在各种冷原子干涉测量系统中, 磁光阱(Magneto Optical Trap, MOT)、补偿及偏置磁场控制是不可或缺的关键技术, 稳定、快速的磁场控制直接影响着原子冷却囚禁、干涉等过程中原子团的精密操控。设计了一套高性能的精密磁场控制系统, 电路结构上通过采用精密放大器驱动的低噪声恒流源拓扑, 以降低磁场驱动电流的噪声水平; 控制方式上采用模拟PID+扰动抑制的控制策略, 以提高磁场驱动电流的开关速度。实验室环境下测试结果表明: 当磁场驱动电流输出为1 A的情况下, 电流开启时间优于300 μs, 关断时间优于50 μs, DC(0 Hz)~250 kHz频率范围内总体电流噪声优于-80 dB。最终, 通过在冷原子绝对重力仪/重力梯度仪与冷原子陀螺系统中的应用测试, 所设计的磁场控制模块满足了冷原子干涉系统控制需求, 达到了预期效果。而且通过自主研制, 解决了对商用磁场控制模块的依赖, 促进了量子测量装置的装备化。

In various cold atomic interferometry systems, MOT, compensation and bias magnetic control are indispensable techniques. The precise manipulation of atomic groups is directly affected by table and fast magnetic field control in the process of atomic cooling, trapping and interference. A set of high-performance precision magnetic field control system is designed in this paper. In circuit topology, the low-noise constant current source based on precision amplifier is used to reduce the noise level of magnetic field driven current. In control mode, analog PID plus disturbance suppression control strategy is adopted to improve the switching speed of magnetic field driven current. The experimental tests are implemented in the laboratory environment. In case of 1 A magnetic field driven current, the opening time is shorter than 300 μs, while the shutdown time is less than 50 μs. Meanwhile, overall current noises are superior to -80 dB at the frequency ranges of DC(0 Hz)~250 kHz. Finally, through experimental tests in cold atom absolute gravimeter/gravity gradiometer and gyroscope, the designed magnetic field control system could meet control requirements of cold atomic interferometry systems and achieve the expected affect. Moreover, its independent development could solve the dependence on commercial magnetic-field control modules, and promote the equipment of quantum measurement devices.