Thermodynamics of hydrogen-helium mixtures at high pressure and finite temperatureA technique is reviewed for calculating thermodynamic quantities for mixtures of light elements at high pressure, in the metallic state. Ensemble averages are calculated with Monte Carlo techniques and periodic boundary conditions. Interparticle potentials are assumed to be coulombic, screened by the electrons in dielectric function theory. This method is quantitatively accurate for alloys at pressures above about 10 Mbar. An alloy of equal parts hydrogen and helium by mass appears to remain liquid and mixed for temperatures above about 3000 K, at pressures of about 15 Mbar. The additive volume law is satisfied to within about 10%, but the Gruneisen equation of state gives poor results. A calculation at 1300 K shows evidence of a hydrogen-helium phase separation.
Document ID
19740003520
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hubbard, W. B. (Texas Univ. Austin, TX, United States)
Date Acquired
August 7, 2013
Publication Date
January 1, 1972
Publication Information
Publication: Univ. Space Res. Assoc. High Pressure Phys. and Planetary Interiors