Design of dipole permanent magnet with high field strength

In order to generate a dipole permanent magnet with magnet field strength several as much as the remanence B/sub r/ of permanent magnet material, an enhanced hollow cylinder permanent magnet array (HCPMA) or magic ring structure is presented, which is made of permanent magnet and ferromagnetic material. Using ferrite with B/sub r/ only 0.375 tesla and electric Armco iron, the prototype of dipole permanent magnet in this paper can generate a field whose max flux density is 0.865 tesla in the center of cylindrical pole gap, the volume of which is 24 mm in diameter multiplied 85 mm in length with external diameter equal about to 414 mm.