THE COMPARISON OF RADIATION AND PHOTOCHEMICAL STABILITY OF LUMINOPHORES IN POLYSTYRENE SCINTILLATORS

The kinetics of photoluminescence and secondary luminophore consumptio n was studied during gamma radiolysis or photolysis of polystyrene fil m scintillators in air. The stability of secondary luminophores was co nsidered as a substantial factor that has an effect on the overall sta bility of scintillators. Radiation chemical and quantum yields of lumi nophore consumption were estimated. The influence of primary luminopho res on the secondary luminophore stability as well as on the overall s tability of scintillators was analysed. It was shown that radiation st ability of scintillators in a number of cases is practically determine d by secondary processes that occur with the participation of excited states of the polymer and luminophores. (C) 1998 Elsevier Science Limi ted. All rights reserved.