Optical Response and Hugoniot State of Shock-Compressed Heavy Liquids

The shock response of heavy liquids was tested in a gas gun to determine index of refraction and Hugoniot equation of state data. Perfluorooctane (PFO), as well as deuterium oxide (D₂O) solutions of sodium polytungstate (SPT) and lithium heteropolytungstate (LST), were confined in a cell with a fused-silica window and subjected to one-dimensional compression from a copper impactor and driver. Photonic Doppler Velocimetry (PDV) was used to measure shock and particle velocity through the liquid cell, and verify optical transparency at pressures between 6.1 and 10.6 GPa. SPT and LST are adjustable density solutions up to approximately 3 g/cm³ and have low toxicity, which allows them to be used as impedance-matched window materials for equation of state experiments. Furthermore, these heavy liquids are good candidates for tamped Richtmyer–Meshkov Instability (RMI) experiments to interrogate dynamic interface instabilities at non-zero pressure. We will present initial radiography measurements and PDV results from RMI experiments in which PFO is used as a tamper.