A model of low-frequency rotating magnetic field with a weak axial gradient

J. Priede^1,2 - G. Gerbeth²

¹ Institute of Physics, University of Latvia , LV-2169 Salaspils, Latvia
² Forschungszentrum Rossendorf, P.O. Box 510119, D-01314 Dresden, Germany

Abstract
We introduce a model of rotating magnetic field with a weak axial gradient which approximates the field generated by a slightly conical and sufficiently long inductor. The axial variation of the free-space field is assumed to be weak and its amplitude is approximated by the first linear term of expansion in a power series of the axial coordinate. This allows us to obtain an analytic solution for the azimuthal harmonics of the induced scalar electric potential and the azimuthal driving force in a cylinder of finite length. The results are verified by comparison with a numerical solution obtained by a Chebyshev tau-method. Figs 3, Refs 5.