Heat Transfer in Superfluids: Effect of Gravity

Melnikovsky, L. A.

doi:10.1007/s10909-005-1528-4

Cited by 5 publications

(4 citation statements)

References 6 publications

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“…Its origin should be clarified. It is shown in [4] that atoms of He II possess an inertial DM caused by their acceleration in sound waves. However, such DM give polarization which is two to three orders of magnitude smaller than the observed value.…”

Section: Induced Dipole Moment Of He II Atomsmentioning

confidence: 99%

“…This is rather unexpected, given that He II is a dielectric and that a free He 4 atom does not possess either dipole or higher multipole moments. Several models have been proposed to explain the electric activity of He II [4][5][6], but each of them encounters with certain difficulties and does not explain the effects of [1][2][3] in a plausible way. In this work, we study a possible nature of the electric activity of He II observed by Rybalko [1] in experiments with second sound.…”

Section: Introductionmentioning

confidence: 99%

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Possible nature of the dielectric activity of He II observed in experiments with second sound

Loktev,

Tomchenko

2008

Preprint

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An attempt is made to explain the nature of the electric signal observed in He II in a second-sound standing wave. Using the general quantum-mechanical principles, we show that, due to interatomic interaction, each atom of He-II acquires a small fluctuating induced dipole moment with the average value of its modulus dat = 2eδ, δ ≃ 2.6 × 10 −4 Å. A directed flux of microscopic vortex ringswhich, together with phonons, are thermal excitations of He II -forms in the second-sound standing halfwave. This flux partially orders the chaotically oriented dipole moments of the atoms, which results in volume polarization of He II. The observed electric induction △U ≈ k B △T /2e can be explained theoretically under the assumption that each vortex ring possesses a dipole moment d vr of the order of ten atomic moments, d vr ∼ 10 dat .It is shown also that the theoretical value of the voltage △U induced in He II by the volume system of dipoles strongly depends on the dimensions of the resonator for dipoles of any origin. The experimental value of △U is the same for two resonators of different size; therefore, this voltage may be not connected with the volume polarization of He II.

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Section: Induced Dipole Moment Of He II Atomsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Possible nature of the dielectric activity of He II observed in experiments with second sound

Loktev,

Tomchenko

2008

Preprint

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show abstract

“…An observation of electric induction in superfluid 4 He induced by relative motion of its normal and superfluid components has been recently reported [1,2]. This new extraordinary effect was revealed in two different types of experiments: electric potential oscillations were generated by a second-sound wave of which the velocities of normal υ n and superfluid υ s components relate as n s s n ρ ρ υ υ = (here ρ s and ρ n are the densities of the superfluid and normal components, respectively), and by liquid helium motion in a torsion oscillator whose walls affect the normal component only.…”

Section: Introductionmentioning

confidence: 99%

“…A reverse effect (second-sound wave generation by an ac electric field) was also observed. The experimental finding of mechanoelectric effect in He II has stimulated a number of theoretical studies aiming to explain its mechanism [3][4][5][6][7][8]. On the basis of experiments [1,2], it could be assumed that the relative motion of the normal and superfluid components is a result of internal electromagnetic forces related to the macroscopic quantum ordering.…”

Section: Introductionmentioning

confidence: 99%