In the ITER Tokamak, components with the simplest of missions—like supporting a very heavy load—are pieces of highly sophisticated technology. Take the gravity supports situated under each toroidal field coil. In essence, they are just pedestals. But as they will be supporting 10,000 tonnes of superconducting magnets at cryogenic temperature—and as that mass will be exposed to intense electromagnetic forces in the course of operation (not to mention seismic loads if they occur)—the 18 gravity supports cannot just be massive and sturdy. They need to be much more than that. Designers and engineers at the ITER Organization, at the Chinese Domestic Agency (responsible for the procurement), and at the Southwestern Institute of Physics, SWIP (tasked with manufacturing the 20-tonne components) faced a major challenge that required many years of prototyping, load analysis and qualification testing.   In order to support the dead weight of the magnetic system*, the gravity supports needed to be extremely strong. But they also needed to be relatively elastic to absorb the loads generated by the machine's wobbling during operations and the possible accelerations generated by a seismic event.   After a lot of design optimization, the potential for flexibility was achieved by creating a structure made of ITER-grade stainless steel plates, arranged vertically and strongly bolted together at the top and bottom of the component to assure structural integrity. Each gravity support is made of twenty-one 30-millimetre-thick plates.   The challenge however was not about structure only. The design of the gravity supports had to take into account the huge difference in temperature between the top of the component, where it interfaces with the toroidal field coil operating at 4K (minus 269 °C), and the bottom that rests on the ring pedestal of the cryostat base at approximately room temperature. At the foot of the 2.65-metre-tall component it will be like mild winter morning in Provence; at the top it will be colder than night-time on Pluto ...   This temperature gradient across the component has two main consequences. One is that "heat" from the cryostat base, if not intercepted, could raise the temperature of the coil winding packs through conduction. Also, if not smoothly distributed throughout the component, the 290 °C difference between head and toe would influence its flexibility.   Protruding from the upper part of the component, a set of pipes and manifolds forms the visible part of a gaseous helium cooling circuit that acts as a thermal buffer to intercept the "heat load" coming from the cryostat base and heading to the magnets. Circulating in two parallel sets of welded pipes for redundancy, the 80 K (minus 193 °C) gaseous flux also cools the component's plates, thus smoothing the temperature gradient of the component.   They were tested again last week to ensure that shipping, handling and unpacking operations had not altered their leak tightness. The 2.65-metre-tall supports will be the next components installed in the Tokamak pit. From left to right: Park Young Min, Inspection and Test coordinator; Cornelis Beemsterboer, Magnet Supports Responsible Officer; Jean-Louis Bersier, vacuum engineer; and Yvan Parsis of the ITER vacuum team. The first two gravity supports to reach ITER were successfully leak tested last week to ensure that shipping, handling and unpacking operations had not altered the leak-tightness that had been tested and qualified in a vacuum chamber in China before shipment.   Another eight have left their manufacturing site at SWIP's contractor Guizhou Aerospace Xinli Casting & Forging Co., Ltd. (HTXL), in southwest China, and are on their way to France, to be followed early next year by the last set of eight.   In the assembly pit at ITER, final preparations are underway for the installation of the first two gravity supports on the cryostat base; each one will be secured with 26 bolts (60- to 85-millimetres thick). When the full set of 18 is in place, forming a perfect circle, the comparison that is often made between the diameter of the cryostat and that of the Stonehenge stone circle will be more pertinent than ever.   * ITER's 18 interlinked toroidal field coils provide the superstructure that anchors the entire superconducting magnet system, including six poloidal field coils, the central solenoid and an array of correction coils. From their position at the bottom of the machine, the toroidal field coil gravity supports will be confronted with about 10,000 tonnes of magnet dead weight—or 580 tonnes per support.

It will be very hot, next summer, on WEST plasma-facing components. Equipped with a full ITER-grade tungsten divertor, the CEA-operated tokamak will enter Phase II of its operational program, extending plasma durations up to 1,000 seconds. Last week, CEA, ITER and Chinese partners celebrated the delivery of the last batch of plasma-facing units which, once assembled in 30-degree sectors, will form the WEST divertor. Like in ITER, the actively cooled component will sustain a heat flux of up to 20 MW per square-metre—ten times more intense than what a spaceship reentering Earth's atmosphere is exposed to. Participants to the celebration had gathered in two locations, half a world away: the EAST tokamak control room at the Institute of Plasma Physics, at China's Academy of Science in Hefei, China, and the hall outside the WEST control room at CEA-Cadarache, less than one kilometre from ITER. Other guests, ITER Director-General Bernard Bigot among them, joined the event remotely.   Initiated more than 40 years ago, the collaboration between research institutions in France and China was reinforced in 2017 with the creation of SIFFER, the SIno-French Fusion Energy centeR that brings together CEA's Institute for Magnetic Fusion Research (IRFM), ASIPP, the Southwestern Institute of Physics (SWIP) and the Chinese Domestic Agency ITER China.   Participants to the celebration had gathered in two locations, half a world away. Here, Jérôme Bucalossi and Tuong Hoang, a fusion physicist and international relations expert at IRFM. Through SIFFER, China has played a key role in upgrading the Tore Supra research tokamak into the ITER test bench and "risk limiter" WEST. Jérôme Bucalossi, the head of IRFM, expressed his "warmest gratitude for the huge effort" by all the members of the research consortium and particularly for the delivery of WEST's 456 ITER-like plasma-facing units.   Having assembled the plasma-facing units into sectors and the sectors into a finalized ITER-grade divertor, IRFM plans to launch Phase II of WEST operation next summer—"an important task for ITER and the next-step fusion devices," said Bucalossi.   The virtual gathering also offered an opportunity to celebrate the upcoming delivery, from ASIPP, of two of the 18 correction coils needed for ITER. "Although small compared to the main ITER magnets, correction coils integrate all the challenges of manufacturing superconducting magnets," said ITER Director-General Bernard Bigot.   Both milestones, he added, "mark another step for the study of burning plasmas."

A consequential grant from the Danish Novo Nordisk Foundation will permit two fusioneers from the Technical University of Denmark (DTU) to broaden their educational outreach efforts with a program called "Fusion Energy for All," designed for high school students and their teachers. _Img1_Søren Bang Korsholm and Alexander Simon Thrysøe estimate that they have given over 200 presentations to high school students over the course of their careers. "We have always felt that we had an obligation to reach out to young people and share the interest and excitement of a career in physics and specifically fusion. As much as time permitted, we were always willing to get involved." But when the Novo Nordisk Foundation called out for applications earlier this year for programs that could "increase the science capital of children and young people by showing them [...] how science and technology improve the lives of people and the sustainability of society," they immediately saw that fusion was a good fit—and that a grant could be a game changer. "Here was the opportunity to do more of what we wanted to do, increasing our interaction with young people and reaching thousands—instead of hundreds—of students." _Img2_And not only students. The project they proposed was two-tiered, with one program for high school students and another for high school teachers. Fusion for high school students: Taking fusion on the road, making presentations at high schools and engaging students in demonstration experiments—20-200 students per presentation, 40 presentations per year All-expense-paid summer school at DTU (5 days), with experiments at the NORTH tokamak and the DTU fusor—30 students, once per year Fusion for high school teachers: Fusion webinars on how to teach fusion energy, with teaching material—20+ teachers per webinar series (a series of three lectures), offered two times per year All-expense-paid autumn school at DTU (3 days), with experiments at the NORTH tokamak and the DTU fusor—15 teachers, once per year In June, the Novo Nordisk Foundation awarded the "Fusion Energy for All" (Fusionenergi til Alle) proposal a four-year outreach grant worth EUR 530 K. Alexander, who is a postdoc in the Physics Department at DTU, will spend about 50 percent of his time the program while Søren, Senior Scientist, will dedicate about 10 percent. The grant will also fund upgrades to the DTU Fusion Roadshow experiments, support from research technicians and student assistants, a new website and branding, the development of teaching materials, and the summer/autumn schools. "We hope to inspire a lot of young people to seek out more information about fusion science and technology, and maybe choose a fusion-related career path. And, in a broader sense, spread the awareness of fusion and its potential." A reminder: The European Fusion Teacher Day takes place remotely on 2 October, organized by the FuseNet association. A consequential grant from the Danish Novo Nordisk Foundation will permit two fusioneers from the Technical University of Denmark (DTU) to broaden their educational outreach efforts with a program called "Fusion Energy for All," designed for high school students and their teachers. The two have given at least 200 presentations over the course of their careers (Alexander is pictured here). "We have always felt that we had an obligation to reach out to young people and share the interest and excitement of a career in physics and specifically fusion." Søren Bang Korsholm and Alexander Simon Thrysøe estimate that they have given over 200 presentations to high school students over the course of their careers. "We have always felt that we had an obligation to reach out to young people and share the interest and excitement of a career in physics and specifically fusion. As much as time permitted, we were always willing to get involved." But when the Novo Nordisk Foundation called out for applications earlier this year for programs that could "increase the science capital of children and young people by showing them [...] how science and technology improve the lives of people and the sustainability of society," they immediately saw that fusion was a good fit—and that a grant could be a game changer. "Here was the opportunity to do more of what we wanted to do, increasing our interaction with young people and reaching thousands—instead of hundreds—of students."

On 22-23 September the International Atomic Energy Agency held its annual Scientific Forum on the margins of its General Conference. This year's theme was "Nuclear Power and the Clean Energy Transition," focused on how innovative forms of nuclear energy can help the world reach its climate goals. ITER Director-General Bernard Bigot participated in the Closing Session panel, discussing how fusion may contribute to the future clean energy mix, in a way that would be complementary to fission and renewable energy.   You can read Dr Bigot's statement here.

The fusion team at the International Atomic Energy Agency (IAEA) has introduced a worldwide tracking and information system for fusion devices, located within the IAEA's Fusion Portal. The Fusion Device Information System (FusDIS), developed and maintained by the IAEA, focuses on experimental fusion research devices worldwide. FusDIS contains information on fusion devices public or private that are currently in operation, under construction, closed or being planned. All information is collected by the IAEA and undergoes a process of review involving the International Fusion Research Council. It currently lists 62 tokamaks, 12 stellarators/heliotrons, 7 laser fusion devices, and 31 innovative/alternate fusion concepts. The IAEA fusion team is interested in feedback on FusDIS. Please send comments to: Fusion-Physics@iaea.org

From the Princeton Plasma Physics Laboratory: The American Nuclear Society has bestowed its distinguished Nuclear Historic Landmark designation on the pioneering Tokamak Fusion Test Reactor (TFTR) that ran from 1982 to 1997 at the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL). The groundbreaking facility laid the foundation for future fusion power plants and set world records for fusion power (10.7 million watts) in 1994 and total fusion energy production (1,500 million joules) from 1993 to 1997.  The achievements marked a major step in fusion history. The designation, which will be formally announced at the American Nuclear Society's November meeting, recognizes TFTR "for demonstrating significant fusion energy production and tritium technologies for future nuclear fusion power plants and the first detailed exploration of magnetically confined deuterium-tritium fusion plasmas." Read the full statement by The American Nuclear Society. Read the original article on the PPPL website.