微颗粒X射线荧光强度MCNPX模拟与WDXRF实验

发布时间：2018-05-10 23:04

本文选题：微颗粒 + X射线荧光分析　；参考：《光谱学与光谱分析》2017年02期

【摘要】：为研究样品微颗粒在X射线荧光(XRF)分析中对测量结果的影响,运用蒙特卡罗模型MCNPX对X射线荧光仪进行建模,研究了样品颗粒粒径对X射线荧光特征峰强度、峰总比和源峰探测效率的影响,并设计波长色散X射线荧光光谱法(WDXRF)分析实验对模拟结果进行了检验。结果表明:对于样品微颗粒X射线荧光强度与粒径尺寸的关系,MCNPX模拟值与理论计算值保持一致;MCNPX模拟结果与WDXRF实验结果存在一定差异,这取决于MCNPX模型对待测样品状态的假设与实际情况存在一定的差异性;运用样品粉碎、研磨至小颗粒并进行压片处理的办法,可使WDXRF实测结果尽可能的减小与MCNPX理论模拟结果的差异性;在待测样品的颗粒粒径达到一定尺寸时,其峰总比、源峰探测效率、特征峰X射线荧光计数均趋于稳定值;颗粒粒径在某一特定尺寸范围之内,颗粒度效应的影响不容忽视;除此之外,颗粒度效应的影响基本可以忽略。论文充分考虑了待测样品颗粒粒径对XRF分析结果的影响,为减小因颗粒度效应引起分析结果的不确定性提供了一种可行的研究思路,该方法也可为X射线分析的生产实践提供一定的技术参考。
[Abstract]:In order to study the influence of sample microparticles on the measured results in X-ray fluorescence (XRF) analysis, the Monte-Carlo model MCNPX was used to model the X-ray fluorescence instrument, and the particle size of the sample to the intensity of the characteristic peak of X-ray fluorescence was studied. The effects of the ratio of peak to total and the efficiency of source peak detection were investigated. The simulation results were tested by WDXRFs using wavelength dispersive X-ray fluorescence spectrometry (WDXRFs). The results show that the relationship between X-ray fluorescence intensity and particle size of the microparticles is consistent with the theoretical results. There are some differences between the simulation results of MCNPX and the experimental results of WDXRF. This depends on the fact that the MCNPX model has some differences between the assumptions and the actual conditions of measuring the state of the sample, and the method of crushing the sample, grinding it to the small particle and pressing the sheet, It can reduce the difference between the measured results of WDXRF and the theoretical simulation results of MCNPX as much as possible. When the particle size of the sample under test reaches a certain size, the total peak ratio, the detection efficiency of the source peak, and the characteristic peak X-ray fluorescence count all tend to be stable. The particle size is within a certain size range, the effect of particle size can not be ignored, in addition, the effect of particle effect can be neglected. In this paper, the influence of particle size on the XRF analysis results is fully considered, which provides a feasible way to reduce the uncertainty of the analysis results caused by the particle size effect. This method can also provide a certain technical reference for the production practice of X-ray analysis.
【作者单位】：成都市环境保护科学研究院;成都理工大学核技术与自动化工程学院;
【基金】：国家(863)计划项目(2012AA061803) 国家自然科学基金项目(41074093)资助
【分类号】：O657.34

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