Of Interest archive

The steel, the pipes, the tangle of cables and wires ... to sum it looks confusingly technological—but to others it's inspiring!

UK artist Sarah Moncrieff specialises in urban scenes and industrial interiors. She first heard of JET, the European fusion research experiment hosted at the Culham Centre for Fusion Energy (CCFE), via a friend who works at the site.

"He thought, quite accurately, that I would be interested in it as a subject for my painting. What I hadn't anticipated was how much I would become interested in the work that is done at Culham. The work is fascinating and the sense of seeing something at the forefront of scientific progress was thrilling for me. I know that excitement informed my paintings."

Sarah's paintings of JET were recently exposed at an on-site Open Day, to popular acclaim. You can see more of Sarah's work on her website.

Read the full article at CCFE.

After celebrating its First Plasma in December 2016, the WEST tokamak (for W Environment in Steady-state Tokamak) was reopened for the installation of two modified LHCD antennas for plasma heating (through lower hybrid current drive), then plasma operations restarted in April 2017.

Although plasma breakdown was routinely achieved, the ramping up of the plasma current was found to be difficult due to induced currents in the passive structures that have been introduced inside the vacuum vessel to produce the divertor configuration.

In effect, the WEST test platform is a modification of the Tore Supra tokamak at the Institute for Magnetic Research (CEA Cadarache, France) that introduces an actively cooled tungsten divertor. The machine has been considerably altered, with a "welcoming structure" for the new divertor, new in-vessel coils, new diagnostics, and adaptations to the heating, fuelling and cooling systems.

The vessel has been reopened to address stray magnetic field compensation through modification of the divertor baffle and a reduction in its electric conductivity to limit induced current. Experiments are expected to resume by the end of June.

Read more in the lastest WEST Newsletter.

For fusion to generate substantial energy, the ultra-hot plasma that fuels fusion reactions must remain stable and kept from cooling. Researchers have recently shown lithium, a soft, silver-white metal, to be effective in both respects during path-setting US-Chinese experiments on the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, China.

Seven US researchers traveled to EAST in December, 2016, to participate in the experiments. They deployed lithium in the Chinese tokamak in three different ways: through a lithium powder injector, a lithium granule injector, and a flowing liquid lithium limiter (FLiLi) that delivered the element in liquid form to the edge of EAST plasmas. Good results were shown by all three techniques.

Leading the US collaboration is the US Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), together with co-principal investigators Los Alamos and Oak Ridge National Laboratories, with Johns Hopkins University, the University of Illinois at Urbana-Champaign, the University of Tennessee-Knoxville, and the Massachusetts Institute of Technology. Scientists from General Atomics also participate via a separate grant.

-- John Greenwald, PPPL

See the full report on the PPPL website.

It is with great regret that the ITER community has learned of the sudden passing of Professor Predhiman Krishan Kaw on 18 June.

Professor Kaw was a well-known and highly respected plasma physicist, author of over 380 research publications in scientific journals. He was the founding director of the Institute for Plasma Research in Gujarat, India, which he led from 1986 to 2012. Named Year of Science Chair by the Indian Department of Science & Technology (DST), Professor Kaw continued to be active in research and in the mentoring and training of the younger generation of plasma physicists as DST Professor at the Institute for Plasma Research.

Professor Kaw was also the first Chair of the ITER Council Science and Technology Advisory Committee (STAC), leading the committee's deliberations from 2007 to 2009, and a regular participant to ITER Council meetings as Representative of India.

For his outstanding contributions to experimental and/or theoretical research in fundamental plasma physics and plasma applications, he was awarded the prestigious Padma Shri award (India's fourth highest honour) in 1985; the Shanti Swarup Bhatnagar Prize for Science and Technology in 1986; the World Academy of Sciences (TWAP) Prize in 2008; and the Subrahmanyan Chandrasekhar Prize of Plasma Physics in 2016 (see related article in Newsline).

See the Institute for Plasma Research website for more information.

Professor Predhiman Krishan Kaw (2nd from left) is seen here on 21 November 2014 at the inauguration of the Cryostat Workshop, where India is assembling the ITER cryostat. With him are the former ITER Director-General Osamu Motojima; M.V. Kotwal, president of Larsen & Toubro's Heavy Engineering Division; and Shishir P. Deshpande, Head of the Indian Domestic Agency.

The Culham Centre for Fusion Energy (CCFE) in the UK is looking for people in the fusion community who could benefit from its new cloud-based computing facility, which has a capacity to crunch data that could help researchers and promote collaborative projects. 

The CUMULUS Modular Data Centre, which opened in May, propels CCFE into the next era of supercomputing. With a total of 1128 cores, 18 terabytes of RAM and 170 TB of high performance storage—and the capacity to grow in sync with CCFE's need for computing power—the cloud-base system is also open to users across the international fusion community.

Interested parties should contact Rob Akers at @email.

Lithium compounds improve plasma performance in fusion devices just as well as pure lithium does, a team of physicists at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) has found.

The research was conducted by former Princeton University physics graduate student Matt Lucia under the guidance of Robert Kaita, principal research physicist at PPPL and one of Lucia's thesis advisors, as well as the team of scientists working on a machine known as the Lithium Tokamak Experiment (LTX).

Lucia used a new device known as the materials analysis and particle probe (MAPP), invented at the University of Illinois at Urbana-Champaign and installed on LTX. The MAPP system lets scientists withdraw samples into a chamber connected to LTX and study them without compromising LTX's vacuum environment. MAPP lets scientists analyze how tokamak plasmas affect a material immediately after the experiment ends. In the past, scientists could only study samples after the machine had been shut down for maintenance; at that point, the vacuum had been broken and the samples had been exposed to many experiments, as well as to air.

Lucia used the evaporation technique to coat a piece of metal with lithium, and then used MAPP to expose the metal to plasma within LTX. As he expected, Lucia observed lithium oxide, which forms when lithium reacts with residual oxygen in LTX's vacuum chamber. He was surprised, however, to find that the compound was just as capable of absorbing deuterium as pure lithium was.

"Matt discovered that even after the lithium coating was allowed to sit on the plasma-facing components within LTX and oxidize, it still was able to bind hydrogen," said Kaita.

Lucia's results are the first direct evidence that lithium oxide forms on tokamak walls and that it retains hydrogen isotopes as well as pure lithium does. They support the observation that lithium oxide can form on both graphite, like the tiles in NSTX, and on metal, and improve plasma performance.

Read the full article by Raphael Rosen on the PPPL website.

-- Physicists Robert Kaita and Michael Jaworski in front of another PPPL fusion device, the NSTX-Upgrade.

In the context of its Roadmap to the realization of fusion electricity EUROfusion, the European Consortium for the Development of Fusion Energy, has identified a number of crucial technical challenges that must be addressed through advanced research.

One of these is finding a viable solution for the heat exhaust in a future fusion reactor, considering that the divertor strategy planned for ITER cannot be extrapolated to a larger, steady-state facility.

Late 2015, EUROfusion called for proposals on plasma exhaust projects, which an independent panel of experts evaluated. The call, termed Plasma Exhaust (PEX) Assessment, received ten proposals that covered conventional and alternative divertors, as well as conventional materials and plasma-facing units as well as advanced materials.

EUROfusion selected six projects for receiving support. These include: ASDEX Upgrade at the Max Planck Institute of Plasma Physics, Garching (Germany); Forschungszentrum Jülich (Germany); Jozef Stefan Institute (Slovenia); MAST-Upgrade, (United Kingdom); TCV at the Swiss Plasma Center (Switzerland); and WEST at CEA (France).

Read the full article at EUROfusion here.

--Photo of the JET tokamak courtesy EUROfusion

After the success of the first fusion writers' edition of Fusion in Europe last year, the magazine is again looking for ambitious volunteer writers for the 2017 autumn issue.

Fusion in Europe is the regular publication of EUROfusion, the European Consortium for the Development of Fusion Energy, which manages European fusion research activitites on behalf of Euratom.

Applicants should be enthusiastic and ambitious, with ideas about how to share the promise of fusion with the world. The deadline is 21 June. For more information, please visit this link.