Of Interest archive

We have learned with profound sadness of the passing of Dr Yasuo Shimomura, who served as ITER Deputy Director from the beginning of the Engineering Design Activities (EDA) in 1992 until 2001. From 2001 until 2003 Dr Shimomura was ITER International Team Co-Leader, and from 2003 until 2005 he was ITER Interim Project Leader; during this last period he led the ITER team through the difficult transitional phase from the design activity to the start of construction in 2006.

A graduate of Osaka University, Dr Shimomura had a distinguished career in fusion research at the Japan Atomic Energy Research Institute, JAERI (now part of the National Institutes for Quantum and Radiological Science and Technology, QST). He was a leading figure in the construction and operation of the JFT-2a/DIVA tokamak, developing a reactor-relevant divertor concept that is currently being applied to ITER. He was also Leader of the JT-60 Experimental Planning and Analysis Group, and in 1986 was appointed as Head of the Large Tokamak Experiment Division at JAERI, with overall responsibility for the JT-60 tokamak. From 1988 he combined the leadership of the JT-60 device and its conversion to JT-60U with an appointment as Head of the Poloidal Field Design Group within the ITER Conceptual Design Activities (CDA). He was appointed ITER Deputy Director within the ITER EDA in July 1992, with responsibility for the design integration of the project. Dr Shimomura also held guest scientist positions at Princeton Plasma Physics Laboratory from 1976 to 1977 and at the Max-Planck-Institut für Plasmaphysik in Garching from 1981 to 1982.

Dr Shimomura will be remembered by his many friends and colleagues in the ITER community as a gifted physicist who contributed greatly to the project during an involvement spanning 20 years. He will be greatly missed by all who knew him and who benefitted from his leadership and guidance.

In ITER, six technological solutions for tritium breeding—in the form of test blanket modules plus associated ancillary systems—will be operated and tested for the first time. Their experimental validation will represent a major step for fusion development beyond ITER, when tritium fuel will necessarily have to be bred within the reactor.

In China, Europe, India, Japan and Korea these solutions are under development, with Russia and the United States contributing R&D and providing general support for the test blanket module program.

Europe is developing two types of test blanket modules, which consist of a steel box containing tritium breeders, neutron multiplier materials and heat extraction plates. Over the past two years, the European Domestic Agency and industrial partners have been manufacturing mockups of these boxes to test welding techniques. A preliminary welding procedure, employing a tungsten inert gas (TIG) welding robot to carry out the tasks within the limited space of the box, has been identified. The welding qualification cycle is expected to end within the next two years.

See the full article on the European Domestic Agency website.

Edmund Synakowski—the Associate Director of the US Department of Energy (DOE) Office of Fusion Energy Sciences and former ITER Council Vice-Chair—has been chosen as the University of Wyoming's vice president for research and economic development. Synakowski will also be a professor in the university's Department of Physics and Astronomy.

The role of the vice president for research and economic development is to support and facilitate the research efforts of University of Wyoming's faculty, staff and students; direct the university's research mission as a public research university; promote the university's research program with stakeholders; and direct technology transfer and commercialization efforts for the university's intellectual property.

Synakowski has held his current position, associate director of science in the Department of Energy, since 2009, administering a budget of about $400 million annually to develop nuclear fusion as an energy source. His agency supports research at more than 50 universities, eight national and two federal laboratories, and 15 industry groups.

He previously led the Fusion Energy Program at the Lawrence Livermore National Laboratory in California and held a number of roles at Princeton University's Plasma Physics Laboratory.

Read the full report on the University of Wyoming's website here.

At least 100 miniature cameras will be installed inside the ITER machine to act as the eyes for operators charged with machine maintenance.

Some of them will give a wide-angle view of the inside of the machine; others will be embedded on the robotic arms used for repairs. By receiving live image from the cameras, engineers hundreds of metres away will be able to operate maintenance and repair equipment with extreme accuracy.

The European Domestic Agency has been working with Oxford Technologies Limited (OTL) to develop and validate the different subsystems of the miniature cameras, which will have to operate within severe space constraints and often in an environment exposed to radiation. Subsystems developed by ISAE, France (image sensors); CEA, France (illumination system); and Jean Monnet University Saint Etienne, France (optic system) have been successfully tested over the past year at Belgium's SCK-CEN facility where they were exposed to different levels of gamma radiation.

The next step will be to develop a camera prototype.

Read the full story on the European Domestic Agency website.

To predict the impact of removing exhaust heat from the ITER Tokamak, researchers are calling on the Titan supercomputer at the Oak Ridge Leadership Computing Facility in the US.

Using the 27-petaflop behemoth, researchers based at Princeton Plasma Physics Laboratory (PPPL) are simulating the area where the plasma edge meets the divertor—the material structure engineered to remove exhaust heat from the vacuum vessel. Specifically, the team has evaluated the heat-flux width at the divertor, or the width of the material surface that might sustain the highest heat load.

Because the divertor directly faces the exhaust flow, it is bombarded with hot particles driven by electromagnetic fluctuations. In ITER, in order to withstand the highest surface heat load, the divertor will be made of the toughest element on Earth: tungsten.

"You don't want to start and stop ITER too often to replace this divertor material, so it has to be able to withstand the heat load," team leader C.S. Chang reports. "Ideally, we want the hot exhaust particles to hit the surface in a much wider area so that it's not damaged."

Based on simulations made possible by Titan's supercomputing capacity, Chang's team predicts that in ITER, due to the size of the plasma, edge plasma turbulence may spread heat across a larger area of the divertor surface and significantly increase the heat-flux width relative to current smaller-scale fusion devices.

Read the full report on research results at OLCF.

At the Swiss Plasma Center in Lausanne, Switzerland, the TCV tokamak was recently shut down for an upgrade of its Thomson scattering diagnostic. The operation was successful: shortly after commissioning the first measurements demonstrated greatly enhanced spatial and spectral resolution for the temperature and density profile measurements of TCV plasmas.

TCV is a variable configuration tokamak with highly specialized capabilities (plasma shaping, versatile electron cyclotron heating, measurement, control systems) for the exploration of the physics of magnetically confined plasmas.

See the full article on the EPFL/Swiss Plasma Center website.

Under contract with the European Domestic Agency, a team of experts has been working for more than a year to identify key technologies to perform the cutting and welding operations that will be required during the change-out of ITER divertor cassettes.

The technical constraints are enormous—the work (both cutting and welding) will have to be performed remotely, the operational space is severely limited, and no lubricant can be applied as ITER is a nuclear environment.

Experts from Assystem UK and the UKAEA robotics development laboratory RACE (for Remote Applications in Challenging Environments) have identified candidate techniques; now trials are underway and the search is on for the best tools to do the work remotely.

Read more on the European Domestic Agency website.

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.