Performances of Crystal Scintillators in a Severe Radiation Environment Caused by Gamma Rays

Because of their superb energy resolution and detection efficiency crystal scintillators are widely used in high energy and nuclear physics experiments. A crucial issue is radiation damage. We report an investigation on γ-ray induced radiation damage in crystal scintillators of large size, including BaF_2, BGO, CeF_3, pure CsI, LSO/LYSO/LFS and PWO with an integrated dose up to 340 Mrad at a dose rate up to 1 Mrad/h. Optical and scintillation properties of these crystal samples were measured before and after irradiations. The result shows that pure CsI crystals have good radiation hardness below 100 krad. BaF_2, BGO and LYSO crystals show good radiation hardness beyond 1 Mrad. In terms of light output degradation LSO/LYSO/LFS is clearly the best among all scintillation crystals.