The formation processes of interstitial-type dislocation loops (I-loops) in high-purity Fe under irradiations with 5keV H+ ions or 1000keV electrons were examined by in situ transmission electron microscopy at temperatures below room temperature, and the results were compared with that obtained under He+ ion irradiation. For the electron irradiation, conventional model of I-loop nucleation based on the assumption that di-interstitial atoms were stable nuclei of I-loops was questioned. The volume density of I-loops by H+ ion irradiation was one-order of magnitude higher than that by electron irradiation, and several times lower than that by He+ ion irradiation. The temperature dependence of the volume density of I-loops by H+ ion irradiation supported the idea that such enhancement of I-loop formation was due to the trapping of self-interstitial atoms by gas atom-vacancy complexes.

Formation Process of Dislocation Loops in Iron under Irradiation with Low-Energy Helium, Hydrogen Ions or High-Energy Electrons. K.Arakawa