| The continuous development and improvement of X-ray fluorescence spectrometer makes X-ray fluorescence analysis technology is widely used in geology,minerals,petroleum,chemical,medical and many other fields.Modern energy dispersive X-ray fluorescence(EDXRF)spectrometer mainly consists of the following parts:X-ray generator(X-ray tube,high voltage power supply),detection system(collimator,detector),signal processing circuit(amplifying circuit and filter circuit)and the recording and counting system(multi-channel analyzer).The EDXRF spectrometer measures the characteristic X-ray spectrum energy and intensity of the elements to be measured in the sample,allowing qualitative and quantitative analysis of the various elements in the sample without damaging the sample structure.This paper fully relies on the existing X-ray analysis of the research results and essence,designing a small laboratory energy dispersive X-ray fluorescence spectrometer.In this paper,high stability and high energy resolution of electric cooled Si-PIN semiconductor detector is used as the detector,high stability and widely range of analysis of X-ray tube is used as the excitation source.The combination of theory and practice is used to determine the best geometric optical path of source-sample-detector.This improves detection efficiency and detection limit of EDXRF spectrometer significantly.This paper designs a plastic amplifier circuit and a peak hold circuit that can be directly connected to the detector output to improve the energy resolution of the instrument.This paper designs a multi-channel pulse amplitude analyzer composed of FPGA as the control core,analog-to-digital conversion circuit,level conversion circuit and RS232 communication circuit.In this paper,the X-ray spectral data processing is described in detail from the aspects of spectral smoothing,background spectral subtraction and peak finding and peak area calculation,and the qualitative and quantitative analysis of the elements is realized.In addition,this article on the instrument system performance test basically achieved the desired results on the instrument detection range,energy resolution,repeatability,stability and linearity error.Finally,this paper designs the user interface of PC based on Lab VIEW,and uses multi-thread technology and database technology to realize the acquisition,analysis and storage of spectral data. |
