Design And Performance Evaluation Of JOM-3 Overhauser Magnetometer

The Overhauser proton magnetometer utilizes the Overhauser effect to excite the solution in the sample chamber of the sensor to generate a nuclear magnetic resonance phenomenon,and the measurement of the geomagnetic field is performed according to the Larmor precession principle.According to the principle of nuclear magnetic resonance,the high energy of the RF signal makes the electrons in the solution doubleresonant with the nucleus,greatly increasing the degree of polarization and reducing the power consumption.The third-generation Overhauser magnetometer independently developed by the laboratory has been optimized on the basis of both the hardware and the software.In this article,the research background and development status of Overhauser magnetometers described firstly,and the great significance of the development of Overhauser magnetometers has been proved.In Chapter 2,the basic principles of magnetometers are introduced.The magnetometer independently developed by the laboratory is mainly divided into two parts: the sensor and the host.And the functions undertaken by each part during the measurement has been introduced.The host can be divided into analog and digital parts.This article focuses on the design of the digital part of the magnetometer host.The digital part of the third-generation magnetometer uses the ARM+CPLD dual-core architecture.From the third chapter,the main part of the magnetometer has been introduced by two aspects: hardware and software.The module design and improvement of the system are described in detail.The key modules,polarization modules,harmonic modules,frequency measurement module are mainly included..Finally,through a series of indoor experiments and field experiments,the performance of the magnetometer was explored.There are sensitivity experiment,sensor omnidirectional experiment,gradient and synchronous contrast experiment.From the noise,sensitivity,time domain analysis,frequency domain analysis and other aspects of the performance of the magnetometer to conduct a comprehensive evaluation.