-2 in %H-2-%N-2 d
ischarges. The results further demonstrate that the dissociation balan
ce and the electronic/ionization balance in these molecular glow disch
arges are strongly coupled and that neither can be studied independent
ly of the other. In the second section of this study, a revised kineti
c analysis of the formation of atomic H- negative ions in volume sourc
es is presented. A new process for the production of H- is introduced
in the analyses. Using data derived from recent experiments, it is sho
wn that the contribution to H- formation from dissociative attachment
to the high Rydberg states of H-2 is comparable to (or greater than) t
hat from H-2(X(1) Sigma(g)(+), v). This additional source term for H-
production may resolve some of the problems in understanding the H- de
nsities in low-pressure H-2 plasmas.