中文摘要：

为研究探测器立体角在X射线荧光（X-ray fluorescence，XRF）分析仪的设计对测量结果的影响，运用蒙特卡罗方法对XRF仪进行建模。结果表明，探测器脉冲计数随着探测器与样品之间距离的增大指数衰减；随着探测器立体角的增大，特征峰计数非线性增大，源峰探测效率指数递减；探测器本征探测效率与探测器立体角无关。本文研究方法和结论可为一些XRF仪的设计提供参考。

英文摘要：

Background： The designing of the X-ray fluorescence （XRF） analyzer＇s geometric layouts need to be considered, such as ＇detector to specimen＇ distance, ＇detector to source＇ distance, ＇source to specimen＇ distance. The desired X-ray collection angle is one of the important factors of the detection performance. However, the experience geometric layouts have been unable to meet every XRF analyzer designing, because the performance of the excitation source or the detector is getting better, sample processing technology is much more advanced, and so on. Purpose： The aim is to study the impact of the desired X-ray collection angle on XRF analyzer designing, and provide a technical guidance on methodologies for XRF analyzer designing. Methods： In this paper, we build the XRF analyzer models by the Monte Carlo method and analyze the impacts of the desired X-ray collection angle on XRF analyzer designing. Results： Kinds of factors with the desired X-ray collection angle are analyzed, such as Cu＇s X-ray characteristic fluorescence peak counts, the ＇detector axis to specimen＇ distance, the Cu＇s ＇peak to source＇ ratio. Conclusions： With the increasing of distance between the detector and the specimen, the detector＇s pulse counts satisfy an exponential decay law. With the desired X-ray collection angle increasing, the Cu＇s X-ray characteristic fluorescence peak counts increase linearly. With the desired X-ray collection angle increasing, the ＇peak to source＇ ratio decays exponentially, but the ＇peak to total＇ ratio remains the same.