Particle Velocity Measurements Of Laser-Induced Shock Waves Using ORVIS

This paper discusses experiments in which 2 to 200-pm-thick aluminum foils were irradiated with Nd/YAG laser pulses at 3-4 GW/cm2 for 10 nsec. An optically recording velocity interferometer system (ORVIS) was used to record the resulting particle-velocity histories with nanosecond resolution. Results show 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-pm-thick foil attains a peak velocity of 0.2 km/sec. 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.