Introducing a new shimming method based on combination of axial and radial Halbach arrays to have a uniform flux density for a low-field portable MRI system

Nowadays, Halbach magnets serve different purposes in electrical machine designs by offering different structures. These structures can be used to shim (improve the inhomogeneity) of new static fields in the magnetic resonance imaging (MRI) system. The shimming method proposed here uses axial and radial Halbach arrays. The inhomogeneity and average field is obtained at a constant diameter of spherical volume. Using the FE Maxwell software, different topologies are evaluated and the best structure is then selected and optimized. The optimum structure is manufactured and all issues related to the construction are explained in details. Comparison between simulation and experimental results shows the effectiveness of the proposed idea.