Electrical resistivity of fluid methane multiply shock compressed to 147 GPa

Abstract

ABSTRACTShock wave experiments were carried out to measure the electrical resistivity of fluid methane. The pressure range of 89–147 GPa and the temperature range from 1800 to 2600 K were achieved with a two-stage light-gas gun. We obtained a minimum electrical resistivity value of 4.5 × 10−2 Ω cm at pressure and temperature of 147 GPa and 2600 K, which is two orders of magnitude higher than that of hydrogen under similar conditions. The data are interpreted in terms of a continuous transition from insulator to semiconductor state. One possibility reason is chemical decomposition of methane in the shock compression process. Along density and temperature increase with Hugoniot pressure, dissociation of fluid methane increases continuously to form a H2-rich fluid.