Absolute Equation-of-State Data in the 10–40 Mbar (1–4 TPa) Regime

A technique has been developed that allows the measurement of equations 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 data on polystyrene up to 40 Mbar (60 times the previous absolutely measured pressure) and beryllium at pressures up to 15 Mbar. The polystyrene data were able to differentiate between existing theoretical models. The beryllium data confirm theoretical Hugoniots of several materials as high as 65 Mbar.