Study of the radiation hardness of CsI(Tl) scintillation crystals

This paper is devoted to the study of a degradation of CsI(Tl) crystals' scintillation characteristics under irradiation with gamma-rays at the uniformly distributed absorbed dose up to 3700 rad. The sample set consisted of 25 crystals of 30 cm long having a truncated pyramid shape and 30 rectangular crystals of the same length. A large difference in the light output deterioration caused by the radiation was observed for the samples of the same shape. A substantial dependence of the average light output loss from the sample shape is seen as well. On the other hand, the crystals from the same ingot behave very similarly under irradiation.