Spatially resolved evaluation of primary displacement damage and activation in the CFETR first-wall components

A spatially resolved computational workflow is proposed for coupled evaluation of neutron-induced primary knock-on atom (PKA) spectra, displacement damage, activation, and shutdown gamma dose rates in a representative CFETR first-wall configuration. The model consists of a tungsten armor layer and an RAFM steel structural layer with embedded cooling channels. An event-level FLUKA user routine was customized to record recoil nuclei and secondary light particles during transport, and a Python-based post-processing pipeline was developed to reduce the resulting data stream into regional PKA spectra, reaction-channel contributions, isotope-resolved damage components, and decay-dependent radiological fields. The PKA spectra and integral damage indicators were benchmarked against SPECTRA-PKA. The results show good agreement for the main recoil-energy domain and for short- to medium-term activation evolution. Spatial analysis reveals nearly uniform damage in the thin tungsten armor, whereas neutron attenuation and spectral softening in RAFM steel progressively suppress high-energy recoil production and shift the dominant damage mechanism toward elastic scattering. Damage decomposition further indicates that heavy transmutation products make a non-negligible contribution to DPA in RAFM steel, whereas H and He contribute little to stable lattice displacement despite their relevance to gas-induced swelling. The proposed workflow provides quantitative support for damage-source characterization, maintenance-dose assessment, and structural optimization of fusion first-wall components.