(Image: MHI)
The contract - the value of which was not disclosed - was awarded by Japan's National Institutes for Quantum Science and Technology (QST) and follows the initial production order for the manufacture of six units (Unit 1 - Unit 6) received in 2021.
With the additional 12 units (Unit 7 - Unit 18), MHI will manufacture 18 of the total 54 outer vertical targets. MHI said production of these units will be completed successively, with delivery to QST expected to begin in 2026.
The divertor is one of the core components of the fusion reactor used in the tokamak. It removes the helium 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 on the divertor reaches a maximum of 20 MWt per square metre. Since the outer vertical target - which directly faces the plasma due to its structure - is used in an extreme environment where it is exposed to the heat load and high energy particle loading from the plasma, and its structure has an extremely complex shape, high-precision fabrication and processing technology is required.
MHI has previously received orders for production for five (of a total of 19) toroidal field coils, another core component of ITER, all of which were shipped by 2023.
In mid-2022, the company delivered equipment for confirming and demonstrating the safety of the 'blanket' of ITER. The blanket is one of the components that comprises the inner wall of the fusion reactor. The testing equipment supplied by MHI comprised four systems: the High Heat Flux Test Equipment, the In Box Water Eruption Test Equipment, the Be-Water Reaction Test Equipment; and the Flow Assisted Corrosion Test Loop.
"Going forward, MHI will continue its efforts for manufacturing of major components such as the divertor and equatorial launcher," the company said. "In addition, MHI will actively support the design and development of the fusion prototype reactor planned to be constructed following the ITER project, contributing to the realisation of fusion energy."
ITER is a major international project to build a tokamak fusion device in Cadarache, France, designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy. The goal of ITER is to operate at 500 MW (for at least 400 seconds continuously) with 50 MW of plasma heating power input. It appears that an additional 300 MWe of electricity input may be required in operation. No electricity will be generated at ITER.
Thirty-five nations are collaborating to build ITER - the European Union is contributing almost half of the cost of its construction, while the other six members (China, India, Japan, South Korea, Russia and the USA) are contributing equally to the rest. Construction began in 2010 and the original 2018 first plasma target date was put back to 2025 by the ITER council in 2016, but is currently in the process of being revised again.
