The Rayleigh–Brillouin spectrum of hydrogen at high densities

Abstract

The Rayleigh–Brillouin spectrum of light scattered from hydrogen at high densities is reported. The observations are compared with translational hydrodynamic theory and ultrasonic experiments. The range of densities includes the relaxation region and we find evidence for multiple relaxation. A mean relaxation time for normal hydrogen at 24 °C of (1.41 ± 0.06) × 10−8 s is found, in agreement with theoretical calculations.