Effect of large gamma-irradiation doses on conversion efficiency and light output of alkali halide scintillators

It is shown that the effect of large irradiation doses on scintillation properties is mainly connected with bubbles which grow due to irradiation-induced diffusion of created vacancies, the number of bubbles remaining approximately constant. To all appearance, some structure defects initially present in a crystal act as coalescence centers for vacancies. Under this assumption, a significant straggling of the examined samples in the sensitivity to gamma-irradiation can be attributed to the difference in the number of coalescence centers.