7 July 2022, Oxford, UK – Tokamak Energy and the University of Illinois have been awarded a US$500,000 grant from the US Department of Energy to collaborate on the development of liquid lithium systems for spherical tokamak devices. This is Tokamak Energy’s sixth INFUSE award, the largest INFUSE grant ever awarded so far and one of the first to involve a US university, rather than a National Laboratory.
The Center for Plasma Material Interactions (CPMI) at the University of Illinois at Urbana Champaign is the premier university-based lithium technology laboratory in the US. CPMI are 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 continuous plasma source and a lithium distillation column to the lithium loop at CPMI to demonstrate that the proposed technology is relevant for spherical tokamak fusion reactors.
The low-hydrogenic-recycling concept aims to achieve higher plasma confinement times, higher core-electron temperatures, a more stable plasma and enable a low-cost fusion reactor. Existing collaboration work being undertaken by the parties seeks to create a reactor-compatible, flowing-lithium-divertor plate for testing in Tokamak Energy’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.
Central questions which will be addressed are: how much tritium does liquid lithium pump and how quickly can unburnt tritium be recovered from the liquid lithium? These questions are essential for any fusion concept which uses lithium. The outcome will inform a model of the fuel cycle within a tokamak fusion reactor, which will describe how much tritium is required and how quickly unburnt tritium may be recovered.
David Kingham, Co-Founder & Executive Vice Chairman of Tokamak Energy, said:
“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. This is further validation that the US 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 reactors. As a result of this research, we are growing our teams in the US and UK working on lithium systems.”
David Ruzic, Able Bliss Professor at Illinois and Director of CPMI, said:
“Tokamak Energy is a great partner. Their concept of a high-magnetic-field spherical tokamak is the leading concept that could make commercial fusion energy possible. The addition of lithium plasma facing technologies has the potential to make this solution even more attractive. 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 US DOE is in full support of this effort.”