Progress on wide-range equation of state for hydrogen and deuterium

Abstract

Hydrogen is the most abundant element in nature and an important object of astrophysics and ICF research. This paper briefly presents an overview of the research progress in wide-range equation of state and especially comments assessment of the most recent shock compression experiments on Omega laser facility and the theoretical models. Based on the previous work, the wide-range equation of state of hydrogen is constructed by using the improved chemical free energy model, the first-principle numerical simulation results and the multi-parameter equation of state model, which is applicable in the temperature range of 20−108 K and the density range of 10−7−2000 g/cm3. Compared with experimental results, such as those of shock compression experiment, static high pressure isotherm experiment and sound velocity experiment, the newly-constructed wide-range equation of state for hydrogen has high confidence and provides high precision data for astrophysics, inertial confinement fusion, international thermonuclear experimental reactor and other engineering physics designs. The construction and validation method of the hydrogen wide-range equation of state can also be applied to its isotope deuterium. In comparison with current models published abroad, the deuterium wide-range equation of state constructed by this method is in better agreement with the experimental data of principal and secondary Hugoniot published in 2019. This paper also points out the temperature-density regimesthat need attention in future research.