Observation of acoustic turbulence in a system of nonlinear second sound waves in superfluid ⁴He

• Published in: Физика низких температур
• Date: 2008
• Main Authors: Ganshin, A.N., Efimov, V.B., Kolmakov, G.V., McClintock, P.V.E., Mezhov-Deglin, L.P.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2008
• Subjects: Жидкий гелий
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/116917
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Observation of acoustic turbulence in a system of nonlinear second sound waves in superfluid ⁴He / A.N. Ganshin, V.B. Efimov, G.V. Kolmakov, P.V.E. McClintock, L.P. Mezhov-Deglin // Физика низких температур. — 2008. — Т. 34, № 4-5. — С. 367–372. — Бібліогр.: 24 назв. — англ.

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.