Suppressing the Static Magnetic Field Error Based on the Rb-Xe Coupling Effect in NMR Angular Velocity Sensor

The nuclear magnetic resonance (NMR) angular velocity sensor exhibits compactness and high precision, leveraging an in situ rubidium (Rb) magnetometer to determine the precession frequencies of double-isotope Xe (Xe-129 and Xe-131), which are critical for angular velocity determination. However, its performance is substantially affected by static magnetic field variations, which not only alter the precession frequencies of Xe-129 and Xe-131 but also induce shifts in Rb precession frequency, thereby introducing measurement errors in angular velocity. To mitigate this challenge, this study investigates the impact of static magnetic field shifts on the precession frequency measurement error and presents a suppression method based on the Rb-Xe coupling effect. This method comprehensively evaluates the influence of static magnetic field shifts on the Rb, Xe-129, and Xe-131 magnetic moment signals, ultimately proposing a static magnetic field error suppression method. Notably, this approach effectively suppresses the static magnetic field error without influencing the measurement sensitivity. Experimental validation reveals a significant 48.8% reduction in static magnetic field error. Long-term stability of precession frequency measurement error between Xe-129 and Xe-131 shows a 24.9% reduction in the maximum variation and a 25.1% decrease in bias instability during 2-h continuous monitoring. This innovative approach offers substantial benefits for advancing the performance and reliability of angular velocity sensor.