Forward and Inverse Analyses of Cylindrical Permanent Magnets

Abstract

This paper describes an inverse analysis of magnetization distribution in cylindrical permanent magnets used in laser printers and copy machines. The magnetization distribution is reconstructed from the magnetic field measured on a circle outside the cylindrical magnet. The singular system matrix, which maps the inner magnetization to the magnetic field on the outer circle for measurement, is regularized by the Tikhonov method. Test samples of magnetization distribution are computed by the forward analysis of magnetization processes on the basis of the vector Preisach model. The numerical results show good coincidence between the original and reconstructed magnetization. Moreover the regularization parameter is shown to be reasonably determined by the L-curve method.