Ultra-high-speed X-ray imaging of laser-driven shock compression using synchrotron light

A high-power, nanosecond-pulsed laser impacting the surface of a material can generate an ablation plasma that drives a shock wave into it; while in situ X-ray imaging can provide a time-resolved probe of the shock-induced material behaviour on macroscopic lengths scales. Here, we report on an investigation into laser-driven shock compression of a polyurethane foam and a graphite rod by means of single-pulse synchrotron X-ray phase-contrast imaging with a MHz frame rate. A 6-J, 10-ns-pulsed laser was used to generate shock compression. Physical processes governing the laser-induced dynamic response such as elastic compression, compaction, pore collapse, fracture, and fragmentation have been imaged; and the advantage of exploiting the partial spatial coherence of a synchrotron source for studying low-density, carbon-based materials is emphasized. The successful combination of a high-energy laser and ultra-high-speed X-ray imaging using synchrotron light demonstrates the potentiality of accessing complementary information from scientific studies of laser-driven shock compression.