Isotope Effects on the Hydrogen Hugoniot

The equation of state of hydrogen isotopes in the warm dense matter regime is integral to understanding the evolution of gas giant planets and igniting thermonuclear fusion implosions. While gas giants like Jupiter are composed of the lightest isotope, protium, and thermonuclear fusion implosion capsules employ a mixture of deuterium and tritium, most hydrogen Hugoniot data are from deuterium. Moreover, what protium data does exist seems to deviate from modern models in the vicinity of 20 GPa. This presentation describes recent experiments to collect accurate data on the protium Hugoniot, from a few GPa into and beyond the warm dense matter regime.