Plasma experts improve detection method for wall erosion in fusion reactor
Researchers from FOM-Rijnhuizen have refined the calibration of the standard procedure to measure wall erosion in future fusion reactors. Ph.D. student Jeroen Westerhout discovered that the calibration technique yields much more signal at relatively low plasma temperatures (around 10,000 °C) than predicted by theory. The research results in a better calibration of the wall erosion, an important factor in the success of energy producing fusion experiments like ITER. They published their results in the journal Applied Physics Letters.
In a fusion reactor, strong magnetic fields keep the hot, charged fuel gas (a plasma) away from the reactor wall. This prevents heat loss and allows the fusion reaction between deuterium and tritium to sustain itself. To remove the fusion product helium, the plasma is transported to the wall of the divertor (the exhaust) of the reactor. Chemical reactions of the hot deuterium and tritium with the carbon wall of the divertor will lead to erosion.
Scientists look at the specific colors of light that are emitted by hydrocarbons to keep track of the deterioration of the wall. In comparable experiments, Jeroen Westerhout has measured up to one thousand times more light than expected from theory. He has explained this by taking into account the light that is emitted as a result of the chemical erosion reactions.
Read the APL-letter online:
http://link.aip.org/link/?APPLAB/95/151501/1
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