Inverse inference of magnetization distribution in cylindrical permanent magnets

In this paper the magnetization distribution in a cylindrical permanent magnet, called magnet roller, used in copy machines and laser printers, is determined from the magnetic fields measured on a circle outside the roller. The system matrix, which is singular because of luck of uniqueness of the solution, is regularized by the Tikhonov method. The determination of the optimal regularization parameter based on the L-curve method is discussed. It is shown that the uniform and distributed magnetization patterns are successfully reconstructed by the present method