Design Method of Cylindrical Self-Shielding Coils in Spindle-Shaped Magnetic Shielding Cylinders Eliminating Ferromagnetic Boundary Coupling

The uniformity of the coils is often compromised by the coupling between ferromagnetic materials and coils. The spindle-shaped magnetic shielding cylinder (sMSC) has additional benefits over the MSC. A single-layer cylindrical self-shielding coil designed by the improved target field method (TFM) that is available inside sMSC is proposed. The method dynamically regulates the internal uniformity and external self-shielding performance by assigning different weights to the internal and external field points. To reduce the dependence of the traditional TFM design on relevant factors, the hunter-prey optimization (HPO) is applied to optimize it. The modeling and experimental findings reveal that the maximum homogeneity deviations of the self-shielding coil are 0.24% and 0.28%, respectively. The self-shielded coil takes up less space in comparison to the normal non-moment Helmholtz coils. This method ensures the uniform performance of the internal magnetic field (MF) while rapidly attenuating the external MF.