Restricted diffusion of polarised He-3 gas in aerogels

Abstract : Polarised He-3 is used to non-destructively probe by NMR the structure of silica aerogels. Using laser optical pumping large spin-echo signals are obtained with small amounts of gas, even at low magnetic field. Attenuation induced by applied field gradients is measured for equivalent He-3 pressures ranging from 5 mbar to 3 bar. Systematic diffusion studies are performed by NMR on custom-made (98% porous) and commercial (97% porous) aerogels used by research groups to study quantum fluids in confined geometries. The observed pressure dependence suggests a non-uniform structure of both aerogel samples on length scales up to tens of microns. (C) 2003 Elsevier Science B.V. All rights reserved.
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Contributor : Geneviève Tastevin <>
Submitted on : Wednesday, February 13, 2019 - 9:36:58 PM
Last modification on : Tuesday, May 14, 2019 - 10:41:55 AM

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  • HAL Id : hal-02018539, version 1

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G. Tastevin, Pierre-Jean Nacher, J. Choukeife. Restricted diffusion of polarised He-3 gas in aerogels. Physica B: Condensed Matter, Elsevier, 2003, 329-333, pp.303-304. ⟨hal-02018539⟩

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