Radiative Characteristics of N₂ Second Positive Bands With Non-Boltzmann Rotational Population Distribution

(Modeling Based Upon Simple Collision Theory and Effect of Radiative Transition)

Abstract

The characteristic intensity distribution in the N₂ second positive bands observed in high-temperature air plasmas generated by air micro-plasmajets was reconstructed by the theoretical spectra with the effects of predissociation and non-Boltzmann rotational population distribution. In order to construct the precise theoretical spectra, collisional transition rate coefficient that was applicable at high temperatures was proposed based upon a simple collision theory. In addition, the effect of the radiative transition from C ³Π_u to B ³Π_g state was included in the master equation. The theoretical spectra with non-Boltzmann rotational population distribution calculated with such factors agreed very well with the experimental ones.