Shock-Ramp Compression of Bismuth: Melt Curve Constraint and Recrystallization Studies

Advanced laser pulse shaping techniques have opened new avenues for exploring previously inaccessible regions of the pressure-temperature space by enabling dynamic compression paths that bridge the gap between the shock Hugoniot and ramp quasi-isentrope. Leveraging the cutting-edge pulse shaping capabilities of the National Ignition Facility (NIF), we have shock-compressed bismuth samples into the liquid phase, followed by ramp compression back across the melt curve into the solid bcc phase, taking two x-ray diffraction snapshots during compression. These experiments provide information about the bismuth melt curve at the highest pressures and temperatures recorded to date. Additionally, diffraction data reveal texture in the recrystallized bismuth, offering potential insights into the nucleation mechanisms of the solid phase.