Particle-velocity measurements of laser-induced shock waves using ORVIS

Experiments in which 2 to 200-(SIGMA)m-thick aluminum foils were irradiated with Nd/YAG laser pulses at 3 to 4 GW/cm(2) for 10 ns are discussed. An optically recording velocity interferometer system (ORVIS) was used to record the resulting particle velocity histories with nanosecond resolution. It is shown that foils suspended in air are accelerated, over a period about three times the length of the laser pulse, to a final velocity inversely proportional to foil thickness. A 12-(SIGMA)m-thick foil attains a peak velocity of 0.2 km/s. Foils confined by water undergo most of their acceleration during the laser pulse and attain surface velocities three times greater than do air suspended foils of the same thickness.