Neutral Beam Test Facility
High voltage component for MITICA
Creating reliable high-energy neutral beams at ITER parameters, from a negative ion source, requires such a large technological leap that the components of the neutral beam injection system are being tested in advance at the ITER Neutral Beam Test Facility in Padua, Italy. Construction of the testbed MITICA advanced another step this month, as a critical high voltage component was installed.
At the ITER Neutral Beam Test Facility in Padua, Italy, a 50-tonne high voltage bushing has been installed on the MITICA vacuum vessel. The bushing acts like a feedthrough between the transmission line and the injector.
Neutral beam injection is one of the external heating systems on ITER that will bring the plasma to fusion temperature.
At the ITER Neutral Beam Test Facility in Italy, the MITICA experiment (for Megavolt ITER Injector and Concept Advancement) is a full-scale prototype of the ITER heating neutral beam injector, with a deuterium beam of 1 MeV and 16.5 MW of power.
Europe is contributing all MITICA mechanical components (including beam sources and accelerators); the MITICA low-voltage power supply and high-voltage deck; plant auxiliaries (cooling, vacuum and gas injection systems, insulating SF6 gas handling, cryogenic plant); diagnostics; and instrumentation and control. Japan is providing high voltage components for the 1 MV power supply system of MITICA (including the megavolt bushing, the megavolt transmission line and the high voltage part of the megavolt power supply); Italy is providing the buildings, auxiliaries and power grid; and host lab Consorzio RFX lab is providing expertise through a large contribution to staffing.
On 10 June, the high voltage bushing procured by the ITER Japan in collaboration with Hitachi was installed on MITICA vacuum vessel procured by the European Domestic Agency (Fusion for Energy) in collaboration with manufacturer De Pretto Industrie SrL.
The high voltage bushing is a highly innovative component, whose design required significant R&D. It works not only as an electric feedthrough between the transmission line and the injector, but also as an interface between two environments—the ultra-high vacuum inside the vessel and the high-pressure SF6-gas- insulated transmission line.
"So many actors have been involved in this operation, each of them with different responsibilities: Fusion for Energy and ITER Japan for procurement; the ITER Organization as the final owner of the components; the companies involved in manufacturing and installation activities; and Consorzio RFX for the integration," says Vanni Toigo, project manager of the Neutral Beam Test Facility.
All MITICA "utilities" will pass through the high voltage bushing—the voltage of 1 MV, water for cooling, and gas for the plasma—in 50 tonnes of highly concentrated technology.
See more about the ITER Neutral Beam Test Facility here.
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