Analysis Of Energy Dispersive X-ray Fluorescence Spectrum And Design Of Application System

Energy dispersive X-ray fluorescence spectrometer,as a multi-element analyzer,has the characteristics of simple structure,fast measurement speed and non-destructive analysis.It has played an important role in many fields such as chemical analysis,field measurement and environmental investigation.This paper focuses on the two key issues of peak position detection and overlapping peak decomposition of X-ray fluorescence spectrum,and comprehensively designs a set of X-ray fluorescence spectrum data processing system based on MATLAB graphical user interface(GUI).The main contents of the thesis are as follows:(1)It is the goal of X-ray fluorescence spectrum qualitative analysis to detect the peak position accurately.Based on the analysis of the principle of the traditional continuous wavelet transform peak-seeking method and the reason why false peaks are easily identified in the overlapping peak area,an improved continuous wavelet transform peak-seeking method is proposed.Simulation results show that the improved peak-finding method effectively eliminates false peaks identified by the continuous wavelet transform method and the relative deviation of the corrected peak position is within 1.That is,this method improves the ability of the traditional continuous wavelet transform method to suppress false peaks,and has better peak-detecting effect.(2)Decomposition of overlapping peaks has always been a hot and difficult point in Xray fluorescence analysis.First,the thesis simulated the three peak overlapping methods of peak sharpening,wavelet transform and double-tree complex wavelet transform to verify their effectiveness.Then,the degree of spectral peak overlap is quantified by the resolution in the field of chromatographic analysis,and overlapping peaks with a resolution lower than0.45 are taken as the research object,low-resolution overlapping peak decomposition method combining a peak sharpening method with a double-tree complex wavelet transform is proposed.Finally,the new method is used to decompose the three sets of simulated lowresolution overlapping peaks that actually exist in the X-ray fluorescence spectrum.The relative error of the peak position after decomposition is within 0.5%,and the relative error of the peak area after decomposition is within 6%.That is,it is proved that the proposed new method can accurately decompose the low-resolution overlapping peaks of X-ray fluorescence spectrum.(3)A set of X-ray fluorescence spectrum data processing system is designed based on MATLAB GUI.The interface of the system is composed of two parts: the spectral data processing area and the spectral analysis result display area.The thesis has programmed the spectral processing method of each functional module in the system,and introduced the system operation process.Next,the system is used to analyze the measured copper alloy data to prove the feasibility of the system.The measured data processing results show that the relative error of the relative content of Cu element is 2.09%,and the relative error of the relative content of Zn element is 0.07%,that is,the difference between the analysis result and the standard value is small,which proves that the system is feasible.