Diffusion Coefficients and Nuclear Magnetic Susceptibility of Dilute<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>-He II Solutions

Opfer, J.E.; Luszczynski, K.; Norberg, R. E.

doi:10.1103/physrev.172.192

Cited by 30 publications

(10 citation statements)

References 10 publications

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“…The diffusion coefficient measured with the CPMG sequence in sample 2 is smaller (D ¼ 1.3 Â 10 À3 cm 2 /s for X ¼ 4.5%). Both values agree with published data [21].…”

Section: Discussionsupporting

confidence: 93%

Nonlinear NMR dynamics in hyperpolarized liquid 3He

Baudin

Hayden

Tastevin

et al. 2007

Comptes Rendus. Chimie

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In a highly polarized liquid (laser-polarized 3He-4He mixtures in our experiment), dipolar magnetic interactions within the liquid introduce a significant nonlinear and nonlocal contribution to the Bloch equation that leads to instabilities during NMR evolution. We have launched a study of these instabilities using spin echo techniques. At high magnetizations, a simple 180 degree rf pulse fails to refocus magnetization, so we use a standard solid-state NMR pulse sequence: the magic sandwich. We report an experimental and numerical investigation of the effect of this sequence on unstable NMR evolution. Using a series of repeated magic sandwich sequences, the transverse magnetization lifetime can be increased by up to three orders of magnitude.Comment: Accepted for publication in C. R. Chim. (2007), doi:10.1016/j.crci.2007.07.005 v2: typo corrected in Eq. (2

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“…The diffusion coefficient measured with the CPMG sequence in sample 2 is smaller (D ¼ 1.3 Â 10 À3 cm 2 /s for X ¼ 4.5%). Both values agree with published data [21].…”

Section: Discussionsupporting

confidence: 93%

Nonlinear NMR dynamics in hyperpolarized liquid 3He

Baudin

Hayden

Tastevin

et al. 2007

Comptes Rendus. Chimie

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“…Here, the two decay rates Γ extracted from traces a and c in Fig. 1 yield D = 1.54 × 10 −3 cm 2 /s at X = 2.8%, in good agreement with published values [5,14]. The RMS sequence appears to be a lot more robust than the CPMG sequence against dipolar effects.…”

Section: Discussionsupporting

confidence: 75%

NMR Time Reversal Experiments in Highly Polarised Liquid 3He-4He Mixtures

et al. 2007

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Long-range magnetic interactions in highly magnetised liquids (laser-polarised 3 He-4 He dilute mixtures at 1 K in our experiment) introduce a significant non-linear and non-local contribution to the evolution of nuclear magnetisation that leads to instabilities during free precession. We recently demonstrated that a multi-echo NMR sequence, based on the magic sandwich pulse scheme developed for solid-state NMR, can be used to stabilise the magnetisation against the effect of distant dipolar fields. Here, we report investigations of echo attenuation in an applied field gradient that show the potential of this NMR sequence for spin diffusion measurements at high magnetisation densities.

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“…From these results it follows that the increase of the coefficient D with growing 3He concentration is characteristic for the spin diffusion only, but the mass diffusion remains about the same for concentrated and for more dilute solutions. In the superfluid 3He-4He solutions there is also a difference between the mass and the spin diffusion; the former was measured by Ptukha 3 a~ad Herzlinger and King, 4 the latter by Opfer et al 13 Both spin and mass diffusion coefficients are equal in the limit of small 3He concentrations, but as the 3He concentration is increased the spin diffusion decreases, because 3He-4He collisions limit the free passage of 3He in the definite spin state. This is in accordance with the 3He-quasiparticle model developed in the theory of Khalatnikov and Zharkov 14 for dilute superfluid 3He-4He solutions.…”

Section: Discussionmentioning

confidence: 99%

Mass diffusion in 3He-4He solutions

Vvedensky

Peshkov

1978

J Low Temp Phys

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The mass diffusion coefficient in nonsuperfluid 3He-4He solutions was measured at temperatures 0.55-1.05K and at a pressure of 26 atm in the concentration range 60-100% 3He by the method of crystal dissolution. This coefficient has a value of about 2xlO-Scm2/sec, which is 1.5 times less than the spin diffusion coefficient for the same concentrations. This experimental result shows the importance of the spin fluctuations for the description of liquid 3He at temperatures above O. 1 K. The experiment in the solid at O. 6 K and at 31 atm has shown that the mass diffusion coefficient on the solid 3He-solid 4He interface is very small, D < 6 x 10 -11 cm2/sec.

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Diffusion Coefficients and Nuclear Magnetic Susceptibility of DiluteHe3-He II Solutions

Abstract: can also be derived by expanding the exact S of Eq. (16) to second order and dropping the constant terms and those which correspond to the redistributed, steady-state energy, that is, to the second term in Eq. (36).

Cited by 30 publications

References 10 publications

Nonlinear NMR dynamics in hyperpolarized liquid 3He

Nonlinear NMR dynamics in hyperpolarized liquid 3He

NMR Time Reversal Experiments in Highly Polarised Liquid 3He-4He Mixtures

Mass diffusion in 3He-4He solutions

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