Thermodynamic Properties of Liquid Helium Three. I. The Specific Heat and Entropy

Specific Heat ofHe3below 1°K

“…Since the difference between the specific heat under 12 to 15 cm Hg and under the saturated vapor pressure is small in the range of our measurements, it is permissible to compare this figure with the value of 1.44 cal/mole-deg calculated for Siiq at saturated vapor pressure from the most recent vapor pressure data. 7 We feel that the experimental results reported here, together with the magnetic susceptibility data of Fairbank et al 8 and the recent theoretical work of Brueckner and Gammel, 9 now provide sufficient evidence to give a high degree of certainty to the linear extrapolation that we have made, particularly in view of the close agreement (within about 2%) between the experimental and theoretical values of the linear term. Rigorously there always remains the experimental possibility of a transition, possibly accompanied by the appearance of superfluidity, at temperatures lower than those of our measurements; but we feel that the data presented here make this possibility now unlikely.…”

Thermodynamic Diagrams of 3He from 0.2 K to 300 K Based Upon its Debye Fluid Equation of State

“…Fig. 5 Entropy of saturated helium-3; •-Singwi [8]; -Roberts and Sydoriak [9]; -Abraham et al [10]; -Brewer et al [11]; -Brewer and Daunt [12]; +-Strongin et al [13]; * -Lee et al [14]; ×-Rauch [15]; -Roberts et al [16]; -Colyer [17]; Solid line-calculations on the saturated liquid Table 2, together with Fig. 6, presents the studies of the enthalpies on the saturated line of 3 He.…”

Helium-3 and the Liquid Helium Problem

“…Twenty standard cubic centimeters of this material were liquefied at Los Alamos in the fall of 1948, and some of its properties investigated (22). Some crude specific heat measurements indicated no -transition (20,23). Then at the Argonne National Laboratory in 1949, Osborne, Weinstock, and Abraham (78) showed that pure helium-3 showed no superfluid properties down to 1.05°K.…”

“…But the effect was small and, unfortunately, little attention was paid to it. Oddly enough, some 20 years passed from the date of its first liquefaction before it was recognized that this most normal liquid, this potential paragon of liquids, was in fact most peculiar and anything but normal. Within the next few years, liquid helium was found to exhibit so many remarkable properties that present-day authors of monographs on liquids have found it most expedient barely to admit its existence.…”