Laser-shock compression and Hugoniot measurements of liquid hydrogen to 55 GPa

Abstract

The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under laser-driven shock loading. The pressure and density of compressed hydrogen were determined by impedance matching to a quartz standard. The shock temperature was independently measured from the brightness of the shock front. Hugoniot data of hydrogen provide a good benchmark to modern theories of condensed matter. The initial number density of liquid hydrogen is lower than that for liquid deuterium, and this results in shock-compressed hydrogen having a higher compression and higher temperature than deuterium at the same shock pressure.