Research on the Design Method of Uniform Magnetic Field Coil Based on the MSR

The uniform magnetic field coil can be placed in the magnetic shielding room (MSR) to provide a more accurate magnetic source. The coil could generate a uniform magnetic field by the conventional design method, but when placed in the MSR, the uniformity of the field would be affected. The magnetic field analysis model of coil based on cuboid ferromagnetic boundary condition is constructed by the image method. This paper proposes a new design method of coil parameters based on the deviation of magnetic field distribution in volumes boundary. The coil system in the shield designed by the new method is compared with the conventional coil system, which not only solves the problem of uniformity reducing, but also further improves the uniformity of the magnetic field. The influence of the ratio k_t of coil side length to MSR side length on coil parameters is found. The correspondence between the coil parameters and the k_t can be used to guide the design of the coil system under the future ferromagnetic boundary conditions. The validity and significance of the analytical model as well as the new design method are proved by the results of finite-element software and experiments.