Lithium Alloy Creation for the Advancement of Liquid Metal Plasma Facing Components

The interest in using liquid lithium as a plasma facing component (PFC) in fusion reactors has grown in recent years due to the PFC’s self-healing surface, and low hydrogen recycling. However, the liquid PFC is hindered by its relatively high vapor pressure (about 1Pa at 800K). This hinderance introduces relatively high Z material into the bulk plasma, potentially decreasing the reactor’s efficiency. Yet, this decrease may be mitigated by using a lithium alloy: such as tin lithium. With liquid tin’s substantially lower vapor pressure (about 10nPa at 800K), these alloys may limit the vapor pressure of the liquid PFC while keeping the benefits of liquid lithium.

The goal of this work is to further characterize lithium alloys through constructing a chamber and method that produces consistent alloys, specifically focusing on tin lithium and lead lithium. A computer will be the primary control for the process to ensure sample consistency. To further improve the consistency, a load lock system will protect the samples in an inert argon atmosphere as they are moved between the chamber and storage. Initial characterization of the alloys will include measurements of vapor pressure using Knudsen effusion, wetting contact, and alloy composition.