Of Interest archive

The table turns slowly as strips of composite material are wound into a perfect ring. One hundred sixty-four turns later, the 3.4-tonne component, with an internal diameter of 5 metres, is ready for bonding, compression, curing, dry machining, inspection and testing.

These are ITER's pre-compression rings, a set of nine composite rings that will support the toroidal field magnet superstructure in the face of huge electromagnetic forces during operation. Encircling the tips of the coil structures at top and bottom, two sets of three rings will "push back" with a centripetal force of thousands of tonnes, suppressing any coil deflection and greatly reducing cyclic fatigue stresses.

The European Domestic Agency is working with principal contractor CNIM (Toulon, France) for the procurement of nine pre-compression rings (six, plus three spares). The raw material—pultrude laminate—is being procured by the European agency from the Finnish company Exel, while the equipment for last-phase testing was built under an ITER Organization contract awarded to Douce Hydro (France) in collaboration with CNIM. 

Production techniques and processes were validated during lengthy prototyping and qualification phases, and series production is underway now.

Visit the European Domestic Agency website to see a video of the production process.  

In advance of the June G20 Summit in Osaka, Japan, Prime Minister Shinzo Abe and French President Emmanuel Macron held bilateral talks that resulted in the release of a five-year cooperation plan. Notably, ITER was one of the items on the agenda.

The plan provides a roadmap for partnership in the fields of maritime security, infrastructure development, global trade, space, cyberspace, cultural and scientific exchange, and the environment.

In Chapter IV (page 5-6), the two countries pledge to reinforce economic partnership with a particular emphasis on innovation—including ways of transitioning to energy systems that are low-carbon or carbon-neutral, affordable and stable. ITER makes that list, as well as the European-Japanese activities of the Broader Approach (advanced fusion energy research taking place in Japan).

Download the roadmap in Japanese or French

Superconductivity is a miracle of physics: when cooled down to temperatures close to absolute zero, certain alloys, or compounds, cease to oppose resistance to the passage of electricity. In electromagnets made of superconducting coils like ITER's, electrical consumption drops to zero and, as an added advantage, no heat is generated inside the magnets.

Magnet cooling, however, requires a vast quantity of energy. Cooling fluids must be circulated through the entire length of the superconducting coils which, at ITER, means maintaining a forced flow of 25 tonnes of liquid helium at 4 K (minus 269 °C) throughout approximately 180 kilometres (and 10,000 tonnes) of conductor.

For many years, research worldwide has struggled to develop materials that would transition to the superconducting state at less frigid temperatures—so-called "high-temperature" superconductors.

Used in electromagnets, these "high-temperature" superconductors would allow the production of more powerful magnetic fields, passing the present limitation of low-temperature conductors (At its maximum in the centre of the ITER central solenoid, the magnetic field has an intensity of 13 Tesla.)

The National High Magnetic Field Laboratory in Tallahassee, Florida, recently announced an important breakthrough in the quest for "high-temperature" superconductors: the manufacturing and testing of a half-pint "little big coil" that operated inside the bore of large outer copper coil in a background field of approximately 30 T, itself generating an additional 14.4 T, thus generating a combined record magnetic field of 45.5 Tesla in its (small) bore. This experiment demonstrated the capability of high temperature superconductors to operate in very high magnetic fields under large stresses. This could open the way to a new generation of magnets for biomedical research and fusion reactors.

 More information on the National High Magnetic Field Laboratory website and in this month's issue of Nature.

Every two years, the Festival de Théorie aims to promote interactions between PhD students, postdocs and young scientists in fusion plasma physics and related fields including astrophysics, fluid mechanics and geophysics.

Many of the principles governing the turbulence and magneto-hydrodynamic phenomena observed in fusion plasmas are similar to those found in naturally occurring astrophysical plasmas in the Sun. Fluid mechanics and planetary atmospheric physics also share common threads, reporting observations that often reflect the experimental measurements taken in tokamaks. This is where the Festival de Théorie comes in, fostering cross-disciplinary collaboration and providing an invaluable forum for tackling some of the key issues posed by ITER.

The theme selected this year is: Phase Dynamics. The 2019 program is organized around four weeks of study and research in collaboration with a core group of prominent scientists. Participants begin with two weeks of seminars and lectures, followed by research projects in weeks 3 and 4 on topics spanning plasma physics, fluid dynamics, astrophysics, and applied mathematics.

The 10th edition of the Festival de Théorie will take place in Aix-en-Provence, France, from 1 to 26 July 2019. Registration is open now.

The US Department of Energy (DOE) has announced the launch of INFUSE, a program created to encourage partnerships in fusion research between industry and DOE national laboratories.

The Innovation Network for Fusion Energy (INFUSE) will select a number of projects for awards between $50,000 and $200,000 each, with a 20 percent project cost share for industry partners. Of particular focus will be "enabling technologies" that could contribute to accelerating the development of fusion energy such as new and improved superconducting magnets, materials science, diagnostics, modelling and simulation, and experimental capabilities.

DOE's Oak Ridge National Laboratory (ORNL) will manage the new program with the Princeton Plasma Physics Laboratory (PPPL). ORNL's Dennis Youchison, a fusion engineer with extensive experience in plasma-facing components, will serve as director, and PPPL's Ahmed Diallo, a physicist with expertise in laser diagnostics, will serve as deputy director.

"I am excited about the potential of INFUSE and believe this step will instill a new vitality to the entire fusion community," says Youchison in the DOE press release. "With growing interest in developing cost-effective sources of fusion energy, INFUSE will help focus current research. Multiple private companies in the United States are pursuing fusion energy systems, and we want to contribute scientific solutions that help make fusion a reality."

The first call for proposals has been issued (deadline 30 June).

See the 4 June press release and the INFUSE website.

Fusion is the star of a recent Babbage podcast from The Economist, which aired on 5 June 2019. In "Fusing the future—a power struggle," science correspondent Alok Jha investigates the technology "that could solve all of the world's energy problems in a stroke."

Moving from the ITER Project—the "world's make or break fusion experiment"—to private startups, he investigates how close we are to the long-promised dream of nuclear fusion. Featuring interviews with Bernard Bigot, Director-General of the ITER Organization; Stephen Dean, Fusion Power Associates (US); Melanie Windridge, plasma physicist and author; Nicholas Hawker, CEO of First Light Fusion (UK); and David King, Executive Vice Chairman of Tokamak Energy (UK).

Listen here (runtime: 20 minutes).

High above the concrete fortress that will house the ITER Tokamak, a steel lattice of pillars and beams will soon rise to complete the structure—both providing a roof (once covered over with cladding) and providing sheltered manoeuvring room for the heavy assembly cranes that will be travelling back and forth from the Assembly Hall carrying components.

Twenty steel pillars (ten on either side) will support the roof structure as well as resist the tremendous forces exerted by the movement of the bridge cranes.

The lower segments of the pillars (see photo) will be directly anchored in the concrete of the Tokamak Building, either on concrete columns or on weight-bearing "brackets" called corbels. The rest of the roof structure will be assembled in five modules on the ground and lifted into place by crane.

The roof of the Tokamak Building will weigh approximately 2,000 tonnes.

Read the full story on the Fusion for Energy website.

Researchers from the MIT Plasma Science and Fusion Center, PSFC, and the University of Texas at Austin have had promising results in terms of plasma stability in experiments with "negative triangularity" on the DIII-D tokamak; that is, with reversing the conventional shape of the plasma in the tokamak chamber.

In results published recently in Physical Review Letters and Physics of Plasmas, researchers Alessandro Marinoni (MIT) and Max Austin (UT Austin) discovered evidence that reversing the conventional shape of the plasma in the tokamak chamber can create a more stable environment for fusion to occur, even under high pressure.

Marinoni and colleagues are planning future experiments to further demonstrate the potential of this approach in an even more fusion-power relevant magnetic topology, based on a "diverted" tokamak concept.

Read more on the subject on the PFSC website.

At ITER's Neutral Beam Test Facility, one testbed has been launched and another is in the procurement/assembly phase.

SPIDER—the ITER-scale negative ion source—turned on last year. Experiments on MITICA—a full-size prototype of ITER's 1 MV heating neutral beam injectors—are scheduled beginning 2022. Procurement is underway in Europe on the beam source and at Consorzio RFX in Padua, Italy, work is underway to install auxiliary components and systems.

In May, the first part of the MITICA beam source vacuum vessel was installed (photo). This stainless steel component was procured by the European Domestic Agency, Fusion for Energy, as a voluntary contribution to the ITER neutral beam development program.

See more about the manufacturing of the vessel here.

See more about the Neutral Beam Test Facility at Consorzio RFX here.

Physics of Plasmas (American Institute of Physics) has published a paper on research carried out under a collaboration between the Eindhoven Technical University (TU/e, Netherlands) and the ITER Organization.

"Kinetic modeling of ELM-induced tungsten transport in a tokamak plasma" (D. C. van Vugt, G. T. A. Huijsmans, M. Hoelzl, A. Loarte, et al) describes the role of edge-localized modes (ELMs) in exhausting tungsten impurities from the core plasma of tokamaks to ensure that their concentration remains low.

The collaboration modelled tungsten impurity behaviour and power fluxes to plasma-facing components during controlled ELMs in ITER with advanced modelling by the JOREK code, which required specific upgrades to the code to include the necessary plasma-wall interaction and impurity transport processes.

The authors write: "This publication shows that the role of ELMs in cleaning up the plasma from tungsten eroded at the divertor in ITER can be opposite to that in present experiments, particularly when we approach the conditions required for high fusion energy production gain. This implies that the use of the ELM control coils, included in the ITER baseline design to modify ELM behaviour and eventually suppress ELMs, will be required not only for the control of power fluxes to the divertor but also to exhaust the eroded tungsten from the confined plasma to keep it clean."

Read the complete article on the TU/e website here.

In his time at DIFFER (the Dutch Institute for Fundamental Energy Research) and the Swiss Plasma Center, fusion researcher Wouter Vijvers developed a novel imaging diagnostic known as MANTIS (Multispectral Advanced Narrowband Tokamak Imaging System).

Today, as CEO of the fusion spin-off Chromodynamics, he is hoping to use his real-time imaging technique in applications such as medical diagnosis and industrial quality and process control.

Imagine if a surgeon removing a malignant tumour from a patient could precisely see the contours of the tumour while operating. "Healthy tissues and malignant tissues have different chemical profiles, and this difference is what multispectral imaging will be able to capture and show," he explains. "Combine that with real-time capabilities, and a surgeon could see the image of the malignant tissue while operating to ensure complete removal."

In the meantime, Vijvers is still using his technology to study the plasma edge. In a Cooperation Agreement signed in February with the ITER Organization, Chromodynamics is joining Dutch research institutes TNO and DIFFER as well as Active Space Technologies (Europe) to develop a diagnostic tool capable of measuring the impurity content of the plasma.

See the full article on the EUROfusion website.

Lithium, the light silvery metal used in everything from pharmaceutical applications to the batteries that power your smartphone or electric car, could also help harness fusion energy on Earth. Lithium can maintain the heat and protect the tokamak vessel walls, and it will be used to produce tritium, the hydrogen isotope that will combine with deuterium to fuel fusion.

At the Princeton Plasma Physics Laboratory (PPPL) in the US, researchers have completed a three-year upgrade of the Lithium Tokamak Experiment, now called the Lithium Tokamak Experiment-Beta. This unique device will be able to test the ability of lithium to maintain the heat and protect the walls of the tokamak.

Photo: Interior view of the Lithium Tokamak Experiment prior to the upgrade.

See plans for the machine on the PPPL website.

Vigyan Samagam, the first-ever mega-science exhibition on show in India, starts its ten-month multi-venue tour at the Nehru Science Centre in Mumbai on 8 May. The aim is to bring mega-science closer to society and raise awareness and enthusiasm—especially among the younger generations, inspiring them to consider science and research as formidable career options.

The exhibition will allow visitors to get first-hand impressions of the big science projects that are redefining the boundaries of human knowledge for the benefit of all, and in which India is participating. ITER is one of the seven projects featured (with CERN, the Facility for Antiproton and Ion Research (FAIR), the India-based Neutrino Observatory (INO), the Laser Interferometer Gravitational Wave Observatory (LIGO), the Square Kilometre Array (SKA), and the Thirty Meter Telescope (TMT) International Observatory).

After staying in Mumbai for the first two months, the exhibition will then travel to Bengaluru, Kolkata and Delhi.

For more information on the event, please click here.

The ITER neutral beam injectors will be first of a kind, operating at 1MV with negative ion beams up to 40A. As part of a risk mitigation strategy, the ITER Organization is testing key system components in advance of operation at the ITER Neutral Beam Test Facility in Padua, Italy. This facility, housed at the Consorzio RFX laboratory, is the only one in the world capable of demonstrating ITER heating neutral beam requirements simultaneously.

Experiments began last year on SPIDER, a full-scale negative ion source. A second testbed will come on line in 2022: MITICA, a full-scale prototype 1 MV injector that will allow scientists to test and optimize the beam source, accelerator, and beamline components.

Work is progressing on the assembly of the MITICA test bed now. Acceptance tests have been run on the high voltage power sources supplied by Europe and Japan (see this page for photos) and, recently, Europe delivered the vacuum chamber that will house the MITICA beam source (photo).

The 5-metre-tall, 67-tonne chamber was manufactured by De Pretto Industrie (Italy) under a contract signed with the European Domestic Agency Fusion for Energy.

See more about the component on the Fusion for Energy website.

-- Final acceptance tests underway on the MITICA vacuum vessel at De Pretto Industrie.

In this new photomontage by General Atomics and US ITER, watch how ITER's 1,000-tonne central electromagnet is fabricated in a specialized workshop in Poway, California. It takes approximately 22-24 months to manufacture one central solenoid module, and six are needed for the ITER machine (plus a seventh as a spare). © General Atomics/US ITER

Click here to see the video.

Funding has been secured for the Joint European Tokamak (JET) through the end of 2020, providing welcome visibility to the world's largest operating fusion research facility in the context of uncertainty surrounding Brexit.

The future of JET has been under discussion since 2017 as its work is covered by the Euratom Treaty, which the UK Government intends to leave as part of the process of leaving the European Union.

The new contract signed last week between the UK and the European Commission provides reassurance for over 500 staff at JET, including many from outside the UK. It also means JET can conduct a series of vital fusion tests planned for 2020 that will serve as a "dress rehearsal" for ITER.

JET is operated by the UK Atomic Energy Authority at the Culham Centre for Fusion Energy (CCFE). Scientists from 28 European countries use it to conduct research into fusion energy through work coordinated by the EUROfusion consortium, which manages and funds European fusion research activities on behalf of Euratom.

Ian Chapman, CEO of the UK Atomic Energy Authority, said: "The extension to the contract is excellent news for both European Union and UK science. JET has been a shining example of scientific cooperation between European Union members, and this news means that these mutually beneficial collaborations will continue, allowing us to do essential experiments on the path to delivering fusion power."

Tony Donné, Programme Manager of EUROfusion, added: "A heavy weight has been lifted off our shoulders. This is extraordinarily good news for EUROfusion and the European fusion community as a whole. We can now continue to work on the realization of fusion energy together with the indispensable experience of our British partner."

See the EUROfusion and CCFE websites for more on the funding news.

Physics and engineering students of European universities are invited to attend the 2019 Summer University at the Max Planck Institute for Plasma Physics (IPP) in Garching, Germany, from 16 to 20 September.

The IPP Summer University for Plasma Physics and Fusion Research is designed for those students who have completed their bachelor's degree, but who have not yet decided on a PhD topic.

Lectures are planned on plasma physics, plasma-wall interaction and materials research, ITER and the next steps toward fusion energy, and more. The course will include a tour of the ASDEX Upgrade tokamak experiment (pictured) and laboratories.

Sign up by 31 May here.

Fusion scientists keep looking for ways to address the challenge of plasma disruptions, which can halt fusion reactions and potentially damage the plasma-facing components of a fusion device.

Researchers at the Princeton Plasma Physics Laboratory (PPPL) and the University of Washington have developed a prototype device to control plasma disruptions. The electromagnetic particle injector, EPI, is a type of railgun that fires a high-velocity projectile, a sabot, from a pair of electrified rails into a plasma that is on the verge of disruption. The sabot releases light-metal pellets into the centre of the plasma that would spread out the energy of the disruption from the centre of the plasma to the edge, thus weakening its impact on the vessel walls.

The EPI can deliver the pellets more deeply into the plasma than other techniques. For physicist Roger Raman of the University of Washington, the primary advantage of the new device is "its potential to meet short-warning time scales." Pellets should be delivered in less than 20 milliseconds from the warning of a disruption, with 10 milliseconds as ideal. During tests, the EPI delivered pellets in less than 10 milliseconds. In comparison, the gas-propelled system needs 30 milliseconds.

Read the full article on the PPPL website, which includes a slow-motion video of an EPI shot.

(Photo by Elle Starkman)

The 56h Culham Plasma Physics Summer School is open to applications.

The school will cover fundamental plasma physics,  together with a broad understanding of its fields of application. No previous knowledge of the subject is expected, but familiarity with electromagnetism and applied mathematics at first degree level is recommended. 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.

For more details and to apply please visit: https://culhamsummerschool.org.uk/

Discount for early registrations before 15 May.

The deadline for applications is 25 May.

Researchers at the Los Alamos National Laboratory in the United States have developed thin films made of a tungsten alloy that could be used inside fusion reactors. The material, a nanocrystalline tungsten-tantalum-vanadium-chromium alloy, showed "outstanding radiation resistance when compared to pure nanocrystalline tungsten materials," said researcher Osman El Atawi in an article published in The Engineer.

The inside of a fusion reactor vessel faces the hot plasma and must withstand extremely high temperatures as well as bombardment by charged and neutral particles. Tungsten, which is currently considered the most suitable material to protect the inside of a vacuum vessel, tends to fracture after radiation, while the newly developed alloy material retains its mechanical properties.

Osman El Atawi (left) and Enrique Martinez collaborated with researchers from several scientific institutes in the United States, Poland and the United Kingdom. Their joint paper is published in Science Advances.