DYNAMICS OF LASER-PRODUCED SHOCKS IN FOAM-SOLID TARGETS

The influence of foams on laser shocks was studied with ns laser pulse s smoothed with phase zone plates and focused onto layered foam-alumin um targets. Foams of 5 - 200 mg/cm(3) density and 60 mu m thickness we re used. A strong pressure increase was measured with the foam in comp arison to focusing the beam directly onto aluminum due to impedance mi smatch at the aluminum-foam interface. Below a particular density, the measured pressure decreased as a result of hydrodynamics effects. Res ults are compared with computer simulations. (C) 1998 American Institu te of Physics.