Amorphization of β-thorium phosphate diphosphate (β-TPD) irradiated with high energy krypton ions

As potential actinide-bearing phase for geological deposit of nuclear wastes, the β-Thorium Phosphate Diphosphate ceramic (β-TPD), Th4(PO4)4P2O7, must be resistant against radiation. A high-energy ion beam (840-MeV Kr) was used to check this property by simulating the electronic effects of radiation. The amorphization of the material was followed in situ by using the on line XRD analysis setup (CHEXPIR) of the GANIL accelerator. XRD measurements show a complete amorphization of the material with a kinetics which fits to a direct impact model. Thermal annealing of amorphized samples leads to a complete recrystallization of the structure at 1023 K.