Studies of the field distribution of the modulating width multipole permanent magnets

In this paper, the magnetic field distribution of the modulating width multipole permanent magnets is analyzed. Only radially magnetized permanent magnet segments are used and the required magnetic field is formed by modulating the widths of the segments in this project. In 2-dimensional ideal case, pure 2N-pole magnetic field can be formed. The spatial expressions of the scalar potential for the ideal and real 2-dimensional cases are given. And the methods for reducing the undesirable higher harmonics of the magnetic field in the real case are also discussed