Equation of state and transport properties of low Z materials at extreme pressure

Summary form only given. Recent principle Hugoniot, pre-compressed Hugoniot, and multiple shock experiments provide equation of state data for several low Z materials including He, H/sub 2/, carbon, and SiO/sub 2/ over an unprecedented pressure-temperature-density regime. We have observed the evolution of these materials from an insulator, to a fluid metal, to a dense plasma, with increasing pressure and density from .5 to 30 Mbar, compression ratios up to 8 fold, and temperatures up to several eV. We present new equation of state and reflectivity data over this P-rho-T range, the inferred high-pressure chemistry, and implications of these data for planetary science.