Mitsubishi Heavy Industries, Ltd. (MHI) has been an active contributor to the development of the International Thermonuclear Experimental Reactor (ITER) now being assembled in France. The Tokyo-based company recently supplied five toroidal field coils and equipment for confirming and demonstrating the safety of the blanket engineered for the tokamak. MHI will next deliver 12 outer vertical targets for the divertor; the company will have manufactured 18 of the 54 target components when the order is fulfilled in 2026.

The divertor captures the helium ashes in the core plasma produced by the fusion reaction in addition to unburned fuel and other impurities and removes high heat load and particle loading, which are essential for stable plasma confinement. This element consists of the outer vertical target being procured by Japan, the cassette body and inner vertical target being manufactured in the European Union, and the dome being produced in Russia.

As the heat load reaches a maximum of 20 MWt/m2 in the ITER core, special welding procedures that minimize deformation have been engineered for the fabrication of the divertor and tungsten plasma-facing unit components. These processes are based on narrow-gap tungsten inert gas (TIG) welding and electron-beam welding technologies.

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