Discussion on population kinetics and number densities of excited species of low‐pressure discharge nitrogen plasma

Abstract

A numerical model is constructed to calculate the number densities of some excited species of nitrogen in low‐pressure discharge nitrogen plasma, together with simultaneous solution of the self‐consistent electron energy distribution function and N2‐vibration distribution function. We consider species N2(X), N2(A), N2(B), N2(C), N2(a), N2(a′), N2+, N4+, N(4S) ande−. In addition to electron collisional reactions, diffusion losses and molecular relations are included. It is found that the ratio of number densities of N2(B) and N2(C) states can be a good measure of the electron kinetic temperature. The N2(C) state is found to be almost in a corona equilibrium, whereas the N2(B) state becomes mainly populated by N2(X,v≥6) + N2(A) reaction and depopulated by collisional relaxation by the ground‐state N2(X) molecule. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.