摘要
碘化铯(CsI)光阴极响应灵敏度是软X射线条纹相机用于X射线能谱定量诊断的重要参数,其理论计算具有重要指导意义.目前的理论解析模型基于薄膜光阴极产生次级电子的一维随机行走模型发展而来,具体包括X射线正入射、能量大于1 ke V条件下的Henke模型,以及变角度入射、光阴极厚度大于100 nm条件下的Fraser模型,都存在一定局限性.本文进一步引入次级电子输运概率的基础表达式,推导了CsI光阴极在更大参数范围内(X射线能量0.1—10 ke V、光阴极厚度10—200 nm)响应灵敏度随X射线能量E、光阴极厚度t、X射线与阴极表面夹角θ变化的一般表达式.最后,将本文的理论计算结果与Henke模型、Fraser模型、文献及北京同步辐射的实验数据分别进行了比较和讨论分析,验证了计算模型的准确性和普适性,并且为高时间分辨光谱定量测量实验中Cs I光阴极的优化设计提供了理论参考.
The response sensitivity of CsI photocathode is an important parameter for the quantitative diagnosis of X-ray spectroscopy by soft X-ray streak camera,and its theoretical calculation has important guiding significance.The current theoretical analytical models are based on the one-dimensional random walking model of secondary electrons generated by thin film photocathodes,including the Henke model under the condition of normal incidence of X-rays and energy greater than 1 keV,and the Fraser model under variable angle incidence and photocathode thickness greater than 100 nm,which have certain limitations.In this paper,the basic expression of the probability of secondary electron transmission is introduced,and the general expression of the response sensitivity of CsI photocathode is deduced,which varies with X-ray energy E,photocathode thickness t,and angleθbetween X-ray and cathode surface in a larger parameter range(X-ray energy 0.1-10 keV,photocathode thickness 10-200 nm).Finally,the theoretical calculation results of this paper are discussed by comparing it with those from the Henke model,Fraser model,literature data and experimental data on Beijing synchrotron radiation facility,which verifies the accuracy and universality of the computational model,and a theoretical reference is provided for optimally designing the CsI photocathode in high-time-resolution spectrometric quantitative measurement.
作者
何小安
杨家敏
黎宇坤
李晋
熊刚
He Xiao-An;Yang Jia-Min;†Li Yu-Kun;Li Jin;Xiong Gang(Laser Fusion Research Center,China Academy of Sciences,Mianyang 621900,China;Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE),Institute of Modern Physics,Fudan University,Shanghai 200433,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第24期204-211,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11735013)
国家重点研发计划(批准号:2017YFA0403200)
中国工程物理研究院院长基金(批准号:YZJJLX2017010)资助的课题。
