Equation of State for Normal Liquid Helium-3 from 0.1 to 3.3157 K

Computational Study of the Structures of Gaseous Helium-3 at Low Temperature

“…On the other hand, because of the lower atomic mass of 3 He and of the lower temperatures that can be reached without entering the quantum exchange regime, pure diffraction effects in assemblies of 3 He atoms [e.g., associated with large de Broglie wavelenthgs λ B ) h/(2πmk B T) 1/2 ] can become far larger than those observed in 4 He and can therefore be perfectly studied with path integrals. 6 In spite of the very low natural abundance of 3 He (it is mostly obtained as a byproduct of neutron bombardment of lithium), 1 its applications to cryogenics and its potential use as a fuel for future fusion reactors have prompted a number of thorough experimental and computational works addressing different relevant issues of this system (e.g., equation of state, [11][12][13] melting line, 14 properties near criticality). 9,15 However, to the knowledge of this author, the attention devoted to the computation of the structural features of 3 He in the gas or in the condensed phases has been mostly focused upon situations at T ) 0 K. [16][17][18] In this regard, it has to be remarked that path-integrals (PI) can be utilized to provide the most complete answers to the structure questions related to quantum diffraction effects at nonzero temperatures.…”

“…In spite of the very low natural abundance of 3 He (it is mostly obtained as a byproduct of neutron bombardment of lithium), its applications to cryogenics and its potential use as a fuel for future fusion reactors have prompted a number of thorough experimental and computational works addressing different relevant issues of this system (e.g., equation of state, – melting line, properties near criticality). , However, to the knowledge of this author, the attention devoted to the computation of the structural features of 3 He in the gas or in the condensed phases has been mostly focused upon situations at T = 0 K. – In this regard, it has to be remarked that path-integrals (PI) can be utilized to provide the most complete answers to the structure questions related to quantum diffraction effects at nonzero temperatures. ,,– Therefore, the aim of this article is to contribute to this area by studying gaseous 3 He under conditions for which experimental work has revealed that there are considerable structural features. – The present analysis concentrates on the pair and triplet structures that can be found in this gas at T = 5.23 K for densities below 0.0021 Å −3 . Hereafter, for the sake of brevity, the normal spatial functions depending upon the distance r between pairs of particles or upon the triplets of distances ( r , s , u ) will be referred to as functions in r space, whereas their associated Fourier space functions depending upon the wave vector k or upon the wave vector triplets ( k 1 , k 2 ,θ 12 ) will be referred to as functions in k space.…”