In order to generate clean nuclear fusion energy, the sun's core needs to be simulated in a reactor. How do you ensure that this extreme environment does not damage the metals of the reactor wall? A team of researchers from the Netherlands and the United States are investigating whether a liquid wall is the solution to the problem.
The wall of future fusion energy reactors must be able to cope with a continuous bombardment of hot, fast atomic nuclei from the plasma. Whatever material is chosen, the wall will be damaged, leading to costly and time-consuming replacement. Scientists from FOM institute DIFFER together with a team from the University of Illinois are investigating a liquid reactor wall. The idea is that a liquid wall will refresh itself. Damage will then become a thing of the past.
Lithium flows automatically
In DIFFER's facility for plasma wall research, Magnum-PSI, scientists have tested whether they can construct the divertor of a fusion reactor from flowing liquid lithium. The experiment is called LiMIT. That is the acronym for Lithium Metal Infused Trenches. The lithium flows automatically through a series of trenches and hence the experiment's name.
Plasma remains clean
The experiments have revealed that the flow rate of the liquid lithium agrees with the theoretical predictions. It appears that the flowing lithium can dissipate the heat from the plasma beam. Furthermore, thanks to the trenches in the lithium container, far fewer drops arise than is the case for an open basin of liquid lithium. An associated advantage of this is that the plasma no longer becomes contaminated.