Lattice Dynamics of Shocked, Single-Crystal Tantalum Characterized using Dynamic White-Light Laue X-ray Diffraction

We report on recent experiments at the Omega laser facility that demonstrate the use of broadband x-ray diffraction to probe the lattice dynamics of tantalum crystals under a range of shock-loaded conditions (1 -- 2.2MBar). In the experiments, an implosion capsule x-ray backlighter (approx 150 ps duration) driven by 44 Omega beams (22 kJ total in a 1 ns square pulse) was employed to produce the white light diffraction pattern. VISAR was employed simultaneously to infer the high-pressure conditions in the shocked Ta crystal. We show how the residual strain present in a 1D-to-3D relaxed lattice can be obtained from the x-ray diffraction data. This information, when combined with an elastic constant calculated from first principles for the pressure as determined from VISAR, allows the strength of the crystal to be inferred.