Relationship between Melt Composition and Stability of Scintillation Properties of PbWO4:Y3+ Crystals
熔体组成与PbWO4:Y3+晶体闪烁性能稳定性的关系

The light yield of some Y3+ doping PbWO4 crystals increases after low dose rate irradiation, and the radiation hardness is sensitive to annealing temperature. In this study, the experiments among Sb, La3+, Y3+ doping and La3+/Sb, Y3+/Sb co-doping PWO crystals were carried out, the composition of the melt in the top of the crystals was also measured by the XRF method. The experimental results show that this exceptional behavior only exists in PWO crystals containing Y3+ ions. In addition those crystals have 420nm absorption band in optical transmission spectra. In the processes of PWO crystal growth by the modified Bridgeman method, it is salutary to keep the melt in a negative charge environment, thus preventing the formation of interstitial oxygen. Integrating with the data obtained, the mechanism of this phenomenon was discussed, and the principles of choosing dopants to suppress it were also brought forward.