Ions to travel through 8960 holes at top energy

The prospect of beating all previous records by delivering a piece of equipment that will push forward R&D is on its own enticing enough to get involved in a project. If one gets to be a pioneer but also has the opportunity to acquire know-how which could yield substantial benefits the temptation is even greater. Take for instance the beam source for MITICA, the second experiment of the prestigious ITER Neutral Beam Test Facility, which will help us to fine-tune key fusion technologies. It’s an invitation to make history in the field of negative ion beams.

To achieve ITER’s super-hot plasma reaching temperatures ten times those in the core of the Sun, approximately 150 million °C, we need powerful heating equipment. Due to ITER’s massive size, particle beams will have to be more powerful and individual particles will need to travel faster to penetrate into the core of the hot gas. For this reason, negative ion injectors are being developed to fire their ions at an unprecedented energy of 1 MV. At MITICA (Megavolt ITER Injector and Concept Advancement), located in Padua (Italy), the ITER Parties of Europe, Japan, ITER Organization, and Consorzio RFX will test one of the heating systems of ITER – a full-scale prototype of the Neutral Beam Injector (NBI) that will operate at full beam power (17 MW).

F4E has signed a contract for approximately 20 million EUR with ALSYOM-SEIV (ALCEN group) to deliver the MITICA beam source. The equipment consists of two main parts: a radio frequency ion source and an accelerator of seven grids. The beam source will measure 3 x 3 x 4.5 m and will weigh in total 15 t. Inside this piece of equipment, negative ions will be produced. Thanks to a powerful accelerator they will travel at top energy through 8960 holes and eventually will crush on the calorimeter, which measures beam power based on the level of the heat produced. Given the fact that MITICA mimics the ITER NBI, scientists will be able to make several calculations. For instance, they will be able to have good estimates of the heating power that will be transmitted to the ITER plasma. It will take roughly four years for the equipment to be ready and teams from F4E, ALSYOM-SEIV, ITER Organization (IO), and Consorzio RFX will be fully involved in the follow up of this challenging piece of equipment.

Illustration of the MITICA (Megavolt ITER Injector and Concept Advancement) beam source, part of the ITER Neutral Beam Test Facility, Consorzio RFX, Padua, Italy. The equipment, financed by F4E, consists of two main parts: a radio frequency ion source and an accelerator of seven grids. The beam source will measure 3 x 3 x 4.5 m and will weigh in total 15 t. At MITICA, a full-scale prototype of the Neutral Beam Injector (NBI) will operate at full beam power (17 MW).

“In mid-2015 we started putting on paper the specifications of the beam source and then worked our way through the tender”, explains Antonio Masiello managing this contract on behalf F4E. “The signature of the contract is the result of years of work, consultations and technical meetings bringing together experts from the Neutral Beam community. Now it’s time to convert the specs into equipment.” At the kick-off meeting, Tullio Bonicelli, F4E Project Manager for Neutral Beam, Electron Cyclotron, Power Supplies and Sources, took the opportunity to highlight the importance of “working together as one team to deliver our contribution to the NBTF and to learn through this collaboration how to produce the most powerful neutral bean injector.”  

At the kick-off meeting of the MITICA beam source, which took place on 13 November 2018 in Barcelona, we got the opportunity to speak to Eric Giguet, Head of Sales and Marketing for ALSYOM. “The variety of the technologies required to manufacture the MITICA beam source demonstrate the capacity of ALSYOM-SEIV to deliver complex systems required by ITER and Big Science projects in general. We are very proud and excited to reinforce our long term partnership with F4E, ITER Organization and Consorzio RFX through this challenging project where quality and timing are of pivotal importance,” he explained.

Pierluigi Zaccaria, Project Leader for the Neutral Beam Test Facility (NBTF) Thermo-mechanics, working in Consorzio RFX, was also present at the meeting, and elaborated on the significance of this milestone for the host institute.  “The signature of the contract for the MITICA beam source marks the beginning for a key prototype component of ITER– Heating Neutral Beam Injectors.  We have reached this milestone by using the best expertise in plasma physics, beam optics, high voltage insulation, heat removal and stress/fatigue mitigation. The joint efforts and close collaboration of skilled researchers, engineers and physicists from NBTF Team and the ALSYOM-SEIV consortium will be the key for managing and solving the challenging technological issues we will experience during manufacturing. Meanwhile, the operation of the SPIDER beam source at the NBTF site in Padua, offers a great opportunity to an already competent team of experts to get better prepared for the operation and optimisation of MITICA,” he stated.

For ITER Organization (IO) the MITICA beam source, which happens to be the prototype of the ITER injector beam source, is the most critical and challenging component for the ITER Neutral Beam Injectors. Members of the IO Neutral Beam team explain that “the start of the F4E contract to manufacture this component is an important milestone for the NBTF Team, the community of experts working in neutral beams, F4E and ITER. The successful delivery of this component will help us carry out experiments at MITICA, which will define the performance of the ITER Neutral Beams. This positive progression in the project is the result of extensive collaboration between F4E, IO, and RFX. Within this framework an important industrial partner, ALSYOM-SEIV, is now included, which has been entrusted to manufacture the most complex and  technologically challenging beam source – the heart of MITICA and the ITER injectors.”