Brillouin scattering from liquid CCl4 at high pressures

Brillouin spectra were obtained from liquid carbon tetrachloride at pressures ranging from 1 to 1500 bar and at three temperatures (298, 323, and 348 K). Using Mountain’s theory the relaxation time τv of the bulk viscosity and the energy relaxation time τE=Cv⋅τv/(cv−ci) were derived from the experimental spectra. At constant temperature τE decreases with increasing density, and at constant density τE decreases with increasing temperature. From τE the effective collision diameter was calculated for hard spheres (HS): σHS=5.24±0.05 Å.