Annihilation behavior of irradiation defects induced by γ-ray in biphasic tritium breeding materials xLi2TiO3-(1-x) Li4SiO4

Abstract For the operation of D-T fusion reactor, tritium breeding materials will be adopted to produce tritium. Li2TiO3–Li4SiO4 biphasic breeders are considered as promising breeding materials due to combining the advantages of Li2TiO3 and Li4SiO4. The annihilation kinetics of defects induced by γ-ray irradiation in xLi2TiO3-(1-x) Li4SiO4 (molar ratio: x = 0.25,0.5,0.75) have been investigated. ESR and Easyspin simulation were employed to elucidate the annihilation processes of the irradiation defects. The defects of E′-center and O--center were introduced by irradiation. The amount of defects decreased as the molar ratio of Li2TiO3/Li4SiO4 increased. It was indicated that the irradiation stability of Li2TiO3 was better than that of Li4SiO4. According to Easyspin simulation, the defect density of E′-center and O--center was obtained respectively and the amount of defects decreased as the annealing temperature increased. The activation energy and kinetics equation of E′-center and O--center in xLi2TiO3-(1-x) Li4SiO4 (x = 0.25,0.5,0.75) were obtained. Based on annihilation kinetics, the correlation between annihilation of irradiation defects and tritium release was given.