面向超快闪烁成像屏的大尺寸Yb:YAG晶体生长、缺陷和性能研究

高能量密度物理态是物理学重要的研究前沿方向之一，我国和其它发达国家竞相开展研究，以电子束、硬X射线和伽马射线等为探针的超快辐射成像探测技术是高能量密度物理态研究的重要手段。由于高能量密度态的物理过程演变速度极快，需要超快辐射探测有足够高的时间分辨和空间分辨，Yb:YAG晶体由于衰减时间短、中子/伽马射线甄别能力强等优点，成为首选的探测材料。但是目前Yb:YAG晶体尺寸小、发光效率偏低、抗辐照损伤能力差，只能通过拼接方式制备超快辐射探测成像屏，而且寿命短、成本高昂。.本项目面对高能量密度物理态前沿研究对成像屏的需求，围绕Yb:YAG晶体存在的问题开展工作，探明导模法生长的Yb:YAG晶体闪烁性能和辐照硬度的影响因素及作用机制，优化晶体闪烁性能和抗辐照能力，实现导模法生长大尺寸Yb:YAG晶体，制备出大尺寸无拼接超快辐射探测成像屏，为X射线、电子束流和伽马射线等超快探测提供支撑。

High energy density physics(HEDP) is one of the important research frontiers in physics. Our country and other developed countries are competing to carry out research on it. Due to the extremely fast evolution of the physical process of the high energy density solid state, the ultra-fast radiation detection method with high enough time resolution and spatial resolution is required. Currently, Yb:YAG is the most preferred detection material due to its short decay time and high n/γ discrimination capability. However, at present, the luminous efficiency and radiation hardness of Yb:YAG are relatively low. And the size of Yb:YAG crystal are not big enough for radiation imaging. Therefore, the imaging screen can only be prepared by splicing, which lead to short service life and high cost..To meet the demand of HEDP for large imaging screen, the project is trying to solve the problems of Yb:YAG crystals. We will explore the influence factors of scintillation properties radiation hardness and effect mechanisms of Yb:YAG crystal grown by edge defined film fed growth method, and optimize scintillation and irradiation properties. And then we prepare the large imaging screen using large size Yb:YAG crystal without splicing. This research will supply technical support for X-ray, electron beam and gamma rays detection.