Following particle paths in magnetic fusion experiments
he interior wall of a large magnetic-fusion experiment can take a beating:
As it circulates, plasma—an ionized gas that fuels fusion energy
production—attacks the reactor wall.
If too many wall particles slough off and join
the plasma, they poison the fusion reaction, says Assistant Professor
Dennis Whyte (pictured). Conversely, a
vigorous plasma could eat through the interior reactor wall. And most
critically, some of the radioactive tritium generated through fusion
fuel can embed in the reactor walls, creating safety issues.
“We need to answer those questions now
before we start building larger and larger devices where these problems
become more and more acute,” he says.
Using the tokamak at the DIII-D National Fusion
Facility, San Diego, Whyte and his collaborators will insert carbon-13-doped
methane in one reactor location, then discharge the plasma. Following
that first experimental phase, he will use his ion-beam to non-destructively
examine sections of the reactor wall and map where the carbon-13 and
other particles deposited in the wall. With that data, he hopes to develop
models to explain how turbulent transport carries these particles around.
Whyte is collaborating with researchers from
General Atomics, the University of Toronto, the University of California-San
Diego and Sandia National Laboratories.
The project is funded with a three-year, $450,000
grant from the Department of Energy and a nine-month, $35,000 grant
from General Atomics.