Proton irradiation effects in Zr-1.0 Nb-1.0 Sn-0.1 Fe probed by positron annihilation

Samples of a new zirconium-based alloy (zirlo) were proton-irradiated and the structural defects were characterised by positron annihilation. The lifetimes of positrons trapped in the defects generated at different doses of irradiation appeared to suggest significant interaction of the defects with the substitutional solute atoms. The isochronal recovery of the sample irradiated at the highest dose showed three distinct stages. The initial annealing of free vacancy clusters was followed by a solute atom-vacancy dissociation stage above 673 K. The vacancies thus released annealed out at 973 K. (orig.)