Si-PIN探测器响应函数模型及其在EDXRF技术中的应用

Si-PIN Detector Response Function Model and Its Applications in EDXRF Technology

建立探测器响应函数模型，实现对测量X射线能谱的分析，可提高EDXRF技术中谱数据处理的自动化程度和计算精度。通过对X射线的探测物理过程进行分析，建立了一种Si-PIN探测器响应函数模型，该模型包括4部分：全能峰低能侧的连续平台、全能峰的高斯型主成分、高斯型的Si逃逸和全能峰低能侧的指数拖尾。模型形式简单。各部分物理意义明确。各参数用自行编制的基于加权最小二乘法的程序拟合得到。对19种单元素样品的特征X射线谱进行了拟合。计算得到相应的拟合优度因子在1．05—2．71范围内。表明该模型可以较好地表征Si-PIN探测测量的X射线谱峰峰形，有助于提高EDXRF的自动化分析过程。

The spectrum analysis can be carried out via establishing the detector response function（DRF）, to improve the automation level and the computation accuracy of the spectrum data processing. A general DRF model is established for Si-PIN detectors via the analysis of the X-ray physical detect procedure. The model contains four parts： a flat continuum shift from zero to full energy; a Gaussian shaped principal component of full energy peak; a Gaussian shaped Si escape peak; and an exponential tail on the low energy side of the full energy peak. Each part of the model, with a simple format, has a clear and definite physical meaning. Parameters are obtained by using the program, based on the Weighted Least-Squares （WLS） method. Nineteen elementsI X-ray spectra in total are fitted in the study, and the fitting reduced chi-squares are also obtained simultaneously, which is in the range of 1.05-2.71. It is shown that this DRF model can represent the characteristic X-ray spectrum peak shape very well.