Multi-Mbar re-solidification of Pb on the nanosecond timescale at the National Ignition Facility

Here we present results investigating high-pressure re-solidification of molten Pb on the nanosecond timescale. We have performed a series of experiments using the TARDIS platform at the National Ignition Facility (NIF) to measure x-ray diffraction of samples dynamically compressed to multi-Mbar pressure. Samples are initially shock compressed into the molten state, which is probed with x-ray diffraction. In the same experiment, the samples are then shocklessly compressed along the adiabat set by the initial shock pressure back into the solid state, which is probed with a second x-ray diffraction measurement. We report a series of experiments that provide a new constraint on the Pb melt curve up to ~6 Mbar as well as the crystal structure just below the melt curve.