Collision-induced light scattering: Integrated intensity of argon

Abstract

The collision-induced light scattering of argon has been measured as a function of density in the gas phase up to 530 amagat at room temperature and in the liquid phase near the triple point. The present measurement of the integrated intensity near the triple point is in strong disagreement with the previous result of Fleury and McTague and is much closer (within a factor of 1.5) to the molecular-dynamics calculations of Alder, Weiss, and Strauss. When the interaction function for collision-induced anisotropy, which accounts well for the results of the dilute-gas experiment, was used in the molecular-dynamics calculations the agreement between the calculated and measured integrated intensity at the triple point was found to be within the experimental error. It is concluded that the effect on the intensity of higher-order terms (i.e., other than the double-double scattering) cannot account for more than ≃ 10% of the total integrated intensity of argon.