基于填充Gd_(2)O_(2)S:Tb毛细玻璃管阵列的冷中子成像荧光屏的研究  

Study on cold neutron imaging scintillation screen based on glass capillary array filled with Gd_(2)O_(2)S:Tb phosphor

作　　者：李达 谭西早 张继龙 薛云飞 骆无瑕 靳柯 杨丽芳 武朝辉 LI Da;TAN Xizao;ZHANG Jilong;XUE Yunfei;LUO Wuxia;JIN Ke;YANG Lifang;WU Zhaohui(School of Materials,Beijing University of Technology,Beijing 100081,China;State Nuclear Security Technology Center,Beijing 102401,China)

机构地区：[1]北京理工大学材料学院,北京100081 [2]国家核安保技术中心,北京102401

出　　处：《核技术》2021年第7期24-30,共7页Nuclear Techniques

摘　　要：冷中子照相是一种优异的无损检测技术,中子转换屏是冷中子照相装置的关键部件。基于填充有闪烁/荧光粉末毛细玻璃管阵列的荧光屏是一种新型的冷中子照相转换屏,具有本征分辨率高、工艺简单及成本低等特点。基于毛细玻璃管阵列填充荧光粉末(Gd_(2)O_(2)S:Tb)制备了一种新型荧光屏。具体制作步骤包括:荧光粉研磨、粒径筛选和抽滤法填充。实验结果显示:对于10μm孔径的毛细玻璃管阵列,荧光粉在毛细玻璃管阵列中的填充效率可达70%。利用该工艺流程加工得到的荧光屏对西门子星型冷中子空间分辨测试靶进行了冷中子成像实验,测量结果显示其空间分辨率约达300μm@CTF=3%。[Background]As an excellent nondestructive testing technology,cold neutron radiography is widely employed to image materials of interest in many basic and application research fields.One of key components of such device is the neutron sensitive scintillation screen.Normally,these screens are made up of scintillation or phosphor powder mixed with/without neutron sensing isotopes,such as 6LiF:ZnS(Ag)and Gd_(2)O_(2)S:Tb.Uniform scintillation screens are very difficult to make a trade-off between spatial resolution and neutron detection efficiency.Recently a new type of micro-structural scintillation screens has been proposed,which is expected to have higher spatial resolution while maintaining higher neutron detection efficiency.Following this idea,a scintillation screen has been proposed,developed,and studied by our group.[Purpose]This study aims to develop a new type of scintillation screens based on a glass capillary array filled with scintillation powders to achieve high spatial resolution and neutron detection efficiency.[Methods]First of all,a neutron sensing scintillation screen was made by filling very fine grinded Gd_(2)O_(2)S:Tb phosphor powder into glass capillary arrays.Three main steps,i.e.the phosphor powder grinding,the particle size screening,and the vacuum suction filtration process,were taken making such screens.Then,photographs of Gd_(2)O_(2)S:Tb phosphor before and after grinding were taken with a scanning electron microscope(SEM)to examine the filling efficiency of scintillation powder in the glass capillary arrays.Finally,experimental test of spatial resolution of such scintillation screens was carried out by using an optical system to read out the scintillation light emitted by the screen,and a Siemens Star neutron test target to characterize the screens'spatial resolution with cold neutrons.[Results]X-ray luminescence spectra show that the grinding process reduces the light yield of the phosphor.The filling efficiency of scintillation powder in the glass capillary arrays is up to 70%.The cold

关 键 词：冷中子成像 中子荧光屏 毛细玻璃管阵列 

分 类 号：TL816.3[核科学技术—核技术及应用]