Scintillation Properties of Lu3Al5O12, Lu2SiO5 and LaBr3 Crystals Activated with Cerium

The performances of Ce-activated Lu3Al5O12 (LuAG:Ce), Lu2SiO5 (LSO:Ce) and LaBr3 (LaBr3:Ce) scintillator crystals were investigated for γ-ray detection. The light yield and energy resolution were measured using photomultiplier tube (XP5500B PMT) readout. For 662 keV (137Cs source), an energy resolution of 3.5% obtained for LaBr3:Ce is much better than that of 6.7% and 8.3%, respectively, for LuAG:Ce and LSO:Ce. The light yield nonproportionality and energy resolution versus energy of γ-rays were measured and the intrinsic resolution of the crystals was determined. The LaBr3:Ce exhibits a good proportionality within 7% deviation from unity at 16.6 keV, which is much better than that of 22% and 45%, respectively, for LuAG:Ce and LSO:Ce. The photofraction was determined at 320, 662 and 835 keV for studied crystals and compared with the ratio of the cross-sections for the photoelectric effect to the total one calculated using WinXCom program.