New analysis of the density effects observed on the rotational line profile of induced spectra of H2 and D2 dissolved in argon

Abstract

The induced rototranslational absorption spectra of H2 and D2 dissolved in argon have been measured at T = 165 K at different densities up to about 650 amagats. These new and accurate measurements allow us to derive reliable experimental profiles for the single rotational line. From the induced dipole moment autocorrelation function as obtained from the experimental profile, we have derived a characteristic time suitable to parametrize the density narrowing of the spectral lines. We show how using this new analysis we can solve the inconsistencies and the ambiguity found in previous works on the narrowing effect. The main features of the narrowing phenomena are discussed with the help of simple models.