In-situ diffraction of shock compressed hydrous minerals and complex geomaterials using large area X-ray detectors at MEC

We present measurements of structure of shock compressed hydrous minerals brucite, Mg(OH)2, and Fe-epoxy slurry using newly commissioned large area VAREX X-ray detectors at the Matter in Extreme Conditions (MEC) end-station at the Linac Coherent Light Source (LCLS) at SLAC National Laboratory. Large area VAREX detectors offer major improvements in azimuthal and scattering angle coverage which enables analysis of single crystal diffraction, crystallographic texture and liquids under dynamic compression at MEC. The pair of VAREX detectors are oriented in the horizontal scattering plane appropriate for the polarization of the LCLS XFEL. This orientation provides some practical flexibility with detector placement, which will be reviewed in this presentation in comparison with the recently commissioned VAREX detectors at HED instrument located at European XFEL. In this experiment, we commissioned the detectors using crystalline (CeO₂) and glass (Fe-Si-B-C) standards and compare the detector performance at the two facilities. We discuss results on the detection of shock-melting in single-crystal brucite samples and Fe-epoxy slurry with implications for water delivery and storage during planetary scale impacts.