DIFFER group leader Thomas Morgan has won a prestigious Vidi grant to investigate the concept of liquid metal layers to protect the walls of future fusion power plants. Liquid metals are exciting as a wall design because they can repair and even shield themselves from the harsh conditions in such an artificial star. Developing robust reactor walls is one of the main challenges in the international quest for clean, safe and abundant fusion energy.
Surface of the sun
Fusion researchers want to generate energy from the same process powering the sun and stars. This places enormous demands on the reactor walls. The exhaust or divertor of the reactor will have to withstand heat loads and particle bombardments like those at the surface of the sun. "In the ITER experiment which wil begin operation in 2025, we will reach the limits of our best materials such as solid tungsten", says Thomas Morgan. The power plants after ITER will need even sturdier designs, that can hold out for months or years between maintenance.
Morgan: "In this project we will test the idea of a protective layer of liquid metal flowing over the divertor wall. The idea is that you can constantly replenish that layer to counter erosion. Even better, the vapour cloud that will form above it will absorb part of the incoming heat before it can reach the surface."
Thomas Morgan and his team will use DIFFER's facility Magnum-PSI to test the performance of liquid metals such as tin or lithium under the same conditions as expected in ITER. Although ITER has already decided to install a tungsten divertor, the design of demonstration power plants (DEMO) is ongoing. "It would be wonderful if we could deliver a self-repairing wall and bring fusion closer."
The Vidi grant of the Dutch Research Council NWO gives mid-career scientists the opportunity to start their own research group on an innovative topic. The 800,000 Euro grant has a runtime of five years. Thomas Morgan will use the grant to appoint two PhD students and one post-doc researcher. DIFFER will support his research project with an additional investment of 200,000 Euro.