Performance of pixelated CsI scintillation screen with hexagonal array arrangement prepared by vacuum melting injection method
Performance of pixelated CsI scintillation screen with hexagonal array arrangement prepared by vacuum melting injection method
复制标题
真空熔融注射法制备六边形阵列像素化CsI闪烁屏的性能
DOI：
10.1016/j.nima.2018.06.051
复制
发表时间：
2018-09-21
影响因子：
1.4
通讯作者：
Zhang, Juannan
中科院分区：
文献类型：
--
作者：
Liu, Si;Gu, Mu;Zhang, Juannan
像素化闪烁屏作为X射线成像探测器的重要组成部分，有效地解决了闪烁光的横向扩散问题，提高了X射线成像的空间分辨率。本工作以孔距约4 μ m、孔径约3 μ m的硅孔模板为基础，采用真空熔融注入法制备了六边形和正方形排列的像素化CsI闪烁屏。研究了薄膜的形貌、结晶度、X射线激发发光和X射线成像性能。结果表明，即使CsI微柱填充深度达到100 μ m，CsI闪烁体也能均匀、致密地填充到硅孔模板中，没有微气泡。像素化闪烁屏表现出良好的CsI结晶度，具有（110）择优取向。与相同厚度的正方形闪烁屏相比，六边形排列的CsI闪烁屏的X射线激发光致发光强度提高了14.3%。此外，100 μ m厚的像素化CsI屏的强度比40 μ m厚的屏的强度高34.1%。六角排列像素化CsI闪烁屏的X射线成像系统的空间分辨率约为115 lp/mm，对屏厚不敏感，比正方形排列屏的空间分辨率提高11.5%。六角形排列的CsI闪烁屏的探测量子效率比相同厚度的正方形排列的闪烁屏的探测量子效率高，并且随着闪烁屏厚度的增加而增加。这意味着六边形排列的像素化CsI闪烁屏的X射线成像性能优于正方形阵列排列的闪烁屏。
The pixelated scintillation screen as an important component of the X-ray imaging detector effectively solves the issue of the lateral spreading of scintillation light and improves the spatial resolution of X-ray imaging. In this work, the hexagonal as well as square arranged pixelated CsI scintillation screens based on the silicon pore templates with pore pitch about 4 mu m and diameter about 3 mu m were fabricated by vacuum melting injection method. The morphology, crystallinity, X-ray excited optical luminescence and X-ray imaging performance of the screens were investigated. The results show that the CsI scintillator was filled into the silicon pore templates uniformly and compactly without microbubbles even if the depth of the filled CsI microcolumns reaches 100 mu m. The pixelated scintillation screen exhibits good CsI crystallinity with (110) preferred orientation. The intensity of X-ray excited optical luminescence of the hexagonal arranged pixelated CsI scintillation screen increases by 14.3% compared with that of the square arranged screen with same thickness. Furthermore, the intensity of the pixelated CsI screen with 100 mu m thickness is 34.1% higher than that of the screen with 40 mu m thickness. The spatial resolution of the X-ray imaging system with the hexagonal arranged pixelated CsI scintillation screen is about 115 lp/mm and not sensitive to the screen thickness, which is 11.5% higher than that with the square arranged screen. The detective quantum efficiency of the system with the hexagonal arranged pixelated CsI scintillation screen appears relatively higher than that with the square arranged screen with same thickness and increases with the thickness of the screen. This means the X-ray imaging performance of the hexagonal arranged pixelated CsI scintillation screen is better than that of the square array arranged screen.