EPJ Techn Instrum (2014) 1: 8
https://doi.org/10.1140/epjti/s40485-014-0008-0

Research Article

Development of a ³He magnetometer for a neutron electric dipole moment experiment

¹ Institute of Physics, Johannes Gutenberg University, Mainz, 55128, Germany
² Physics Department, University of Fribourg, Fribourg, CH-1700, Switzerland
³ Institute of Nuclear Chemistry, Johannes Gutenberg University, Mainz, 55128, Germany
⁴ Paul Scherrer Institute, Villigen, CH-5232, Switzerland
⁵ Ioffe Institute, St Petersburg, 194021, Russian Federation
⁶ Present address: CENPA, Department of Physics, University of Washington, Seattle, WA 98195, USA
⁷ Present address: Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM-II), Lichtenbergstrasse 1, Garching, 85748, Germany
⁸ Petersburg Nuclear Physics Institute, Gatchina, 188300, Russian Federation

^* e-mail: kraftan@u.washington.edu

Received: 3 July 2014
Accepted: 30 July 2014
Published online: 1 October 2014

Abstract

Abstract

We have developed a highly sensitive ³He magnetometer for the accurate measurement of the magnetic field in an experiment searching for an electric dipole moment of the neutron. By measuring the Larmor frequency of nuclear spin polarized ³He atoms a sensitivity on the femto-Tesla scale can be achieved. A ³He/Cs-test facility was established at the Institute of Physics of the Johannes Gutenberg University in Mainz to investigate the readout of ³He free induction decay with a lamp-pumped Cs magnetometer. For this we designed and built an ultra-compact and transportable polarizer unit which polarizes ³He gas up to 55% by metastability exchange optical pumping. The polarized ³He was successfully transfered from the polarizer into a glass cell mounted in a magnetic shield and the ³He free induction decay was detected by a lamp-pumped Cs magnetometer.

PACS numbers

07.55.Ge Magnetometers for magnetic field measurements; 13.40 Electric and magnetic moments; 14.20 Protons and neutrons