基于DDS的氦光泵磁力仪射频场智能调频研究

DDS-based intelligent modulation of the radio frequency field of helium optically pumped magnetometers

地磁场测量在基础地质研究、矿产资源勘查和军事探测等领域得到广泛应用,作为磁场测量核心之一的氦光泵磁力仪探头,其射频场调频精度是决定其磁测精度的重要影响因素。为实现易调节、高精度、高可靠性的调频信号,本文利用直接数字频率合成器(DDS)与微控制器(MCU)相结合方式,研究了磁力仪探头射频场智能精密调频技术,可灵活、实时、自动、精密地对磁力仪探头射频场进行调频。调频信号加载到氦光泵磁力仪系统的联调试验表明,磁力仪获得了稳定精密的磁共振信号,从而保证了磁力仪实现高精度的磁场测量。

Geomagnetic field surveys have been widely applied in the fields such as basic geological study,mineral resource exploration,and military detection.A key tool for geomagnetic field surveys is helium optically pumped magnetometer probes.The frequency modulation precision of the radio frequency field used in the probes is an important factor affecting geomagnetic survey precision.To achieve frequency modulation signals featuring easy modulation,high precision,and high reliability,this study proposed an intelligent frequency modulation technology for the radio frequency field of the magnetometer probes by combining the direct digital frequency synthesizer(DDS)and the microcontroller unit(MCU).This technology can achieve flexible,real-time,automatic,and precise frequency modulation of the radio frequency field of the magnetometer probes.As revealed by the integration tests in which frequency modulation signals were loaded into the helium optically pumped magnetometer system,the magnetometer can obtain stable and precise magnetic resonance signals,thus ensuring high-precision geomagnetic field surveys.