@article{9273,
  author = {J.D. Coburn and F. Effenberg and M.A. Cusentino and C.C. Hargrove and M. Ialovega and M. Morbey and L. Nuckols and Z. Popovic and Z. Bergstrom and S. Zamperini and T. Abrams},
  title = {Overview of advanced plasma-facing materials testing for Fusion Pilot Plants at DIII-D},
  abstract = {Characterization and testing of advanced plasma-facing materials (PFMs) for Fusion Pilot Plants (FPP) is being conducted at the DIII-D National Fusion Facility through the ongoing two-year FPP Candidate Materials Thrust. Year one tested 17 novel materials utilizing the Divertor Materials Evaluation System (DiMES), with samples analyzed pre- and post-experiment via SEM, EDS, and confocal microscopy. Repeatable reference discharges were developed to ensure uniformity between experiments, including a new strike-point rastering scenario to provide more uniform heat/particle flux across DiMES during ELMing H-mode discharges. Various sample geometries and temperatures were used to achieve FPP-relevant conditions, including samples angled 10° towards the incident plasma flux and pre-heating up to 500 °C. The first exposure of liquid lithium (Li) capillary porous structures in a tokamak demonstrated uniform emission of Li vapor and suppression of Li droplets in H-mode when preheated to 350 °C. Dispersoid-strengthened W with 1 wt% TaC, TiC, and ZrC exposed to H-mode showed cracking and dispersoid ejection for all varieties except TiC, providing a clear down-selection. Ultra-high temperature ceramic materials TiB2 and ZrB2 showed minimal degradation under L-mode exposure. Silicon carbide (SiC) fiber composites showed arcing along edges, while CVD SiC remained pristine. Atmospheric plasma-sprayed W and SiC coatings endured H-mode exposure without macroscopic delamination; SiC exhibited granular ejection, while W showed increased outgassing. Additional W-based alloys were stress tested in H-mode, including Ni-based W heavy alloys, WfSiCf/W composites, W multi-principle element alloys, and functionally-graded W/SiC, to varying degrees of success.},
  year = {2026},
  journal = {Nuclear Materials and Energy},
  volume = {46},
  pages = {102064},
  doi = {10.1016/j.nme.2026.102064},
  language = {eng},
}