Europe delivers the final components for testing the system that will heat the ITER plasma to 150 million °C

Europe has delivered the last two major components for MITICA, the full-scale prototype of the system that will test the technology used for heating plasma in the experimental fusion reactor ITER. The components have arrived at the Neutral Beam Test Facility in Padova, northern Italy, where an injector capable of preparing the necessary technology to achieve fusion temperatures is being built.

In short

MITICA is the full-scale prototype of the neutral particle injectors that will be used at ITER. The ITER injectors will contribute to heating the plasma to approximately 150 million °C. Each injector will deliver 16.5 MW by sending high-speed neutralized particles into the plasma. Fusion for Energy has delivered the last two major components: the beam source and the calorimeter. The installation of the beam source and the beam line is expected to begin next year.

MITICA, short for Megavolt ITER Test Injector and Concept Advancement, is built to demonstrate a crucial technology for the future ITER reactor: the injection of high-energy neutral particles into the plasma. The plasma must be heated to extreme temperatures of about 150 million °C for the atoms to be able to fuse.

The technology of neutral particle injectors is not completely new, but the size and power required for ITER are unprecedented. The ITER injectors will each need to deliver 16.5 MW of energy, sending high-speed neutralized particles into the plasma. To reduce technical risk, Europe, Japan, the ITER Organization, and Consorzio RFX have built MITICA as a demonstrator before the system is used at ITER.

Fusion for Energy, the European agency responsible for the EU's contribution to ITER, has taken over most of the components for MITICA. Among these are the beam source, beam line, electrical supplies, and cryopumps.

The first of the last two delivered components is the beam source. It was assembled and tested by ALSYMEX in Tarbes, France, and then transported by road to the testing facility in Padova. Upon arrival, the component passed helium leak tests, confirming that it is ready for operation in a vacuum.

The second delivered component is the calorimeter. It is part of the MITICA beam line, along with the neutralizer and ion dump, which will be delivered in 2024. The calorimeter was manufactured through the collaboration of Fusion for Energy with the Spanish consortium AVS-Tecnalia.

The role of the calorimeter is to measure the beam power and allow its passage to the plasma when the required parameters are reached. During the MITICA tests, the calorimeter will remain in a closed position, as it must handle the extreme energy loads of the beam. To dissipate heat, the component includes a network of cooling water pipes.

Manufacturing the calorimeter was challenging because the geometry of the piece left very little room for errors. The spiral shape of the tubes and the large number of joints required a precise and methodical welding process. F4E states that suppliers shaped and assembled the tube bundles using specialized techniques, and the component has completed the final tests.

Eduard Bragulat, Technical Officer at Fusion for Energy, said that the teamwork between F4E and AVS-Tecnalia has turned a complex design into reality by producing and integrating the necessary technologies. He stated that the suppliers have demonstrated technical excellence and have consistently shown interest in the project.

Mónica Iriarte, Project Manager at AVS, said that the delivery and on-site testing of the calorimeter marks a major milestone in the contract. She pointed out that the MITICA beam line project has significantly strengthened AVS's capabilities in designing and manufacturing technologies for fusion and provides a basis for future contributions in this market.

At the Neutral Beam Test Facility, teams are checking the last delivered components. After these inspections, they will be prepared for integration into MITICA. Consorzio RFX is set to begin preparations for the installation of the beam source and beam line, a step expected next year.

In parallel, Fusion for Energy, the ITER Organization, Consorzio RFX, and AVS-Tecnalia will work on an improved calorimeter, which will be used later in the high-power operation phase.

ITER is the international project testing whether nuclear fusion can become a source of energy on an industrial scale. MITICA is not the reactor itself, but the testing facility for one of the technologies that must make the reactor possible: heating the plasma through neutral particle injectors.