Transport properties of dilute superfluid mixtures of {sup 3}He in {sup 4}He

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00753561· OSTI ID:98768

Murphy, D; Meyer, H ^[1]

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1. Duke Univ., Durham, NC (United States)

Measurements of the heat transport are reported for dilute superfluid mixtures of {sup 3}He in {sup 4}He between 1.6 and 2.17 K. The temperature transients leading to relaxation times also are presented. The {sup 3}He molar concentration X ranged from 1 x 10{sup {minus}6} to 1 x 10{sup {minus}2}. Cells with different fluid layer thicknesses h were used with 0.5 < h < 4.8 mm. The fluid mixture thermal resistance was obtained from the steady state data, after correction for the boundary (Kapitza) resistance R{sub b} measured with pure {sup 4}He. The bulk fluid results were found to be in agreement with the predictions by F. London and I.M. Khalatnikov. However there is an additional thermal resistance R{sub 0} that dominates for the most dilute mixtures. R{sub 0} is compared with R{sub b} and both are found to have nearly the same temperature dependence and a comparable magnitude. A description and discussion of the onset of non-linear behavior at a critical heat current is presented. Analysis of the transient experiments shows that the observed relaxation times are larger than expected for the bulk fluid. This additional bottleneck is ascribed to R{sub 0} and possible origins of these effects are proposed. In the Appendix, analysis of observed relaxation times in the normal phase of {sup 4}He near T{sub {lambda}} and correction for instrumental contributions are described. The intrinsic fluid relaxation times scale with h{sup 2} and agree quantitatively with predictions. This analysis, including the corrections, is then extended to dilute {sup 3}He-{sup 4}He mixtures in the superfluid phase.

• OSTI ID: 98768
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 5-6 Vol. 99; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
HEAT TRANSFER
HELIUM 3
HELIUM 4
MIXTURES
SUPERFLUIDITY
TEMPERATURE GRADIENTS