Research on the high sensitivity of Tri-axial Fluxgate Magnetometer

In order to improve the performance of the small-volume triaxial fluxgate probe and obtain high sensitivity, this paper proposes a method to increase the amplitude of the induced electromotive force pulse generated on the detection coil by changing the center distance of the core of the square annular array on the basis of analyzing that the fluxgate sensitivity is mainly affected by the electromagnetic and physical parameters of the core. The finite element simulation software Ansys Maxwell was used to model the core structures with center distances of $0 \mathrm{~mm}, \mathbf{4 m m}, 8 \mathrm{~mm} . .30 .8 \mathrm{~mm}$ and the magnetic flux at the detection coil was calculated at different center distances. It is shown that the concentration of magnetic flux at the detection coil can be significantly increased by optimizing the core structure, and the magnitude of the induced electromotive force to characterize the external magnetic field can be further improved according to Faraday’s law of induction, thereby improving the sensitivity of the probe. The probe is equipped with a triaxial multicoil feedback winding optimized based on a rectangular Helmholtz coil. Maxwell simulation was used to optimize the uniformity of the magnetic field generated by the feedback coil, and the average magnetic field deviation rate of the feedback coil along the axis of the magnetic core was verified to be within 2%. The results show that this study provides technical ideas and data support for the small fluxgate to improve the sensitivity of the probe by changing the core topology.