热中子探测用高光产额Ce3+掺杂Li-6硅酸盐氟化物纳米微晶玻璃闪烁体的制备及其闪烁机理研究

Due to good chemical stability, resistance to high temperature impact, adjustable compositions, easy to make large size and scale production, good neutron-gamma ray discrimination characteristic, Ce3+ doped Li-6 glass scintillator becomes a research hotspot in the field of thermal neutron detection materials, and has a broad application prospect in the application fields of thermal neutron detection technology, such as nuclear radiation detection, petroleum logging, homeland security. However, due to the amorphous structure and the presence of many defects, glass is easy to produce carriers' nonradiative recombination, resulting in low emission intensity of Ce3+ and low light yield of glass scintillator. This has seriously hindered its pratical applications. Aiming to low light yield problem of glass scintillator, this investigation intends to carry out the investigation on the composition design, the preparation, the luminescence mechanism, and the scintillation mechanism of Ce3+ doped Li-6 silicate glass ceramic containing fluoride nanocrystals.Through the composition design and the heat treatment,transparent fluoride nanocrystals will be crystallized in glass, Ce3+ emission will be enhanced, the light yield of scintillator will be increased. This project will focus on solving the key scientific issues of the composition design and the scintillation mechanism of Ce3+ doped Li-6 silicate glass ceramic scintillator containing fluoride nanocrystals. It is expected to obtain high light yield Ce3+ doped Li-6 silicate glass ceramic scintillator containing fluoride nanocrystals, and will establish a good foundation of the research and the application in the field of thermal neutron detection technology.

Ce3+掺杂Li-6玻璃闪烁体由于化学稳定性好、耐高温热冲击、组成可调、易制得大尺寸和规模化生产、优良的中子-伽马射线甄别特性，日益成为热中子探测材料的研究热点，在核辐射检测、石油测井、国土安全等热中子探测技术领域应用前景广阔。但是，因其非晶态结构和存在较多缺陷，玻璃易产生载流子的无辐射复合，造成Ce3+发光强度低，玻璃闪烁体光产额低，严重阻碍其实际应用。 本项目针对玻璃闪烁体光产额低的问题，拟开展Ce3+掺杂Li-6硅酸盐氟化物纳米微晶玻璃闪烁体的组分设计、制备和发光机理及闪烁机理研究。通过组分设计和热处理，在玻璃中可控析出透明氟化物纳米晶，增强Ce3+发光，提高闪烁体的光产额。重点解决Ce3+掺杂Li-6硅酸盐氟化物纳米微晶玻璃闪烁体的组分设计及其闪烁机理的关键科学问题。预期得到高光产额Ce3+掺杂Li-6硅酸盐氟化物纳米微晶玻璃闪烁体，为其在热中子探测技术的研究和应用奠定良好的基础。

由于化学稳定性好、耐高温热冲击、组成可调、易制得大尺寸和规模化生产、优良的中子-伽马射线甄别特性，Ce3+掺杂Li-6玻璃闪烁体日益成为热中子探测材料的研究热点，在核辐射检测、石油测井、国土安全等热中子探测技术领域应用前景广阔。但是，因其非晶态结构和存在较多缺陷，玻璃易产生载流子的无辐射复合，造成Ce3+发光强度低，玻璃闪烁体光产额低，严重阻碍其实际应用。本项目针对玻璃闪烁体光产额低的问题，开展了Ce3+掺杂硅酸盐氟化物纳米微晶玻璃闪烁体的组分设计、制备和发光机理及闪烁机理研究。研究了玻璃组分、熔制工艺、热处理工艺、氟化物纳米晶种类和晶粒大小等因素对Ce3+发光性能的影响，阐明Ce3+的发光机理。通过组分设计和热处理，在玻璃中可控析出透明LiYF4或LiLuF4氟化物纳米晶，增强了Ce3+发光，提高闪烁体的光产额。重点解决了Ce3+掺杂硅酸盐氟化物纳米微晶玻璃闪烁体的组分设计及其闪烁机理的关键科学问题。本课题研究的Ce3+掺杂硅酸盐氟化物纳米微晶玻璃闪烁体，可为发展稀土离子掺杂的玻璃闪烁体在热中子探测技术的研究和应用提供科学依据和技术储备。