STUDY ON RADIATION DAMAGE OF CHINESE-MADE HIGH-Z SCINTILLATION CRYSTALS

Radiation damage effects of several Chinese-made high-Z scintillation crystals have been studied on a ⁶⁰Co irradiation unit of 100KCi Results on small size BGO crystals irradiated by 60Co γ rays with various doses from 5×10³ to 7.5×10⁵rad are presented.The decrease in scintillation light output depends non-linearly on the dose applied and saturation effects above 5×10⁴rad have been observed.The spontaneous recovery of the light output can be described by the sum of at least three exponential functions.The radiation damage effects of small size BaF₂,CsI(Tl) and ZnWO₄ crystals at 5×10⁵rad were also investigated.Serious damage to BaF₂ has been found.Preliminary analyses indicate that this may be attributed to the inclusion of certain critical elements in the crystal.CsI(T1) after irradiation does not exhibit strong afterglow of noticeable coloration as were reported in the literature.