Multipeak pulse x-ray diffraction study of shocked single crystals

The geometry of a pulse x-ray diffraction survey is suggested to obtain a multipeak x-ray diffraction pattern from a single crystal sample in planar impact experiments. This geometry allows simultaneous recording of x-ray reflections from different crystal planes. The corresponding mathematical expressions for screen (detector) positions of the reflections produced by both strained and unstrained crystals are developed. In the case of the reflections from (200) and (220) crystal planes, the expressions enable the, strain tensor components to be extracted from the relative shifts of diffraction peaks. The expressions were applied to interpret the multipeak diffraction patterns obtained from NaCl single crystals both shock-compressed and unloaded after the shock compression. The lattice strain alterations observed may be explained within the framework of dislocation theory of plastic deformation. (C) 2003 American Institute of Physics.