Ultrasensitive 3He magnetometer for measurements of high magnetic fields

Anna Nikiel; Peter Blümler; Werner Heil; Manfred Hehn; Sergej Karpuk; Andreas Maul; Ernst Otten; Laura M. Schreiber; Maxim Terekhov

doi:10.1140/epjd/e2014-50401-3

2021 Impact factor 1.611

Atomic, Molecular, Optical and Plasma Physics

Eur. Phys. J. D (2014) 68: 330
https://doi.org/10.1140/epjd/e2014-50401-3

Regular Article

Ultrasensitive ³He magnetometer for measurements of high magnetic fields

Anna Nikiel¹^,2, Peter Blümler¹, Werner Heil¹^a, Manfred Hehn³, Sergej Karpuk¹, Andreas Maul¹, Ernst Otten¹, Laura M. Schreiber⁴ and Maxim Terekhov⁴

¹ Institute of Physics, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
² Helmholtz-Institute Mainz, Johann-Joachim-Becherweg 36, 55128 Mainz, Germany
³ MPI for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
⁴ University Medical Center Mainz Langenbeckstrasse 1, 55131 Mainz, Germany

^a e-mail: wheil@uni-mainz.de

Received: 23 May 2014
Received in final form: 30 August 2014
Published online: 3 November 2014

Abstract

We describe a ³He magnetometer capable to measure high magnetic fields (B> 0.1 T) with a relative accuracy of better than 10^-12. Our approach is based on the measurement of the free induction decay of gaseous, nuclear spin polarized ³He following a resonant radio frequency pulse excitation. The measurement sensitivity can be attributed to the long coherent spin precession time T₂^∗ being of order minutes which is achieved for spherical sample cells in the regime of “motional narrowing” where the disturbing influence of field inhomogeneities is strongly suppressed. The ³He gas is spin polarized in situ using a new, non-standard variant of the metastability exchange optical pumping. We show that miniaturization helps to increase T₂^∗ further and that the measurement sensitivity is not significantly affected by temporal field fluctuations of order 10^-4.