A summit organized at ITER Headquarters from 3 to 6 June brought together the international teams that will deliver the sub-systems of the ITER Tritium Plant. If the keyword at the 2023 Tritium Plant Summit was 'standardize,' in 2024 it was 'delivery.' With 70 team members from the ITER Organization and the Domestic Agencies attending in person, and a further 30 connected remotely, the Council Room provided an inspiring setting for the type of international collaboration that makes the ITER Project unique. The mission statement for the 2024 Summit was to continue to develop a shared vision and culture to successfully deliver the Tritium Plant project on time and on budget. With this aim in mind, the stated goals were to: Share lessons learned from design to construction  Agree on standardization to help identify opportunities to accelerate delivery Work collaboratively on technical challenges to develop plant-wide solutions Identify areas of common work to avoid duplicated effort to save costs The next five years are critical for delivery of the tokamak exhaust system (US ITER), the tritium storage and delivery system (ITER Korea), the air detritiation system (ITER Japan/ITER Organization), and the isotope separation and water detritiation systems (Fusion for Energy, Europe) that make up the Tritium Plant. Although at different levels of maturity, all Domestic Agencies are gearing up to deliver their systems through a series of gate reviews that will culminate in the physical realization of years of research and design. In the near term, the ITER Tritium Plant project central team is gaining valuable experience working in partnership with industry to deliver the condensing and filtration skid and the first exhaust system, which are required for ITER's first research phase (called the Start of Research Operations, SRO) and to support commissioning of Tritium Plant systems. Subsequently, discussions focused on practical and logistical aspects associated with manufacturing quality control, the availability of vendors, assembly, transport and installation. The range of challenges is significant—from the implementation of quality requirements for procurement of proven-in-use commercial off-the-shelf components, to shipment and installation of four-metre-long glovebox modules, to inspectability of complex unit operations inside vacuum jackets. A wealth of experience with the design, fabrication, operation, maintenance and decommissioning of tritium facilities was concentrated at the summit—including representatives from the Tritium Process Laboratory in Japan, the Savannah River National Laboratory in the United States, and the DU SPOVE in South Korea—which meant the right people were in the room to find solutions to tritium-specific design considerations. The recent experiences of the European Domestic Agency, Fusion for Energy, in designing and installing the ITER cryoplant also provided valuable lessons learned for working with the supply chain. The updated ITER Baseline was of key importance to discussions; notable impacts to the Tritium Plant include changes to the throughput and the implementation of a boronization process for the tungsten wall. Standardization remains critical to achieving project aims, not only standardization in technical terms such as equipment selection, technical specifications, interpretation and application of local regulations, but also in organizational terms such as adopting common ways of working. There are many benefits to standardization that will be realized throughout the ITER lifecycle, such as producing consistent and compatible design documents, harmonizing procurement activities, optimizing qualification efforts, enabling fewer spare components, and ensuring consistent maintenance work—all of which will contribute to streamline delivery and operation of the Tritium Plant. It is an objective that appears simple at first glance, but with each Domestic Agency having its own experience with tritium technologies and local supply chains to develop, a conscious effort by all teams, coordinated by the ITER Organization, is needed to maximize the implementation of standard solutions. An evening meal in Vinon, and possibly the most international pétanque tournament ever assembled, ensured that colleagues were able to share experiences and ideas in a more informal setting. Overall, the 2024 Summit provided a timely opportunity to refocus on shared objectives. Participants agreed that delivery of the Tritium Plant will be founded on continuous wide-ranging collaboration in between summits, while these periodic in-person events remain essential to maintaining the working relationships and informal contact that lubricate the wheels of success.

The ITER vacuum team, the European Domestic Agency Fusion for Energy, Research Instruments (RI), and the ITER Director-General were all excited to welcome the delivery of the ITER first production cryopump on 30 May. "This delivery is the first of 8 units to roll off the industrial production line with cryopumps now set to arrive at ITER at a rate of one per month," says Robert Pearce, ITER Vacuum System Project Leader. "This delivery achieves an iconic ITER milestone, the culmination of much innovative and challenging work collaboratively performed by the ITER team, including the European Domestic Agency, European industry and associations.' The torus and cryostat cryopumps are among the most complex components to be designed and manufactured for ITER. Operating at temperatures as low as 4.5 K and as high as 200° C, they contain precision mechanics with moving parts that form the world's largest all-metal vacuum valve. The cryopumps will safely pump and confine the fusion exhaust of helium, tritium and deuterium as well as provide insulating vacuum in the ITER cryostat. ITER completed the build-to-print design of the pumps in 2017, after building the pre-production cryopump. Constant effort and attention to detail were required to successfully manufacture these pumps. Challenges during manufacturing included damage to components due to flash flooding from severe storms in Germany, the Covid-19 pandemic, and the need to develop a new adhesion method for the cryopump coconut charcoal after corrosive chlorine was found in the previously used glue. The pumps were initially planned to be installed for a first plasma in 2025, however it will be a few years before the vacuum vessels divertor ports are ready to receive the pumps. In the meantime a cryopump test facility is being built within the ITER cryoplant, allowing each pump to be tested in advance at cold temperatures (4.5 K) and for ITER's pumping scenarios, ultimately saving significant amounts of time during commissioning. Many people have worked on the cryopumps over the last 20 years or so; even Director-General Pietro Barabaschi recalls doing an analysis back in ITER's Engineering Design Activities days. As such, this delivery is akin to the joyous arrival of a heathy baby—it's just that this baby has many proud parents who have contributed from conception through R&D, design, qualification and manufacturing through to this momentous delivery! See a related story on the Fusion for Energy website.

Thinking outside the box, teamwork and ingenuity are the ingredients that make for a successful robotics engineer—all qualities that are cultivated by participating in the annual ITER Robots competition. The 13th ITER Robots competition took place on 4 June 2024 in Vitrolles, France. The annual event—which challenges students up to the age of 18 with designing miniature robots to execute ITER-like remote handling tasks—brought together 620 attendees, including students, teachers, organizers, and companies. For first time, the event welcomed four primary schools as well as a team from the Lycée français of Los Angeles participating virtually from California. The teams competed in events designed around robotics, communication, and general cultural knowledge. They also took part in various games and activities at the 32 stands present throughout the day. The ITER Robots competition, held annually since 2012, is organized by Agence Iter France in partnership with Académie d'Aix-Marseille, ITER Organization and the French Alternative Energies and Atomic Energy Commission (CEA). See some scenes from the day in this video published by Agence Iter France.

The ITER Organization mourns the passing of an outstanding physicist and beloved colleague. It is with the deepest sadness and a profound sense of loss that we learned that our colleague, friend and outstanding physicist, Dr. Michael Lehnen, lost his courageous and dignified struggle against a long illness on Sunday morning, 16 June 2024.  We mourn the passing of this exceptional scientist who was a towering figure in the critically important field of tokamak disruptions and their mitigation. Michael was born on 4 October 1969 in Köln, Germany and graduated in physics from the city's university in 1997.  His PhD, conducted jointly at the University of Düsseldorf and the Forschungszentrum Jülich (FZJ), focussed on an experimental technique using beams of neutral helium atoms to measure the plasma density and temperature in the cool plasma boundary regions of the FZJ tokamak TEXTOR. After completion of his doctoral studies in 2000, Michael continued in Jülich as a research scientist, joining the plasma exhaust team working with the TEXTOR Dynamic Ergodic Divertor, a complex set of helical in-vessel magnetic coils designed to perturb the magnetic equilibrium of the tokamak and influence the plasma magnetohydrodynamic stability and transport properties. These early experiments were amongst the precursors to the modern technique of resonant magnetic perturbations, used in many tokamaks and planned in ITER, to suppress edge localized mode activity. It was during this period, 2000-2013, that Michael's interest in disruption physics really began and which established the foundation for him to become one of the world's preeminent experts in this key area for the success of tokamak fusion. He worked principally on the physics of runaway electron generation, suppression and interaction with materials, and on the technique of massive gas injection (MGI) as a means to mitigate the impact of disruption forces and transient heat loads. Throughout these Jülich years, he set the scene for what was to become a recurring feature in his career—collaboration with fusion scientists from across the globe, including teams at ITER, JET, DIII-D, MAST, Tore Supra and LHD devices—in the areas of disruption physics, helium exhaust and plasma-wall interactions. As a long-term secondee at the JET tokamak in the UK from 2011 to 2013, he took responsibility for the bolometry diagnostic and continued his role as scientific coordinator for JET MGI experiments.  He was also a prominent figure in the European fusion program, leading special working groups in transient heat loads and the development of systems for disruption and runaway electron mitigation within the European Fusion Development Agreement, the precursor to the current EUROfusion Consortium. This formative period in Jülich was the ideal preparation for Michael's move to ITER in 2013, assuming the challenging role of Scientific Coordinator for Disruption Physics within the Science Division, filling the position vacated through retirement by our much-respected colleague Masayoshi Sugihara, himself internationally recognized in disruption physics. This is a post on which lies so much responsibility given the importance of disruption avoidance and mitigation on a fusion reactor at the ITER scale, with thermal and magnetic stored energies orders of magnitude higher than on current research tokamaks. On his broad shoulders was placed the task of providing assessments and advice across the project regarding disruption electromagnetic and thermal loads, runaway electron formation and impact and physics support to the design of the ITER disruption mitigation system—a system at a scale unprecedented in fusion research.  Matters became considerably more complex once it was realized that the baseline technique, MGI, was not going to be practically achievable on ITER.  Instead, focus switched to the approach of cryogenic solid pellet injection (SPI) using mixtures of hydrogenic and impurity gases, then just in the early phase of physics studies on research tokamaks. Appointed in 2018 to the leadership of the Disruption Mitigation System (DMS) Task Force, Michael embarked on a six-year crusade to establish the physics basis for SPI in support of the design of this enormously complex ITER system which successfully passed its final design review in March this year.  He took on this daunting task with everything in his considerable armoury, marshalling the international tokamak community—both through the International Tokamak Physics Activity (ITPA), of which he was the co-Chair of the MHD Topical Group, and through ITER Organization contracts—to exploit existing systems and, in many cases, install completely new ones (in particular on the ASDEX Upgrade and KSTAR tokamaks). Rarely, if ever, has such an extensive international mobilisation of the tokamak physics community, been witnessed.  The impact has been nothing short of remarkable. Those present at the March DMS design review, will not forget the masterful presentation of the DMS Physics Basis which Michael delivered. Nor will we ever forget that he was able to manage the preparation of this presentation and the accompanying report whilst facing difficult medical issues.  It is a lasting testimony to the character, competence and dedication of this most exceptional scientist.  Without his contribution and that of all his many colleagues in the DMS technology and design teams, this vitally important system for the success of ITER would simply not have reached the level of maturity required on the timescale needed. Michael leaves behind a magnificent legacy in the field of tokamak physics.  Throughout his career, he has been a regular and familiar figure in all the major fusion science conferences, delivering many plenary and invited presentations and figuring as author or co-author on hundreds of scientific papers. He combined the very rare talents of deep physical insight and superb experimental technique. His wisdom and advice were sought by all at ITER in his specialised area and, for his colleagues in the Science Division, he was always ready to assist and provide counsel, with the very special dry sense of humour that all of us who knew him well will always remember with great fondness. The ITER Organization and the entire ITER research community has lost one of our own. He will be profoundly missed. We express our most sincere condolences to those closest to Michael and to all of his many colleagues and friends throughout the fusion world.  For anyone wishing to express their condolences or leave messages of tribute in Michael's memory, a website has been established that can be accessed here.