Macroscopic vortices on the surface
of superfluid He II
A.A. Levchenko1,2, L.P. Mezhov-Deglin1,2, and A.A. Pelmenev2,3
1Institute of Solid State Physics Russian Academy of Sciences
Chernogolovka, Moscow District, 2 Academician Ossipyan str., 142432 Russia
2L.D. Landau Institute for Theoretical Physics of Russian Academy of Sciences,Moscow Region, Chernogolovka, Akademika Semenova av., 1-A,142432 Russia
3Institut of Energy Problems for Chemical Physics, Moscow reg., Noginskii rayon, Chernogolovka, prospekt acad. Semenova, 1, korp. 10, 142432 Russia pos Анотація:
Received May 7, 2018, published online August 28, 2018
The visualization of phenomena on the surface of superfluid He II by light glass tracers localized in a thin layer below the surface of a liquid made it possible to observe for the first time the appearance of a vortex flow and two-dimensional macroscopic vortices on the surface of a superfluid liquid in a vibrating cell that are formed as a result of a nonlinear interaction between noncollinear Faraday waves. Standing Faraday waves are excited on the He II surface with vertical vibrations of the cell with a relative variable acceleration above the threshold of the parametric instability β > βс ≈ 0.04. It was found that, with intense wave pumping at a frequency of 40 Hz and a prolonged exposure for ~ 270 s, the dependence of the kinetic energy of the vortex system on the wave vector E(k) at k ≥ 4.5 cm–1 can be described by a power law of the form Е(k) ~ k –3, i.e., in a system of macroscopic vortices generated by waves on the surface of a He II layer with a depth of ~ 0.4 cm in a vibrating cell, in time, not only the inverse but also the direct turbulent cascade can form.
Key words: Faraday waves, superfluid He II, macroscopic vortices.