Radiation resistivity of BGO crystals due to low-energy gamma-rays

Radiation resistivity of 4×4×30 mm3 BGO crystals from three suppliers has been studied for doses 104 Gy (106 rad) and 105 Gy (107 rad). Radiation hardness was examined by the measurement of optical transmission through BGO crystals before and after 60Co gamma-ray irradiations. The absolute degradation of transmission for 104 and 105 Gy doses at 480 nm wavelength of the peak emission of BGO, was found to be lower than 3.4% and 7.5%, respectively. The results have been also compared with radiation hardness measurements for a large volume ∅30×30 mm3 BGO crystal as well as another heavy scintillation crystals: fluorides and tungstates. Complete recovery of BGO radiation damage was observed only after few days.