In-Situ Probing of Lattice Response in Shock Compressed Materials Using X-Ray Diffraction

Abstract

Abstract. Lattice level measurements of material response under extreme conditions are required to build a phenomenological understanding of the shock response of solids. We have successfully used laser produced plasma x-ray sources coincident with laser driven shock waves to make in-situ measurements of the lattice response during shock compression for both single crystal and polycrystalline materials. Using a detailed analysis of shocked single crystal iron which has undergone the α − ε phase transition we can constrain the transition mechanism to be consistent with a compression and shuffle of alternate lattice planes.

Nanosecond white-light Laue diffraction measurements of dislocation microstructure in shock-compressed single-crystal copper

“…Given that the fundamental understanding sought is of the physics that is occurring at the lattice level, the development of techniques of X-ray diffraction on nanosecond and sub-nanosecond timescales, with the X-ray pulse synchronized to the shock, appears a promising approach for such investigations. Indeed, such time-resolved X-ray diffraction (TXRD) methods have been used extensively to study shock phenomena for several decades [12][13][14][15][16][17][18][19][20] , with several notable successes, including the direct observation of the a À e transition in shock-compressed iron 6,21 . Some progress in understanding rapid shock-induced plasticity has been made: diffraction of monochromatic X-rays from planes parallel and perpendicular to the shock propagation direction has directly detected elastic strain in both directions (which gives a measure of plastic strain, as the total strain (elastic plus plastic) perpendicular to the shock propagation direction in a uniaxially strained material is zero) 16,[22][23][24][25] .…”