Thermal response of superfluid {sup 4}He near T{sub {lambda}} to an AC heat flux

Journal Article · Mon Dec 01 04:00:00 EST 1997 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1023/A:1022206019489· OSTI ID:569808

Murphy, D; Meyer, H ^[1]

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

We have measured the thermal response of a superfluid {sup 4}He layer near T{sub {lambda}} to a time-varying heat flux. In the low-frequency range studied, 1 x 10{sup -3} < f < 0.1 Hz, we find the response to be independent of the applied frequency f, a result consistent with the expectation that the measured response is due to the boundary resistance R{sub b} alone. These findings differ from those by Olafsen and Behringer. The thermal conductivity cell used by these authors had extraneous surfaces in contact with the superfluid which were eliminated in the cell used for our experiments; we believe these surfaces were responsible for the frequency dependence observed in previous work. Furthermore, we show that AC and DC measurements of R{sub b} differ by no more than 1% and that both exhibit a weak singularity near T{sub {lambda}}.

• OSTI ID: 569808
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 5-6 Vol. 109; ISSN 0022-2291; ISSN JLTPAC
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
HEAT FLUX
HELIUM 4
SUPERFLUIDITY
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY