Equation-of-State Measurements in Ta2O5 Aerogel

LLE Review, Volume 111 154 Introduction In the last 15 years, there has been considerable interest in experiments that use laser-driven shock waves to measure high-energy-density equation-of-state (HED-EOS) data.1–5 During this time, the generation of laser-driven shock waves has been refined, and the accuracy of the techniques employed has been improved significantly. Highly accurate optical studies of SiO2 with laser-driven shock waves have shown strong agreement with experimental results obtained with other established drivers;6 these measurements have extended the available data to many millions of atmospheres and identified new mechanisms that affect the material’s HED-EOS.7 Many HED-EOS experiments use standards or reference materials to which the behavior of the studied material is compared. These impedance-matching experiments are particularly important in laser-driven shock-wave experiments where nonreferenced HED-EOS measurements are complex.8,9 The measurements on SiO2 and the consistent structure of quartz lend themselves to the establishment of quartz as a standard material, as will be demonstrated in this study.