Application of the thermal conduction model to rotational relaxation in molecular beams

Abstract

A simple approach to the estimation of rotational relaxation times and collision numbers in supersonic expansions based on the use of the thermal conduction model is presented. Expressions are derived for the calculation of these quantities and relaxation times are calculated as a function of mean kinetic temperature and axial distance from the nozzle exit for the homonuclear diatomic species H₂, N₂, O₂ and Cl₂.