Creating First-Wall Materials That Can Resist High-Energy Neutron Damage

The first wall is the innermost boundary facing a fusion plasma, and no material yet does everything asked of it. Tungsten leads on heat handling but can embrittle under neutron damage, while steels, vanadium alloys, silicon-carbide composites, and ultra-high-temperature ceramics each trade one strength for another. A newer approach abandons the solid surface entirely in favor of flowing liquid metal. ITER has switched from beryllium to tungsten in its revised baseline, European suppliers have opened series-production lines, and Germany’s DINERWA project is developing next-generation alloys for high-heat-flux testing. Yet no fusion first wall has established a commercial operating record, and that gap, between industrialization and a bankable power plant, is where the real question sits.