Temperature and melting of laser-shocked iron releasing into an LiF window

Absolute reflectivity and self-emission diagnostics are used to determine the gray-body equivalent temperature of laser-shocked iron partially releasing into a lithium fluoride window. Pressure and reflectivity are measured simultaneously by means of velocity interferometer system for any reflector interferometers. In the temperature-pressure plane, a temperature plateau in the release is observed which is attributed to iron’s melting line. Extrapolation of data leads to a melting temperature at Earth’s inner-outer core boundary of 7800±1200K, in good agreement with previous works based on dynamic compression. Shock temperatures were calculated and found to be in the liquid phase.