CPT磁场测量传感器温控技术研究

发布时间：2018-03-18 00:04

本文选题：CPT原子磁力仪　切入点：温度控制　出处：《中国科学院大学(中国科学院国家空间科学中心)》2017年硕士论文　论文类型：学位论文

【摘要】：相干布居囚禁(Coherent Population Trapping,CPT)原子磁力仪是一种全光学原子磁力仪,通过磁探头原子气室内的工作元素的原子在外磁场下的塞曼效应和CPT共振信号来测量外界磁场。所以该类原子磁力仪原子气室内参与工作的的工作元素原子数密度直接关系到磁测信号的质量进而影响测量灵敏度和精度。这就需要为磁传感器设计一套温控系统,该系统既能控制磁传感器原子气室的工作温度,又能够产生较小甚至是不产生干扰磁场。本文正是针对CPT原子磁力仪的温控需求,为了提高原子磁力仪传感器工作环境的温度稳定性,改善磁力仪灵敏度和准确度,提出了一种基于数字式PID算法的无磁加热技术,完成了传感器气室的温度控制系统。实现了对磁力仪高精度的加热以及控温功能。首先,本论文对课题的背景意义进行了简要介绍,概括了几种常见的原子磁力仪及其研究现状,并重点介绍了CPT原子磁力仪的国内外研究现状。同时对各类原子磁力仪中所使用的原子气室的加热方式进行了调研和总结,简述了各加热方式的基本工作原理以及他们各自的特点。其次,重点阐述了CPT原子磁力仪的工作原理,再结合原子磁力仪的灵敏度公式以及气室内原子气体随温度的变化曲线关系,研究和分析了原子磁力仪的温控需求和必要性,提出了本温控系统的技术指标。然后,完成了系统的方案设计,并利用仿真计算验证了系统的性能,论文对原子磁力仪传感器进行了有限元热仿真,通过Matlab最小二乘法函数方法拟合热力学参数,确定了原子磁力仪传感器的传递函数。使用Matlab的Simulink工具,搭建控制系统模型并进行参数调试和仿真以确定最佳控制参数组合,仿真验证了温度控制精度优于±0.05°C,验证了控制系统在低功耗要求下的可行性和稳定性。最后,利用控制系统仿真得到的控制参数,对磁传感器的温控系统装置进行了温度加热效果和温度控制性能的实验验证,并与仿真结果进行了比较分析。实际的测量结果显示该温控系统能够实现温控需求,并且系统实现稳态后的波动最大峰峰值在0.35°C以内,满足±1°C的设计要求,且该温控系统具有良好的适应性和稳定性。该温控系统的实现和验证也为其他类型的原子磁传感器原子气室的温度控制提供了一种新的设计思路和可行性方案。
[Abstract]:The coherent population trapping device (CPT) atomic magnetometer is an all-optical atomic magnetometer. The external magnetic field is measured by the Zeeman effect and the CPT resonance signal of the working elements of the atomic gas chamber under the external magnetic field of the atomic gas chamber. Therefore, the working element number of the working element in the atomic magnetometer of this kind of atomic magnetometer is dense. The quality of the magnetic measurement signal is directly related to the quality of the measurement signal, which affects the sensitivity and accuracy of the measurement, which requires the design of a temperature control system for the magnetic sensor. The system can not only control the working temperature of the atomic gas chamber of the magnetic sensor, but also produce a small or even non-interference magnetic field. This paper aims at the temperature control requirements of the CPT atomic magnetometer. In order to improve the temperature stability of the atomic magnetometer sensor and improve the sensitivity and accuracy of the magnetometer, a non-magnetic heating technique based on digital PID algorithm is proposed. The temperature control system of the sensor chamber is completed. The high-precision heating and temperature control functions of the magnetometer are realized. Firstly, the background significance of this paper is briefly introduced. This paper summarizes several common atomic magnetometers and their research status, and emphatically introduces the research status of CPT atomic magnetometers at home and abroad. At the same time, the heating methods of atomic gas chambers used in various atomic magnetometers are investigated and summarized. The basic working principle of each heating mode and their respective characteristics are briefly described. Secondly, the working principle of CPT atomic magnetometer is expounded emphatically. Based on the sensitivity formula of atomic magnetometer and the relationship between atomic gas and temperature in gas chamber, the requirement and necessity of temperature control of atomic magnetometer are studied and analyzed, and the technical index of the temperature control system is put forward. The scheme design of the system is completed, and the performance of the system is verified by the simulation calculation. The finite element thermal simulation of the atomic magnetometer sensor is carried out in this paper, and the thermodynamic parameters are fitted by the Matlab least square function method. The transfer function of the atomic magnetometer sensor is determined. Using the Simulink tool of Matlab, the control system model is built and the parameters are debugged and simulated to determine the optimal control parameter combination. The simulation results show that the temperature control accuracy is better than 卤0.05 掳C, and the feasibility and stability of the control system under the low power requirement are verified. Finally, the control parameters are obtained by the simulation of the control system. The temperature control system of the magnetic sensor has been verified by experiments on the effect of temperature heating and the performance of temperature control, and has been compared with the simulation results. The actual measurement results show that the temperature control system can meet the temperature control requirements. And the maximum peak value of fluctuation after steady state is within 0.35 掳C, which meets the design requirement of 卤1 掳C. The temperature control system has good adaptability and stability. The realization and verification of the temperature control system also provides a new design idea and feasible scheme for the temperature control of atomic gas chamber of other kinds of atomic magnetic sensors.
【学位授予单位】：中国科学院大学(中国科学院国家空间科学中心)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM936.1;TP273

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