Equation Of State And Thermophysical Properties Of Helium-3

~3He is one stable isotope of helium, which is expensive because of its sparsity. ~3He is increasingly being used in a number of areas such as fundamental physics, cryogenic engineering, space technology and nuclear fusion. Optimum system design generally requires knowledge of ~3He properties. For many fluids, including the isotope ~3He, their known Helmholtz potential function allows thermodynamically consistent calculation of all state properties as a function of pressure and temperature (or other pairs). For ~3He, however, though many state properties have been individually measured, the corresponding Helmholtz potential function has never been obtained. Further, no rounded thermodynamic diagrams and modern computer programs are available to calculate the thermophysical properties of ~3He. Scaling by "Corresponding states" arguments between ~3He and ~4He fails at temperatures much below their critical points and above the critical points up to at least some dozens of Kelvin, because of their dramatically different superfluid regimes, related to the difference between Fermi-Dirac and Bose-Einstein statistics. In order to provide thermophysical property standards for ~3He and to remove the obstacle for the further development of ~3He applications, the present work focuses on the following sessions:1. Experimental data mining and disposing for thermophysical properties of ~3HeSufficient reference data are necessary for developing empirical or semi-empirical equations of state. Quantity of experimental measurements and theoretical calculations for the properties such as pvT, isochoric specific heat, isobaric specific heat, velocity of sound, enthalpy, entropy, expansion coefficient, compression coefficient, latent heat, second and third virial coefficients, Joule-Thomson coefficient, thermal conductivity, viscosity and surface tension of ~3He have been collected into a searchable database. Information on units, temperature scale and reference etc. are included. For the sake of consistency, the outdated units and temperature scales of the reference data were converted to SI units and ITS-90 scale. The data after filtering and weighting were used to produce T-s and p-h diagrams for ~3He in the questioned temperature and pressure range by numerical interpolation.2. State equations along the vapor-liquid equilibrium line of ~3HeThermodynamic properties including vapor pressure, orthobaric density, latent heat, specific heat, enthalpy and entropy were extensively investigated along the vapor-liquid equilibrium line. High precision vapor pressure equation and orthobaric density equation have been developed in the wide range for temperature from 0.003 K to the critical point 3.3157 K of ~He. The former not only defines the precise vapor pressure - temperature dependence along the saturation line, but also provides theoretical support for extending the currently widespread international temperature scale 1990 to much lower temperatures. The latter, in dimensionless form both for saturated liquid and vapor, exceeds the lower application limit of similar equations for other fluids.