The influence of molecular multipole moments on the dielectric relaxation of polar gases

Abstract

A phenomenological model permitting the approximate calculation of the high absorption of microwaves in the transmission windows of the microwaves spectra of polar gases is developed. According to the model, events during collision of polar molecules may be regarded as giving rise to a bulk polarization with a typical relaxation time of 5 × 10 −13 seconds. This polarization results in a broad nonresonant spectrum similar to dielectric relaxation in symmetric top molecules. The resonant spectra are superimposed on this absorption. The absorption is a sensitive function of molecular multipole parameters which in turn can be calculated from the experimental data. Estimates of these parameters for mixtures of H 2O with H 2O, CO 2, and N 2 and for mixtures of HCl with HCl, CO 2 CO, CH 4, and N 2 are in fair agreement with values obtained by other sources.