Computation of the fringe field due to a flux source near a large permeable block

A theoretical calculation of three-dimensional magnetic fringe fields generated by a magnetic pole placed near an infinite cylindrical wedge of high permeability has been performed. Two methods were employed and the results compared. One approach involved development and numerical evaluation of an analytic solution deriving from a Green´s function analysis of the boundary value problem. The second method was a numerical computation using a reduced scalar potential finite element method. The agreement between the results from the two methods is quite good. We have used the computed fringe fields to estimate medium erasure effects due to particulate magnetic contaminants adhering to a magnetic slider in a magnetic disk storage device.