Of Interest archive

One of the big challenges in developing fusion energy is controlling the plasma. Disruptions of the burning plasma can halt the fusion reaction and damage the walls of the fusion device. Scientists therefore are keen to learn how to predict plasma disruptions.

Researchers at the Princeton Plasma Physics Laboratory (PPPL) employ artificial intelligence to improve predictive capability. They developed predictive software, the Fusion Recurrent Neural Network (FRNN) code, which is a form of what is called "deep learning"—a powerful version of modern machine-learning software. (Research team: William Tang, to the left; Eliot Feibush; and Alexey Svyatkovskiy, seated)

Drawing from data of the JET facility in the UK, the team has demonstrated the tool's ability to predict disruptions more accurately than previous methods. Turning their attention now to ITER, the team aims to improve the correct prediction of disruptions and reduce the number of false alarms.

The deep learning software is also a challenge for computing hardware. Several tests with the FRNN on modern powerful supercomputing devices, so-called GPU clusters, in the United States, Europe and Asia showed promising results.

Read the full article on the PPPL website.

At the joint meeting of the 26th International Toki Conference (ITC) and the 11th Asia Plasma and Fusion Association (APFA) conference—held from 5 to 8 December in Toki, Japan—ITER Science & Operations Department head David Campbell gave a plenary talk on ITER progress.

It was the occasion to recognize the many contributions of Dr Campbell to fusion research over the course of his career. The chair of the international program committee, Yutaka Kamada, and the chair of the international advisory committee, Yasuhiko Takeiri, both presented tributes. Dr Campbell retired in December from the ITER Organization.

The theme this year of the ITC meeting was "A new era in plasma and fusion research." The launch of deuterium experiments in Japan's Large Helical Device, and the first experimental results, were highlighted at the meeting, which also brought together academics and researchers from Japan, China, Korea and India in the context of the biennial APFA meeting. Three hundred participants in all took part in the four-day event. 

The UK's nuclear fusion research program can expect a big financial boost. A £86 million government investment—announced last week—will benefit the UK's Atomic Energy Authority's (UKAEA's) Culham Science Centre and its plan to build a National Fusion Technology Platform.

The platform will comprise two centres of excellence:

-        The Hydrogen-3 Advanced Technology (H3AT) centre to research how to process and store tritium;

-        The Fusion Technology Facilities to conduct tests on prototype components under conditions they would experience in future fusion reactors.

The new national fusion technology platform will open in 2020. It will enhance the UK's expertise in critical areas of fusion research and help British industry to secure contracts from ITER and other global fusion projects. It will also provide a powerful signal of the UK's intent to continue its participation in international science collaboration after leaving the European Union.

Taking a longer term view, the platform's two centres will help the UK to prepare the grounds for the first nuclear fusion power plants.

The Head of the UKAEA, Ian Chapman, said that this latest development means that: "...the UK will be at the forefront of developing fusion and bringing cleaner energy to the world."

Read the full article here.

The starting shot for the 2018 SOFT Innovation Prize has sounded. The prize is a feature of the Symposium on Fusion Technology (SOFT), a biennial conference organized by the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). It rewards outstanding researchers or companies who find new physics or technology solutions to address the challenges of fusion, with the potential of wider application.

The competition is open to researchers, research teams and companies from around the world. Anyone interested to enter the competition needs to apply through the Research and Innovation portal of the European Commission; the deadline for submissions is 8 March 2018. An independent jury of experts in technology transfer will select the three winners and the award ceremony will take place as part of the 30th SOFT conference taking place in Giardini Naxos, Sicily, Italy, from 17-21 September.

Last year's winners were awarded the prize for a novel type of high temperature superconductor cable based on REBCO tape material, a new membrane technology to produce ultra-pure hydrogen and a new virtual reality software technology to improve radioprotection.

SOFT is an important conference in the area of fusion technology and research in Europe. It attracts over 800 scientists, engineers, industry representatives and exhibitors from around the world.

Read the full article here.

Physicist François Ryter, of the Max Planck Institute for Plasma Physics (IPP) in Garching, Germany, has received the 2017 Nuclear Fusion Award.

The annual award recognizes exceptional work that has appeared in Nuclear Fusion, and that has had the greatest influence in the two years following publication.

Ryter was honoured for his 2014 paper on experiments in Garching's ASDEX Upgrade tokamak. "Delivering an outstanding piece of work on L—H transition physics, Ryter et al present a systematic and rigorous experimental study revealing the key role of the ion heat flux at the plasma edge. This explains the nonlinear dependence of the L—H threshold power on density and enables the derivation of a general expression for the density minimum. This is an important physics finding, with implications for ITER operation," the award panel announced.

See a full report on the IPP website.

"Few projects in the world combine such ambition, cutting-edge science and technology, and energy for future generations."

With these words Johannes Schwemmer, the Director of the European Domestic Agency, opened the 10-year anniversary celebration of Europe's involvement in ITER on 30 November.

European Commissioner for Climate Action and Energy, Miguel Arias Cañete, went on to highlight the human capital behind this one-of-kind project and praised "the work of so-many scientists and engineers, and the fact that countries, industries and research centres are working together to translate a common vision into a reality." The Mayor of the city of Barcelona, Ada Colau, explained that it was "an honour to host the European Agency and this was also proof of Barcelona's commitment to science and innovation." For Spain's Secretary of State for Research, Development and Innovation, Carmen Vela, ITER will "also open the door to the commercialization of fusion energy by laying the industrial foundations in each of its parties." 

View more on the event, as well as anniversary video clips, here.

The US Department of Energy (DOE) has awarded physicist Edmund Synakowski with its Meritorious Service Award. He received the honour "for strong and insightful leadership" during his eight years as Associate Director of the DOE's Office of Fusion Energy Sciences and for having "reshaped and improved the national fusion energy sciences program," administering an annual budget of about US $400 million to develop nuclear fusion as an energy source.

Synakowski is the new vice president for research and economic development of the University of Wyoming where the award ceremony took place on 29 November 2017. He previously led the fusion energy program at the Lawrence Livermore National Laboratory and held a number of roles at Princeton University's Plasma Physics Laboratory.

Synakowski is an expert in plasma physics and has authored over 160 peer-reviewed articles on plasma fusion science.

Read the full article by the University of Wyoming here.

An unknown version of the famous Beatles song? No—a new way of exploring the experimental fusion device Wendelstein 7-X, located at the Max Planck Institute for Plasma Physics in Greifswald, Germany.

Similar to ITER, Wendelstein 7-X aims to replicate the process at work in the core of the Sun to develop a clean and abundant energy source. This fusion device of the stellarator variety celebrated its first plasma in December 2015.

Are you interested in having a peek inside an extraordinary feat of science and technology? Normally accessible to experts only, Wendelstein 7-X has now opened its virtual doors and invites the interested public to a 360-degree tour. You can look into every corner of the experimentation hall, climb into the plasma vessel itself and visit the beam duct or listen to scientists explain the intricacies of the device and present their work. Information panels provide further background on plasma, superconducting magnets, graphite cladding, divertors and much more.

Go to this address to take a tour on your PC, tablet or smartphone.

At the Dutch Institute for Fundamental Energy Research, DIFFER, scientists are working to accelerate the transition to a sustainable society.

In the latest edition of the newsletter EXPLORE, researchers report on the promise of liquid metal walls in fusion reactors, the possibility of vapour shielding, and the institute's strategic plan for 2017-2022, which maintains a strong focus on fusion energy and solar fuels.

Read the latest DIFFER newsletter here.

Plasma science is about to get a new online outlet. Aptly named Plasma, the cross-disciplinary scholarly journal will be a platform for all aspects of plasma science such as plasma physics, plasma chemistry and space plasma. Publication formats include research articles, reviews, short communications and letters.

The international, open-access and peer-reviewed scientific journal will be published quarterly by the Swiss online publisher MDPI. The first volume of the new journal is expected to come out in 2018.

David A. Gates, principal research physicist and Stellarator Physics Division Head at the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL), is the newly appointed editor-in-chief of the journal. Following his nomination Gates said: "I look forward to helping advance the international research arena in plasma science. This is an outstanding opportunity to help promote the research of a vital area of physics and to open the door to communicating that research to the global community."

Plasma is the fourth state of matter. It is a hot, electrically charged gas and the most abundant form of visible matter in the universe. Some 99 percent of the known universe is in plasma state. Plasma can also be found on Earth such as in lightning and fluorescent light bulbs.

Read more about the journal and its new editor-in-chief.

Representatives of the European Commission and delegates to the Council of the European Union responsible for science and research visited ITER on 20 November.

Their aim was to get first-hand information on the current status of the ITER Project to allow member states to respond to the Commission. Thirty-four delegates from 18 states plus Switzerland participated.

In a communication issued in June 2017, the Commission had requested support from the European Parliament and for a mandate from the Council of the European Union to approve—on behalf of Euratom—the new ITER Baseline, including the new schedule and the associated resource requirements.

The request was based on the Commission's positive assessment of the changes in the overall management of the ITER Project and the completion of important milestones in the preceding two years.

The Culham Centre for Fusion Energy (CCFE) in the United Kingdom, owned and operated by the UK Atomic Energy Authority (UKAEA), is home to two magnetic fusion experiments.

The European tokamak JET is currently getting ready for a run of experiments using the high-power fuel mixture of deuterium and tritium (DT), while the Mega Amp Spherical Tokamak (MAST) is nearing the end of an upgrade program (completion 2018) to investigate the super-X divertor—a magnetic configuration that spreads the heat loads at the divertor area of the machine.

MAST is about to undergo a baking operation in order to clean the interior surfaces of the vessel and enable the ultra-high vacuum required for operation. In this picture, the machine has been fitted with a thermal jacket, ready for baking at 160 °C.

Read more about the operation on the CCFE website.

Fourteen authors and one illustrator share their passion for fusion in special October issue of Fusion in Europe. The issue contains a variety of topics ranging from ITER, JET, Brexit, material science, the Lawson Criterion, plasma turbulence and the history of fusion research in Mexico.

What is also special about the issue is that most of the authors are students or young researchers from around the world. The newsletter is thus a window onto the views of the next generation of fusion professionals and enthusiasts.

Click here to view the full October issue of Fusion in Europe.

A major challenge in the development of fusion energy is maintaining the ultra-hot plasma of a fusion device in a steady state, or stable form. While superconductors can allow a fusion reactor to operate indefinitely, controlling the plasma with superconductors presents a challenge because engineering constraints limit their response time compared to the more energy consuming copper coils.

The slower pace makes it difficult to operate a stable discharge with the large plasma volume or extended vertical height required for producing fusion power. Exploration of this issue in a current superconducting device is particularly helpful for ITER, which will be operational in 2025.

At the leading edge of this control challenge is the Korea Superconducting Tokamak Advanced Research (KSTAR) device, one of the largest superconducting tokamaks in the world. Its superconductors are made of niobium and tin, the same conductor that is planned for use in ITER.

A team of US and Korean researchers, led by physicist Dennis Mueller (photo) of the Princeton Plasma Physics Laboratory (PPPL), has now sharply improved the stability of the elongated plasma in KSTAR, setting an example for how to address similar issues in other superconducting devices such as ITER. The successful control method, demonstrated this summer by Mueller and physicists from the National Fusion Research Institute (NFRI) in South Korea, which operates the tokamak, and General Atomics in San Diego, caps years of effort to control the vertical instability, which had allowed the plasma to bounce up and down in the 11-foot-high vacuum vessel.

See how they did it in the full article on the PPPL website.

It is inscribed in bold letters on the large poster that is affixed to the ITER Assembly Hall: harnessing fusion energy is akin to "bringing the power of the Sun to Earth."

And it is true: like the Sun, the ITER Tokamak will produce energy by fusing hydrogen nuclei into helium.

The fusion reaction in our machine, however, is not like that which occurs in Sun-like stars. Although the end product (helium) and the ingredients (hydrogen isotopes in one case, hydrogen in the other) are the same, the nature of the process is profoundly different.

In a recent article on the Forbes website astrophysicist Ethan Siegel explains how "hydrogen-fusing-into-helium makes up less than half of all nuclear reactions in our Sun," and how the nuclear physics in stellar bodies abounds in "strange, unearthly phenomena."

The inscription on the Assembly Hall remains nonetheless true. ITER is indeed "bringing the power of the Sun to Earth." It's just that stars and tokamaks have different ways of obtaining a similar result.

Click here to read the full Forbes.com article.

An international team of fusion experts working at the DIII-D National Fusion Facility in San Diego, California, has discovered a way to minimize the effects of a phenomenon that can decrease the performance of fusion reactors and even possibly cause damage to the device. This work shows that localized electron heating by microwaves is an effective tool for modifying Alfvén eigenmode activity in DIII-D and other devices worldwide.

Alfvén waves can cause redistribution or loss of the injected neutral beam ions that are needed to heat fusion devices and of the helium nuclei (alpha particles) produced by the fusion reaction that also contribute to the continued heating of the plasma. If left to grow unabated, the Alfvén waves can result in reduced performance and potentially damage vessel components.

Powerful microwave beams deposited near the location of so-called reversed shear Alfvén eigenmodes (RSAEs) are found to modify the wave activity significantly—in some cases completely removing the modes. Based on experiments run at the DIII-D tokamak, the team has arrived at a simple model that determines how to predictably minimize RSAEs by using microwaves to heat the electrons at particular points in the plasma.

Read the full report here.

-- Spectrograms showing the change in wave activity with and without microwave heating. With no heating (top), upward frequency sweeping RSAEs are observed. With heating near the wave location (bottom), no RSAEs are expected or observed. Adapted from: M.A. Van Zeeland, W.W. Heidbrink , S.E. Sharapov , D. Spong , A. Cappa, et.al., Nucl. Fusion 56, 112007 (2016).

An update on ITER has been published in the Autumn 2017 issue of Energy Focus, the flagship magazine of the UK-based Energy Industries Council.

Titled "Is Fusion the Fuel of the Future?" the article describes recent project performance, concerns about the effect of Brexit, and why it's all worth it.

You can read the article on line at Energy Focus (pp 46-47).

A new National Geographic series on renewable energy, called "Positive Energy," will be featuring the ITER Project in one of its upcoming episodes.

The episode will be viewable on the National Geographic Channel in Europe on Wednesday 1 November at 10:00 p.m. 

It has already been broadcast on the National Geographic Channel in Africa and China (25 October) and in the Americas (18 October).

See more on the "Positive Energy" website.

For hydrogen atoms to fuse into helium, the heat of the ultrahot plasma in the tokamak must be maintained. But, like boiling water, plasma has blobs (or bubbles) that percolate within the plasma edge, reducing the performance of the plasma by taking away heat that sustains the fusion reactions.

Now, scientists at the Princeton Plasma Physics Laboratory (PPPL) in the US have completed new simulations that could provide insight into how blobs at the plasma edge behave. The simulations, produced by a code called XGC1 developed by a national team based at PPPL, performed kinetic simulations of two different regions of the plasma edge simultaneously. This ability produces a more fundamental and fuller picture of how heat moves from plasma to the walls, potentially causing damage.

Blobs play an important role in the outward movement of particles in plasma. Blobs cause approximately 50 percent of the particle loss at the plasma edge, and researchers have observed blobs in a wide range of plasma devices, including tokamaks, figure-eight-shaped fusion devices known as stellarators, and linear machines. "The big picture is that blobs can pull energy and particles out of the plasma, and you don't want that," said PPPL physicist Michael Churchill, lead author of a paper describing the results in the journal Plasma Physics and Controlled Fusion. Churchill said. "You want to keep things confined."

Read more on the PPPL website.

-- Physicist Michael Churchill

Researchers led by the Princeton Plasma Physics Laboratory (PPPL) have proposed an innovative design to improve the ability of future fusion power plants to generate safe, clean and abundant energy in a steady state, or constant, manner. The design uses loops of liquid lithium to clean and recycle the tritium, the radioactive hydrogen isotope that fuels fusion reactions, and to protect the divertor plates from intense exhaust heat from the tokamak that contains the reactions.

"There are many challenges to developing fusion energy and the handling of heat on divertor plates is among them," said PPPL physicist Masa Ono, lead author of a paper about the design published in the journal Nuclear Fusion. "We wanted to see how we can protect the divertor plates and keep the fusion chamber clean."

The system that Ono and colleagues designed calls for pumping liquid lithium in and out of a tokamak, a type of magnetic fusion device, to maintain steady state operation while cleaning out dust and other impurities from the plasma and safeguarding the divertor. The lithium, a silvery metal that readily combines with other elements, would serve a number of functions, including protecting the divertor plates, capturing tritium for recycling, and removing dust and other unwanted elements.

Continue reading on the PPPL website.

-- Physicist Masa Ono of the Princeton Plasma Physics Laboratory.