Analysis of comprehensive magnetic shielding and optimization design of high-conductive layers in magnetic shielding devices for atomic magnetometer

Abstract

Since the frequency of the biological magnetic field is DC to 500 Hz, it is important to improve the ability of the magnetic shielding device within this range for the measurement of the biological magnetic field and the reduction of the magnetic noise of the SERF magnetometer. At present, the optimization of AC magnetic field shielding in the frequency range of 0.01 to 500 Hz is rarely considered. To optimize the AC shielding factor, this paper analyzed the influence of the position and structure of the high-conductive layer in the magnetic shielding device and proposed an optimized structure of the high conductive layer. What’s more, the theoretical formula was improved by introducing frequency coefficients, solving the problem of significant differences between theoretical calculation results, FEM results and measurement results. Finally, it was verified by experiments that the optimized high-conductivity layer structure can improve the AC shielding factor of magnetic shielding device.