Thermal transport properties in helium near the superfluid transition. III. Dilute /sup 3/He-/sup 4/He mixtures in the normal phase
An experimental study is presented for the thermal conductivity kappa and the thermal relaxation for dilute mixtures of /sup 3/He in /sup 4/He with concentration 9 x 10/sup -4/ less than or equal to X(/sup 3/He) less than or equal to 5 x 10/sup -2/ at saturated vapor pressure and in the normal phase near the superfluid transition. The conductivity results for kappa are compared with predictions by Dohm and Folk from field-theoretic renormalization group (RG) theory. The conductivity kappa/sub s/ = (kappa/sup -1/ (t) - kappa/sup -1/ (T/sub lambda/))/sup -1/, is compared with Ahlers' phenomenological arguments, and also with predictions by Dohm and Folk and by Onuki. The temperature difference transient ..delta..T(t) across the fluid, measured as a function of time t after switching on and off the heat current is analyzed. The thermal diffusion ratio k/sub T/ and the mass diffusion coefficient D are obtained by fitting the calculated transient to the experimental one. The results are compared with the predictions that follow from the RG approach by Dohm and Folk. Very good agreement is obtained for k/sub T/. The transient is not very sensitive to D, and hence the determination is not accurate. Yet within the uncertainty, the deduced D also agrees with predictions. Appendices give (1) the corrections to kappa from finite heat effects, (2) the calculation of the concentration susceptibility (deltaX/delta..delta..)/sub T,P/, and (3) the calculation procedure for kappa, k/sub T/, and D using the RG approach of Dohm and Folk.
- Research Organization:
- Duke Univ., Durham, NC
- OSTI ID:
- 6060523
- Journal Information:
- J. Low Temp. Phys.; (United States), Vol. 68:1-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal-transport properties in the normal phase of dilute sup 3 He- sup 4 He mixtures
Thermal transport properties in helium near the superfluid transition I. /sup 4/He in the normal phase
Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HELIUM 3
SUPERFLUIDITY
THERMAL CONDUCTIVITY
HELIUM 4
BINARY MIXTURES
DILUTION
ENTROPY
GROUP THEORY
HEAT TRANSFER
HYDRODYNAMICS
J-J COUPLING
MAGNETIC SUSCEPTIBILITY
MATHEMATICAL MODELS
RELAXATION TIME
RENORMALIZATION
TEMPERATURE GRADIENTS
TEMPERATURE MEASUREMENT
THERMAL DIFFUSION
THERMAL DIFFUSIVITY
TIME DEPENDENCE
ULTRALOW TEMPERATURE
COUPLING
DIFFUSION
DISPERSIONS
ENERGY TRANSFER
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FLUID MECHANICS
HELIUM ISOTOPES
INTERMEDIATE COUPLING
ISOTOPES
LIGHT NUCLEI
MAGNETIC PROPERTIES
MATHEMATICS
MECHANICS
MIXTURES
NUCLEI
PHYSICAL PROPERTIES
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
640450* - Fluid Physics- Superfluidity