Unshielded portable optically pumped magnetometer for the remote detection of conductive objects using eddy current measurements.
Unshielded portable optically pumped magnetometer for the remote detection of conductive objects using eddy current measurements.
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DOI：
10.1063/5.0102402
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
L. M. Rushton;T. Pyragius;A. Meraki;L. Elson;K. Jensen
中科院分区：
文献类型：
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作者：
L. M. Rushton;T. Pyragius;A. Meraki;L. Elson;K. Jensen
可以使用电磁感应原理来检测导电物体，其中初级振荡磁场在物体中感应出涡电流，这反过来又产生可以用磁力计测量的次级磁场。我们开发了一种便携式射频光泵磁力仪（RF OPM），在非屏蔽条件下工作，用于检测小振荡磁场时具有sub-pT/Hz的磁场灵敏度，为便携式RF OPM在非屏蔽条件下的灵敏度设定了新的基准。利用这种OPM，我们已经检测到的感应磁场，从铝盘直径小至1.5厘米，与磁盘是1.25厘米的励磁线圈和磁强计。当用于涡流检测时，我们的磁力计可实现2-6 pT/Hz的灵敏度。我们还检测到一个移动的铝盘使用我们的RF OPM和分析的磁力计信号，这取决于磁盘的位置，说明了高灵敏度RF OPM的遥感应用的潜力。
Electrically conductive objects can be detected using the principle of electromagnetic induction, where a primary oscillating magnetic field induces eddy currents in the object, which in turn produce a secondary magnetic field that can be measured with a magnetometer. We have developed a portable radio-frequency optically pumped magnetometer (RF OPM) working in unshielded conditions with sub-pT/Hz magnetic field sensitivity when used for the detection of small oscillating magnetic fields, setting a new benchmark for the sensitivity of a portable RF OPM in unshielded conditions. Using this OPM, we have detected the induced magnetic field from aluminum disks with diameters as small as 1.5 cm and with the disks being ∼25 cm from both the excitation coil and the magnetometer. When used for eddy current detection, our magnetometer achieves a sensitivity of a 2-6 pT/Hz. We have also detected a moving aluminum disk using our RF OPM and analyzed the magnetometer signals, which depend on the position of the disk, illustrating the potential of high sensitivity RF OPMs for remote sensing applications.