Zobrazeno 1 - 10
of 158
pro vyhledávání: '"O. Avenel"'
Publikováno v:
Journal of Low Temperature Physics. 135:745-772
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2901bea487b3b02adef41938d2077f94
https://doi.org/10.1023/b:jolt.0000029517.55783.91
https://doi.org/10.1023/b:jolt.0000029517.55783.91
Publikováno v:
Physica B: Condensed Matter. 255:55-74
Flow-induced pinning and unpinning of vortices have been investigated experimentally in superfluid 4He at temperatures varying from 14 to 44 mK. The lifetime and unpinning velocities of pinned vortices could be measured by following the apparent chan
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0b8a5680e5fd80f9509599a96046bb6f
https://doi.org/10.1016/s0921-4526(98)00454-2
https://doi.org/10.1016/s0921-4526(98)00454-2
Publikováno v:
Physical Review Letters. 81:3451-3454
We have observed two critical velocity levels for phase slips in superfluid ${}^{4}\mathrm{He}$ at temperatures between 14 and 44 mK, due to microparticles formed in the cell at low temperature. We interpret these observations as evidence for pinning
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::20a1a78059a02bc9ed522577819c9a6e
https://doi.org/10.1103/physrevlett.81.3451
https://doi.org/10.1103/physrevlett.81.3451
Publikováno v:
Journal of Low Temperature Physics. 110:709-718
Superfluid gyrometers can monitor absolute rotations by measuring the rotation induced velocity of superfluid helium flowing in a closed loop. We compare the operation characteristics of two working prototypes and discuss possible improvements and in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a59d4f8a1ceb839206ffe10bbe80d0f9
https://doi.org/10.1023/a:1022516513035
https://doi.org/10.1023/a:1022516513035
Publikováno v:
Journal of Low Temperature Physics. 113:915-920
We present the numerical analysis of a Helmholtz resonator-based4He analog of the rf-SQUID. This device has been demonstrated to act as a sensitive gyrometer. The rotation is detected by its effect on the apparent critical velocity of helium superflo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4110489f1951781f3b630c290d19dd3b
https://doi.org/10.1023/a:1022519409689
https://doi.org/10.1023/a:1022519409689
Publikováno v:
Journal of Low Temperature Physics. 110:503-508
One of the ways to reach a zero-vorticity state in superfluid4He is to melt solid helium slowly at temperatures well below Tλ. This method takes advantage of the small density difference between the liquid and solid phases and of the high critical v
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d0c64510ee5fe0a8d1c57b6f46e182ef
https://doi.org/10.1023/a:1022598514427
https://doi.org/10.1023/a:1022598514427
Publikováno v:
Journal of Low Temperature Physics. 101:821-826
Phase slips by 2π in the critical flow of superfluid 4He through an orifice have been known to exist for some time. Besides these small, regular events, large and precipitous drops of the velocity which may cause up to a full collapse of the flow th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::309548bf238933367827fc0be4e1612b
https://doi.org/10.1007/bf00753397
https://doi.org/10.1007/bf00753397
Publikováno v:
Physica B: Condensed Matter. 210:215-233
Although phase slippage across an orifice in its purest form takes place by individual phase increments by 2π, there are many instances of flow in which the energy dissipation occurs by lumps involving much larger phase difference changes. Such even
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d30c077cbf30d954db76e99065d81f8e
https://doi.org/10.1016/0921-4526(94)01110-m
https://doi.org/10.1016/0921-4526(94)01110-m
Autor:
Eric Varoquaux, O. Avenel
Publikováno v:
Physica B: Condensed Matter. 197:306-314
The phase of the quantum wave function describing a superfluid is a macroscopic variable. This statement, first made by F. London, has implications on the flow properties of helium through small orifices. These implications were explored in 1966 by P
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::38c31971adcc66d3a287e1235277a3ea
https://doi.org/10.1016/0921-4526(94)90227-5
https://doi.org/10.1016/0921-4526(94)90227-5
Publikováno v:
Physical Review Letters. 72:380-383
Slips of the superfluid wavefunction phase occur when the flow velocity through an aperture exceeds a critical threshold $ v_c. $ We propose a phase slip mechanism in which a microscopic vortex half-ring is nucleated at the wall of the aperture. Its
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ca036200878e097e86d8644f3fe64357
https://doi.org/10.1103/physrevlett.72.380
https://doi.org/10.1103/physrevlett.72.380