A challenging design

ITER is being designed as a "tokamak" - a large toroidal configuration in which to create and maintain the conditions for controlled fusion reactions. The volume of plasma in ITER must be big enough to ensure that high energy multiplication conditions are reached. Superconducting magnets confine and control the reacting plasma and induce an electrical current through it. The energy generated in the fusion reactions is absorbed by the components lining the inside surface of the vessel. These components also maintain plasma purity, heat and diagnose it, and carry test pieces for future DEMO blanket development. A bioshield surrounds the magnets and vessel. This concrete structure brings the radiation dose to levels which avoid activation of surrounding equipment and which allow personnel access to that equipment not long after the tokamak has stopped operating. The bioshield is an integral part of the tokamak building which, among other buildings, houses support systems such as power supplies and cooling. All these components and systems need to be assembled and tested before operation.