X-ray diffraction technique with VISAR support for study of shock-compressed single crystals

A new geometry of X-ray diffraction survey of single crystal in the monochromatic X-ray radiation was used to obtain a diffraction patterns of shock-compressed NaCl single crystals. Shock compression of the 2-mm [100]-oriented single crystals backed with 0.7-mm graphite window was produced by 6-mm Al impactors accelerated up to velocities 320-330 m/sec in 25-mm pneumatic gun. The velocity of the free surface of the graphite window was monitored by VISAR. In two shots the 30-nsec pulse X-ray source was triggered after the arrival of the elastic precursor and the plastic wave front at the NaCl-window interface. No evidence of the transversal strain were found in the diffraction patterns of the shock-compressed NaCl. The material seems to be able to maintain the state of 1-D strain under intensive plastic deformation