Efimov, V. B. and Ganshyn, A. N. and McClintock, Peter V. E. and Kolmakov, G. V. and Mezhov-Deglin, L. P. (2007) Nonlinear second sound waves and acoustic turbulence in superfluid He-4. Journal of Low Temperature Physics, 148 (3-4). pp. 251-255. ISSN 0022-2291
The preliminary results of an investigation of nonlinear second sound waves in a high quality resonator filled with superfluid 4He are presented and discussed. It is found that, for a sufficiently strong periodic driving force, a cascade of second sound waves is formed at multiple harmonics of the driving frequency over the extremely wide frequency range 1–100 kHz. It can be described by a power law A ω =const.×ω −m , where the scaling index m≈1. These observation can be attributed to the formation of a Kolmogorov-like turbulent cascade in the system of second sound waves, accompanied by directed energy flux through the frequency scales. It manifests itself as a limiting of the amplitude of a standing wave, a distortion of the shape of the initially harmonic waves, and a reduction of the effective quality factor Q of the resonator.
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