PbWO_4:(Sb,Y)晶体的发光和闪烁性能研究

Investigation of Luminescence and Scintillation Properties of PbWO_4: (Sb,Y) Crystals

本文报道了用多坩埚下降法生长的大尺寸PbWO4: (Sb,Y)晶体的光谱和闪烁性能。基于透射光谱、X射线激发的发射谱、紫外激发及其发射谱、光产额和超短脉冲X射线激发荧光寿命等方面的测试,讨论了Sb,Y双掺杂对PbWO4 晶体的光谱和闪烁性能的作用。结果表明:Sb,Y双掺杂能显著改善PbWO4 晶体的光谱性能和闪烁性能,使PbWO4 晶体在短波方向的透过率明显提高;对于尺寸为 23×23×20mm3 的掺杂晶体样品,光产额最大值大约为 50p.e. /MeV,约为BGO光产额的 6. 0%;发光成份中有 1. 9ns和 15. 8ns两个衰减时间常数的快成份。

This paper presents the luminescence and scintillation properties studies on doubly-doped PbWO4:(Sb, Y) crystals. Based on the results of measuring their transmission spectra, X-ray excited luminescence spectra, photoluminescence spectra, light yield and luminescence decay time, the influences of combined doping with Sb and Y dopants on the optical and scintillation properties of PbWO4 crystals have been discussed. The results show that doping PbWO4 crystals with Sb and Y can improve the light yield and spectroscopic properties. The maximum light yield of 50 p.e./MeV (about 6% of light yield in BGO) was obtained in PbWO4:(Sb, Y) crystal with bialkali photomultiplier for a fixed condition of the crystal size of 23 × 23 × 20 mm3 and the gate width of 200ns. The Sb and Y co-doped PbWO4 crystal presents a faster decay component tau;(τ1=1.9 ns, τ=15.8 ns) than the undoped PbWO4 (τ=2.7 ns, τ2=9.6 ns, τ3=37.0 ns).