Self-consistent kinetic model of the short-lived afterglow in flowing nitrogen

A detailed kinetic model for the flowing nitrogen microwave discharge and post-discharge is developed with the aim of gaining a deeper understanding into the processes responsible for the formation of the short-lived afterglow of nitrogen and for the enhancement of the concentration of N2(A3Σ+) metastable, measured at approximately the same position in Sadeghi et al (2001 J. Phys. D: Appl. Phys. 34 1779). The present work shows that the peaks observed in the afterglow, for the density of molecules in radiative N2(B 3Πg) and N2+(B2Σu+) and metastable N2(A3Σu+) states, can be explained as a result of a pumping-up phenomenon into the vibrational ladder produced by near-resonant V-V energy-exchange collisions, involving vibrationally excited molecules N2(X1Σg+,v) in levels as high as v ∼ 35. The present predictions are shown to be in good agreement with the measured concentrations for N2(A3Σu+) metastables and N(4S) atoms, and with the emission intensities of 1+ and 1- system bands of N2