Overview of the FIRE project: Advancing Liquid Metal Plasma-Facing Materials

While solids, such as tungsten, are the leading candidates for future plasma-facing component (PFC) materials, the power exhaust requirements for fusion energy systems far exceed present-day devices. Moreover, achieving high energy confinement with high-Z walls has proven challenging in present-day, large fusion experiments. Flowing liquid metals (LM) used as divertor/wall materials hold the promise of higher power exhaust capability than solid components. Also, LM offer the prospect of a self-healing wall from plasma-material interaction damage. Low-Z LM, particularly lithium, enable access to high energy confinement under optimized conditions. Research on LM technology for fusion energy systems is currently focused on design and deployment in test stands and fusion experiments for the advancement of Technical Readiness Levels (TRL). Through this FIRE Collaborative project, we will de-risk LM technologies by addressing specific scientific and technological gaps identified by a cohort of prospective private and public end-users. The gaps must be overcome to develop next-step integrated fusion test facilities and pilot plants. TRL gaps include: Integrated PFC Testing and Analysis, Material Properties, LM Flows in Magnetic Fields, and Novel LM Alloys. While most of the program focuses on liquid lithium, some R&D will be done using Galinstan (a gallium alloy) and novel alloys that can be used in low or high recycling scenarios. The R&D program objectives and initial results will be presented.