In May 2022, the first of nine sector modules that form the tokamak torus was installed in the assembly pit. In a reverse operation last week, the same 1,350-tonne module was removed, as dimensional non-conformities observed in the vacuum vessel sector's bevel (welding joint) region, combined with corrosion-induced cracks in thermal shield piping, meant that the sector module had to return to tooling in the Assembly Hall for disassembly. Although not foreseen in the original specifications of the assembly tools, the reverse lift operation was performed with the same hardware successfully. The reverse lift—an operation that took close to four days, excluding advanced preparation activities—did not simply consist of reversing what had been done more than one year before. Procedures had to be adapted and additional guiding systems had to be manufactured and installed. 'A lift-off is not exactly a reverse landing,' summarizes Daniel Coelho, the ITER assembly engineer who coordinated last week's operation. The extraction began in earnest on 4 July with a 'pre-lift' that raised the load a few centimetres from its landed position. For the main operation, more than one hundred different steps had been defined, validated and integrated into the lifting procedure—from detaching the module from its moorings in the assembly pit, to lifting and transporting it to the sub-assembly tool on the other side of the wall in the Assembly Hall. To carry out the planned succession of moves—lifting, rotating, advancing, rotating, advancing, lowering—it was essential to determine with utmost precision the relative position of each of the elements concerned: the load itself, the overhead crane's complex rigging and the tool support systems at the receiving end. Just like during the May 2022 operation, one of the main challenges was to determine the load's centre of gravity. 'The module is of a composite nature. When sitting in the pit, the vacuum vessel and the toroidal field coils are not mechanically connected,' explains Coelho. 'It's only during the lifting phase that, thanks to the bracing tools that attach vacuum vessel and coils together, they become one homogeneous load with a common centre of gravity.' Lessons learned in 2022 were essential to this operation's success. 'We have made considerable progress in terms of alignment accuracy and, what is also very important, we operated with the same team. Everybody knew his/her part perfectly, and coordination among the team members was smooth.' Although it was a highly sophisticated operation that relied heavily on sensors and strategically positioned cameras, 'spotters' played a crucial part in precision and overall safety. 'A sensor will give you an indication. But only the human eye, and the brains to which it is connected, can analyze and understand a situation and take the right decision,' says Coelho. On 5 and 6 July, during the actual lifting and landing of the module, close to a dozen spotters closely monitored the most delicate passages: along the pit's central column, over the separating wall and during the insertion into the sector sub-assembly tool. A towering presence inside the assembly pit for close to 15 months, the sector module is now standing in the tool's embrace. Disassembly activities have already started in preparation for the synchronized opening of the tools' wings and the removal of the toroidal field coils, followed by the removal of the thermal shield panels. By then, the vacuum vessel sector will stand alone in the tool. Once rid of its equipment and 'stripped naked,' preparation for repairs—starting with metrology to define the metal build-up and machining zones—will begin. See a video of the lift operation in this edition of the ITER Newsline or on the ITER YouTube channel here.

And they're off. Fusioneers are gathering this week in Oxford (United Kingdom) for the 30th IEEE Symposium on Fusion Engineering (SOFE). More than 700 delegates from 26 countries—including a group of 20 from the ITER Project—are discussing what steps at the forefront of science, engineering, and technology are necessary to make fusion energy a reality. Speaking ahead of today's opening ceremony, Heather Lewtas, chair of the event and UKAEA's Head of Innovation, said, "It is an extremely exciting time for fusion energy in the UK and internationally. SOFE 2023 provides an important platform where technical conversations between public and private fusion organizations can take place alongside the supply chain and academia. There has already been fantastic development in our field, but it will be the strength of our global community that will make fusion energy part of the world's future power supply." In a plenary session this morning, Kathy McCarthy, director of the US ITER Project at Oak Ridge National Laboratory, gave an update on ITER achievements, challenges and path to operations. Scientists and engineers from the ITER Project are giving a number of presentations and poster sessions during the week (see the event program here). We'll have a full report in the next ITER Newsline.

The 12th ITER International School concluded successfully in Aix-en-Provence, France, on 30 June after five days of lectures and discussions on the impact and consequences of energetic particles on fusion plasmas. The 2023 ITER International School gathered 160 participants from 26 different countries, representing a diverse and international community of experts in the field. The lectures were delivered by 13 prominent specialists in the field of energetic particle physics in magnetic fusion devices. The ITER International School was the 12th in the series, which alternates between sites in Aix-en-Provence, in the south of France, close to where ITER is being constructed, and external hosts within the ITER Member countries. This time, after a hiatus due to Covid, the school took place at the Faculty of Law Campus in Aix-en-Provence, which provided excellent logistical support and facilities for the participants. A notable contribution to the success of the school was made by Aix-Marseille University, which not only provided financial support but also played a crucial role in hosting the event. The subject of this year's school focused on the impact and consequences of energetic particles on fusion plasmas, a particularly relevant multidisciplinary topic for ITER whose missions rely upon successfully harnessing the power released in the form of energetic alpha-particles to sustain a self-heating plasma.  Energetic particles are created by auxiliary heating systems (radiofrequency heating and neutral-beam injection), fusion reactions and (in the case of runaway electrons) electric fields parallel to the magnetic field. Interactions between the energetic particles and the magnetic fields can lead to instabilities that can modify the field itself and the energetic particles' distributions (density and energy). At the school, approaches to understanding this interaction to various levels of complexity were presented and discussed. This ranged from linear approaches near marginal stability to complex nonlinear simulations which explain many observations of energetic particle-driven instabilities and allow a deeper understanding of the interactions taking place. A deeper understanding of the physics of particular instabilities also opens the door to future advanced control opportunities to mitigate the consequences in terms of energetic particle transport and loss. The school also discussed diagnostic methods and interpretation techniques that enable the consequences of plasma instabilities driven by energetic particles to be quantified in terms of particle transport and loss. While most of the material presented at the school focused on energetic ions, energetic electrons were not neglected. In particular the physics of so-called runaway electrons that can reach relativistic speeds in the presence of an accelerating electric field were introduced, together with experimental observations and detailed modelling. At the school, leading experts in the field of energetic particle physics provided many hours of lectures on the interlinked multidisciplinary topics outlined above. This was complemented with a combination of worked examples, tutorials and quizzes, that allowed the participants to gain a deeper understanding of the many facets of energetic particle physics.   One of the highlights of the school was a visit to the ITER construction site. This opportunity allowed participants to witness first-hand the progress and advancements being made in the field of fusion energy. It provided valuable insights and a deeper understanding of the practical aspects of the research being conducted. In addition to the visit to the ITER site, the school also featured three lectures given in the auditorium of ITER Headquarters. These lectures, delivered by prominent ITER experts, offered participants a unique opportunity to learn from and interact with leaders in the fusion energy community. Overall, the 12th 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 in the field of energetic particles and fusion plasma. The support from Aix Marseille University, the ITER Organization, the US Burning Plasma Organization and the International Atomic Energy Agency (IAEA) greatly contributed to the success of this event. The slides of the 2023 lectures are available on this ITER webpage, together with information on past ITER International Schools.

The DIII-D National Fusion Facility has announced the end of a productive two-year experimentation campaign, with 200 days of operation and 1,600 plasma research hours. In operation since the 1980s, the DIII-D tokamak is the largest magnetic fusion research facility in the United States. Operated by General Atomics for the US Department of Energy, it played an important role in providing data for the engineering design phase of ITER, and continues to work to establish the scientific basis for the optimization of the tokamak approach to fusion energy production. DIII-D explores a wide range of scientific issues that will help to prepare for ITER operation, including the exploration of the effect that internal stabilization coils have on preventing energy bursts from the plasma edge, the development of high-power microwave transmission line components with low energy losses, and software for controlling the plasma and protecting the ITER machine. Key achievements of the latest campaign, as reported in a press release from General Atomics, include: The demonstration of high performance 'diverted negative triangularity' plasma configurations, which alter the shape of the plasma to improve performance and heat dissipation and potentially revolutionize the path to cost-effective fusion energy. The deployment of a new radio-frequency wave injection technology known as 'helicon current drive' with an innovative antenna that improves the delivery of energy to the plasma, potentially creating a new method for efficiently sustaining plasmas in a more compact and cost-effective manner. Significant optimizations to DIII-D's flexible three-dimensional magnetic field configurations, which improved particle confinement and protections for the plasma-facing walls of the machine. Findings from these and other areas of research will be announced in upcoming scientific journals and conferences. A number of upgrades—such as a new divertor system and increased current drive capability—are planned to bring DIII-D to higher performance levels and to enable new research to improve plasma control and efficiency. See the original press release here. 

Offering unsurpassed hardness, broad band optical transparency, and extremely high thermal conductivity, synthetic diamonds are the material of choice for 60 small windows that offer access to the machine for the high-frequency electromagnetic waves of ITER's electron cyclotron heating system, yet ensure a tight vacuum boundary. The European Domestic Agency for ITER, Fusion for Energy, has procured 60 synthetic diamond discs through the German firm Diamond Materials. Now they must be polished, optically inspected, and finally joined with the diamond window unit through brazing. See the original story on the Fusion for Energy website for all the details.