Thermal response of a3He-superfluid-4He mixture |
| |
Authors: | R P Behringer |
| |
Affiliation: | (1) Department of Physics and Center for Nonlinear Studies, Duke University, Durham, North Carolina |
| |
Abstract: | The response of a layer of superfluid mixture to an ac heat source,Q(t)=Q
0
exp(i t), is determined. In the low-frequency regime, the temperature response at the heated side of a superfluid layer is essentially identical to that of an ordinary fluid having a thermal conductivity eff and a thermal diffusion coefficient
0
/2. Here eff is the effective conductivity of Khalatnikov, and
0
is the diffusion coefficient of Griffin. At much higher frequencies, the results are more complicated. The low-frequency regime is defined in terms of the second sound velocityu
2
by ![ohgr](/content/t254k11385jvnk34/xxlarge969.gif) u
2
2
/
0
. The ac response function is valuable in a number of ways. It can be used to obtain the system response to more complicated time-dependent variations inQ such as step changes inQ. A knowledge of the response function in the low-frequency regime provides a mechanism for directly determining the Kapitza resistance in mixtures. Finally, a knowledge of the response function provides an additional opportunity to test two-fluid hydrodynamics. Alternative tests of superfluid hydrodynamics are of particular interest in light of recent experiments that show anomalous values for eff in the low
3
He concentration limit |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|