<u>X-Pinch source characterization for the study of material behavior under shock loading towards X-ray diffraction</u>

The use of X-Pinch generators constitutes an alternative way to implement fast intense X-ray emission to study short phenomenon towards radiography or X-ray diffraction. CEA Gramat has developed a X-Pinch source coupled to a single stage gas gun which is able to perform X-ray diffraction under shock loading. The first experiments showed promising results, however, the source intensity profile has shown significant differences. A better understanding of the source emission over 10 keV in terms of size and spectral emission is needed to optimize the diffraction parameters. These characterizations were done using loads made of gold wires of 25 µm diameter previously used for diffraction. A crystal spectrometer and point-projection imaging were both implemented at each flash and the results compared. Characteristic time integrated spectra were obtained with a spatial integration of the crystal spectrometer image. Point-projection imaging showed that up to three different vertically shifted sources could be involved in the emission. Classical geometrical relations are not adapted in this case and a specific tool was designed to simulate the spatial profile overlap and try to reproduce experimental measurements. The first simulations showed that the different source diameter spread from several hundred microns to over a millimeter. The intensity profile seems to influence weakly the measurements. This first study showed encouraging results and further experiments are planned to validate the tools. A database could be then built over various material wires and diameter.