Search

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.