The full range Joule-Thomson inversion curve of helium-3

This paper reports the full range Joule-Thomson inversion curve of helium-3 (3He) constructed by a virial-type equation of state of this quantum fluid. In order to evaluate the equation of state, the virial coefficients of 3He calculated from the result of the analysis of this study are compared with previous studies. The inversion curve is confirmed to agree with the empirical inversion points reported previously. The peak temperature and the peak pressure of the inversion curve are respectively determined to be 19.6 K and 2.588 MPa. The minimum and the maximum inversion temperatures at zero pressure are estimated to be 2.8 K and 48.5 K, respectively. The reduced inversion curve of 3He is also obtained with the critical parameters and it is compared with other reduced inversion curves of quantum and non-quantum fluids. The discrepancy of the reduced inversion curve of 3He from the general reduced inversion curves is explained by means of the thermal de Broglie wavelength, similar to other quantum fluids.