Application of higher order boundary integral equations of two-dimensional magnetic head problems

Two-dimensional boundary integral equations with sources having linear or quadratic variation over each element are introduced to analyze three different magnetic head configurations. 1) The harmonic response of a symmetric thin film head is computed and compared with earlier superposition theory. Also, the amplitude and phase of the harmonic response is deduced for a nonsymmetric thin film head. 2) The computed harmonic response of a shielded magneto-resistive head demonstrates that there is no true gap null (i.e., the response never goes through a zero) even if the head is symmetrically disposed between the shields. 3) The flux pattern of a conventional inductive head is mapped. It is shown that the output of a flux sensing loop just above the surface of the head can be used as a measure of head efficiency provided loop dimensions are small enough.