Analysis and demonstration of the in-situ magnetometer for nuclear magnetic resonance gyroscopes

Shu Qiang; Ji Fang; Zhu Mingzhi

doi:10.1016/j.jmr.2021.107128

Analysis and demonstration of the in-situ magnetometer for nuclear magnetic resonance gyroscopes

J Magn Reson. 2022 Feb:335:107128. doi: 10.1016/j.jmr.2021.107128. Epub 2021 Dec 15.

Authors

Shu Qiang¹, Ji Fang², Zhu Mingzhi³

Affiliations

¹ Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China; Institute of Mechanical Manufacturing Technology, Mianyang 621999, China. Electronic address: qiangzhongshu@126.com.
² Institute of Mechanical Manufacturing Technology, Mianyang 621999, China.
³ Institute of Systems Engineering, Mianyang 621999, China.

PMID: 34942575
DOI: 10.1016/j.jmr.2021.107128

Abstract

Rb atom serves as both polarization medium and an in-situ magnetometer in a nuclear magnetic resonance gyroscope. Analytical solution for the in-situ magnetometer output is obtained. The output gains and the decoupling phases for the transverse fields are developed analytically. A method to determine experimentally the decoupling phases for the x and y outputs by scanning the phases at different offsets of the magnetometer is proposed. Influence of magnetic field parameters on the output gains and the decoupling phases are analyzed by experiment and theoretical computations. It is found that the main static field B₀ and the sinusoidal carrier amplitude B_c and their ratios have significant effects on the output gains and decoupling phases. Accurate determination of the decoupling phases needs careful minimization of the constant residual field. The performance of the in-situ magnetometer is evaluated by experiment with the coupled output characteristic bellow ±0.16 nT when the transverse input field is within ±100 nT and the transverse output sensitivity 0.01nT/Hz^0.5 within the bandwidth except the low frequency part.

Keywords: In-situ magnetometer; Influence analysis; Nuclear magnetic resonance gyroscope.