Optimizing the field distribution of a Halbach type permanent magnet cylinder using the soft iron and superhard magnet

Highlights: • The scenarios of field and magnetization inside the array material are predicted. • The field uniformity and magnetic flux in the pole gap are modulated by soft iron and superhard magnet. • The optimized material substitution parameters are given for a strong field HCPMA. When a conventional Halbach type Hollow Cylindrical Permanent Magnet Array (HCPMA) is used to generate magnetic induction over the magnitude of coercivity μ₀H_c, some detrimental parasitic magnetic phenomena, such as the demagnetization, magnetization reversal, and vortexes of magnetization, can appear in the interior of the magnets. We present a self-consistent quantitative analysis of the magnetization and magnetic induction distributions inside the magnetic array by considering the anisotropic and nonlinear magnetization functions of the materials consisting of the array. These numeric simulations reveal novel magnetization structures resulted from the self-field of array. We demonstrate that both the field uniformity and magnetic flux in the pole gap can be modulated by partially substituting the magnets of high energy products with the soft irons and the superhard magnets. We also show how the optimized substitution parameters can be obtained for a HCPMA achieving the best field uniformity or the maximum magnetic flux.