ISSN:
1573-7357
Keywords:
67.60.Dm
;
51.10.+y
;
67.55.Lf
;
67.55.Hc
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The diffusion coefficient D and the thermal diffusion factor γT, for4He in liquid3He at low temperatures T, have recently been calculated by solving the Boltzmann equation derived from Fermi-liquid theory. As T → 0, γT approaches a constant and D varies as 1/T. Both transport coefficients are determined solely by a 0 34 , the l = 0 forward scattering amplitude. Because a 0 34 can be found from thermodynamic data, e.g. the solubility of4He in liquid3He, X 4 sat , a strict test of the theory is possible. We have built an apparatus to measure D and X 4 sat as functions of pressure and temperature. The ratio of the capacitances of two parallel plate capacitors measures the number of4He 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 ∼ 10−8 in the4He concentration can be detected.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00754573
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