Li掺杂浓度对NaI∶Tl,Li晶体光学和闪烁性能的影响  

Influence of Li Doping Concentration on the Optical and Scintillation Properties of NaI∶Tl,Li Crystals

作　　者：王京康 王承二 孙希磊[3] 王治华 李云云 李焕英[2] 任国浩[2] 吴云涛 WANG Jingkang;WANG Chenger;SUN Xilei;WANG Zhihua;LI Yunyun;LI Huanying;REN Guohao;WU Yuntao(University of Shanghai for Science and Technology,Shanghai 200082,China;Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 201899,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]上海理工大学,上海200082 [2]中国科学院上海硅酸盐研究所,上海201899 [3]中国科学院高能物理研究所,北京100049

出　　处：《人工晶体学报》2023年第9期1582-1588,共7页Journal of Synthetic Crystals

基　　金：国家重点研发计划(2022YFB3503600);国家自然科学基金(U2030115)。

摘　　要：具有中子-伽马双模探测能力的卤化物闪烁晶体在辐射探测领域展现出广阔的应用前景。本文使用布里奇曼法生长得到高光学质量的NaI∶Tl和NaI∶Tl,Li闪烁晶体,并系统研究了不同Li浓度掺杂NaI∶Tl晶体的光致激发和发射光谱、时间分辨光致发光曲线、X射线辐照发光光谱、伽马射线激发能谱,以及中子-伽马甄别性能。研究表明,NaI∶Tl晶体和NaI∶Tl,Li晶体在X射线激发下的发光峰位于345和410 nm,均来源于Tl^(+)的sp-s^(2)跃迁发光。随着Li浓度的增加,晶体的光产额由41000 photons/MeV下降到23000 photons/MeV,662 keV处的能量分辨率由7.0%劣化到9.6%。1%Li(原子数分数)掺杂的NaI∶Tl晶体具有最优的中子-伽马脉冲形状甄别(PSD)性能,品质因子(FoM)值达到4.56。Halide scintillation crystals with neutron-gamma dual detection capabilities show broad application prospects in the field of radiation detection.High optical quality NaI∶Tl and NaI∶Tl,Li scintillation crystals were grown by Bridgman method in this paper.The photoluminescence excitation(PLE)and emission(PL),time-resolved photoluminescence,X-ray excited radioluminescence(XEL),γ-ray detection performance and neutron-gamma discrimination performance of NaI∶Tl co-doped with different Li concentrations were systematically studied.Under the excitation of X-ray,NaI∶Tl and NaI∶Tl,Li crystals show emission peaking at 345 and 410 nm respectively,which are related to sp-s^(2)transitions of Tl^(+)ion.As the increase of Li co-doping concentration,the light yield of the crystal decreases from 41000 photons/MeV to 23000 photons/MeV,while the energy resolution at 662 keV deteriorates from 7.0%to 9.6%.Among the tested samples,the NaI∶Tl crystal co-doped with 1%Li has the best neutron-gamma pulse shape discrimination(PSD)performance,and the neutron-gamma PSD figure-of-merits(FoM)reaches 4.56.

关 键 词：NaI∶Tl Li 闪烁晶体 布里奇曼法 sp-s 2跃迁 中子-伽马甄别 

分 类 号：O734[理学—晶体学]