Zr4+共掺对Cs2LaLiBr6∶Ce晶体的中子/伽马甄别性能的影响
Effect of Zr4+Co-doping on Neutron/Gamma Discrimination of Cs2LaLiBr6∶Ce Crystals
郑中秋 1魏钦华 1童宇枫 2唐高 1尹航 1秦来顺1
作者信息
- 1. 中国计量大学材料与化学学院,杭州 310018
- 2. 中国计量大学材料与化学学院,杭州 310018;中国科学院上海硅酸盐研究所,人工晶体研究中心,上海 201899
- 折叠
摘要
中子探测技术广泛用于国土安全、核材料安全检测以及高能物理等领域,由于3He资源紧缺,近年来急需开发出能够同时甄别中子/伽马的新型闪烁晶体,Cs2LaLiBr6∶Ce(CLLB∶Ce)晶体具有良好的中子/伽马甄别能力、优异的能量分辨率以及高的光输出,但其中子/伽马甄别性能有待进一步提高.本研究采用垂直布里奇曼法成功生长了Zr4+共掺杂的CLLB∶Ce晶体.通过不同表征手段研究了 Zr4+共掺杂CLLB∶Ce晶体的结构和组分,结果表明Zr4+成功掺入基质材料且对基质晶体结构不产生明显的影响,Zr4+共掺杂后没有产生新的发光中心,紫外衰减时间约为27.0 ns,仍具有较快的荧光衰减.Zr4+共掺杂CLLB∶Ce晶体的品质因子(Figure of Merit,FOM)从1.2提高到1.5,表明其中子/伽马甄别能力得到改善.结合热稳定性和闪烁衰减时间,探讨了衰减时间对FOM的影响机制,Zr4+共掺杂可以抑制浅电子陷阱和Vk中心,减少电子捕获和脱陷过程,使Ce3+直接捕获的概率大大增加,从而表现出更快的衰减速率.本研究显示,Zr4+共掺杂CLLB∶Ce晶体在中子/伽马探测领域具有潜在的应用前景.
Abstract
Neutron detection technology is widely used in homeland security,nuclear material security detection,and high energy physics,etc.Due to the shortage of 3He resources,it is urgent to develop a novel scintillator that can discriminate neutron and gamma.The Cs2LaLiBr6∶Ce(CLLB∶Ce)crystal has good neutron/gamma discrimination capacity,excellent energy resolution and high light yield,but its neutron/gamma discrimination performance needs further improvement.Here,the CLLB∶Ce crystals co-doped with Zr4+were grown successfully by the vertical Bridgman method.The results of different characterization methods prove that the Zr4+was successfully doped into the matrix and did not effect on the structure of host.Meanwhile,no new luminescence center was generated after Zr4+doping.The UV decay time is about 27 ns,presenting a fast fluorescence decay.Figure of merit(FOM)of CLLB∶Ce crystal is enhanced from 1.2 to 1.5 by co-doping Zr4+,which means that the neutron/gamma discrimination performance of CLLB∶Ce crystals is improved.Combined with the thermal stability and scintillation decay time,relationship between decay time and FOM was also analyzed.The co-doping of Zr4+can inhibit shallow electron trap and VK centers,reduce electron trapping-detrapping process,and greatly increase the probability of Ce3+direct capturing electron,which results in a shorter decay time.Data from this study indicate that the CLLB∶Ce crystals exhibit a huge application prospect in the field of neutron/gamma detection.
关键词
闪烁晶体/CLLB∶Ce/中子/伽马甄别/钾冰晶石结构Key words
scintillation crystal/CLLB∶Ce/neutron/gamma discrimination/elpasolite structure引用本文复制引用
基金项目
国家自然科学基金(12275262)
国家重点研发计划(2022YFB3503600)
浙江省自然科学基金(LGG22E020001)
浙江省自然科学基金(Z23E020002)
出版年
2024
国家科技期刊平台
NSTL
万方数据