Evaluation of different analytical methods for the design of ELF magnetic field shields

The aim of this work is the evaluation of different analytical methods devoted to the study of shielding of extremely low frequency (ELF) magnetic fields with conducting and ferromagnetic materials. In this paper an extensive analysis of some approaches are presented and compared to a numerical method based on a hybrid FEM/BEM formulation. The study wants to underline the accuracy of the different methods, evaluating their limits of validity depending on physical and geometrical shield parameters.