Structural modifications in uranium dioxide irradiated with swift heavy ions

An extensive knowledge of radiation damage in nuclear fuel elements is of considerable importance for technological applications. Ion bombardment and ion-beam analysis techniques provide efficient tools in order to simulate and characterize the structural modifications induced by irradiation. This paper deals with the study of radiation effects induced in UO2 single crystals irradiated with 340-MeV Xe ions which simulate high electronic excitations sensed by the nuclear fuel during the slowing-down of fission fragments. Radiation damage was characterized by the RBS-channeling techniques. Resonant scattering O-16(He-4,He-4)O-16 occurring at 3.045 MeV was applied to the study of oxygen sublattice modifications. A strong disordering of both U and O sublattices was observed, even at very low ion irradiation fluence (similar to 10(13) cm(-2)).