Long-term use of lithium plasma-facing components (PFCs) cannot rely on the use of static liquid lithium. As lithium is a strong getter of fuel and impurity species, a stagnant surface will readily form an impurity layer which will diminish the benefits of the lithium surface. Therefore, a flowing system must be employed to keep the lithium surface free of impurities. The Actively Pumped Open-surface Lithium LOop (APOLLO) aims to demonstrate the technology for such a system on the lab scale.
APOLLO will consist of liquid lithium pumps, flowmeters, safety systems, and PFCs all with real-time response. Lithium is pumped from a reservoir into a vacuum system with an open-surface plate. This plate utilizes the Liquid Metal Infused Trench (LiMIT) concept to drive the liquid lithium flow using thermo-electric magnetohydrodynamics (TEMHD) when a heat flux is applied. APOLLO aims to demonstrate the technology readiness of liquid lithium components for use in larger scale devices.