Normal Fluid Density, Second Sound, and Fourth Sound in an Anisotropic Superfluid

1973 ◽  
Vol 31 (14) ◽  
pp. 870-873 ◽  
Author(s):  
W. M. Saslow
Keyword(s):  
Second Sound ◽  
Fluid Density ◽  
Normal Fluid ◽  
Fourth Sound

Normal Fluid Density of LiquidHe3-B

1979 ◽  
Vol 43 (2) ◽  
pp. 139-143 ◽  
Author(s):  
C. N. Archie ◽  
T. A. Alvesalo ◽  
J. D. Reppy ◽  
R. C. Richardson
Keyword(s):  
Fluid Density ◽  
Normal Fluid

Ultrasonic studies of liquid helium in porous media

1987 ◽  
Vol 65 (11) ◽  
pp. 1557-1559 ◽  
Author(s):  
J. R. Beamish ◽  
K. Warner
Keyword(s):  
Porous Media ◽  
Sound Propagation ◽  
Porous Ceramic ◽  
Ultrasonic Waves ◽  
Effective Density ◽  
Biot Theory ◽  
Fluid Density ◽  
Normal Fluid ◽  
Superfluid Fraction ◽  
Viscous Losses

We have studied the propagation of 12 MHz transverse ultrasonic waves in a porous ceramic containing liquid 4He. Both the sound velocity and the attenuation clearly show the superfluid nature of helium. The helium in the pores increases the system's effective density by an amount proportional to the normal-fluid density and so decreases the sound speed. The decoupling of the superfluid fraction below the lambda transition allows us to use the shear wave essentially as a "high-frequency torsional oscillator" to determine the superfluid density and pore tortuosity. The sound attenuation in this system is due to the same mechanism as for fourth sound, namely, viscous losses due to motion of the normal-fluid component. We observed an attenuation proportional to the normal-fluid density and compare this result to predictions of the Biot theory of sound propagation in fluid-filled porous media.

Normal fluid density of superfluid 3He-B

Nature ◽  
1979 ◽  
Vol 281 (5728) ◽  
pp. 179-180
Author(s):  
P.V.E. McClintock
Keyword(s):  
Superfluid 3He ◽  
Fluid Density ◽  
Normal Fluid

scholarly journals On the Effective Normal Fluid Density tf Solution of He3in He4

1957 ◽  
Vol 17 (1) ◽  
pp. 126-128
Author(s):  
S. K. Trikha ◽  
V. S. Nanda
Keyword(s):  
Fluid Density ◽  
Normal Fluid

Superfluid and normal-fluid density in the cuprate superconductors

2001 ◽  
Vol 249 (1) ◽  
pp. 175-184
Author(s):  
D. B. Tanner ◽  
F. Gao ◽  
K. Kamaras ◽  
H. L. Liu ◽  
M. A. Quijada ◽  
...  
Keyword(s):  
Cuprate Superconductors ◽  
Fluid Density ◽  
Normal Fluid

Scattering of light from entropy fluctuations in 3He–4He mixtures

1968 ◽  
Vol 46 (17) ◽  
pp. 1895-1903 ◽  
Author(s):  
B. N. Ganguly ◽  
A. Griffin
Keyword(s):  
Critical Point ◽  
Concentration Fluctuations ◽  
Complete Analysis ◽  
Second Sound ◽  
Hydrodynamic Equations ◽  
Normal Fluid ◽  
Strongly Coupled ◽  
Scattering Of Light ◽  
First Sound ◽  
Scatter Light

In 1957, Gor'kov and Pitaevskii showed that second sound in 3He–4He mixtures is strongly coupled into the concentration fluctuations, which, in turn, scatter light quite strongly (especially near the critical point). In this paper, we give a more complete analysis of the fluctuations in density, entropy, and concentration. Our discussion is based on the hydrodynamic equations of Khalatnikov, which assume that the 3He atoms move with the normal fluid, and for simplicity we omit all dissipative coefficients. If we limit ourselves to scattering from density and concentration fluctuations, our results for the first and second sound intensities agree essentially with those of Gor'kov and Pitaevskii. Near the critical point, second sound scatters light about six times more strongly than first sound does.

Frictional Relaxation Time of 3He Normal Fluid Component in Aerogel Obtained by Fourth Sound Resonance

2009 ◽  
Vol 158 (1-2) ◽  
pp. 182-187
Author(s):  
C. Kato ◽  
T. Matsukura ◽  
Y. Nago ◽  
K. Obara ◽  
H. Yano ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Normal Fluid ◽  
Fluid Component ◽  
Fourth Sound

scholarly journals Two-fluid hydrodynamics of a Bose gas including damping from normal fluid transport coefficients

2000 ◽  
Vol 78 (5-6) ◽  
pp. 415-432 ◽  
Author(s):  
T Nikuni ◽  
A Griffin ◽  
E Zaremba
Keyword(s):  
Fluid Transport ◽  
Transport Coefficients ◽  
Thermal Fluctuations ◽  
Bose Gas ◽  
Second Sound ◽  
Hydrodynamic Modes ◽  
Normal Fluid ◽  
Strongly Coupled ◽  
Fluid Hydrodynamics ◽  
Two Fluid

We extend our recent work on the two-fluid hydrodynamics of the condensate and noncondensate in a trapped Bose gas by including the dissipation associated with viscosity and thermal conduction in the thermal cloud. For purposes of illustration, we consider the hydrodynamic modes in the case of a uniform Bose gas. A finite thermal conductivity and shear viscosity give rise to a damping of the first and second sound modes, in addition to the damping found previously due to the lack of diffusive equilibrium between the condensate and noncondensate. The relaxational mode associated with this equilibration process is strongly coupled to thermal fluctuations and reduces to the usual thermal diffusion mode above the Bose-Einstein transition. In contrast to the standard Landau two-fluid hydrodynamics, we predict a damped mode centered at zero frequency, in addition to the usual second sound doublet.PACS Nos.: 03.75.Fi, 05.30Jp, 67.40.Db

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