Logo
You're currently reading the news digest published from 30 June 2025 to 7 July 2025.
Featured (5)
Of interest (1)
Video (1)
Press (13)
Featured

Boronization system takes shape as ITER prepares for a tungsten wall

With the help of the fusion community, design modifications are underway to get boron in and out of the machine. When the ITER Organization made the key decision in 2023 to change the armour tiles of the plasma chamber from beryllium to tungsten, it meant adding a new wall conditioning system to buffer the plasma from the associated increase in impurities. Called boronization, the system will apply a thin layer (~10-100 nanometers) of boron over all plasma-facing surfaces to capture, or “getter,” oxygen that could otherwise increase radiative losses of the plasma, particularly during the sensitive discharge-initiation phase.ITER engineers and scientists are now working on the diverse aspects of the project—including designing a gas injection system to deliver the carrier gas to different points in the vessel—and plans for the system are advancing quickly, with initial modelling and preliminary design reviews near completion and a long-term strategy defined. â€œIt’s been a good challenge to integrate boronization into the existing wall conditioning system,” says Tom Keenan, the ITER wall conditioning engineer who is the technical responsible officer for the system. “We’re working with a proven technology, but it’s never been done on this scale or in a tritiated environment, so it’s interesting territory.” Diborane for boronWhen the design for the new wall conditioning system began, one of the first decisions the team made was to use diborane, a compound of hydrogen and boron, for the boronization process. There will be a 5% concentration of diborane in a carrier gas, with helium being the preferred option. Because diborane is both toxic and explosive, a highly secure storage site called a “gas cabin” must be built outside of the Diagnostics Building. 21 gas injection points will be added to the inside of the vacuum vessel for the boronization system. The design team has developed an optimized model for the placement and size of the injection points given the available space. Another requirement is a gas injection system that will bring the diborane into the tokamak. The preliminary design calls for more than one kilometre of injection lines inside the Tokamak Building, another 400 metres of lines in the vessel, and 21 gas injection points to be integrated into the vacuum vessel. An optimized distribution of in-vessel gas supply locations has been achieved that is consistent with the performance benefits identified via the boronization modelling activities and respects the constraints of the existing available vacuum vessel gas feedthroughs. Gabor Kiss, a fuelling process integration engineer at ITER who is working on the integration study, says these adaptations are not expected to impact plant installation sequences. A bigger role for the glow discharge systemOnce injected into the machine, diborane decomposes and deposits on the plasma-facing walls via a glow-discharge-assisted layer deposition method. In glow discharge, an electrical current between the wall (cathode) and "glow anodes" creates a cold plasma, like a neon light, that accelerates ions against the wall. This process causes boron to bond chemically onto the material surface and form a thin film.ITER already plans to use glow discharge cleaning for wall conditioning during maintenance periods, but adapting it for more frequent use and for boronization raises two main challenges. The first issue is whether ITER’s anode design—which delivers about ten times more energy than those in current tokamaks—is compatible with frequent boronization cycles; upcoming tests at the EAST tokamak in China aim to answer this. The second question involves determining the optimal placement of anodes to ensure even boron coverage on ITER’s plasma-facing surfaces. Through modelling and collaborative testing with the ASDEX Upgrade (Germany) and WEST (France) tokamaks, the team decided to add four additional anodes to the vacuum vessel to obtain the most effective boron distribution.“This has been a major joint effort with experts from the International Tokamak Physics Activity,” says Tom Wauters, who specializes in plasma-wall interactions at ITER. “We’ve had very good support from the international science and engineering community that has helped us move forward with ITER’s boronization system.” The new configuration for optimized boronization dispersal through the glow discharge system adds four more anodes (in blue). The placement of the anodes is essential for achieving an even layer of boron on the plasma-facing surfaces. Determining how often boronization should be performed in ITER hinges on two factors—how much oxygen the boron layer can absorb and how quickly the plasma erodes these layers. Recent studies suggest that a single boron application could be effective for anywhere between 2.5 and 12.5 weeks of campaign time, leading to a planned maximum boronization interval of every two weeks. Upcoming dedicated tests on operational tokamaks will also accurately measure how much oxygen can be captured by the boronized surfaces. This information will guide the ideal frequency for boronization and clarify how much oxygen—such as that introduced by a minor atmospheric leak—the vessel can tolerate.Diborane usageIn a glow discharge boronization procedure, a low percentage of diborane will remain non-decomposed. The diborane that is pumped out of the tokamak must be safely neutralized due to its high toxicity. Two destruction methods are currently being evaluated: one involves heating the diborane to 700 °C for thermal breakdown, while the other uses a proprietary chemical trap, used in the semiconductor industry, to absorb and neutralize the gas.“We are very confident in both systems,” says Peter Speller, the process engineer overseeing diborane treatment. “Thermal destruction has already worked at WEST and DIII-D (USA) tokamaks, while the chemical trapping system has been successful at ASDEX Upgrade, so we just need to determine which is best suited to ITER.”Whatever method is chosen, space is being made in the Tritium Building for the diborane removal system, which will treat the exhaust gases from the tokamak during boronization. The installation of the boronization system is expected to begin in 2028. 

Awe and pride in the Radiofrequency Building

They knew what was in the box. They had contributed to the component’s conception and design, followed the progress of fabrication from prototype to reality, and anxiously waited for delivery. How it worked, delivering highly concentrated fluxes of energy, contained no secrets for them. Still, when the big crate was opened and raised to vertical, revealing its contents, the feeling this morning on the third floor of the Radiofrequency Building was one of awe and pride. What a strange-looking, out-of-this-world object! On Monday 7 July, the first of the many gyrotrons required for plasma heating by way of a technique called electron cyclotron resonance heating was unpacked and positioned on its support structure. The component was delivered by Japan in February 2022, part of a global procurement program for gyrotrons that involves Russia, Europe and India.Gyrotrons have historically had only a few applications, which are essentially concentrated in the realm of magnetic fusion and material processing—for instance growing crystal windows or special ceramics. A radically new application under development is the use of megawatt-class gyrotrons like ITER’s for providing access to deep geothermal heat without complex downhole equipment. Because they can focus tremendous amounts of energy on a determined surface, a bit like lasers, gyrotrons could drill kilometres deeper and faster than conventional techniques, avoiding tool wear and considerably reducing the activity’s environmental footprint.Besides heating a plasma to hundreds of millions of degrees (no small feat!) this is what the device the teams were taking in and handling could do. Whether scientists from ITER, from Japan’s National Institutes for Quantum Science and Technology, or from the installation consortium Fincatieri, their awe and pride was understandable.

18 months of negotiation to achieve unanimity

Two decades ago, in the summer of 2005, a decades-long process was nearing its end. After many challenges the international collaboration in “controlled thermonuclear fusion” that Ronald Reagan and Mikhaïl Gorbachev had advocated for as early as 1985—later christened “ITER”—had produced a final design for the machine that would be tasked with demonstrating the feasibility of this new kind of energy. For the ITER Members, the time had come to decide on where the installation would be built. Late in 2003, ITER Members China, the European Union, Japan, Korea, Russia and the United States (India would join in December 2005) began seriously considering the question of where to site the future project. The short list was down to two names: Rokkasho-Mura, proposed by Japan—an industrial site long devoted to nuclear activities in the northernmost part of the archipelago’s central island—and Cadarache, advocated by Europe—the site of the largest energy research centre on the continent, in southern France.For reasons that were technical as well as political, the Members were split.From the week before Christmas 2003, when Member delegates first met in Reston in the Washington D.C. suburbs, to the summer of 2005, when they finally reached a unanimous decision in Moscow, a full year and a half of negotiations was to pass.What was as stake was larger than just deciding on ITER’s future location. It was about demonstrating that, despite the international tensions of the moment¹, unanimity was not only possible but indispensable to the future of the project. For close to two decades, throughout the different efforts that led to the installation’s final design, the ITER scientists and engineers had always managed to reach consensus even in the most difficult circumstances. The government officials who would eventually cast their vote belonged to another world, however. Although they adhered to the unique collaborative nature of the project, they were still preoccupied par their national interests and by those of their closest allies.The Members were evenly split and, on both sides, pressure was exerted to convince at least one Member to reconsider its choice. If successful, the gambit would have led to a 4-to-2 majority—something that works in politics but that was not desirable for ITER. As a consequence, a lot was going on behind the scenes in the sidelines of the official negotiations that sometimes found an echo in the media, significantly complicating the way to an agreement.There were hopes that at the ministerial-level meeting in Reston, the Members would quickly reach a decision. That did not happen. “We have two excellent sites,” stated the Ministers in their communiqué. "So excellent, in fact, that we need further evaluation before making our decisions based on consensus." The ITER team was asked to “conduct a rapid exploration of the advantages of a broader approach to fusion power”—one that would include specific research installations, a satellite machine, and other projects indispensable to the long-term success of fusion energy. That idea was not new, but at this point in the negotiation process it had the effect of opening a path to a set of compensatory measures for the Member who was not chosen to host the project. Later formalized between Europe and Japan, the Broader Approach, with capital letters this time, is now at the core of global fusion research, supporting the ITER project and paving the way for the next generation of devices, DEMO.The first months of 2004 were marked by untimely political declarations which triggered a strong response from the fusion community, who resented these counter-productive interferences. The European site was challenged because of its relative distance (~100 km) from the industrial harbour where large components would be unloaded, requiring complex logistics to deliver them to the Cadarache site. Seismicity was also the focus of attention. At one expert meeting in Vienna in February another “reunion of experts” was decided for June. The lack of progress triggered impatience, even irritation at times.In order to overcome the gridlock, Brussels officially suggested in November 2004 that ITER could be built by Europe, China and Russia, who were all in favour of the Cadarache site. Part threat, part actual prospect, the proposal had a sobering effect. Capitalizing on long-standing personal relationships, major political figures on both sides—including up to the Head of State level—weighed in on the discussions. Janez Potočnik, the European Commissioner for Science, and Noriaki Nakayama, the Japanese Minister for Education, Culture, Sports, Science and Technology (MEXT), declared on 12 April 2005 that everything was being done to reach a decision before the G8 meeting was to be held in Scotland in July.The deadline was met at the last minute: on 28 June 2005 in Moscow—almost exactly 18 months after the Reston meeting to the day—the six ITER Members unanimously agreed to build the International Thermonuclear Experimental Reactor on the site proposed by Europe. Japan overcame its disappointment and, in the words of Noriaki Nakayama, changed it “into joy." No one had “lost.” And no one had “won” but ITER.¹In the wake of the 9/11 terrorist attack on the Twin Towers in New York, a combined force led by the United States had invaded Iraq in March 2003.Read the comprehensive story of the ITER site negotiations in “ITER le chemin des étoiles,” Robert Arnoux and Jean Jacquinot, Edisud, 2005 (Chapter 9, in French) and in “ITER, the Giant Fusion Reactor,” Michel Claessens, Springer 2023 (Chapter 4, in English.)

On the integrated modelling of magnetic fusion plasmas

The 14th ITER International School concluded successfully in Aix-en-Provence, France, on 4 July 2025 after five days of lectures and discussions. More than 200 students and lecturers from 39 countries participated. The 2025 ITER International School on integrated modelling of magnetic fusion plasmas was successfully held from 30 June to 4 July. The event gathered 232 participants from 39 different countries, representing a diverse and international community of experts in the field. The lectures were delivered by 17 prominent specialists in the integrated modelling of magnetic fusion devices. In line with the evolution of the fusion energy development panorama and with ITER Council guidance, 17 of the students and one lecturer were affiliated with privately funded fusion research initiatives.The ITER International School was the fourteenth in the series, which alternates between sites within the ITER Member countries and Aix-en-Provence, France, close to where ITER is being constructed. This time the school took place in Aix-en-Provence, hosted by Aix-Marseille University (AMU). The venue was the Amphitheatre Guyon, Faculté d'Arts, Lettres, Langues et Sciences Humaines, which had very good conference facilities and was centrally located allowing participants to enjoy the lively city centre.  A day in the life of: the integrated modelling lectures covered a wide range of topics, with domain experts presenting talks ranging from very-high-fidelity integrated modelling to full integrated tokamak scenario simulations including plasma control. Photo: R. Kraaijenhagen (TULP Fusion Foundation) This year’s school focused on the integrated modelling of magnetic fusion plasmas. Reliable predictions of ITER plasmas, spanning the entire cross-section from the plasma core, the scrape-off layer, and up to the material surface are key to the achievement of ITER’s fusion power demonstration goals. These predictions are essential for defining and preparing plasma operational scenarios and analyzing plasma pulses that will be executed in ITER, as well as for evaluating the required control schemes through the simulations of measurements, actuators, and the associated plasma responses. Given the strong non-linear coupling of processes governing burning plasma behaviour, separate modelling of individual processes and/or plasma regions is not sufficient. A holistic, integrated approach is therefore mandatory. Lectures spanned a wide range of topics, from whole-fusion-device integrated modelling with a wide range of sophistication and computational cost to specific modelling of interlinked physics and control processes. These included edge-plasma physics/plasma-wall interactions, fast particle physics and magneto-hydrodynamic instabilities, etc., as well as flight simulators to cite a few examples. The application of artificial intelligence to facilitate integrated modelling was a recurring theme in some presentations this year as a promising way forward for this field.  Exchanges between participants highlighted how the various approaches to integrated modelling can be used to address complex physics and control from the micro-scale/millisecond time scale to full-scenario simulations.   Participants are photographed in the lobby of ITER Headquarters. The visit to the worksite to see the tokamak in construction was one of the highlights of the 2025 ITER International School. Photo: R. Kraaijenhagen (TULP Fusion Foundation) One of the highlights of the school was the visit to the ITER Organization, allowing school participants to see the progress in the construction of ITER and to learn more about ITER status and plans and how integrated modelling is being developed and applied to support the development and refinement of these plans. The students had the opportunity to present their research work in two poster sessions. The quality of the work presented during the two poster sessions held at this year’s school was very high. The school lecturers along with the scientific committee selected three participants per poster session and awarded their outstanding research work with the presentation of several ITER “goodies” including a piece of ITER itself (a slide of poloidal field coil superconducting cable) for the first prizes of each session. Visit of the ITER International School attendants to the ITER Organization. The students awarded the prizes were:First prizes â€¢    Ivan Kudashev from Aix-Marseille University, CNRS, Centrale Méditerranée, M2P2:  â€œSynthetic diagnostics application for diagnostics design and confrontation of SolEdge-HDG 2D fluid integrated transport simulations with experiments” â€¢    Fabian Solfronk from the Max-Planck-Institute für Plasmaphysik, Garching: "Expanding the Physics Modelling Capabilities of ASTRA from Core to SOL and from Tokamak to Stellarator Towards Application in a Multi-Device Flight Simulator"Second prizes â€¢    Veronika Korzueva from Peter the Great St.-Petersburg Polytechnic University: “SOLPS-ITER modelling with applied neoclassical corrections to the transport of impurities”•    Haley Wilson from Columbia University: “Using integrated modelling to explore the core operational space around a reactor-class negative triangularity tokamak”Third prizes â€¢    Theo Fonghetti from CEA Institut de Recherche sur la Fusion par confinement Magnétique:  "Towards high performance long pulse operation with combined LHCD and ECCD in WEST”•    Hong-Sik Yun from Seoul National University: “Development of an Integrated Data Analysis Platform for the BEST Tokamak” Photo of prize award winners at the closing ceremony of the 14th ITER International School. Overall, the 14th ITER International School was a resounding success, bringing together a diverse group of participants from around the world to exchange knowledge, share experiences, and foster collaboration on integrated modelling of magnetic fusion devices. The support from Aix-Marseille University (AMU) and, in particular, its Institute for Fusion and Instrumentation Sciences in Nuclear Environments (ISFIN), the ITER Organization, the Burning Plasma Organization (USA), the National Institute for Fusion Science (Japan), EUROfusion (EU), Fusenet (EU), the International Atomic Energy Agency, and the TULP Fusion Foundation greatly contributed to the success of this event.The slides of the lectures will be available later this week on this ITER webpage together with the information on past ITER International Schools. 

Main server rooom soon handed over to ITER

Installation of the cubicles hosting the servers that will orchestrate the approximately 5 million “variables” of the ITER machine during operation began a little more than a year and half ago and is now nearing completion. In a couple of weeks, the European Domestic Agency Fusion for Energy (F4E), responsible for delivering the Control Building and its equipment, will hand them over to the ITER Organization.This candid was taken during a recent visit of F4E representatives and b.NEXT personnel to the Control Building’s main server room for a last check before the handover.
Of interest

EUROfusion Engineering Grants

https://www.iter.org/of-interest?id=31968
EUROfusion has opened applications for its 2026 Engineering Grants program, supporting the education and development of a new generation of fusion engineers. These two-year grants are aimed at young engineers with a Master's and/or PhD degree working in or entering the EUROfusion program. Around 14 grants are expected to be awarded.The grants support career development in key competency areas for fusion and are awarded based on the excellence of the candidates. New eligibility rules now allow applicants who completed their MSc degree between 1 June 2019 and 28 July 2025, and candidates may complete their PhD during the grant period.The application deadline is 28 July 2025. See further details about the program and how to apply here. 
Video

ITER by drone - May 2025

Press

El nuevo salto hacia la fusión nuclear se gesta a fuego lento con IA en pleno Madrid: "Nos va a dar unos ojos que no tenemos"

https://www.elmundo.es/economia/empresas/2025/07/07/6867f750fdddffe36a8b4592.html

フュージョンエネルギー産業協、核融合エネの普及へ「白書」

https://www.nikkan.co.jp/articles/view/00753229?gnr_footer=0082383&mc_cid=7a0eed2242&mc_eid=294fed31c3

Record-Breaking Results Bring Fusion Power Closer to Reality

https://www.scientificamerican.com/article/record-breaking-results-bring-fusion-power-closer-to-reality/

2040년 한국에 뜰 인공태양 에너지, 고온초전도체·AI가 구현

https://v.daum.net/v/20250704085932265

Westinghouse awarded $180M ITER contract

https://www.ans.org/news/article-7170/westinghouse-awarded-180m-iter-contract/

웨스팅하우스, 이터 핵융합 진공용기 조립 1억8000만 달러 계약

https://www.g-enews.com/article/Global-Biz/2025/07/202507030650051610fbbec65dfb_1

Heart of the world’s largest nuclear fusion reactor to be assembled by US firm

https://interestingengineering.com/energy/westinghouse-to-assemble-iter-vacuum-vessel

Westinghouse Wins $180 Million Contract For Assembly Of Iter Vacuum Vessel (paywall)

https://www.nucnet.org/news/westinghouse-wins-usd180-million-contract-for-assembly-of-iter-vacuum-vessel-7-3-2025

Slovenian Fusion Association Celebrates 20 Years of Contribution to Fusion Science

https://euro-fusion.org/eurofusion-news/slovenian-fusion-association-celebrates-20-years-of-contribution-to-fusion-science/

Official launch of the joint WEST / KSTAR experimental program

https://irfm.cea.fr/en/2025/06/official-launch-of-the-joint-west-kstar-experimental-program/

Kilometres of pipes manufactured to cool down the core of ITER

https://fusionforenergy.europa.eu/news/iter-blanket-cooling-manifold-pipes/

Westinghouse contracted to assemble ITER torus

https://www.world-nuclear-news.org/articles/westinghouse-contracted-to-assemble-iter-torus

The Weld That Could Power Humanity: Inside Westinghouse's $180M ITER Gambit

https://www.ctol.digital/news/westinghouse-180m-iter-fusion-gambit/#the-weld-that-could-power-humanity-inside-westinghouses-180m-iter-gambit