Spin diffusion measurements in spin-polarised liquid He-3-He-4 mixtures

Abstract : We report on investigations of spin diffusion in isotopic helium liquid mixtures using a multi-echo technique in applied magnetic field gradients. Samples (up to 1 cm(3) in volume) are obtained by liquefaction of optically polarised gas. NMR measurements are performed at saturated vapour pressure in a low magnetic field (2.2 mT). Signal-to-noise ratios stay high down to He-3 concentrations of order a few parts per thousand at 1K for instance. We demonstrate that the experimental accuracy of spin diffusion measurements is substantially improved using optically polarised mixtures. We have observed that the dynamics of the precession of the transverse magnetisation can be altered due to large dipolar fields at high magnetisation densities. Effects on spin-echo signals and implications for the extension of spin diffusion measurements with our technique are discussed.
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Contributor : Geneviève Tastevin <>
Submitted on : Wednesday, February 13, 2019 - 8:55:43 PM
Last modification on : Saturday, March 23, 2019 - 1:38:47 AM

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  • HAL Id : hal-02018487, version 1

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N. Piegay, Geneviève Tastevin, Pierre-Jean Nacher. Spin diffusion measurements in spin-polarised liquid He-3-He-4 mixtures. Journal of Low Temperature Physics, 2000, 121 (5-6), pp.785-790. ⟨hal-02018487⟩

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