Nuclear fusion could be an ideal solution to mankind's energy problem, guaranteeing a virtually limitless source of power without greenhouse gas emissions. But there are still huge technological challenges to overcome before getting there, and some of them have to do with materials.
Fusion reactors need materials that can be used at the interface with plasma, in conditions that are nothing short of extreme. The design of the experimental European reactor ITER being built in the south of France, in particular, includes a component called a divertor, which extracts heat and ash produced by the fusion reaction and directs the flow of heat and particles from the plasma to specific surfaces for cooling. On the divertor, the plasma-facing materials not only withstand extremely high temperatures, but are constantly bombarded by a flux of neutrons, electrons, charged ions and high-energy radiation.
In the design for the ITER project, the divertor is made of tungsten, a metal known for its excellent heat resistance. But alternatives such as carbon fibers or ceramic materials were considered in the past, and it is still not certain whether for future reactors, tungsten would really be the best option.
Can theory and computation methods help the search for the best divertor material and thus contribute to making fusion a reality? Scientists in Nicola Marzari's MARVEL laboratory at EPFL decided to answer the question, and in a new article in PRX Energy they present a method for a large-scale screening of potential plasma-facing materials, and a shortlist of the most promising ones.
To read more, click here.