Current Dipole Images and Reference Potentials

The paper reviews the application of image theory to the problem of a current dipole in a homogeneous conducting medium where the boundary is a plane or circular cylinder, and shows how the technique applies to the case of a radial dipole in a spherical volume. The use of images for arbitrary shaped volumes is then considered. A rough criterion is developed and the approximation checked for the case of a "horizontal" dipole in a sphere. Finally the question of zero potentials is reviewed in the context of the previous work and in general.