Recoil stabilization of 128I in solid magnesium iodate following (n,γ) process: thermal and radiation annealing study

Chemical effects of nuclear transformation of 128I in magnesium iodate has been studied for hydrous and anhydrous targets in the context of thermal and associated radiation annealing treatments. Initial retention and plateau were found to be higher for anhydrous than hydrous iodate. Pre-activation thermal treatments gave lower saturation retention than post-activation heat treatments. This is viewed as reduced participation of reducing defects on heating. Annealing of recoil damage, in the present case, follows first order kinetics. The low values of activation energies in anhydrous iodate computed from classical Arrhenius plot suggest that there is a recombination of recoil fragments before final stabilization and the participation of defect controlled reactions during thermal annealing, leading to saturation retention. (author)