Lithium as a plasma facing component to optimize the edge plasma

The use of lithium to coat plasma-facing components (PFCs) or serve directly as liquid PFCs has resulted in energy confinement improvement in several devices. Coupled with the demonstrated ability of liquid Li to exhaust high power fluxes, the use of Li could resolve the two leading problems of high-Z PFCs. The effect of Li in NSTX, EAST, and DIII-D is compared, and common features are identified. A compact spherical tokamak-based Fusion Nuclear Science Facility design could deliver an attractive neutral wall loading for materials testing, with Li PFCs enabling access to the required high confinement scenarios.