On the use of neutron tomography for morphological analysis of highly corroded Kofun-period iron weapon fragments supported by quantitative neutron diffraction analysis and X-ray-based techniques

Cantini, F.*; Ryan, J.*; Guidorzi, L.*; Magalini, M.*; Sans-Planell, O.*; Giudice, A. L.*; Garagiola, C.*; Re, A.*; Diana, E.*; 篠原 武尚*; 松本 吉弘*; Gong, W.   ; Harjo, S.   ; Grazzi, F.*

Cantini, F.*; Ryan, J.*; Guidorzi, L.*; Magalini, M.*; Sans-Planell, O.*; Giudice, A. L.*; Garagiola, C.*; Re, A.*; Diana, E.*; Shinohara, Takenao*; Matsumoto, Yoshihiro*; Gong, W.; Harjo, S.; Grazzi, F.*

Iron artifacts from Japan's Kofun period (mid-3rd to early 7th century AD) are often recovered as heavily mineralized fragments, making it difficult to identify their original morphology and composition. Since archaeometallurgical studies require statistical analysis of many artifacts, non-destructive methods are essential. In this study, neutron tomography was applied to heavily mineralized iron sword fragments from Kofun-period tombs in Okayama Prefecture, Japan. The technique successfully visualized contrasts between iron-rich corrosion products and surrounding non-metal regions, enabling morphological analysis even when little metallic iron remained. Combined with neutron diffraction and X-ray techniques, the method provided new archaeometallurgical insights in a completely non-invasive manner.