SHOCK IMPEDANCE MATCHING EXPERIMENTS IN FOAM-SOLID TARGETS - IMPLICATIONS FOR FOAM-BUFFERED ICF

The influence of foams on laser-produced shocks has been studied exper imentally using sub-ns laser pulses smoothed with phase zone plates an d focused on layered foam-aluminium targets. A strong pressure increas e was measured when the foam was present in comparison with that obtai ned by focusing the beam directly onto the aluminium target, due to im pedance mismatch at the aluminium-foam interface. Results are compared with computer simulations. The impact of these measurements on the po ssible use of 'foam-buffered targets' for direct-drive inertial confin ement fusion is briefly discussed.