Interaction of a rectangular ferrite slab with magnetic fields

The general problem of permeable body in external magnetic fields is formulated as a two-dimensional Fredholm integral equation of the second kind. Using the method of averaging functional corrections, the equation is solved approximately for a highly-permeable rectangular solid (a) in a uniform field and (b) in the field of a rectangular current loop wound around the midsection of the solid. A large magnetic flux concentration is found in both cases for a thin solid. The results are applicable to the analysis of an aircraft VLF magnetic loop receiving antenna.