An ultrafast X-ray diffraction apparatus for the study of shock waves

The use of X-ray diffraction for the study of shock physics has been pursued for decades. Conceptually, changes in the diffraction line, including broadening and shifts, provide details about the nature of compression, plasticity, phase, and kinetics of the phase transition for the material being shock-loaded. In practice, X-ray source brightness, sample preparation, and turn-around times have limited the applicability to a few crystalline systems. We report our development of an ultrafast X-ray diffraction instrument suitable for studying rapid phase changes, including both solid-solid and solid-melt, in shock-loaded materials. Due to the relatively small sample sizes needed and to the ability to conduct thousands of shock physics experiments with these small samples, we can build up the statistics required to study elastic-plastic transitions, the kinetics of phase changes, as well as the mechanistic details of phase changes in nearly all materials, including high-Z samples. An overview of the technique and our initial source characterization are discussed.