核磁共振陀螺静磁系统端口漏磁抑制技术

Port magnetic flux leakage suppression technology for static magnetic system of nuclear magnetic resonance gyroscope

核磁共振陀螺作为目前世界上体积最小的导航级陀螺,受到了国内外的广泛重视。核磁共振陀螺通过检测磁场中原子核自旋进动频率的改变确定载体角速度,核磁共振陀螺的陀螺精度与静磁场的均匀性、稳定性密切相关。然而核磁共振陀螺静磁系统往往存在端口漏磁,形成杂散磁场,在长期工作过程中会磁化磁屏蔽罩,最终干扰陀螺精度。从核磁共振陀螺静磁场分布的理论分析出发,通过数学计算和计算机仿真,分析和研究了静磁系统的端口漏磁,并对静磁系统进行了优化设计。设计的核磁共振陀螺静磁系统端口漏磁在1.5倍螺线管直径范围内较传统方案平均减小45.4%,满足了核磁共振陀螺的使用需求。该工作为核磁共振陀螺仪设计和制造提供了一定的理论依据和参考价值。

Nuclear magnetic resonance gyro（NMR）, as the smallest navigation grade gyroscopes in the world, has been widely appreciated. The nuclear magnetic resonance gyro determines the angular velocity of the carrier by detecting the change of the spin frequency of the nucleus in the magnetic field. The precision of the nuclear magnetic resonance gyro is closely related to the static magnetic field＇s uniformity and stability. However, the static magnetic systems of magnetic resonance gyros often have port leakage, forming stray magnetic field, which will magnetize the magnetic shield in long working process and finally degrade the gyroscope precision. Based on the theoretical analysis of static magnetic field distribution of the nuclear magnetic resonance gyro and through mathematical computation and computer simulation, the port magnetic flux leakage of the static magnetic system is analyzed and studied, and by optimizing the design of the static magnetic system, the leakage is reduced by 45.4% in the diameter of 1.5 x solenoid, which satisfies the usage demand of nuclear magnetic resonance gyro. This work provides theoretical basis and reference value for the design and manufacture of nuclear magnetic resonance gyro.