Coupling a X-Pinch X-ray generator with a gas gun launcher to perform a crystallographic analysis of shocked materials under shock loading towards X-ray diffraction

The comprehension of materials mechanical behavior under dynamic loading needs to be detailed particularly when a phase change occurs to improve actual numerical models. Macroscopic velocity measurements usually implemented in dynamic experiments are not sufficient to fully understand the transition kinetics. X-ray diffraction is a complementary technique well suited to investigate the shocked materials crystal structure. CEA Gramat has set up a X-Pinch X-ray source adapted to carry out X-ray diffraction on the nanosecond scale. An experiment was set up to perform X-ray diffraction on reflection geometry of both static and shocked samples. A synchronization system was especially designed to couple the source and a single stage gas gun. The beam emission of this X-Pinch source is triggered directly into the impacted target and delayed long enough to let the shock waves reach the sample under investigation. Diffraction patterns are collected onto imaging plates before and during the experiment. Standard velocimetry is also used to retrieve the material state evolution and verify the synchronization with the beam emission. Several experiment were carried out to investigate tin solid-solid phase transition between beta and gamma phases. Shots at pressures beneath and above the transition were performed to observe the crystallographic evolution of tin single crystals. X-ray emission hardly ever spread over 100 ns and synchronization was quite satisfying in most of cases. The collected diffraction patterns showed promising results to propose the first hypothesis of tin behavior under shock loading thanks to this X-Pinch source. Similar experiments carried out on synchrotron showed similar trends, which is encouraging to continue such experiments.