Advancing Plasma-Facing Materials for Fusion Pilot Plants at DIII-D

Characterization of advanced plasma-facing materials (PFMs) for Fusion Pilot Plants (FPP) has revealed superior morphology (low surface defects, high density), compositional stability, and thermal properties compared to PFMs previously tested at DIII-D. The improved materials include tungsten (W) (alloys, fibers, dispersoids, micro-structured), W capillary porous structures (CPS) with liquid lithium, thermal and cold-spray W coatings, ultra-high temperature ceramics (UHTCs) and SiC (CVD, coatings, fibers), analyzed via SEM, EDS, and confocal microscopy.

These PFMs will undergo exposures in the DIII-D tokamak to test their response to an integrated, reactor-like environment in upcoming campaigns. The tests will be coordinated through a two-year “FPP Candidate Materials Thrust” at DIII-D, allowing for down-selection of the most promising PFMs. Tests aim to quantify erosion rates, fuel retention, and material integrity under L- and H-mode conditions, leveraging DIII-D’s diagnostic and divertor exposure capabilities. This thrust will integrate materials from private and public institutions, advancing the Technological Readiness Level (TRL) of promising PFMs.