The Radiation Annealing of Phosphorus-32 with Cobalt-60 Gamma-rays for Several Neutron-irradiated Inorganic Phosphorus Compounds

Abstract

Abstract Radiation annealings with cobalt-60 gammarays have been investigated for several neutronirradiated inorganic phosphorus compounds. The group separation technique by one-dimensional paper-partition chromatography was adopted to separate chemical species containing phosphorus-32. The reduced species in the sodium and potassium orthophosphate salts and in the sodium pyrophosphate salt decreased upon gamma irradiation, and an increase in the retention was observed. However, the polyphosphate increased initially in the several orthophosphate salts. Three processes has been observed, the rate constants for these processes have been estimated, and two other processes have been suggested. The main process is the oxidation of the reduced species to phosphorus(V) species. Radiation annealing have been studied for phosphates as a functions of the dose rate, the total dose of irradiation, and the temperature during gamma irradiation, it has been found that annealings are dependent upon the total dose and the temperature during irradiation and are independent of the dose rate. In orthophosphates and pyrophosphate, chemical species other than the parent species are easily annealed by gamma irradiation, whereas no detectable annealing has been observed in sodium orthophosphite or sodium hypophosphite. In series of sodium and potassium orthophosphates, annealing was affected by the hydrogen content of the salts.