An experiment to measure the diffusion of {sup 4}He in {sup 3}He in the Fermi liquid region

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00754573· OSTI ID:198168

He, Jizhong; Culman, T G; Edwards, D O; Hjort, H H ^[1]

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1. Ohio State Univ., Columbus, OH (United States)

The diffusion coefficient D and the thermal diffusion factor {gamma}T, for {sup 4}He in liquid {sup 3}He at low temperatures T, have recently been calculated by solving the Boltzmann equation derived from Fermi-liquid theory. As T {yields} 0, {gamma}T approaches a constant and D varies as 1/T. Both transport coefficients are determined solely by a{sub 0}{sup 34}, the {ell}=0 forward scattering amplitude. Because a{sub 0}{sup 34} can be found from thermodynamic data, e.g. the solubility of {sup 4}He in liquid {sup 3}He, X{sub 4}{sup sat}, a strict test of the theory is possible. We have built an apparatus to measure D and X{sub 4}{sup sat} as functions of pressure and temperature. The ratio of the capacitances of two parallel plate capacitors measures the number of {sup 4}He atoms diffusing out of the liquid into the superfluid film. A bellows initiates the diffusion by changing the pressure in the liquid and thus the equilibrium concentration. A change of {approximately}10{sup -8} in the {sup 4}He concentration can be detected.

• Sponsoring Organization: USDOE
• OSTI ID: 198168
• Report Number(s): CONF-950676--
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 1-2 Vol. 101; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
FERMI GAS
HELIUM 3
HELIUM 4
LANDAU LIQUID HELIUM THEORY
SCATTERING AMPLITUDES
THERMAL DIFFUSION