High Energy Density Materials Science on Lasers*

The field of high energy density (HED) materials science refers to regimes at energy densities greater than ~10¹² erg/cm³ or pressures greater then ~1 Mbar, accessible on high energy, pulsed laser facilities.  In this talk, a selection of experiments done on the NIF, Omega, and Omega EP lasers will be presented on a variety of materials ranging from deuterium to lead. [1-16]  Examples include high pressure equations of state measurements using VISAR diagnostics; and time resolved x-ray diffraction to determine the lattice structure at high pressures.  X-ray Thomson scattering has been used to characterize the ionization state, density, and temperature in HED plasma experiments.  Radiography has been used to characterize the sample density and optical depth on the Hugoniot at pressures from 25 – 800 Mbar.  Strength Rayleigh-Taylor instability experiments have been done in the solid state, plastic flow regime at high pressures and strain rates.  Water experiments at 1-4 Mbar have observed the superionic phase whereby the oxygen freezes into a crystalline fcc lattice, whereas the H remains itinerant.  And finally, EXAFS experiments for measuring sample temperatures at high pressures have been done on Omega, and are under development on NIF.  Examples from the above will be given.