CHEMISTRY OF 82GBR RECOILS IN NEUTRON-IRRADIATED CRYSTALLINE ALKALI METAL BROMATES

The analysis of neutron-irradiated crystalline alkali metal bromates by anion-exchange chromatography showed that the 82gBr recoils produced in the crystals were distributed in varying amounts among four oxidation states of the element : BrO3-, BrO2-, BrO-, and Br-. The species BrO- and BrO2- were labile and disappeared on heating the irradiated crystals. A nearly complete recombination of all radiobromine to bromate was effected by heating neutron-bombarded LiBrO3, KBrO3, and CsBrO3 for 1 hr at temperatures approaching their melting points. Irradiation with “Co y rays also induced the recombination to bromate, and significant differences in annealing rates depending on the cation in the salt were observed. The transfer to bromate by heating of radiobromide added to pure alkali metal bromate crystals was demonstrated. Neutron irradiations of mixed crystals of NaBrO3 + NaClO3 showed that the fraction of 82gBr combined as bromate doubled on going from pure NaBrO3 crystals to a 1 % by weight solid solution of NaBrO3-NaClO3. A model based on the production of radiobromine recoils in small, isolated regions of localized disorder in the crystal was employed in a discussion of the kinetics of their thermal and radiation annealing to form radiobromate. © 1968, American Chemical Society. All rights reserved.