Solid-state experiments at high pressure and strain rate

Experiments have been developed using high powered laser facilities to stud y the response of materials in the solid state under extreme pressures and strain rates. Details of the target and drive development required for soli d-state experiments and results from two separate experiments are presented . In the first, thin foils were compressed to a peak pressure of 180 GPa an d accelerated. A pre-imposed modulation at the embedded Rayleigh-Taylor uns table interface was observed to grow. The growth rates were fluid-like at e arly time, but suppressed at later time. This result is suggestive of the t heory of localized heating in shear bands, followed by conduction of the he at into the bulk material, allowing for recovery of the bulk material stren gth. In the second experiment, the response of Si was studied by dynamic x- ray diffraction. The crystal was observed to respond with uni-axial compres sion at a peak pressure 11.5-13.5 GPa. (C) 2000 American Institute of Physi cs. [S1070-664X(00)94505-1].