Design Considerations of Ring-Type Magnets

This paper presents an analytical solution for the magnetic field between two poles of an axially oriented ring magnet. The method involves expanding the scalar potential between the two poles into McLauren series. The magnetic field is then linked to the field along the axis of the ring. The resulted solution shows the relationship between the geometry of the ring and magnetic field. From this solution, a geometrical relationship can be found to generate near uniform field at the center region of the ring. We also present a geometrical relationship of the ring to generate a peak field at the center. The results are then compared with boundary element analysis (BEA).