基于Overhauser效应的磁场梯度探测器  

Magnetic field gradient detector based on the nuclear Overhauser effect

作　　者：刘欢[1] 董浩斌[2] 葛健[1,2] 赵志卓 

机构地区：[1]中国地质大学地球物理与空间信息学院,武汉430074 [2]中国地质大学自动化学院,武汉430074 [3]总装备部工程兵科研一所,无锡214035

出　　处：《仪器仪表学报》2015年第3期592-600,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(41474158);国家重大专项(Sino Probe-09-05);国家863计划(2007AA12Z129);国防预研项目(404070201)资助项目

摘　　要：为提高单探头磁力仪在自然环境中的抗干扰能力,设计了一种基于Overhauser效应的双探头磁场梯度探测器。文中介绍了Overhauser效应的基本原理,对仪器的射频激发系统、信号调理系统和频率计做了详细的描述。论文分析了射频系统的不稳定因素,并给出解决方案。针对拉莫尔旋进信号,提出一种基于FPGA的多通道测频算法,并对比测试使用该算法前后的结果,分析了实验数据。同时对仪器双探头的数据一致性进行比对,给出了测试方法和测试结果。最后将该仪器和商用仪器进行室内、室外以及磁异常探测等对比试验,结果表明,其性能接近商用仪器水平,具有野外操作便捷、测量磁场精度高、抗干扰能力强等优点,证明了所研制的基于Overhauser效应的磁场梯度探测器在梯度测量中的有效性。In order to improve the anti-interference ability of single probe magnetometer in natural environment,a dual probe structure magnetic gradient detector based on nuclear Overhauser effect was designed.This paper introduces the basic principle of nuclear Overhauser effect,makes a detailed description about the RF excitation system,the signal conditioning system and the frequency meter of the instrument.The instability of the RF system is analyzed,and the solution is given.Aiming at the Larmor precession signal,a multi-channel frequency measurement algorithm based on FPGA is proposed.The test results before and after using the algorithm are compared,and the experiment data are analyzed.The test data consistency of the dual probe is discussed,and the test method and results are given.Finally,the comparison experiments between the proposed instrument and commercial instrument under indoor,outdoor and magnetic anomaly conditions were conducted; the test results show that the performance of the instrument is close to that of the commercial instrument; the instrument has the advantages of convenient for field operation,high field magnetic measurement precision,strong anti-interference and etc,which proves the effectiveness of the dual probe structure magnetic gradient detector based on nuclear Overhauser effect in magnetic gradient measurement.

关 键 词：Overhauser效应 双探头 磁场梯度 多通道测频算法 硅振荡器 

分 类 号：TH762.3[机械工程—仪器科学与技术]