Combined Radiometry and Velocimetry for Phase Change Detection in Shock Loaded Tin

Reliable detection of phase transitions in multiphase materials studied in dynamic experiments has been a continuing challenge in shock physics. We report results from simultaneous radiometry and velocimetry measurements of dynamically loaded tin under a LiF window. When tin melts on release at the tin/LiF interface, a radiometric signature is observed at multiple wavelengths along with the velocimetry signature. The temperature of the tin/LiF interface is also obtained. Calculations of melt on release using a multiphase EOS for tin provide additional insight into the dynamics of the material when compared to the observables.