The Study On Equation Of State For Mixtures Of Dense Hydrogen And Helium

The equation of states under high temperatures and high pressures, phase -transition and metalization for H₂ and its isotopes are one of the hot topics of scientific studies for a long time. H₂ and He, which are the simplest diatomic and monatomic molecules respectively, are always one of advancing areas for those scientists working at theoretical and experimental study on condensed state physics. As two kinds of the most abundant elements in universe the studies on equation of states of high temperatures and high pressure of H₂,He and their mixtures have great scientific significance and application values for inertial confinement fusion and for constructing inner structure and evolution law of Saturn and Jupiter, and so on.The studies on equation of states for pure hydrogen, deuterium and helium(solid and liquid) been reported so much; however, the studies on their mixtures under high temperatures and high pressures have not been reported so far overseas and experiment data for mixtures published in our country have low pressure and temperature ranges (P2+He mixtures under high temperatures and high pressures are performed in this work. In order to increase shock temperatures and pressures, the device of low temperatures high pressures is designed which can increases initial density of of H₂+He mixture (mole ratio is 1:1) upto ¹/2 density of liquid Hydrogen. With the help of a two-stagelight-gas gun, transient radiation pyrometer, and MAVIS systems, the Hugoniot curve and shock temperatures of Hfe+He mixture (initial temperature is 28OK, initial pressure is 20MPa ,and initial rrtole ratio is 1:1.2088) are measured (pressures over l²8GPa and temperatures over 300O-70O0K) and the feature of the multi-shock are successfully captured; Based on fluid perturbation variational theory a theoretical model is constructed, and the shock compression properties of Hb+He mixture are calculated by using of exp-6 potential function. Comparisons between the model calculations, experiment measurements, and sesame database show they have a good agreement.