基于透镜耦合的X射线成像探测器闪烁体厚度对成像质量的影响  

Influence of scintillator's thickness on imaging quality of lens-coupled hard X-ray imaging detector

作　　者：张永兴[1,2] 谢红兰[1] 杜国浩[1] 陈荣昌[1] 肖体乔[1] 

机构地区：[1]中国科学院上海应用物理研究所张江园区,上海201204 [2]中国科学院大学,北京100049

出　　处：《核技术》2014年第7期7-12,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.11375257)资助

摘　　要：闪烁体是同步辐射X射线成像探测器的重要组成部分,它将入射X射线转换为可见光,再由可见光成像探测器接收成像。闪烁体的厚度对成像的空间分辨率、图像衬度有较大的影响,选取合适的厚度的闪烁体,与探测器物镜(数值孔径)及X射线能量等实验条件达到最理想的匹配,将有助于获得高质量的X射线成像结果。但目前上海光源(Shanghai Synchrotron Radiation Facility,SSRF)用户在开展X射线成像实验时,基本都未考虑到闪烁体厚度对成像质量影响的这个因素,难以获得最佳图像质量的实验结果。本文先根据理论的分辨率曲线预测了探测器各个镜头的闪烁体的最佳匹配厚度,并利用上海光源成像线站(BL13W1)配备的PCO2000探测器以及不同厚度的YAG闪烁体进行了实验验证,经过对实验结果的图像衬度进行分析,获得了探测器各个物镜镜头的最佳匹配闪烁体厚度,实验结果与理论预测值基本相符,这将为上海光源成像线站基于透镜耦合的X射线成像探测器的高效使用提供指导。Background： Scintillator is an important component of synchrotron X-ray imaging detectors, which converts the incident X-rays into visible light to be imaged by visible light imaging detectors. The thickness of scintillators has a great impact on the spatial resolution and contrast of the images. When the thickness of the scintillator is matched with detector lens （NA）, image quality of experimental results will be improved obviously. But in fact, users doing X-ray imaging experiments at Shanghai Synchrotron Radiation Facility （SSRF） don＇t take into account this factor and it is difficult to obtain the best results with high image quality. Purpose： Matching thickness of scintillators with NA of objective can help us get good experimental results with high-quality images. Methods： We obtain the optimal thickness of scintillator for every objective lens by the way of mathematical computations of resolution theoretical curves and analysis of image contrast of experimental results. Results： Both of the results are nearly in accordance with each other. Conclusion： Users of SSRF will get better results of X-ray imaging experiment than before when they chose the optimal thickness of scintillator matched with the objective lens.

关 键 词：X射线成像探测器 闪烁体 空间分辨率 衬度 

分 类 号：TL816.1[核科学技术—核技术及应用]