Numerical Analysis Supporting the Operation of an Open-Surface Fast-Flow Liquid Lithium Experiment for Divertor Cooling in Fusion Reactors

As fusion technology progresses toward the development of power-producing machines, the unresolved technical challenges are being addressed with a focus in technology readiness. The fusion plasma performance in tokamaks and stellarators benefit from low-recycling operation that can be achieved using liquid lithium on the first wall and the divertor. In addition, liquid lithium can help removing the intense heat flux at the divertor by creating a fast-flowing film on top of the solid substrate. In this framework, Tokamak Energy, through the DOE’s Milestone Program, developed a liquid lithium experiment at the University of Illinois Urbana-Champaign. The Hybrid Illinois Device for Research and Applications (HIDRA) will provide the skewed magnetic field that reproduces the fusion-relevant conditions to test the lithium film fast-flow mock-up. This paper summarizes the modeling activities performed by Oak Ridge National Laboratory and the University of Tennessee to support this experimental campaign. Our numerical parametric study using OpenFOAM informs the required conditions (flow rate and magnetic field intensity) to establish and sustain a successful fast flow of lithium in HIDRA.