空间锶原子光钟磁场分析及主动补偿系统

Magnetic field analysis and active compensation system for strontium optical lattice clock in space

空间锶原子光钟在轨运行过程中会感受到幅度约为80μT的地磁场变化,通过引入同等大小的外磁场变化,实验观测了变化地磁场对空间光钟冷原子由磁光阱装载到光晶格的影响。理论分析了地磁场变化对钟跃迁探测的影响,并对磁场稳定性需求进行了分析。通过电动旋转台和永磁体模拟空间环境变化的磁场,利用三维磁通门进行实时探测,设计了主动补偿系统并对外界磁场进行实时补偿,使空间光钟磁光阱中心区域磁场波动在亚μT量级,满足了空间光钟对磁场的补偿与控制需求。

The strontium atomic optical clock in space experiences changes in the geomagnetic field during its orbit of amplitudes of approximately 80 μT. By introducing changes in the external magnetic field of the same magnitude,the influence of the changing magnetic field on the loading of cold atoms from the magneto-optical trap to the optical lattice of the space optical clock is observed. The influence of the changing geomagnetic field on the detection of clock transitions is theoretically analyzed,and the need for magnetic field stability is investigated. The magnetic field of the space environment is simulated by rotating a permanent magnet. Furthermore,a three-dimensional fluxgate probe is used for real-time detection,and an active compensation system is designed to compensate the external magnetic field synchronously. Because the magnetic field in the central area of the magnetic optical trap of the space optical clock fluctuates by a sub-μT magnitude,it can meet the compensation and control requirements of the space optical clock with respect to the magnetic field.