The effects of damage-rate upon defect structural development in Ni and Ni-Sn were studied via the comparison of neutron irradiation with Ni ions. Particular attention was paid to damage structural evolution near to grain boundaries, which was affected by the 1-dimensional motion of self-interstitial atom clusters. The 1-dimensional motion of self-interstitial atom clusters was observed in Ni irradiated to low fluences in the cases of both neutron and ion irradiation. The alloying element, Sn, prevented 1-dimensional motion. The irradiation temperature required to cause the same damage structural evolution in Ni and Ni-Sn shifted to 200 and 100K, respectively, with increasing damage rate.

Effects of Oversized Element Sn on Diffusion of Interstitial Clusters in Ni Irradiated by Ions and Neutrons. Q.Xu, T.Yoshiie, H.Watanabe, N.Yoshida: Journal of Nuclear Materials, 2007, 367-370[1], 361-7