Scintillation response of Lu1.95Y0.05SiO5:Ce and Y2SiO5:Ce single crystal scintillators

The scintillation response of the new cerium-doped rare-earth scintillator lutetium–yttrium oxyorthosilicate (Lu1.95Y0.05SiO5:Ce, LYSO:Ce) were investigated and compared to those of cerium-doped yttrium oxyorthosilicate (Y2SiO5:Ce, YSO:Ce) crystal. The light yield and energy resolution were measured using photomultiplier tube (PMT) readout. The non-proportionality of the light yield and energy resolution versus γ-ray energy were measured and the intrinsic resolution of the crystals was calculated. For 662 keV γ-rays (137Cs source), LYSO:Ce showed a light yield of 37,400 ± 3700 ph/MeV, which is much higher than that of 26,300 ± 2600 ph/MeV obtained for YSO:Ce. The energy resolution of 6.8 ± 0.2% obtained with YSO:Ce is better than that of 7.7 ± 0.2% obtained with LYSO:Ce, due to its better intrinsic resolution and proportionality in light yield. The photofraction was determined for both crystals and compared with the cross-sections ratio calculated using WinXCom program. The experimental results of the total mass attenuation coefficients for both crystals are in good agreement with the theoretical values, within the experimental uncertainty.