Photoacoustic measurements to determine acoustic velocities in shocked condensed materials: Application to liquid benzene

Experimental methods were developed to obtain single-shot, photoacoustic measurements in shock compressed thin samples. Impulsive stimulated thermal scattering measurements were used to measure acoustic velocities normal to the shock propagation direction in liquid benzene compressed to nearly 1 GPa. Although the resulting pressure-temperature states correspond to the solid region of the benzene phase diagram, shocked benzene remains a liquid at pressures well above the static compression threshold for freezing. Photoacoustic measurements provide a useful approach to examine structural changes in shocked materials.