SPALLATION OF METAL TARGETS SUBJECTED TO INTENSE LASER SHOCKS

Piezoelectric polymer gauge measurements were performed on the rear su rface of plane copper and aluminum foils irradiated by infrared laser pulses of 1.5 ns duration, with intensities up to about 7 T W/cm(2), u sing recently developed transducers made of a vinylidene-fluoride and trifluoroethylene copolymer. Some gauge records have indicated that in cipient spall damage occurs in the samples subjected to very intense s hocks. This was confirmed by post-test examination of the targets. The experiments were simulated using two computer codes: one describes la ser-matter interaction and provides input to the second code that hand les wave propagation. A spall model for ductile metals is integrated i n the wave code. The ability of those computer models to predict the e xperimental results was thereby tested. Overall agreement was obtained between the gauge measurements and calculations, except for some disc repancies that are discussed. (C) 1997 American Institute of Physics.