Magnetization analysis of ITER In-Wall Shielding

Abstract In ITER machine, the In-Wall Shielding (IWS) blocks are arranged between vacuum vessel double walls in order to screen the neutrons. Some of these blocks are made of ferromagnetic material plates (ferromagnetic insert) in order to reduce toroidal magnetic field ripple and then they undergo Maxwell forces during ITER operations. The In-Wall Shielding blocks have to be dimensioned not only for neutron shielding but also for eddy current and magnetization forces. In the frame of the ITER Organization (IO) design review activity, the feasibility of In-Wall Shielding blocks with ferromagnetic inserts requires a detailed analysis using Finite Element (FE) detailed approach. The Maxwell forces acting on the IWS blocks were evaluated using PVW (Principle of Virtual Works) and MST (Maxwell Stress Tensor). This paper outlines the engineering aspects from the EM point of view of the ITER IWS blocks and focuses on the EM feasibility of the present design.