培训X射线荧光分析导论.pptVIP

电子波谱 1kHz - 1014Hz Theory The Hardware Sources End Window X-Ray Tube Side Window X-Ray Tube Radioisotopes Other Sources Source Modifiers Source Filters Filter Transmission Curve Filter Fluorescence Method Filter Absorption Method Secondary Targets Secondary Targets Secondary Target Method Polarizing Target Theory Collimators Focusing Optics Detectors Detector Principles Si(Li) Detector Si(Li) Cross Section PIN Diode Detector Silicon Drift Detector- SDD Proportional Counter Scintillation Detector Spectral Comparison - Au Detector Filters Detector Filter Transmission Filter Vs. No Filter Ross Vs. Hull Filters Wavelength Dispersive XRF Diffraction Multilayers Soller Collimators Cooling and Temperature Control Chamber Atmosphere Changers and Spinners Energy Dispersive Electronics Multi-Channel Analyser WDXRF Pulse Processing Evaluating Spectra K L Spectral Lines K L Spectral Peaks Scatter Rayleigh Scatter Compton Scatter Sum Peaks Escape Peaks Brehmstrahlung Interferences Spectral Interferences Environmental Interferences Matrix Interferences Absorption-Enhancement Affects Software Semi-Quantitative Analysis Quantitative Analysis Standards Sample Preparation Qualitative Scan Peak ID This spectrum also contrasts the resolution of a PIN diode detector with a proportional counter to illustrate the importance of detector resolution with regard to qualitative analysis. Automated Peak identification programs are a useful qualitative examination tool Element Tags Polymer Detector Windows Optional thin polymer windows compared to a standard beryllium windows Affords 10x improvement in the MDL for sodium (Na) Filters are positioned between the sample and detector in some EDXRF and NDXRF systems to filter out unwanted x-ray peaks. Sample Detector X-Ray Source Detector Filter % T R A N S M I T T E D ENERGY Low energy x-rays are absorbed EOI is transmitted Absorption Edge X-rays above the absorption edge energy are absorbed Very high energy x-rays are transmitted