Laser-driven single shock compression of fluid deuterium from 45 to 220 GPa

The compression $(\ensuremath{\eta})$ of liquid deuterium between 45 and 220 GPa under laser-driven shock loading has been measured using impedance matching to an aluminum (Al) standard. An Al impedance-match model derived from a best fit to absolute Hugoniot data has been used to quantify and minimize the systematic errors caused by uncertainties in the high-pressure Al equation of state. In deuterium below 100 GPa results show that $\ensuremath{\eta}\ensuremath{\simeq}4.2$, in agreement with previous impedance-match data from magnetically driven flyer and convergent-explosive shock wave experiments; between 100 and 220 GPa $\ensuremath{\eta}$ reaches a maximum of $\ensuremath{\sim}5.0$, which is less than the sixfold compression observed on the earliest laser-shock experiments but greater than expected from simple extrapolations of lower-pressure data. Previous laser-driven double shock results are found to be in good agreement with these single shock measurements over the entire range under study. Both sets of laser-shock data indicate that deuterium undergoes an abrupt increase in compression at around 110 GPa.