Decay of Turbulence Generated by Spin-Down to Rest in Superfluid He

We report on the extension of the experiments (P.M. Walmsley et al., Phys. Rev. Lett. 99:265302, 2007) on the decay of quasiclassical turbulence generated by an impulsive spin-down from angular velocity Omega to rest of superfluid He in a cubic container at temperatures 0.15 K-1.6 K. The density of...

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Bibliographic Details
Published in:Journal of low temperature physics 2008-12, Vol.153 (5-6), p.127-139
Main Authors: Walmsley, P M, Golov, A I, Hall, H E, Vinen, W F, Levchenko, A A
Format: Article
Language:English
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Summary:We report on the extension of the experiments (P.M. Walmsley et al., Phys. Rev. Lett. 99:265302, 2007) on the decay of quasiclassical turbulence generated by an impulsive spin-down from angular velocity Omega to rest of superfluid He in a cubic container at temperatures 0.15 K-1.6 K. The density of quantized vortex lines L is measured by scattering negative ions. Following the spin-down, the maximal density of vortices is observed after time t~10Omega. By observing the propagation of ions along the axis of the initial rotation, the transient dynamics of the turbulence spreading from the perimeter of the container into its central region is investigated. Nearly homogeneous turbulence develops after time t~100Omega and decays as L {proportional to} t. The effective kinematic viscosity in T=0 limit is nu=0.003kappa, where kappa=10 cms is the circulation quantum.
ISSN:0022-2291
DOI:10.1007/s10909-008-9832-4