Liquid Lithium Loop for Open-Surface Flow on PFCs

Interest in liquid lithium as a plasma facing component (PFC) has significantly increased as of recent. This is likely due to lithium’s gettering abilities which can provide access to low recycling regimes, as well as its heat flux handling capabilites. At the University of Illinois, extensive research has been focused on liquid lithium PFC geometries, particularly with thermoelectrically driven flow (TEMHD), which have been shown to handle near 10 MW m⁻² of heat flux. A clean, flowing lithium surface will getter hydrogen and impurities from the plasma which then must be removed from the PFC. To provide a continuously refreshing surface, a loop system has been designed to provide lithium from an external reservoir, to the PFC, and removed. Components such as the lithium reservoir, liquid metal pumps, flow meters, and safety systems have been designed, constructed, and are being tested. Experimentally, the lithium will be pumped into the SLiDE device at the University of Illinois, where the lithium will flow across a PFC with a 3-D LiMIT style geometry in a variable magnetic field (up to 2000 G). Heat fluxes up to 15 MW m⁻² will be applied to the lithium plate via a linear electron beam. Separately, deuterium plasma exposure will be tested to verify hydrogenic species extraction in a fully circulating scenario. Results from the various loop component testing will be presented.