ABSOLUTE EQUATION-OF-STATE DATA IN THE 10-40 MBAR (1-4 TPA) REGIME

A technique has been developed that allows the measurement of equation s of state of low-atomic-number materials in regimes of extremely high pressure. Using this technique we have obtained absolute multimegabar measurements on the principal Hugoniots of low-Z solids, including da ta on polystyrene up to 40 Mbar (60 times the previous absolutely meas ured pressure) and beryllium at pressures up to 15 Mbar. The polystyre ne data were able to differentiate between existing theoretical models . The beryllium data confirm theoretical Hugoniots of several material s as high as 65 Mbar.