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Torsional oscillator studies of the superfluidity of 3He in aerogel

H. Alles·J. J. Kaplinsky·P. S. Wootton·J. D. Reppy·J. R. Hook
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Abstract

We have made simultaneous torsional oscillator and transverse NMR measurements (at 165 kHz) on 3He contained within aerogels with nominal densities of 1% and 2% of solid glass. The superfluid transition is seen simultaneously by both techniques and occurs at a temperature which agrees semi-quantitatively with that expected for homogeneous isotropic pair-breaking scattering of 3He atoms by strands of silica. Values obtained for the superfluid density rho_s in the 2% sample are in reasonable agreement with those observed previously. Coupling of the torsional mode to a parasitic resonance prevented accurate determination of rho_s for the 1% aerogel. We have identified other resonances coupling to the torsional oscillations as sound modes within the helium/aerogel medium.

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H. Alles, J. J. Kaplinsky, P. S. Wootton, J. D. Reppy, J. R. Hook. 1999-03-31. Torsional oscillator studies of the superfluidity of 3He in aerogel. https://doi.org/10.1016/s0921-4526(98)00446-3

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