Tokamak Energy and the University of Illinois Urbana-Champaign have been awarded a $500,000 grant from the U.S. Department of Energy to collaborate on the development of liquid lithium systems. This is Tokamak Energy’s sixth INFUSE award, the largest INFUSE grant ever awarded so far and one of the first to involve a U.S. university, rather than a national laboratory.
The Center for Plasma-Material Interactions (CPMI) at the University of Illinois is the premier university-based lithium technology laboratory in the US. CPMI is developing novel divertor concepts that utilize flowing liquid lithium as a solution to the erosion and impurity accumulation challenges faced by solid divertors. Lithium is very effective at pumping deuterium and tritium and has been shown to improve plasma performance by enabling access to new operating regimes. This new work will add a plasma source to the lithium loop at CPMI to demonstrate that the proposed technology is indeed reactor relevant for fusion energy devices.
The low-recycling concept achieves higher plasma confinement times, higher core-electron temperatures, a more stable plasma and can lead to a much more affordable fusion-energy device. Existing work with Tokamak Energy seeks to create a reactor-compatible flowing-lithium-divertor plate for testing in the company’s latest spherical tokamak, the ST40. Earlier this year, the ST40 demonstrated a world first, achieving a plasma temperature of 100 million degrees Celsius, the threshold required for commercial fusion energy. This is, by far, the highest temperature ever achieved in a spherical tokamak and by any privately-funded tokamak.
A central question which has not yet been satisfactorily answered is: “How much tritium does liquid lithium pump and how quickly can the unburnt tritium be recovered from the liquid lithium?” This project aims quantifiably answer these questions, which are essential to answer for any fusion concepts which uses lithium. The final outcome will be a model of the fuel cycle within a tokamak fusion reactor, which will describe how much tritium is required on site and how quickly the unburnt tritium is recovered.
“We are delighted to receive our sixth - and largest - INFUSE grant from the US Department of Energy and particularly one that strengthens our collaboration with the University of Illinois,” David Kingham, Co-Founder & Executive Vice Chairman of Tokamak Energy, said. “This is further validation that the U.S. Government places great importance on the development of commercial fusion energy. This is vital research which can lead to higher performance and reduced cost of energy from compact spherical tokamak fusion power plants. As a result of this research, we are growing our teams in the US and UK working on lithium systems.”
“Tokamak Energy is a great partner,” David Ruzic, Abel Bliss Professor of Engineering at UIUC and Director of CPMI, said. “Their concept of a high-magnetic-field spherical torus with lithium walls is the leading concept that could make commercial fusion energy possible. The INFUSE grant will allow us to measure and then find solutions to the tritium recovery issue. This is a very important step in lithium fusion technology development and we are thrilled that the U.S. DOE is in full support of this effort.”