Transverse demagnetizing factors of long rectangular bars: I. Analytical expressions for extreme values of susceptibility

The demagnetizing problem should be studied numerically in nonellipsoids with nonzero susceptibility chi, except for a few limiting cases where analytical treatment turns out to be practical. In this work, for an infinitely long bar with rectangular cross section 2ax2b and chi=infinity and -1 in a uniform transverse applied field H-a along dimension a or b, analytical expressions for the surface pole or current distributions and the fluxmetric and magnetometric demagnetizing factors N-f,N-m are derived using a technique of conformal transformation. From the new as well as the existing formulas, N-f,N-m(chi=infinity,0,-1) are evaluated, plotted, and tabulated as functions of a/b. (C) 2002 American Institute of Physics.