Density dependence of the depolarized light scattering spectrum of xenon

Measurements of the depolarized light scattering spectra of xenon at densities between 0.2 and 2.6 times the critical density are presented. The density dependences of the first three even spectral moments are compared with the predictions by the theory under several simplifying assumptions where use is made of data for the static structure factor from the literature. Comparison is also possible between some characteristics of the experimental spectra and thermodynamic data and transport properties. It is clearly shown that the theory hitherto used is valid up to densities slightly above the critical density. At higher densities the density dependence of the spectral moments as well as the spectral distribution seems to follow the density dependence of the fluctuations with wave vector kσ≊π. That such fluctuations would render the dominant contributions to the spectrum in contrast with the theoretical predictions is attributed to the incorrectness of the substitution of density fluctuations for dielectric fluctuations with corresponding wave vectors.