Radiation hardness of PbWO4 Cherenkov radiators heavily doped with trivalent rare-earth ions

PbWO4 single crystals heavily doped with trivalent rare-earth (RE) ions were proposed a few years ago as one of the heaviest Cherenkov radiators. We have found that their radiation damage due to 60Co γ-rays are almost saturated at 103 Gy (1 Gy=100 rad). The radiation-induced absorption coefficient μir at 420 nm slightly above the short-wavelength cutoff was 3.1, 5.4 and 7.2 m−1 at 105 Gy in PbWO4:Gd3+(3 at%), PbWO4:La3+(5 at%) and PbWO4:La3+(8 at%), respectively.