QuSpin zero-field magnetometer characterization for the TUCAN experiment

Abstract The TUCAN neutron electric dipole moment experiment utilizes the QuSpin Zero-Field Magnetometer (QZFM) to accurately map residual fields within a large magnetically shielded room. Three potential flaws of the QZFM are characterized in preparation for mapping. The magnetometer’s intrinsic offset was measured to be within <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>±</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:mrow> </mml:math> nT and stable over a period of one year. The response was shown to be within 2 percent of linearity in the zero-field regime, up to 2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>nT</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>pp</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> , and then follows a smooth dispersion curve. Crosstalk effects induced by multisensor operation were determined to have a small effect, and inconsequential with a separation above 6 cm. These results enable the QZFM for accurate measurement of DC fields, increase the operational range of QZFM by a factor of more than an order of magnitude, and allow for higher efficiency and flexibility by green-lighting simultaneous operation of multiple QZFMs.