光纤锥基微柱结构CsI(Tl)闪烁转换屏的研究

项目名称： 光纤锥基微柱结构CsI(Tl)闪烁转换屏的研究

项目编号： No.10875085

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 顾牡

作者单位： 同济大学

项目金额： 34万元

中文摘要： 具有微柱结构CsI(Tl)闪烁转换屏的研究对于发展高分辨率X射线成像探测器件具有重要意义。依据薄膜生长理论，以光纤面板为衬底，系统研究了具有微柱结构CsI(Tl)转换屏的制备工艺，采用热蒸镀法，率先引入气氛调节，实现了对CsI(Tl)转换屏微柱结构和结晶性能的有效调控，所研制的转换屏微柱排列整齐、柱形完整、无断裂，平均柱径可达1.5微米，并首次获得了只有（200）单一晶面择优取向的CsI(Tl)转换屏，近乎垂直于屏面的微柱可引导闪烁光沿柱向传播，从而有效提高转换屏成像的空间分辨率，更细的微柱柱径、单一的晶面择优取向有利于闪烁光的传播更为局域且散射更少，对提高成像空间分辨率至关重要。系统研究了CsI(Tl)转换屏的发光和闪烁性能，经表征转换屏可实现的成像分辨率达23lp/mm，同时还证明光纤面板对转换屏空间分辨率的影响基本可略。 以网状结构模板为衬底，开展了CsI(Tl)闪烁转换屏的拓展性研究，所获得的转换屏成像分辨率为10lp/mm。此外，基于高分辨率X射线成像等的共同需求，还开展了Lu2SiO5:Ce、GdTaO4:Eu3+闪烁转换屏以及X射线显微成像等方面的研究，取得了积极的成果。

中文关键词： CsI(Tl)闪烁转换屏；微柱结构；晶面择优取向；光纤面板；空间分辨率

英文摘要： It is of great significance for the development of high-resolution X-ray imaging detector to study micro-columnar CsI(Tl) scintillation screen. According to the theory of film growth, the preparation process of the structured CsI(Tl) scintillation screens was comprehensively studied on the substrates of optical fiber panels. The effective regulation of micro-column morphology and crystalline of CsI(Tl) scintillation screen was achieved by using thermal evaporation method with inert gas atmosphere adjustment. The micro-columns of the developed scintillation screen arranged in neat rows with perfected morphology and without fracture. The average column diameter can reach to 1.5 micron. Moreover, the preferred orientation of some screens shows only (200) plane which has been achieved first time. The micro-columns of the screen almost perpendicular to the screen surface can guide the scintillation light along the columns, so as to effectively improve the spatial resolution of X-ray imaging. Finer micro-column diameter and better preferred orientation of crystal plane are more conducive to limit the transverse propagation and scattering of scintillation light. These are critical for the spatial resolution of X-ray imaging. The luminescent and scintillatiing properties, spatial resolutions of CsI (Tl) screens were studied. The results showed that the imaging resolution of the screens could achieve up to 23lp/mm, and also proved that the fiber optical panels have almost no side effect on spatial resolution of scintillation screens. The substrates of CsI(Tl) scintillation screens were also expanded to network structure templates. The imaging resolution of the developed screens can reach to 10lp/mm. In addition, based on the common needs of high-resolution X-ray imaging, the research on Lu2SiO5:Ce, GdTaO4:Eu3+ scintillation screen, X-ray in-line phase contrast imaging and etc. were carried out. Some valuable results were achieved.

英文关键词： CsI(Tl) scintillation screen; micro-columnar structure; preferred orientation of crystal plane; fiber optical panel; spatial resolution