A method to compute the shielding of a 3-D conductor array by a semi-infinite permeable layer

A simple image method is described to predict the attenuation caused by a semi-infinite permeable layer on the static magnetic field produced by a 3-D conductor array. It is shown that the permeable layer gives rise to a array of current element images, of progressively smaller magnitude and increasing distance from the layer. The convergence of the method is examined. The method is applied to the problem of evaluating bottom electrode bus designs for a DC electric arc furnace