Transport Properties of Spin-Polarized Atomic Hydrogen Using Generalized Scattering Theory

2018

Phys. Scr.

The thermophysical properties of spin-polarized atomic tritum (T↓) are calculated in the temperature range 0.01 K-10 K using the Galitskii-Migdal-Feynman (GMF) formalism. The calculations are performed using Silvera and Born-Oppenheimer triplet-state potentials. It is concluded that T↓ may form a liquid at very low temperatures. At low T, the effective s-wave scattering length a 0 <0, which corresponds to a very weak attractive interaction. There is no bound state for the T↓ dimer, but the negative a 0 indicates that it is only slightly short of binding. The transport properties of T↓ increase with increasing temperature. This behavior shows that T↓ remains as a gas in this T-range. The transport properties of 3 He and 4 He are included for comparison purposes. The difference in the transport properties of T↓ and 3 He is due to the fact that T↓ atoms obey Bose statistics while 3 He atoms obey Fermi statistics, whereas the difference with the 4 He (Boson) is due to the mass difference between T↓ and 4 He.

Section: Gmf T-matrixmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The thermophysical properties of spin-polarized atomic tritium (T↓) in the temperature range 0.01 K–10 K

Sandouqa

2018

Phys. Scr.

“…We have already used the Lippmann-Schwinger [11] and Galitskii-Migdal-Feynman [12] frameworks to calculate the scattering and transport properties of H↓. In addition, the ground-state properties of H↓ have been evaluated within the Brueckner-Bethe-Goldstone formalism [13].…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Properties and Critical Behavior of Spin-Polarized Atomic Hydrogen (H↓) Using the Quantum Second-Virial Coefficient

2023

Int J Thermophys

Self Cite

The quantum-mechanical formulations for the second virial, and the acoustic virial, coefficients are derived for spin-polarized atomic hydrogen (H↓). The dependence of these coefficients on the temperature T as well as the nuclear polarization  is analyzed. This is done for the first time. The main inputs in these computations are the scattering phase shifts, which are obtained using the Lippmann-Schwinger equation, with the Silvera triplet-state potential.Starting with these phase shifts, comprehensive calculations of the thermophysical properties for this system are performed for T ranging from 1µK to 100 K, and  varying from 0 to 1. These properties include, in addition to the quantum second virial coefficient and the acoustic virial coefficient: the pressure-polarization-temperature ( )PT −  − behavior, the entropy (per atom), the speed of sound, the second virial correction (to the total internal energy per atom and unit density), and the specific heat capacity (per atom and unit density).The Boyle temperature and the Joule inversion temperature are determined. The Tdependence of these thermophysical properties, and related quantities, is explored. As expected, this dependence is most evident in the low-T limit, where quantum effects predominate. The corresponding  -dependence becomes noticeable at 80 K and below. It is observed that the virial coefficients tend to decrease with increasing  . Comparison of the present results to previous results are included whenever possible. The overall agreement is very good.As T is lowered, the disruptive effects of thermal energy are weakened relative to the attractive interactions between the atoms. Consequently, the H↓ gas makes a transition to a state of higher order and lower entropy -Bose-Einstein condensation (BEC). This is explored carefully.

“…These are then fed into the Beth-Uhlenbeck equation to compute Bq. The thermophysical properties follow directly from well-known expressions [1,22,24,25,26,27,28,29,30,31]. These properties include: the virial equation of state, compressibility factor, total internal energy, specific heat capacity, and entropy.…”

Section: Introductionmentioning

confidence: 99%

4 He Gas in the Temperature-Range 1mK-5K: Thermodynamic Properties from the Quantum Second Virial Coefficient

Sandouqa

Al-Obeidat

et al. 2022

Preprint

Self Cite

The quantum second virial coefficient Bq of low-dense 4He gas is calculated over the temperature-range 1 mK-5K. This is the first step in determining, according to standard expressions, the thermodynamic properties of the system, namely, the virial equation of state, compressibility factor, total internal energy, specific heat capacity, and entropy. These are compared to previous results wherever available. A large negative Bq is obtained. It is argued that this is intimately related to the formation of small clusters. Based on semi-quantitative analysis, the cluster formation is predicted to occur in the present system at a fairly low temperature ~ 0.049 K to 2.254 K.