Study of temperature and radiation induced microstructural changes in Xe-implanted UO2 by TEM, STEM, SIMS and positron spectroscopy

Doppler broadening of annihilation gamma-line combined with a slow positron beam (SPB) was used to measure the momentum density distribution of annihilating pairs in a set of sintered UO2 samples implantated with 800-keV 136Xe2+ at fluences of 1 × 1015 and 1 × 1016 Xe cm−2. The effect of prolonged post-implantation annealing at 1673 and 1873 K, grain size, and 152-MeV Iodine irradiation were studied by analysis of S(E) profiles and S-W maps and discussed versus secondary ion mass spectroscopy (SIMS), scanning transmission electron microscopy results. Spectroscopy with SPB and SIMS is an excellent combination of complementary techniques for studying the formation and evolution of Xe-bubbles, and Xe retention.