Theory of Intercollisional Interference Effects. III. Collision-Induced Light Scattering

The kinetic theory of intercollisional interference effects in optical spectra of gases developed in two previous papers is extended to the collision-induced light scattering from monatomic gases. The quadratic dependence of the incremental polarizability on the direction cosines of the intermolecular axis, compared to the linear dependence for the induced dipole moment, makes the effect quite different for light scattering and absorption. For a hard-sphere model an intercollisional peak, rather than a dip, of a relative height of 25% and a width proportional to the density is predicted to appear on top of the intracollisional light scattering spectrum.