A four-year program to manufacture and test a full-scale prototype of the divertor outer vertical target has successfully come to an end in Japan, as manufacturer Mitsubishi Heavy Industries receives the green light for series fabrication. Jointly developed by Japan's National Institutes for Quantum Science and Technology (QST) and Mitsubishi Heavy Industries, the full-scale mockup of the outer vertical target has passed all performance and manufacturability tests and demonstrated the technology that will now be used by Mitsubishi to produce the 18* units that QST has ordered. The ITER divertor is the component at the bottom of the vacuum vessel that, in extracting heat and ash produced by the fusion reaction, withstands the highest surface heat loads of the machine. Its role is critical—without the constant "hoovering" of impurities and exhaust, the plasma could not be maintained. Specially armoured with tungsten tiles and actively cooled by water circulating in their structures, the divertor "targets" (the dome, outer vertical target and inner vertical target) receive the brunt of the heat load and particle flux from the plasma and withstand the highest surface loads of the ITER machine—estimated to reach 20 MW/m², or ten times the heat load of a spacecraft re-entering Earth's atmosphere. The front-facing elements of the outer vertical target—the plasma-facing units, are composed of tungsten blocks bonded to cooling pipes. They have successfully passed high heat flux testing, confirming their durability and heat removal capabilities in the extreme operating environment of the ITER machine. In a press release published this summer, Mitsubishi stressed the challenge of working with tungsten—a high-temperature material, with a melting point that is the highest of any metal, but that is difficult to machine because it is brittle and prone to cracking. The company also stressed the high-precision fabrication and processing technologies that are required to produce the outer vertical target structures and the stringent alignment requirements for the plasma-facing units. Each tungsten tile (or "monoblock"). for instance. must be aligned with an accuracy of 0.5 mm or less in terms of inclination, surface level and clearance. "QST, backed by its innovative R&D capabilities, has been focusing on tokamak divertor development since before ITER, and MHI has leveraged its outstanding manufacturing capabilities to successfully produce a prototype of the outer vertical target." Like for the other divertor targets—the dome produced in Russia and the inner vertical target produced in Europe—the performance of a Mitsubishi test assembly of tungsten plasma-facing units for the outer vertical target was assessed at the divertor high heat flux test facility in Russia, where it successfully passed 6,000 test cycles with loads from 5 to 20 MW/m². The ITER Organization has now certified the prototype's heat removal performance as well as the manufacturing process for the highly technical plasma-facing units. Series production can begin. *Of the 58 outer vertical target units that QST will deliver to ITER, Mitsubishi Heavy Industries is responsible for manufacturing 18. See the Mitsubishi Heavy Industries press release in English and Japanese.

The ITER superconducting magnets, which operate at the ultra-cold temperature of 4 K (minus 269 °C), must be protected from any type of heat transfer. Several components contribute to the magnetic system's thermal insulation: the vacuum in the cryostat ensures that no heat is transferred by convection, the structures that support the vertical coils (gravity supports) greatly reduce conduction by contact, and the thermal shield system raises an obstacle against the radiative heat transfer (electromagnetic waves) generated by sources of heat. One of the most efficient ways of blocking thermal radiation is to coat thermal shield panels with a thin layer of pure silver, a "low-emissivity" element. However during early machine assembly, it was discovered that the processes involved in silver-coating operations and thermal shield cooling pipe welding had in some cases resulted in the presence of chlorine residues and associated corrosion, with millimetre-deep cracks. Two sets of vacuum vessel thermal shield panels were sent to India (soon to be followed by 5 others) for repair. Repair entailed removing all cooling pipes, grinding to remove up to approximately ~2mm of base material just under the cooling pipes, and finally re-attaching new pipes. In terms of thermal emissivity, ultra-high polishing ensures a similar performance to silver coating. One set has already been shipped back to ITER where its silver coating was removed and its surface polished to mirror-like perfection (less than 80 microns rugosity). In terms of thermal emissivity ultra-high polishing ensures a similar performance as silver coating. The outboard panel pictured here in the former Cryostat Workshop will soon join the two other elements of the thermal shield set for vacuum vessel sector #7 already in place in the handling tool in the Assembly Hall.

The 33rd Symposium on Fusion Technology (SOFT 2024) opened on Monday 23 September in Gaelic. Dublin City University Vice President for Academic Affairs, Lisa Looney, wished conference participants a traditional Irish welcome—conveying 100 welcomes for each of the 1,000 scientists, engineers, industry representatives and other fusion aficionados who had travelled to Dublin for the largest fusion technology conference in Europe. Over the next five days, participants will focus on the latest developments in fusion technologies, fusion experiments and related activities. SOFT 2024 will include invited, oral and poster presentations, as well as an industry day and exhibitions. As Vice President Looney put it, "the latest developments in fusion are not soft at all but important big science." The chair of the international organizing committee, DCU's Miles Turner, emphasized that the development of fusion energy has never been more urgent. "Fusion has the potential to mitigate the effects of climate change, which poses an existential threat to our way of life as seen in the recent disastrous flooding across Europe." Poster presentations, an industry day, exhibitions ... as the preeminent conference in fusion technology, SOFT has attracted over 1,000 participants. ITER Director-General Pietro Barabaschi delivered the first talk of the symposium. After presenting an update on the project, he turned to recent challenges and said that it was important to share ITER's experience with the fusion community and the private sector. "We have to provide information on what not to do and about what else can be done," he said, referring to ITER's very valuable lessons learned.  The ITER Newsline will have a full report after the conference.

In 2023, 1,000 workdays were lost to accidents and injuries on the ITER site. This is considerably less than the average in European countries but approximately twice more than, for instance, on the EPR nuclear plant construction site in northern France. Also preoccupying are what safety experts call "high potential events"—events in which a small change in circumstances could have resulted in significant harm to personnel and even fatalities. Thirty such "high potential events" occurred last year on the ITER construction site. Figures, however, are heading in the right direction: over the past four years, accidents and "near misses" have been divided by two. The observance of rules, improved trainings, the analysis of events, lessons learned from events and engagement with contractors account for a large part of this positive trend. But there is more to it. "Safety is not just a policy—it is a responsibility that belongs to all of us and makes us all accountable," said ITER Director-General Pietro Barabaschi in a video address to staff on the eve of the 2024 ITER Safety Day last Thursday, 19 September. "Safety is not just a priority, it is a core value that must guide our everyday actions," adds ITER Head of the Safety & Quality Department Gilles Perrier. Four years ago, his Department organized the first edition of what was to become a regular September event—the ITER Safety Day. Through hands-on workshops, exchanges with experts, demonstrations and games, the operation aims to ensure that everyone who works at ITER, whether in the offices or on the construction site, is focused on safety as "core value" and is well informed about ITER's safety procedures. Over the years, as the project entered machine assembly and the start of plant commissioning, the annual safety days grew in attendance and focused on new, emerging risks. The 2021 edition fitted booths, animations and participants inside a contractor parking lot structure; last week's edition required a much larger space which only the partly unoccupied, former poloidal field coils winding facility could provide. "We are making progress," acknowledge both the ITER Director-General and the Head of Safety & Quality. Beyond statistics and figures (270 lost days due to accidents this year so far), participation in the 2024 ITER Safety Day illustrated the assimilation by staff and contractors of safety awareness: from 800 in 2022, the 2024 edition attracted 1,800 participants. The event was the occasion to promote five commitments (see gallery) that will guide and inspire ITER actions in the coming years.

It was a photo finish last Thursday 19 September. After 900 km and 10,000 metres of climbing, the Ride 4 Fusion team that had started in Padua ten days earlier crossed the entrance to the ITER site. Inspired by the University of Padua cycling community Scholares Vagantes, the team from the Consorzio RFX (home of the ITER Neutral Beam Test Facility) and the ITER Organization had cycled the distance in nine stages, travelling through northern Italy and southern France to promote the quest for fusion energy and engage with the public and young scientists along the way. After they were waved off by city and University of Padua officials on 10 September, the 15 cyclists set off for stages that included stops in Piacenza (Campus Arata, PoliMI) and Pavia (Museum of Electrical Technology) where they engaged with university students, local companies and communities to celebrate 65 years of fusion science in Italy and exciting career opportunities. In Marseille, France—one of their last stops before ITER—the Ride 4 Fusion cyclists were invited to share their experiences and perspectives with students and teachers of the Aix-Marseille University. On Thursday 19 September, joined by ITER staff including Director-General Pietro Barabaschi, the group arrived at the ITER Organization Headquarters finish line. They arrived physically exhausted, but deeply fulfilled by having accomplished the mission. Researchers from the Italian laboratory Consorzio RFX, the Fusion Research Center of the University of Padua, the CNR Institute for Plasma Science and Technology in Milan, the ENEA Fusion Center in Frascati, and the ITER Organization took part in the 10-day adventure (not all are pictured here). "Ride 4 Fusion beautifully builds connections, friendships, and enthusiasm for fusion research," said Yannick Marandet, CNRS, and director of the ISFIN Institute at Aix-Marseille University who joined the last leg of the journey. "Ride 4 Fusion isn't just a unique way to promote fusion; it's also a gateway to incredible opportunities. All throughout this event we showcased the exciting prospects in fusion at ITER and through the European Fusion Education Network, Fusenet.

After Wendelstein 7-X generated a record plasma in February 2023 (lasting 8 minutes with an energy output of 1.3 gigajoules), the stellarator at the Max Planck Institute for Plasma Physics (IPP) in Greifswald, Germany, was shut down for a one-year maintenance phase. W7-X began a new experimental phase on 10 September, after significant improvements and optimizations were made to the device (see the detail here) to improve the availability and reliability of the systems. In addition, the scientific capabilities of all systems were significantly expanded and important new observation instruments were added. The scientific program ahead should gradually see an increase in performance parameters, specifically higher heating powers. Wendelstein 7-X is the world's largest fusion device of the stellarator type. See the press release in English or German. (Photo Jan Hosan, 2021)

Through a newly launched web platform—the European Fusion Technology Marketplace—Fusion for Energy (F4E), the European Domestic Agency for ITER, and EUROfusion, a consortium of European fusion laboratories, are inviting companies to discover and benefit from fusion spinoff technologies. The website offers companies and experts a diverse portfolio of technologies developed by F4E’s industrial partners and EUROfusion laboratories as part of work for international research programmes and projects such as: ITER, Europe's DEMOstration fusion power plant, the joint Europe/Japan JT-60SA tokamak, the International Fusion Materials Irradiation Facility (IFMIF), and the International Fusion Energy Research Center IFERC. "Our experts work to identify their business potential and to facilitate their commercial use. Our services are offered to all companies looking for new market opportunities. We are here to help entrepreneurs, scientists and business willing to integrate fusion technologies in the development of their products," according to the marketplace website. See all information here.