AbstractThis paper deals with the design of a new system developed for the stabilization and the active control of the magnetic configuration of RFX. The system consists of a conductive shell and a set of saddle coils closely fitting the plasma region, supported by a stainless steel toroidal structure. These new components are intended for replacing the present shell, keeping the existing vacuum vessel, the poloidal field coils and the toroidal field coils unchanged. The paper presents the electromagnetic analyses, performed by means of 2D integral formulation and 3D finite element codes, which provided basic inputs for the design of the new passive components and for the mechanical assessment of the existing ones, in the new foreseen operating conditions.