The method of auxiliary sources for analysis low frequency EM field scattering from composite object

The motivation of this work is the need for an efficient numerical method to analyze low frequency electromagnetic field scattering from highly permeable and conducting materials. The principle idea of the method of auxiliary sources (MAS) is based on the concept of distributing a set of auxiliary current/charge/dipole sources with unknown coefficients on virtual surfaces that usually conform to, but do not coincide with the real surface of examined objects. By imposing the boundary conditions on the real surface, the unknown coefficients of the auxiliary sources are determined and hence the secondary field can be easily found. To illustrate the potential of this method, this paper presents a description of the MAS with reference to the work of Shubitidze, O´Neill, Haider, Sun, and Paulsen (see MMET´2000 Proceedings, Kharkov, Ukraine, p.468-70, Sept. 2000), followed by numerical results for highly conducting and permeable material. Special emphasis is given to the detailed investigation of the low frequency scattering from a composite target with and without electrical connection between the constituent parts.