Europhys. Lett.
Volume 68, Number 4, November 2004
Page(s) 480 - 486
Section Atomic and molecular physics
Published online 22 October 2004
Europhys. Lett., 68 (4), pp. 480-486 (2004)
DOI: 10.1209/epl/i2004-10237-y

High nuclear polarization of $\chem{{}^3He}$ at low and high pressure by metastability exchange optical pumping at $\mth{1.5}$ tesla

M. Abboud1, A. Sinatra1, X. Maître2, G. Tastevin1 and P.-J. Nacher1

1  Laboratoire Kastler Brossel, Ecole Normale Supérieure 24 rue Lhomond, 75005 Paris, France (Laboratoire Kastler Brossel is a unité de recherche de l'Ecole Normale Supérieure et de l'Université Pierre et Marie Curie, associée au CNRS (UMR 8552).)
2  U2R2M, Université Paris-Sud and CIERM, Hôpital de Bicêtre 94275 Le Kremlin-Bicêtre Cedex, France (U2R2M (Unité de Recherche en Résonance Magnétique Médicale) is a unité de recherche de l'Université Paris-Sud, associée au CNRS (UMR 8081).)

received 19 July 2004; accepted in final form 21 September 2004
published online 22 October 2004

Metastability exchange optical pumping of helium-3 is performed in a strong magnetic field of 1.5 $\un{T}$. The achieved nuclear polarizations, between 80% at 1.33 $\un{mbar}$ and 25% at 67 $\un{mbar}$, show a substantial improvement at high pressures with respect to standard low-field optical pumping. The specific mechanisms of metastability exchange optical pumping at high field are investigated, advantages and intrinsic limitations are discussed. From a practical point of view, these results open the way to alternative technological solutions for polarized helium-3 applications and in particular for magnetic-resonance imaging of human lungs.

32.80.Bx - Level crossing and optical pumping.
67.65.+z - Spin-polarized hydrogen and helium.
87.61.-c - Magnetic resonance imaging.

© EDP Sciences 2004