you're currently reading the news digest published from 07 Feb 2022 to 14 Feb 2022
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Fusion world | JET makes history, again
The JET tokamak has achieved a first-ever sustained, high-confinement plasma using the same wall materials and fuel mix that ITER will use. The results aligned with prediction ... and this predictability is very good news for the ITER research program and for fusion in general. JET—the Joint European Torus*, used by 4,800 EUROfusion consortium experts, students and staff from across Europe—has set a world record for the most energy produced in a single fusion shot, generating 59 megajoules** of heat from fusion reactions in a sustained manner. Results were announced on 9 February 2022 during a media event that can be watched in replay at this address. The shot was part of a unique experimental campaign run in the last quarter of 2021 on JET, which introduced the high-performance fuel mix of deuterium (D) and tritium (T) for only the second time in the device's history. The heavy hydrogen isotopes deuterium and tritium fuse at temperatures that scientists and engineers can reach in a fusion installation (between 100 million and 200 million degrees Celsius), making them the most promising 'ingredients' for ITER and future fusion power plants. Deuterium-tritium (D-T) fuel has already produced some of the most spectacular records in fusion research. In 1991, the JET tokamak became the first experiment in the world to run a D-T experiment, obtaining close to 2 MW of fusion power in a 2s pulse with a 10 percent tritium mix. Two years later, the Tokamak Test Fusion Reactor (TFTR) in the United States used 50/50 D-T mix to achieve 6.2 MW of fusion power, followed shortly by a record-setting 10.7 MW pulse in 1994. JET vaulted to its own record of 16 MW of peak fusion power in 1997, but even more important during that historic campaign were the more sustained 5-second ~4.5 MW stationary shots in high-confinement mode (H-mode) with a total fusion energy production of 22 MJ. A 'transient' plasma regime is nowhere near as valuable as stable, sustained regimes to researchers; this is also the type of value that will be sought in the operation of ITER and the design of future fusion demonstration power plants. In fact JET's 'stable' results were used to establish the design basis for ITER. The JET team knew it could go further. Not in terms of pulse duration but in terms of total fusion energy. (JET's copper electromagnets are not superconducting and will overheat if a high-energy plasma is maintained for more than 5 seconds). The 1997 experiments had provided valuable data about the behaviour of D-T fuel—most notably that tritium fuel was too easily trapped in the carbon inner wall of the vessel. 'We undertook a major engineering project to change the whole of the inside of the wall of JET—that's 16,000 components, 4,000 tonnes of metal, and all of that was done using some of the most sophisticated robots on the planet,' related Ian Chapman, CEO of the United Kingdom Atomic Energy Authority, during the media event. Other upgrades included increasing installed plasma heating capacity from 24 MW to nearly 40 MW and upgrading measurement and control systems. JET was now ITER's 'nearest neighbor' with the unique capability of achieving fusion conditions that are as close as possible to those expected on ITER. When the team first operated with this new mixture of metals on the inside of the wall, however, performance fell short of expectations. It was 'off the line' of where it needed to be to prove that ITER could meet its goals because the new metal materials were impacting the plasma in unforeseen ways. 'Through perseverance, through ingenuity, through invention our scientists and our engineers found ways to recover, and we recovered the fusion performance,' says Chapman. JET was ready for a new rendezvous with D-T fuel. 
Plasma shot #99971 for the win The goal, this time, wasn't to surpass the peak fusion power of 1997 but to improve on the sustained fusion energy results. The record shot was performed on 21 December 2021 at 14:30 CET (see the GIF video at right). Pulse #99971 achieved total fusion energy of 59 MJ—more than doubling the 1997 record. It maintained an even 10 MW of fusion power, also doubling the previous record, for 5 seconds. The plasma was tritium rich, consuming about 0.1 mg of tritium for 0.07 mg of deuterium. (For comparison: to release the same 59 MJ with fossil fuels, you'd need to burn more than a kilogram of natural gas or two kilograms of coal.) 'A sustained pulse of deuterium-tritium fusion at this power level—nearly industrial scale—delivers a resounding confirmation to all of those involved in the global fusion quest,' said ITER Director-General Bernard Bigot. 'For the ITER Project, the JET results are a strong confidence builder that we are on the right track as we move forward toward demonstrating full fusion power.' The results confirm that sustained high-fusion energy production is achievable using the D-T fuel mix planned on ITER and future devices. They also show that the fusion community has the capability to model what will happen in a fusion reactor. 'The result isn't a surprise; it's actually in accordance with prediction,' explained ITER's Chief Scientist Tim Luce during the event. 'And this is a fundamental result—that fusion is predictable. This will help us. When you talk about timeline—if fusion is predictable then we can optimize without having to do it by proving, in some sense. We can find our way more effectively. These results from JET give us a step up and a step ahead.' See the EUROfusion press release here. *JET (the Joint European Torus) has been operated at the Culham Centre for Fusion Energy as a Joint Undertaking of the European Community since 1977, and operated under UKAEA since 2000. The Euratom Research and Training program has continuously contributed approximately 80 percent of JET operation costs through 2021. **JET produced a total of 59 megajoules of heat energy from fusion over a five-second period. During the experiment, JET averaged a fusion power (i.e., energy per second) of around 11 megawatts. Megawatts are megajoules per second.
Central solenoid | The "table" is set for the first module
The two workers on the cherry picker had spent more than one hour slowly turning the three turnbuckles attached to the straps that held the load. Millimetre by millimetre they had adjusted the straps' length so that, once lifted from its frame, the 110-tonne component would be perfectly balanced and the lift perfectly vertical. Eventually, the electrical motors on the double overhead crane started purring and the load began to lift. Out of the whole operation, performed on Thursday 10 February, this was the most delicate moment: any contact with the fragile electrical connections on the central solenoid module would have had severe consequences. And the clearance was very small. The central solenoid module is one of six more or less identical elements which, once assembled, will form the 'beating heart' of the ITER Tokamak. Procured by the United States, the 1,000-tonne central solenoid has been dubbed 'the most powerful magnet in the world,' capable of lifting an aircraft carrier out of the water. The first module was delivered to ITER in September 2021 and the second one month later. Like the 18 toroidal field coils that surround the vacuum vessel, the central solenoid's superconducting windings, and the protruding 'lead' that feeds the high-voltage, are made of niobium-tin, a compound that, contrary to the niobium-titanium of the poloidal field coils, is quite brittle. This relative fragility explains the extreme care that went into the lift operation's preparation and execution. Having travelled almost the whole length of the Assembly Hall, the module and its lifting frame were eventually lowered and positioned on a simple 'table' where months-long tests will be performed. The module's instrumentation, sensors and superconducting joints need to be carefully checked and tested before it is transferred to the bespoke assembly platform nearby. Lifting, stacking and assembling the six modules into a 18-metre high, 1,000-tonne magnet will require a set of high-precision tools also procured by US ITER and already delivered. The total value of the assembly tooling contracts is in excess of USD 10 million. Once finalized, the ITER central solenoid will be placed at the very centre of the Tokamak pit where the central column (a temporary assembly tool) presently stands.
Festival Yggdrasil | Where fantasy meets the future
Presenting ITER at public conferences and festivals is nothing new. But last weekend, it can be said that ITER entered new territory at the Yggdrasil Festival in Lyon. Ever since 2015, this festival named after a central element of Nordic mythology, the sacred tree Yggdrasil, has managed to attract more than 20,000 fans who regularly turn the Eurexpo exhibition halls into a huge party zone for science fiction and heroic fantasy enthusiasts as well as summoners of the medieval age. So for the first time the ITER exhibition team, who likes to think it knows most of the tricks in the book, was faced with Darth Vaders, Robin Hoods, scary monsters and also ladies dressed in elegant vintage dresses à la Louis XIV. This event would perhaps not have been the ITER Organization's first choice had it not been for the direct invitation from the festival organizers who, this year, wanted to build the bridge between dreaming of the past and imagining the future. Driven by the motto 'Demain—mais en mieux' (Tomorrow—but better) they docked an—imaginative—spaceship in the main hall in which some of the leading European science labs (the European Space Agency, the French National Centre for Scientific Research CNRS, Airbus, the French Alternative Energies and Atomic Energy Commission CEA and others) presented their fields of research. 'We know that the people who are passionate about history and the life and habits of ancient cultures are also curious about the future,' said Franck Barataud, festival organizer. And they were curious! Curious to learn all about fusion, its potential and the state of ITER construction at the ITER stand, and also to hear from ITER Director-General Bernard Bigot during the conference 'Aller toucher les étoiles' ('Let's go touch the stars') about his personal passion for science. Being a star chaser himself, or rather a chaser of the energy of stars, Bernard Bigot had been invited on stage with equally passionate researchers Nathalie Besson, from the CEA team that went in search for the famous Higgs Boson, and Pierre-Olivier Lagage, responsible for the French contribution to the James Webb Space Telescope. As interviewer Mathieu Vidard put it, all three are 'conquering unknown territory.' See the captivating ambiance of Yggdrasil in this short video.
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2022 Culham Summer School announced
The 59th Culham Plasma Physics Summer School will take place from 18 to 28 July 2022 at the Culham Science Centre in Oxfordshire (UK). The aim of the Summer School is to provide an introduction to the fundamental principles of plasma physics, together with a broad understanding of its fields of application. It assumes no previous knowledge of the subject, but familiarity with electromagnetism and applied mathematics at first degree level would be helpful. The 2022 school will cover fundamental plasma physics, as well as important topics in fusion, astrophysical, laser and low temperature plasmas. Lecturers are drawn from the Culham Centre for Fusion Energy (CCFE), the Rutherford Appleton Laboratory (RAL) together with leading European universities. All are renowned experts in their fields. Special arrangements are being made this year to allow for COVID. For more details and to apply visit the dedicated website. The deadline for applications is 20 June 2022.