The System Design Of Energy Dispersive X-Ray Fluorescence Spectrometer

Energy dispersive X-ray fluorescence spectrometer is a new type measuring and analyzing instrument which can complete qualitative analysis and quantitative analysis of materials.Therefore it has been widely applied in the field of the metallurgy,archeology,detection of hazardous substance,mineral analysis and so on.In this paper,a energy dispersive X-ray fluorescence spectrometer will be introduced.The spectrometer mainly consists of the following parts: X-ray generator,high voltage DC supply module,optical system and signal processing circuit.The spectrometer collects and analyses the spectrum signal.The spectrometer adopts the Mo target X-ray tube as its excitation source.Adjust the current and voltage through the high-voltage power supply to get the best range of excitation for X-ray fluorescence.A collimator with filter is designed to optimize source-sample-detector optical structure.It can effectively Reduce the background interference and improve the peak to background ratio of characteristic X-ray detection.High energy resolution of electric cooled Si-PIN semiconductor detector is used as the detector.In order to increase the sensitivity of the spectrometer,a plastic amplifier circuit is designed which can modulate the pulses signal of the detector.Multichannel amplitude analyzer designed based on FPGA,the signal is sampled and converted into digital according to the signal of peak detection circuit.The hardware system uses the Verilog HDL program code,the ModelSim to simulate and the SignalTap II to debug online.This paper designs upper system based on LabVIEW.Multithreading technology and data base are applied in this system.After spectral smoothing,background spectral subtraction and peak finding and peak area calculation,the upper system displays the result of qualitative analysis and quantitative analysis of elements.