Materials Science Under Extreme Conditions of Pressure and Strain Rate

B.A. REMINGTON; G.BAZAN; J.BELAK; E.M. BRINGA

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE

SPRINGER

Lugar: Berlin; Año: 2004 vol. 35 p. 2587 - 2607

1073-5623

Solid-state dynamics experiments at very high pressures and strain rates are becoming possible with highpower laser facilities, albeit over brief intervals of time and spatially small scales. To achieve extreme pressures in the solid state requires that the sample be kept cool, with Tsample < Tmelt. To this end, a shockless, plasma-piston "drive" has been developed on the Omega laser, and a staged shock drive was demonstrated on the Nova laser. To characterize the drive, velocity interferometer measurements allow the high pressures of 10 to 200 GPa (0.1 to 2 Mbar) and strain rates of 106 to 108 s-1 to be determined. Solid-state strength in the sample is inferred at these high pressures using the Rayleigh-Taylor (RT) instability as a "diagnostic." Lattice response and phase can be inferred for single-crystal samples from time-resolved X-ray diffraction. Temperature and compression in polycrystalline samples can be deduced from extended X-ray absorption fine-structure (EXAFS) measurements. Deformation mechanisms and residual melt depth can be identified by examining recovered samples. We will briefly review this new area of laser-based materials-dynamics research, then present a path forward for carrying these solid-state experiments to much higher pressures, P > 103 GPa (10 Mbar), on the National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory