TOKYO, September 18, 2025 - (JCN Newswire) - Mitsubishi Heavy Industries, Ltd. (MHI) has recently been awarded a contract from Japan's National Institutes for Quantum Science and Technology (QST) to manufacture 20 units of outer vertical targets, which are critical components of divertors, for ITER(*1,*2), the experimental fusion reactor currently under construction in southern France.
There are plans to install 58 divertors in ITER, and Japan is scheduled to manufacture all 58 outer vertical targets accordingly. Of the total 58 outer vertical targets, MHI has secured orders to handle the initial production batch of 6 units (Units 1-6) and the second production batch of 12 units (Units 7-18). Having now secured an order for a third batch of 20 units, MHI will proceed to handle the manufacturing of all 38 units ordered.
This acknowledgement results from the advanced manufacturing and mass production technologies MHI has cultivated through developing the prototype completed in 2024 and the ongoing manufacturing of the actual units. With the remaining 20 units in the pipeline, the company remains committed to advancing the ITER project.
The divertor is one of the most core components in the fusion reactor used in the tokamak. It plays a vital role in stabilizing plasma confinement by expelling unburned fuel elements such as helium (He) and impurities generated within the core plasma during fusion reactions.
The heat load in the divertor reaches up to 20 MW/m². This is equivalent to the surface thermal load on an asteroid probe upon re-entering the atmosphere and is approximately 30 times the surface thermal load on the space shuttle. The structural design means the outer vertical target facing the plasma is used in a severe environment exposed to thermal loads and particle loads from the plasma. Consequently, its structure features a highly complex shape, requiring leading edge manufacturing and machining technologies.
MHI was previously awarded a contract from QST for the manufacture of five (of a total of 19) toroidal field (TF) coils, another core component of ITER, and all five units were shipped(*3) by 2023. The company will continue working on the manufacture of subsequent major components such as divertors and horizontal launchers (*4). Furthermore, MHI will actively support the design and development of the prototype nuclear fusion reactor planned for construction following the ITER project, thereby contributing to the realization of fusion energy.
(*1) Fusion is the energy source that enables the sun to keep shining. The ultimate goal is achieving fusion on Earth. Fusion reactions fuse light atomic nuclei (deuterium and tritium) in a plasma environment into the heavier element of helium. Fusion reactions emit zero carbon dioxide, and their source of fuel can be extracted from seawater in virtually unlimited quantities (lithium from which tritium is derived, and deuterium). Fusion energy is expected to provide fundamental solutions to many of the world's energy and environmental problems.
(*2) The ITER Project is an international megaproject to demonstrate, both scientifically and technologically, the feasibility of fusion energy. Seven participating parties (Japan, the EU, the U.S., Russia, South Korea, China, and India) are constructing ITER in Saint-Paul-lès-Durance, France, with a target for full-fledged operational startup of nuclear fusion combustion by 2035. QST, as the ITER Japan domestic agency for the ITER Project designated by Japanese government, is in charge of procuring these components.
(*3) For details on the TF coils for the ITER that QST ordered from MHI, see the following press release.
https://www.mhi.com/news/210524.html
(*4) This is equipment that heats plasma by introducing high-frequency waves.
About MHI Group
Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit www.mhi.com or follow our insights and stories on spectra.mhi.com