Japan’s Mitsubishi Heavy Industries Ltd (MHI) said it has been awarded a first contract from Japan’s National Institutes for Quantum Science and Technology (QST) for manufacture of six units of divertor outer vertical target additional components for the International Thermonuclear Experimental Reactor (ITER) under construction in Saint-Paul-lès-Durance in southern France.
The Outer Vertical Target is one of the parts in the divertor. MHI will handle the manufacturing of the first of a kind units (units 1-6, of a total of 54), with successive completion and delivery scheduled in fiscal 2024.
The divertor is one of the core components of the fusion reactor used in the tokamak. It removes the helium (He) ashes in the core plasma produced by the fusion reaction, unburned fuel and other impurities, as well as removes high heat load and particle loading, which are necessary for stable confinement of the plasma. The divertor comprises four parts: the Outer Vertical Target being procured by Japan, the Cassette Body and Inner Vertical Target being manufactured in the EU, and the Dome being made in Russia.
The heat load in the divertor reaches a maximum of 20MW/m². That is equivalent to the surface thermal load on an asteroid probe re-entering the atmosphere, and approximately 30 times the surface thermal load on the space shuttle. The Outer Vertical Target, which structurally directly faces the fusion plasma, will be used in an extreme environment exposed to the heat load and particle loading from the plasma. In addition, the structure has an extremely complex shape, requiring a leading edge manufacturing and machining technologies.
MHI was previously awarded a contract from QST for manufacture of five (of a total of 19) toroidal field (TF) coils, another core component of ITER. Four of these units have already been shipped, and are in the process of being installed in the device at the ITER site.