High-precision equation of state benchmark for cryogenic liquid deuterium at ultrahigh pressure

We provide a principal Hugoniot of cryogenic liquid deuterium at a pressure of $27<P<240$ GPa, with reflected-shock data of up to $\ensuremath{\sim}830$ GPa. The maximum density reaches $\ensuremath{\sim}1.49$ $\mathrm{g}/{\mathrm{cm}}³$, about 8.7 times the initial density. Our independent principal Hugoniot experimental data broadly support the wide-regime equation of state (WEOS) model, which well matches Fernandez-Pa\~nella et al. [Phys. Rev. Lett. 122, 255702 (2019)] and Knudson et al. [Phys. Rev. Lett. 118, 035501 (2017)] experimental data over the observed pressure range up to 550 GPa, and most of three sets of reflected shock data are in accordance with our theory up to 1 TPa. Our high-precision experimental results establish an important benchmark equation of state of deuterium and conform to the WEOS model quite well. Our work is useful for the development of the high-pressure response of hydrogen's isotopes, directly related to inertial confinement fusion, planetary science, and metallization.