Single-pulse x-ray topography of ambient and shock-compressed diamond

The generation of defects during dynamic compression is well established; however, directly imaging their formation has not been spatially resolved routinely. To address this, we developed an x-ray topography diagnostic to work toward the observation of spatially resolved strain gradients associated with deformation in ambient and shocked materials at the Matter at Extreme Conditions beamline of the Linac Coherent Light Source (LCLS). X-ray topography is a near field technique that reveals defects in single-crystal samples as spatially varying intensity contrast within the diffracted x-ray beam. Owing to its high-quality single-crystal structure and exceptional strength, diamond is an outstanding material for investigating defect generation at both ambient and extreme conditions. Using single x-ray pulses from LCLS, we obtained high-quality topographic images from 〈100〉, 〈110〉, and 〈111〉 oriented diamond crystals under ambient conditions. We then drove laser-generated shocks over a range of stresses to explore whether x-ray topography can visualize the real-time creation of defects governing the onset of plasticity.