The Analysis Of X-ray Fluorescence Through Wavelet Transform

As a kind of analysis method energy, dispersive X-ray fluorescence analysistechnology was applied to many scientific research and production fields.It has thecharacteristics of in situ, rapid, accurate, simple and the advantages of non-destructivemul-tielement analysis at the same time. But because of the statistical fluctuation ofX-ray itself and the interference between the spectral lines, as well as affected by thedetection energy resolution and detection efficiency of instrument, the analysisprecision is limited greatly. So it is necessary to analyze the spectral lines detected byinstrument, and has great significance to improve the accuracy of X fluorescenceanalysis and expand the application fields of X fluorescence analysis technology.This paper comes from major project of the national "863" Program "researchand development of high-precision portable X-ray fluorescence spectrometer"(No:2012AA06180301).This article systematically introduced the basic theory of wavelet analysis, andthis new mathematical analysis method was applied to the analysis of X fluorsparspectral lines.The powerful de-noising ability of wavelet transform was used to smooth theX-ray fluorescence spectrum statistical fluctuation, and illustrated the basic theory ofwavelet transform used in spectrum smooth. It was show that wavelet transform canbe used to smooth the X-ray fluorescence spectrum Based on the treatment effect ofthe actual X-ray fluorescence spectrum.The multi-scale analysis ability of wavelet transform was used to deduct thebackground of the X-ray fluorescence spectrum, and illustrated the basic theory ofwavelet transform used in deducting spectrum background. The background of actualX-ray fluorescence spectrum was deducted by the method of fast "off peak"，and therenderings show clearly that wavelet transform can be used to deduct the backgroundof the X-ray fluorescence spectrum.The wavelet transform filter was used to resolve the overlapping peaks of X-rayfluorescence spectrum, and illustrated the basic theory of wavelet transform used inresolving spectrum overlapping peaks. The resolution factor of spline functioninteract with spline wavelet filter form peak resolution machine, and the overlapped peaks of X-ray fluorescence spectrum were resolved after passing peak resolutionmachine. The method is applied to deal with analog peaks overlap, the doublet andtriplet overlapped peaks were disassembled, and sub-peak positions remainunchanged, the area of peak error is less than4%.It’s combing LabWindows/CVI friendly user interface and convenient andsimple C language program compiled with MATLAB powerful mathematicalcalculation and analysis function, when design the spectrum resolving program.Designed program for X-ray fluorescence spectrum resolving, in order to smooth、deduct the background、resolve the overlapping peaks and calculate the peak area ofspectrum。Program running results show that the LabWindows/CVI and MATLABmixed programming can be reasonably combining the advantages of the two majorsoftware to achieve the spectrum resolving.When analysis the national standard soil samples (GSS) and brass alloy samples,the peak of Mn and peak of Fe were resolved, and the peak of Zn and peak of Cu were resolved. The average relative error of Mn、Fe、Cu、Zn were4.43%、3.24%、1.32%、2.49%, and compared with the results obtained by empiricalcoefficient method the effect obvious improvement, and it’s also said themeasurement accuracy is improved greatly. It’s shows that wavelet transform used toX fluorspar spectrum resolving achieved ideal result.To some extent, Wavelet transform as a new X-ray fluorescence spectrumanalysis method can reduce or even eliminate the statistical fluctuation of X-ray itselfand the interference between the spectrum lines, improve the accuracy of Xfluorescence analysis, provides support for the application of X-ray fluorescenceanalysis technology.