Low Temperature Physics: 34, 288 (2008); https://doi.org/10.1063/1.2908894 (5 pages)
Физика Низких Температур: Том 34, Выпуск 4-5 (Апрель 2008), c. 367-372 ( к оглавлению , назад )
Observation of acoustic turbulence in a system of nonlinear second sound waves in superfluid 4He
A.N. Ganshin1, V.B. Efimov1,2, G.V. Kolmakov1,2, P.V.E. McClintock1, and L.P. Mezhov-Deglin2
1Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK
2Institute of Solid State Physics RAS, Chernogolovka, Moscow region, 142432, Russia
Received October 30, 2007
We discuss the results of recent studies of acoustic turbulence in a system of nonlinear second sound waves in a high-quality resonator filled with superfluid 4He. It was found that, when the driving amplitude was sufficiently increased, a steady-state direct wave cascade is formed involving a flux of energy towards high frequencies. The wave amplitude distribution follows a power law over a wide range of frequencies. Development of a decay instability at high driving amplitudes results in the formation of subharmonics of the driving frequency, and to a backflow of energy towards the low-frequency spectral domain, in addition to the direct cascade.
PACS: 67.25.dg Transport, hydrodynamics, and superflow;
Key words: superfluid helium, second sound, acoustic turbulence, Kolmogorov spectrum.