Thermal disequilibrium effects in a molecular glow discharge

Abstract

An experimental study of the vibrational and rotational temperature behaviour of molecular nitrogen under conditions that are far from equilibrium is presented and a comparison is made with the thermal equilibrium state of nitrogen at elevated temperature. Thermal equilibrium is represented by the temperature situation within a graphite furnace used for atomic absorption spectrometry, whereas the non-equilibrium case can be studied by the vibrational-rotational temperature behaviour within an r.f.-excited carbon dioxide laser. As it is non-intrusive, the non-perturbing thermometric technique served in both instances for the evaluation of nitrogen Q-branch spectra obtained by coherent anti-Stokes Roman scattering.