QFS 2016 Book of Abstracts

Abstracts

P3.20 Motion of negative ions along quantized vortices in superfluid 4 He Paul Walmsley, Andrei Golov School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK We have measured the mobility and limiting terminal velocity of electron bubbles sliding along vortex lines in superfluid 4 He for a broad range of temperatures (0.1 - 1 K). This allows dissipative processes at small length scales to be probed, which can include drag exerted by an excess density of excitations in the vicinity of the vortex core; the scattering and generation of Kelvin waves; and condensation of 3 He impurity atoms onto vortex cores. We have also used this technique to probe the dynamics of agitated vortex arrays and the corresponding timescales for relaxation back towards a rectilinear array, providing new insight into the decay of quantum turbulence at short length scales. P3.21 Heat Transfer Peculiarities in 3 He- 4 He Mixtures in Cylindrical Geometry Nemchenko K., Rogova S. Karazin Kharkiv National University, Physics and Energy department, 61022, Svobody sq.4, Kharkiv, Ukraine Using the system of hydrodynamics equations for superfluid mixtures the problem of temperature and concentration distribution in cylindrical geometry is solved. Temperature excitations are caused by an oscillating heat source situated inside of the cylinder. The obtained solution may serve for better understanding of heat transfer in experiments dealing with oscillating tuning fork.

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