Evolving shock-wave profiles measured in a silicon crystal by picosecond time-resolved x-ray diffraction

Abstract

Picosecond time-resolved x-ray diffraction is used to probe single-crystal silicon under pulsed-laser irradiation (300 ps pulse at 1.4 J/cm2) at an interval of 60 ps. The observed rocking curves show shock compression of the silicon lattice by the laser irradiation. Uniaxial strain profiles perpendicular to the Si(111) plane are estimated using dynamical x-ray diffraction theory. The temporal and spatial evolution of the profiles indicates a propagating shock wave with the velocity of 9.4 km/s inside the silicon crystal. The observed maximum compression is 1.05%, which corresponds to a pressure of 2.18 GPa.