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The OVT is one of the key parts of the diverter, one of the maximum parts of confined magnetic box fusion reactors such as tokamaks. It plays a vital role in removing or escaping unburned fuel in the core plasma and impurities such as helium ash generated through the fusion reaction, which are mandatory for solid confinement of the plasma. The diverter is made up of 4 parts: the OVT, the cassette frame and the inner vertical lens made in the EU, and the dome supplied through Russia.
Last year, the ITER organization carried out the top heat flow test on the OVT Plasma Lining Assemblies (PFU) and the heat removal capability was confirmed. MHI’s PFU production processes were qualified through ITER. MHI has completed a prototype that will be a full-scale mock-up of the OVT and is in a position to mass produce it.
The thermal load on the diverter target reaches a maximum of 20 MWt per square meter. This is equivalent to the thermal load of the surface of an asteroid probe upon re-entry into the atmosphere, and about 30 times the thermal load of the surface of a space shuttle.
The diverter is the component of the tokamak device that is exposed to the thermal load and the amount of high-energy waste in the plasma. For this reason, it requires special materials such as tungsten, which has a high melting point but is difficult to remove. machine. High-precision production and processing technologies have been developed to produce the structures.
In May, MHI won a QST contract for 12 more OVTs for the diverter to be used in ITER. The contract follows the initial production order for the manufacture of six games (1-6) won in 2021. With the additional 12 sets (7-18), MHI will manufacture 18 of the 54 external vertical targets in total. The rest will be manufactured using QST. MHI said production of those sets will end successively and delivery to QST is expected to begin in 2026.
QST in the
ITER is an exclusive global collaboration. As host, Europe contributes almost a part of the prices of its structure (45. 6%), while the other six members of this foreign joint venture (China, India, Japan, South Korea, Russia and the United States) contribute a similar contribution. for the rest, expense (9. 1% each). However, in practice, members make little financial contribution to the project and offer “in-kind” contributions in the form of components, systems or buildings.
ITER’s goal is to operate at 500 MW (for at least 400 seconds at a time) with a plasma heating force of 50 MW. Some 33 countries participate in the ITER structure, which began in 2010, most of them through their national agencies.
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