Research on the High Magnetic Field and Current Measurement System Based on ³He Nuclear Magnetic Resonance

This paper investigates the design and experimental method of a high magnetic field measurement system based on a ³He single-beam hybrid optical pumping nuclear magnetic resonance (NMR) gyroscope, aiming to improve the accuracy and stability of magnetic field measurement by using quantum technology and to meet the needs of modern navigation and power grid systems for high-precision magnetic field measurement. In this paper, the basic operation principle of the ³He NMR gyroscope is firstly presented, including ³He nuclear spin hyperpolarization by hybrid optical pumping technique, the measurement process of nuclear spin precession based on the absorption scheme, and ³He high-field magnetic resonance. Then, the experimental setup of the high-field measurement system is described in detail, including the fabrication of alkali metal atomic vapor cell filled with ³He nuclear spins, non-magnetic electric heating system, biplanar magnetic field coil, radio-frequency magnetic field generator, and an optoelectronic detector and other key components. Subsequently, the closed-loop locking of the magnetic field is achieved by optimizing the experimental parameters, such as the operating temperature, the pumping light intensity, and the modulation magnetic field. Finally, a comprehensive experimental verification of the designed ³He NMR gyroscope high magnetic field measurement system is carried out. In summary, the ³He-based NMR gyroscope for high magnetic field measurement system studied in this paper has good performance in terms of theoretical design, experimental scheme, and comprehensive indexes, which provides a new solution for high-precision high magnetic field measurement and has a broad application prospect.