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Nonlinear second sound waves and acoustic turbulence in superfluid He-4.

Research output: Contribution to journalJournal article

Published

<mark>Journal publication date</mark>08/2007
<mark>Journal</mark>Journal of Low Temperature Physics
Issue3-4
Volume148
Number of pages5
Pages251-255
<mark>Original language</mark>English

Abstract

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.

Bibliographic note

The final publication is available at Springer via http://dx.doi.org/10.1007/s10909-007-9386-x