Kinetic modeling of low-pressure nitrogen discharges and post-discharges

The kinetic modeling of low-pressure (p similar to 1-10 torr) stationary nitrogen discharges and the corresponding afterglows is reviewed. It is shown that a good description of the overall behavior of nitrogen plasmas requires a deep understanding of the coupling between different kinetics. The central role is played by ground-state vibrationally excited molecules, N-2(X (1)Sigma(g)(+), v), which have a strong influence on the shape of the electron energy distribution function, on the creation and destruction of electronically excited states, on the gas heating, dissociation and on afterglow emissions. N-2(X (1)Sigma(g)(+), v) molecules are actually the hinge ensuring a strong link between the various kinetics. The noticeable task done by electronically excited metastable molecules, in particular N-2(A (3)Sigma(u)(+)) and N-2(a' (1)Sigma(u)(-)), is also pointed out. Besides contributing to the same phenomena as vibrationally excited molecules, these electronic metastable states play also a categorical role in ionization. Furthermore, vibrationally excited molecules in high v levels are in the origin of the peaks observed in the. owing afterglow for the concentrations of several species, such as N-2(A (3)Sigma(g)(+)), N-2(B (3)Pi(g)), N-2 + (B-2 Sigma(u)(+))and electrons, which occur downstream from the discharge after a dark zone as a consequence of the V-V pumping-up mechanism.