You are here

    • You are here:
    • Home > ST420 - Tests of a SQUID-based 3He Co-magnetometer Readout for a Neutron EDM Experiment (Contest runner-up)

ST420 - Tests of a SQUID-based 3He Co-magnetometer Readout for a Neutron EDM Experiment (Contest runner-up)

Tests of a SQUID-based 3He Co-magnetometer Readout for a Neutron EDM Experiment

Young Jin Kim1 and Steven M. Clayton2

1Los Alamos National Laboratory, Applied Modern Physics Group, P.O. Box 1663, MS D454, Los Alamos, NM 87545, USA
2Los Alamos National Laboratory, Subatomic Physics Group, MS  H846, Los Alamos, NM 87545, USA
 
 
Abstract  In a new experimental search for an electric dipole moment of the neutron, polarized 3He will occupy the same volume as the neutrons under study to serve as co-magnetometer, enabling precise corrections for ambient magnetic field drifts that would otherwise severely limit the reach of the experiment.  One of the two methods that will be built into the apparatus is to directly detect the 3He magnetization signal using SQUID based gradiometers.  In a previous publication (IEEE Trans. Appl. Supercond., 23 (2013), 2500104), we proposed a candidate design for a SQUID system consistent with experimental requirements and the planned nEDM apparatus. Because the 3He precession signal is at approximately 100 Hz, signal contamination from low frequency magnetic noise could adversely affect the co-magnetometer readout precision; the addition of reference magnetometer channels to the SQUID system could mitigate this risk.  In this paper, we present noise studies of the candidate SQUID system in a test apparatus and demonstrate effective ambient magnetic field noise cancellation with the implementation of reference channels. In addition, we report a demonstration of low-noise SQUID operation while a nearby photomultiplier tube and its high voltage power supply are operating.
 

Keywords (Index Terms)  EDM, magnetic-resonance, 3He co-magnetometer, SQUID, magnetic field noise, reference channel

IEEE/CSC & ESAS SUPERCONDUCTIVITY NEWS FORUM (global edition), January 2015. 
Received August 14, 2014; Accepted September 22, 2014. Reference ST420; Category 4.
ASC 2014 manuscript 3EPo1C-01 published online in IEEE Trans. Appl. Supercond. (IEEE XPLORE) DOI: 10.1109/TASC.2014.2359336, on September 19, 2014.