First-Wall Heat Flux

The thermal energy per unit area impinging on the innermost surface of a fusion reactor's containment vessel. In compact fusion reactors, first-wall heat fluxfirst-wall heat fluxCFR can exceed 10 MW/m² — far higher than conventional tokamaks — due to the higher power density. Managing this heat load is one of the primary engineering challenges in CFR design, requiring advanced materials like Mondaloy superalloys or tungsten coatings.