It was found that by assuming that the density of dislocations in an irradiated material varies as a function of the distance to grain boundaries and that mobile interstitial defect clusters perform three-dimensional diffusional motion it was possible to achieve significantly better agreement with experimental observations of profiles of heterogeneous void swelling than in the model where defects diffuse purely 1-dimensionally. This approach explained the origin of several distinct features which characterized the effect of heterogeneous void swelling, including the variation of the shape of swelling profiles as a function of irradiation dose, the formation of peaks of swelling and void denuded zones, and the occurrence of anomalously large voids in the regions adjacent to grain boundaries.

Heterogeneous Void Swelling Near Grain Boundaries in Irradiated Materials. S.L.Dudarev, A.A.Semenov, C.H.Woo: Physical Review B, 2003, 67[9], 094103 (9pp)