In another step to support global efforts to develop fusion energy, the ITER Organization is releasing the tools it uses for physics modelling and analysis—the ITER Integrated Modelling & Analysis Suite, IMAS—under open-source licenses.  --Visualization with IMAS-ParaView (https://github.com/iterorganization/IMAS-ParaView) of induced currents in vacuum vessel and plasma electron temperature during disruption in ITER simulated with JOREK code (https://jorek.eu/).In line with the ongoing efforts* to facilitate the development of fusion energy in the Members, the ITER Organization is pleased to announce that the Integrated Modeling and Analysis Suite (IMAS), including a wide range of physics modelling codes for tokamak plasma scenarios, is now available for access and use under open-source licenses on the GitHub platform. This culminates the effort initiated earlier this year after the decision by the ITER Director-General to release the IMAS Intellectual Property owned by the ITER Organization as open source, and has only been possible thanks to the support from a wide range of institutions across the ITER Members.The Integrated Modelling and Analysis Suite (IMAS) provides standard tools and applications to support the integrated modelling and data analysis of fusion plasmas and has been developed in close collaboration with the Members’ fusion communities. This development has been guided by the need to address plasma scenario and plasma diagnostic design/performance issues and to optimize the ITER Research Plan towards the achievement of ITER’s goals. The IMAS infrastructure software now released as open source allows users to manipulate and perform a wide range of operations on data that follows the IMAS Data Dictionary. This is a device-agnostic standard for fusion data capable of describing experiments and simulations that has resulted from a decades-long effort by the ITER Organization and the ITER Members. The support of EUROfusion and EURATOM to enable this open-source release is gratefully acknowledged.    Waveform-Editor (https://github.com/iterorganization/Waveform-Editor) showing plasma shape calculated with NICE code (https://gitlab.inria.fr/blfauger/nice) In addition to the infrastructure software, a wide range of physics models used extensively in the fusion modelling community have also been made openly available. This includes SOLPS-ITER (for the modelling of edge plasmas, principally composed of B2.5 and EIRENE), SOLPS-GUI (a graphical interface for SOLPS-ITER), DINA Plasma Simulator (for modelling tokamak scenarios) and a Heating & Current Drive Workflow (HCD-WF). The institutions that own the intellectual property for these codes (Max-Planck-Institut für Plasmaphysik, Forschungszentrum Jülich, Fusion for Energy, and the Plasma Simulation Center) are gratefully acknowledged for their support. Fully aligned with this ITER-led effort, many research institutes from the ITER Members and non-Members have also made their plasma simulation codes openly available under open-source licenses (such as METIS, CHEASE, GACODE, NICE etc.), greatly enhancing the open access of plasma simulation codes to the wider fusion community, including privately funded initiatives.  The IMAS software set available as open source will gradually be expanded moving forward and enriched with additional documentation to help users find the appropriate IMAS software for a given use-case. Near-term steps include the release of synthetic diagnostic models to simulate the expected measurements in tokamak plasma scenarios and support the inference of plasma properties.And of course, contributions in all forms (source code improvements, bug reports, documentation, installation recipes on different platforms, etc.) by the worldwide fusion research community are very much welcome for all these different software packages.See https://github.com/iterorganization. * The ITER Council, in its 33rd (November 2023) and 34th (June 2024) meetings, requested Members to encourage their national entities (government agencies, research institutes, private sector fusion companies) to support global fusion efforts. 

Each of the nine sector modules that form ITER’s plasma chamber is approximately 13 metres tall and, once rid of its lifting rig, weighs in excess of 1,200 tonnes. In terms of height, this is the equivalent of a five-storey building; in terms of load, each module weighs nearly as much as three fully loaded Airbus A380s or Boeing 747s. Once lifted from the giant tool where they were assembled, transferred to the tokamak assembly pit, and positioned on temporary supports, the modules are still a long way from their final position.  Modules are composite in nature, made not of one type of component, but of three: one vacuum vessel sector, its thermal shield, and a pair of toroidal field coils. During the lifting and transfer phase, the vessel sector and coils are mechanically connected by way of “bracing tools” in order to keep them in their relative positions and avoid movement that could result in damage. After the lifting and transfer operations are completed (watch the latest transfer here), and the module has been “temporarily landed” at the bottom of the assembly pit, the bracing tools are loosened to allow adjustments but not totally released—they remain in place until the final positioning of the module to protect it in case of a seismic event.During the module’s descent, operators aim for a “landing position” that is located 140 millimetres away, in the outboard direction, from the final target position. “This distance, called the ‘radial shift,’ is necessary to prevent a collision, or even the slightest contact, between the descending load and the pit environment,” explains Vincent Micheneau, the assembly mechanical engineer responsible for toroidal field coil alignment.The long and complex alignment process consists of a series of small incremental movements performed in parallel on the vacuum vessel sectors and the toroidal field coils.While the hydraulic jacks attached above the sectors to the radial beam allow operators to adjust the vacuum vessel’s position, a bespoke tool—the TIPI tables, manufactured by French contractor CNIM—now enters the stage to play the lead part in the alignment of the coils.  Multi-jack hydraulic devices called TIPI tables will move the toroidal field coils in all three directions (left and right, up and down, forward and backward) until their target position is reached. TIPI (for Toroidal Field Coil In-Pit Installation Tool) tables are multi-jack hydraulic devices that can move the load they support in all three directions (left and right, up and down, forward and backward).Three such tables, two located outboard, one inboard supported by the central column, are operated jointly to position the sector modules.Under each of the toroidal field coils that descend into the tokamak pit as part of a sector module, a sturdy steel purpose-built tool called the “outboard bracket” acts as a cantilevered “foot” that will enable the TIPI table operators to position the coils above their final target—the pedestal-like gravity supports—and lower them to finalize alignment. (Once the coils are installed, the outboard brackets are removed.) This image of the tools below the modules in the pit shows the complexity of the toroidal field coil alignment system. (1) points to one of the two outboard TIPI tables; (2) shows the cantilevered outboard bracket that enables the positioning of the coils on their (3) gravity support. (4) shows the juncture between the two modules, which are not yet aligned. (The blue structure in the photo is not connected to the alignment process.) The module shift is done by five-millimetre increments, first on the pair of toroidal field coils, then on the vacuum vessel sector. As the step-by-step adjustment progresses, metrology plays an essential part by allowing the live tracking of the positioning operation with a precision of a few tenths of millimetres. By the end of the process, once the module’s target position has been validated by an extensive metrological survey, the toroidal field coils can be lowered onto the gravity supports and fastened, thus transferring the load to the building structure. When a vacuum vessel sector is in its final position, it gets attached to the central column by way of an additional bracing tool bolted to its inboard section. This is to prevent movement in the case of a seismic event. The position of each vacuum vessel, however, is deliberately set at a distance of approximately 5 millimetres from target. This gap will be closed at a later stage prior to transferring the load to a dedicated gravity support—something that can only happen once intercoil connections with adjacent sectors are in place. When the vacuum vessel is in its final position, it is attached to the central column by way of an additional bracing tool bolted to its inboard section. This, again, is to prevent movement in the case of a seismic event.Up to five intense workdays elapse between the landing of a module and the validation of alignment—definitive alignment for the toroidal field coils, still requiring a small adjustment for the vacuum vessel sectors.

To prove fusion’s promise, ITER must not only create energy—it must also measure it with great precision. ITER plans to routinely demonstrate a fusion gain of Q=10, meaning that for 50 MW of injected heating power across the plasma, 500 MW of fusion output will be produced. This can only be done if there is a way of accurately measuring the output—and that job is entrusted to neutron diagnostics. “I work on systems that measure neutrons, which are a product of the fusion reaction,” says Silvia di Sarra, diagnostics engineer at ITER. “They tell us how much power is being produced inside the machine.”But the detectors that record neutron flux in the ITER tokamak have to be calibrated first to ensure measurement accuracy—an activity that takes place inside of the vessel using small neutron generators. “Neutron generators are compact accelerators that use fusion reactions to produce neutrons with well-known properties,” explains di Sarra. “By comparing our detectors’ readings to this known reference, we can establish a precise measurement scale. It’s similar to how you would adjust a bathroom scale by putting something of known weight on it and correcting the reading.”Typically, in other tokamaks, neutron sources are placed inside the machine in all the positions occupied by the plasma. But this approach won’t be enough at ITER because the generators have limited power and the vacuum vessel is large and full of heavy shielding. “At ITER, we will only be able to place the neutron sources near the detectors in a relatively small number of places,” says di Sarra.Another consideration at ITER is machine utilization. Since activities have to be put on hold during calibration, the calibration process needs to be as efficient as possible.A hybrid approach to precision“Extensive pre-studies are underway to optimize source placement and minimize machine downtime,” says di Sarra. “For areas we can’t reach, we will use detailed computer simulations to extrapolate the detector response.” Diagnostics engineer Silvia di Sarra holds a small-scale 3D printed model of the neutron generator that will be deployed in the vacuum vessel to calibrate neutron diagnostics. This hybrid approach—combining direct measurement and modelling—will compensate for the limited reach of the neutron sources. “One big advantage is that we have extremely detailed CAD data,” she says. “From that, we can generate very accurate neutronic models of the entire machine—down to the smallest bolts.”These models allow the team to predict neutron transport and detector responses throughout the reactor. “They help us plan the calibration, estimate what the detectors should measure at each source position, and later correct the results during operation. When we can’t measure directly, we simulate.”The modelling itself is done using powerful Monte Carlo particle-transport codes: MCNP, an older tool that is validated for use by nuclear installations in France, and OpenMC, a newer, Python-based code that’s much faster and more flexible, with clear visualizations. “The codes complement each other,” says di Sarra. “We cross-check the results of the two—running one classical simulation and one with the modern tool—to ensure consistency.”Calibration of the ITER neutron diagnostics is positioned in a narrow time gap between two construction phases in 5 or 6 years. “Assembly activities will have concluded, but the integrated commissioning will not yet have begun,” says di Sarra. “It’s the ideal window to carry out calibration.”Trust and teamwork at the coreDi Sarra sees similarities between one of her favorite hobbies, climbing, and the long-term nature of her work at ITER. “In climbing, before you start, you check your partner’s knot and belay device,” she says. “At ITER, it’s the same. We work in teams, follow strict procedures, and rely on each other completely.”That trust is essential in an environment where setbacks are inevitable. “There have been moments when components had to be removed and reinstalled,” she says. “You have to trust your colleagues are doing their best, just as they trust you. We all focus on our part of the work and help each other when needed.”“Whether it’s in climbing or in fusion, you always check twice,” says di Sarra. “You keep calm, and you keep going—one careful step at a time.”

The team at the Max Planck Institute for Plasma Physics in Greifswald, Germany, is celebrating ten years of science on the Wendelstein 7-X stellarator. It started in December 2015 with just one milligram of helium gas, pumped into the strangely twisted plasma chamber of the Wendelstein 7-X stellarator and heated with microwaves to a temperature of one million degrees. The plasma pulse that resulted may have only been one-tenth of a second long, but it signalled that nine years of construction work, more than a million assembly hours, and one year of integrated testing was over and experimental operation to investigate the stellarator concept as an alternative design for the fusion power plants of the future could begin.Ten years and several upgrades later, Wendelstein 7-X has put milestone after milestone on the books and now forms the basis for the power plant projects of several start-up companies. The device maintained a plasma for more than eight minutes for the first time in 2023, a world record for stellarators, and routinely achieves ion temperatures of 40 million degrees Celsius in the plasma. In May of this year, Wendelstein 7-X reached a record triple product in long plasma discharges.See this report on ten years of operation at Wendelstein 7-X. The device is currently undergoing a one-year maintenance phase and will resume operation in September 2026.

FuseNet has opened nominations for its Master Thesis Prize 2025. The prize is open to students who completed fusion-related theses in 2025 and recognizes outstanding academic work carried out at European institutions or in collaboration with international partners.Eligible candidates can submit their candidatures until 9 February 2026. FuseNet advises students to coordinate with their home institution before submitting, as each FuseNet member institution may put forward only one nomination.The 2024 prize recognized three researchers for their theses on divertor modelling, turbulence phenomena in plasmas with varying triangularity, and dimensionality reduction methods applied to magnetohydrodynamic equilibria.FuseNet supports education, training, and collaboration for students and young researchers in the field of fusion energy across Europe.More information available here.

As part of French President Emmanuel Macron’s state visit to China from 3 to 5 December, the two countries issued a joint declaration on "further cooperation in the peaceful uses of nuclear energy." It included a point asserting nuclear fusion is an “essential option” for abundant, decarbonized energy and reaffirmed their commitment to ITER.France and China have a long history of working together to ensure the peaceful use of nuclear energy, dating back to a first protocol signed in 1982. Cooperation on nuclear fusion was cited in the 10th Protocol for Cooperation in Peaceful Use of Nuclear Energy, which was signed in 2009 by former ITER Director-General Bernard Bigot when he was still Chairman of the French Alternative Energies and Atomic Energy Commission (CEA). The most recent joint declaration emphasizes the value of nuclear energy for addressing climate change and ensuring energy security while citing the important role nuclear fusion will play in the future. The declaration states:“Both sides recognize that nuclear fusion energy represents an important direction for the peaceful use of nuclear energy by humanity and an essential option for an abundant and decarbonized energy source for the future. They are ready to continue their extensive participations in the major international scientific project of the Thermonuclear Fusion Experimental Reactor (ITER) in order to contribute to the successful promotion of the ITER project and its timely completion.”Read the full Joint Declaration on Further Cooperation in the Peaceful Uses of Nuclear Energy between France and the People’s Republic of China here.Photograph from the Élysée website.

A new report from the F4E Fusion Observatory analyzes the latest data to provide a global picture of the growing private fusion sector.The second edition of Global Investment in the Private Fusion Sector shows that, following major investments announced this summer, the cumulative funding for private sector initiatives is now at EUR 13 billion, with 77 companies in the field. "This funding is a mix of sources: private capital accounts for the majority at over EUR 8.9 billion while public funds, totalling around EUR 4.1 billion, are increasingly flowing into private ventures through grants and institutional support. A further EUR 84 million comes from hybrid forms like public-private partnerships and state-backed investments." The report goes on to break down investments by region, by technology, and by type of funding model.Fusion for Energy (F4E) is the European Union’s organization for the development of fusion energy. It is mainly responsible for Europe’s contribution to ITER, but is also involved in major fusion projects such as the European/Japanese tokamak JT-60SA and the materials research facility IFMIF-DONES. The F4E Fusion Observatory provides objective analysis and intelligence on global and European fusion policies, R&D, technologies, investments and industrial activity for the benefit of European policy makers, the scientific community and other interested parties.Download the F4E Fusion Observatory report here.