X射线荧光分析导论培训课程课件

培训课件X射线荧光分析导论培训课件X射线荧光分析导论1Theory入射X射线轰击原子的内层电子，如果能量大于它的吸收边，该内层电子被驱逐出整个原子（整个原子处于高能态，即激发态）。较高能级的电子跃迁、补充空穴，整个原子处于低能态，即基态。由高能态转化为低能态，释放能量。

ΔE=Eh-El.

能量将以X射线的释放，产生X射线荧光。Theory入射X射线轰击原子的内层电子，如果能量大于它的吸2TheHardwareSourcesOpticsFilters&TargetsDetectorsTheHardwareSources3SourcesEndWindowX-RayTubesSideWindowX-RayTubesRadioisotopesOtherSourcesScanningElectronMicroscopesSynchrotronsPositronandotherparticlebeams SourcesEndWindowX-RayTubes4EndWindowX-RayTubeX-rayTubesVoltagedetermineswhichelementscanbeexcited.Morepower=lowerdetectionlimitsAnodeselectiondeterminesoptimalsourceexcitation(applicationspecific).EndWindowX-RayTubeX-rayTub5SideWindowX-RayTubeBeWindowSiliconeInsulationGlassEnvelopeFilamentElectronbeamTarget(Ti,Ag,Rh,etc.)CopperAnodeHVLeadSideWindowX-RayTubeBeWindo6RadioisotopesIsotopeFe-55Cm-244Cd-109Am-241Co-57Energy(keV)5.914.3,18.322,8859.5122Elements(K-lines)Al–VTi-BrFe-MoRu-ErBa-UElements(L-lines)Br-II-PbYb-PuNonenoneWhileisotopeshavefallenoutoffavortheyarestillusefulformanygaugingapplications.RadioisotopesIsotopeFe-55Cm-247OtherSourcesSeveralotherradiationsourcesarecapableofexcitingmaterialtoproducex-rayfluorescencesuitableformaterialanalysis.ScanningElectronMicroscopes(SEM)–Electronbeamsexcitethesampleandproducex-rays.ManySEM’sareequippedwithanEDXdetectorforperformingelementalanalysisSynchotrons-ThesebrightlightsourcesaresuitableforresearchandverysophisticatedXRFanalysis.PositronsandotherParticleBeams–Allhighenergyparticlesbeamsionizematerialssuchthattheygiveoffx-rays.PIXEisthemostcommonparticlebeamtechniqueafterSEM.OtherSourcesSeveralotherrad8SourceModifiersSeveralDevicesareusedtomodifytheshapeorintensityofthesourcespectrumorthebeamshapeSourceFiltersSecondaryTargetsPolarizingTargetsCollimatorsFocusingOpticsSourceModifiersSeveralDevice9SourceFiltersFiltersperformoneoftwofunctionsBackgroundReductionImprovedFluorescenceDetectorX-RaySourceSourceFilterSourceFiltersFiltersperform10FilterTransmissionCurve%TRANSMITTEDENERGYLowenergyx-raysareabsorbedAbsorptionEdgeX-raysabovetheabsorptionedgeenergyareabsorbedVeryhighenergyx-raysaretransmittedTiCrTitaniumFiltertransmissioncurveThetransmissioncurveshowsthepartsofthesourcespectrumaretransmittedandthosethatareabsorbedFilterTransmissionCurve%ENER11SourceFilterEOIistransmittedFiltersarepositionedbetweenthesampleanddetectorinsomeEDXRFandNDXRFsystemstofilteroutunwantedx-raypeaks.Inionizedsemiconductorproduceselectron-holepairs,thenumberofpairsproducedisproportionaltotheX-rayphotonenergyRayleighScatterPeaksRadioisotopesSecondaryTargets-Theyfluorescewhilescatteringthesourcex-raysandperformsimilarlytoothersecondarytargets.Standardsshouldvaryindependentlyinconcentrationwhenempiricalabsorptioncorrectionsareused.SourceFiltersAffords10ximprovementintheMDLforsodium(Na)SamplePreparationCollimatorsTheresultisapeakthatappearsinspectrum,at:ElementkeV-SikeV(1.UnfilteredTubetarget,Cl,andArInterferencePeakScintillationDetectorK-alphalines:Lshelle-transitiontofillvacancyinKshell.SecondaryTargetsScintillationDetectortransitionstofillvacancyinKInfluenceCoefficients,sometimescalledalphacorrectionsareusedtomathematicallycorrectforMatrixInterferencesFilterFluorescenceMethodENERGY(keV)TargetpeakWithZnSourcefilterFeRegionContinuumRadiationThefilterfluorescencemethoddecreasesthebackgroundandimprovesthefluorescenceyieldwithoutrequiringhugeamountsofextrapower.SourceFilterFilterFluorescen12FilterAbsorptionMethodENERGY(keV)TargetpeakWithTiSourcefilterFeRegionContinuumRadiationThefilterabsorptionMethoddecreasesthebackgroundwhilemaintainingsimilarexcitationefficiency.FilterAbsorptionMethodENERGY13SecondaryTargetsImprovedFluorescenceandlowerbackgroundThecharacteristicfluorescenceofthecustomlinesourceisusedtoexcitethesample,withthelowestpossiblebackgroundintensity.Itrequiresalmost100xthefluxoffiltermethodsbutgivessuperiorresults.SecondaryTargetsImprovedFluo14SecondaryTargetsSampleX-RayTubeDetectorSecondaryTargetThex-raytubeexcitesthesecondarytargetTheSecondarytargetfluorescesandexcitesthesampleThedetectordetectsx-raysfromthesampleSecondaryTargetsSampleX-RayT15SecondaryTargetMethodENERGY(keV)TubeTargetpeakWithZnSecondaryTargetFeRegionContinuumRadiationSecondaryTargetsproduceamoremonochromaticsourcepeakwithlowerbackgroundthanwithfiltersSecondaryTargetMethodENERGY16SecondaryTargetVsFilterComparisonofoptimizeddirect-filteredexcitationwithsecondarytargetexcitationforminorelementsinNi-200SecondaryTargetVsFilterComp17PolarizingTargetTheoryX-rayarepartiallypolarizedwhenevertheyscatteroffasurfaceIfthesampleandpolarizerareorientedperpendiculartoeachotherandthex-raytubeisnotperpendiculartothetarget,x-raysfromthetubewillnotreachthedetector.TherearethreetypeofPolarizationTargets:BarklaScatteringTargets-Theyscatterallsourceenergiestoreducebackgroundatthedetector.SecondaryTargets-Theyfluorescewhilescatteringthesourcex-raysandperformsimilarlytoothersecondarytargets.DiffractiveTargets-Theyaredesignedtoscatterspecificenergiesmoreefficientlyinordertoproduceastrongerpeakatthatenergy.PolarizingTargetTheoryX-ray18CollimatorsCollimatorsareusuallycircularoraslitandrestrictthesizeorshapeofthesourcebeamforexcitingsmallareasineitherEDXRForuXRFinstruments.TheymayrelyoninternalBraggreflectionforimprovedefficiency.SampleTubeCollimatorsizesrangefrom12micronstoseveralmmCollimatorsCollimatorsareusu19FocusingOpticsBecausesimplecollimationblocksunwantedx-raysitisahighlyinefficientmethod.FocusingopticslikepolycapillarydevicesandotherKumakhovlensdevicesweredevelopedsothatthebeamcouldberedirectedandfocusedonasmallspot.Lessthan75umspotsizesareregularlyachieved.SourceDetectorBraggreflectioninsideaCapillaryFocusingOpticsBecausesimple20DetectorsSi(Li)PINDiodeSiliconDriftDetectorsProportionalCountersScintillationDetectorsDetectorsSi(Li)21DetectorPrinciplesAdetectoriscomposedofanon-conductingorsemi-conductingmaterialbetweentwochargedelectrodes.X-rayradiationionizesthedetectormaterialcausingittobecomeconductive,momentarily.Thenewlyfreedelectronsareacceleratedtowardthedetectoranodetoproduceanoutputpulse.Inionizedsemiconductorproduceselectron-holepairs,thenumberofpairsproducedisproportionaltotheX-rayphotonenergyDetectorPrinciplesAdetector22K-alphalines:Lshelle-transitiontofillvacancyinKshell.X-raysstrikethesampleandpromoteelementalfluorescence.OtherSourcesFocusingOpticsAdditionally,grindinginsuresthatthemeasurementismorerepresentativeoftheentiresample,vs.ThisspectrumalsocontraststheresolutionofaPINdiodedetectorwithaproportionalcountertoillustratetheimportanceofdetectorresolutionwithregardtoqualitativeanalysis.Super-CooledCryostatInfluenceCoefficients,sometimescalledalphacorrectionsareusedtomathematicallycorrectforMatrixInterferencesThisspectrumalsocontraststheresolutionofaPINdiodedetectorwithaproportionalcountertoillustratetheimportanceofdetectorresolutionwithregardtoqualitativeanalysis.Synchrotrons220eVResolutionMatrixInterferencesBrehmstrahlungAutomatedPeakidentificationprogramsareausefulqualitativeexaminationtoolTargetpeakAnodeselectiondeterminesoptimalsourceexcitation(applicationspecific).PurgeinstrumentwithHe(lessdensethanair=lessattenuation).TargetpeakX-RayTubeCoolers,andEnergyisnotlostincollision.Si(Li)DetectorWindowSi(Li)crystalDewarfilledwithLN2Super-CooledCryostatCooling:LN2orPeltierWindow:BerylliumorPolymerCountsRates:3,000–50,000cpsResolution:120-170eVatMnK-alphaFETPre-AmplifierK-alphalines:Lshelle-t23Si(Li)CrossSectionSi(Li)CrossSection24PINDiodeDetectorCooling:Thermoelectricallycooled(Peltier)Window:BerylliumCountRates:3,000–20,000cpsResolution:170-240eVatMnk-alphaPINDiodeDetectorCooling:The25SiliconDriftDetector-SDD

Packaging:SimilartoPINDetector

Cooling:PeltierCountRates;10,000–300,000cps

Resolution:140-180eVatMnK-alphaSiliconDriftDetector-SDD

Pa26ProportionalCounterAnodeFilamentFillGases:Neon,Argon,Xenon,KryptonPressure:0.5-2ATMWindows:BeorPolymerSealedorGasFlowVersionsCountRatesEDX:10,000-40,000cpsWDX:1,000,000+Resolution:500-1000+eVWindowProportionalCounterAnodeFila27ScintillationDetectorPMT(Photo-multipliertube)SodiumIodideDiskElectronicsConnectorWindow:BeorAlCountRates:10,000to1,000,000+cpsResolution:>1000eVScintillationDetectorPMT(Pho28SpectralComparison-AuSi(Li)Detector10vs.14KaratSiPINDiodeDetector10vs.14KaratSpectralComparison-AuSi(Li)29PolymerDetectorWindowsOptionalthinpolymerwindowscompared toastandardberylliumwindowsAffords10ximprovementintheMDLforsodium(Na)PolymerDetectorWindowsOption30DetectorFiltersFiltersarepositionedbetweenthesampleanddetectorinsomeEDXRFandNDXRFsystemstofilteroutunwantedx-raypeaks.SampleDetectorX-RaySourceDetectorFilterDetectorFiltersFiltersarepo31DetectorFilterTransmission%TRANSMITTEDENERGYLowenergyx-raysareabsorbedEOIistransmittedAbsorptionEdgeX-raysabovetheabsorptionedgeenergyareabsorbedVeryhighenergyx-raysaretransmittedSClAniobiumfilterabsorbsClandotherhigherenergysourcex-rayswhilelettingSx-rayspass.Adetectorfiltercansignificantlyimprovedetectionlimits.NiobiumFilterTransmissionandAbsorptionDetectorFilterTransmission%E32FilterVs.NoFilterUnfilteredTubetarget,Cl,andArInterferencePeakDetectorfilterscandramaticallyimprovetheelementofinterestintensity,whiledecreasingthebackground,butrequires4-10timesmoresourceflux.Theyarebestusedwithlargeareadetectorsthatnormallydonotrequiremuchpower.FilterVs.NoFilterUnfiltered33RossVs.HullFiltersThepreviousslidewasanexampleoftheHullorsimplefiltermethod.TheRossmethodillustratedhereforClanalysisusesintensitiesthroughtwofilters,onetransmitting,oneabsorbing,andthedifferenceiscorrelatedtoconcentration.ThisisanNDXRFmethodsincedetectorresolutionisnotimportant.RossVs.HullFiltersTheprevi34WavelengthDispersiveXRFWavelengthDispersiveXRFreliesonadiffractivedevicesuchascrystalormultilayertoisolateapeak,sincethediffractedwavelengthismuchmoreintensethanotherwavelengthsthatscatterofthedevice.

SampleDetectorX-RaySourceDiffractionDeviceCollimatorsWavelengthDispersiveXRFWavel35DiffractionThetwomostcommondiffractiondevicesusedinWDXinstrumentsarethecrystalandmultilayer.Bothworkaccordingtothefollowingformula.nl=2d´sinqn=integerd=crystallatticeormultilayerspacingq=Theincidentangle=wavelengthAtomsDiffractionThetwomostcommon36Helium-ForusewithliquidsorpowderedmaterialsThishasbeenhistoricallythemostcommonlaboratorygradeEDXRFconfiguration.TargetpeakPIXEisthemostcommonparticlebeamtechniqueafterSEM.SecondaryTargetsproduceamoremonochromaticsourcepeakwithlowerbackgroundthanwithfiltersImprovedFluorescenceElectronicsWithTiSourcefilterHeEnvironmentTheyappearasasourcepeakinspectra.InfluenceCoefficients,sometimescalledalphacorrectionsareusedtomathematicallycorrectforMatrixInterferencesVeryhighenergySpectralComparison-AuBraggreflectionSynchrotronsTypicalSi(Li)DetectorInstrumentPINDiodeDetectorComparisonofoptimizeddirect-filteredexcitationwithsecondarytargetexcitationforminorelementsinNi-200VeryhighenergyLowenergyx-raysareabsorbedMultilayersWhilethecrystalspacingisbasedonthenaturalatomicspacingatagivenorientationthemultilayerusesaseriesofthinfilmlayersofdissimilarelementstodothesamething.Modernmultilayersaremoreefficientthancrystalsandcanbeoptimizedforspecificelements.OftenusedforlowZelements.Helium-Forusewithliquids37SollerCollimatorsSollerandsimilartypesofcollimatorsareusedtopreventbeamdivergence.TheareusedinWDXRFtorestricttheanglesthatareallowedtostrikethediffractiondevice,thusimprovingtheeffectiveresolution.SampleCrystalSollerCollimatorsSollerands38CoolingandTemperatureControlThediffractiontechniqueisrelativelyinefficientandWDXdetectorscanoperateatmuchhighercountrates,soWDXInstrumentsaretypicallyoperatedatmuchhigherpowerthandirectexcitationEDXRFsystems.Diffractiondevicesarealsotemperaturesensitive.

ManyWDXRFInstrumentsuse:X-RayTubeCoolers,andThermostaticallycontrolledinstrumentcoolersCoolingandTemperatureContro39ChamberAtmosphereSampleandhardwarechambersofanyXRFinstrumentmaybefilledwithair,butbecauseairabsorbslowenergyx-raysfromelementsparticularlybelowCa,Z=20,andArgonsometimesinterfereswithmeasurementspurgesareoftenused.Thetwomostcommonpurgemethodsare: Vacuum-Forusewithsolidsorpressedpellets Helium-ForusewithliquidsorpowderedmaterialsChamberAtmosphereSampleand40ChangersandSpinnersOthercommonlyavailablesamplehandlingfeaturesaresamplechangersorspinners.AutomaticsamplechangersareusuallyofthecircularorXYZstagevarietyandmayhavehold6to100+samplesSampleSpinnersareusedtoaverageoutsurfacefeaturesandparticlesizeaffectspossiblyoveralargertotalsurfacearea.

ChangersandSpinnersOthercom41TypicalPINDetectorInstrumentThisconfigurationismostcommonlyusedinhigherendbenchtopEDXRFInstruments.TypicalPINDetectorInstrumen42TypicalSi(Li)DetectorInstrumentThishasbeenhistoricallythemostcommonlaboratorygradeEDXRFconfiguration.TypicalSi(Li)DetectorInstru43EnergyDispersiveElectronicsFluorescencegeneratesacurrentinthedetector.InadetectorintendedforenergydispersiveXRF,theheightofthepulseproducedisproportionaltotheenergyoftherespectiveincomingX-ray.DETECTORSignaltoElectronicsElementAElementCElementBElementDEnergyDispersiveElectronicsF44Multi-ChannelAnalyserDetectorcurrentpulsesaretranslatedintocounts(countspersecond,“CPS”).PulsesaresegregatedintochannelsaccordingtoenergyviatheMCA(Multi-ChannelAnalyser).SignalfromDetectorChannels,EnergyIntensity(#ofCPSperChannel)Multi-ChannelAnalyserDetector45WDXRFPulseProcessingTheWDXmethodusesthediffractiondeviceandcollimatorstoobtaingoodresolution,soThedetectordoesnotneedtobecapableofenergydiscrimination.Thissimplifiesthepulseprocessing.Italsomeansthatspectralprocessingissimplifiedsinceintensitysubtractionisfundamentallyanexerciseinbackgroundsubtraction.Note:Someenergydiscriminationisusefulsinceitallowsforrejectionoflowenergynoiseandpulsesfromunwantedhigherenergyx-rays.

WDXRFPulseProcessingTheWDX46CountRates;10,000–300,000cps

Resolution:140-180eVatMnK-alphaFiltersarepositionedbetweenthesampleanddetectorinsomeEDXRFandNDXRFsystemstofilteroutunwantedx-raypeaks.X-raysabovetheabsorptionedgeenergyareabsorbedVeryhighenergyEscapePeaksFocusingOpticsSecondaryTargets-Theyfluorescewhilescatteringthesourcex-raysandperformsimilarlytoothersecondarytargets.Examples:SecondaryTargetsX-raysstrikethesampleandpromoteelementalfluorescence.AdjacentElementOverlapLowenergyx-raysareabsorbedSomeSifluorescenceatthesurfaceofthedetectorescapes,andisnotcollectedbythedetector.OtherSourcesBarklaScatteringTargets-Theyscatterallsourceenergiestoreducebackgroundatthedetector.SignaltoElectronicsSollerandsimilartypesofcollimatorsareusedtopreventbeamdivergence.SomeSifluorescenceatthesurfaceofthedetectorescapes,andisnotcollectedbythedetector.ThishasbeenhistoricallythemostcommonlaboratorygradeEDXRFconfiguration.ElementTagsAnodeselectiondeterminesoptimalsourceexcitation(applicationspecific).Detectorfilterscandramaticallyimprovetheelementofinterestintensity,whiledecreasingthebackground,butrequires4-10timesmoresourceflux.EvaluatingSpectraK&LSpectralPeaksRayleighScatterPeaksComptonScatterPeaksEscapePeaksSumPeaksBremstrahlungInadditiontoelementalpeaks,otherpeaksappearinthespectra:CountRates;10,000–300,00047K&LSpectralLinesK-alphalines:

Lshelle-transitiontofillvacancyinKshell.Mostfrequenttransition,hencemostintensepeak.

K-betalines:

Mshelle-transitionstofillvacancyinKshell.LShellKShell

L-alphalines:

Mshelle-transitiontofillvacancyinLshell.

L-betalines:

Nshelle-transitiontofillvacancyinLshell.KalphaKbetaMShellLalphaNShellLbetaK&LSpectralLinesK-alpha48K&LSpectralPeaksRhX-rayTubeL-linesK-LinesK&LSpectralPeaksRhX-rayT49ScatterSomeofthesourceX-raysstrikethesampleandarescatteredbackatthedetector.

Sometimescalled “backscatter”SampleSourceDetectorScatterSomeofthesourceX-ra50RayleighScatterX-raysfromtheX-raytubeortargetstrikeatomwithoutpromotingfluorescence.Energyisnotlostincollision.(EI=EO)Theyappearasasourcepeakinspectra.AKA-“Elastic”ScatterEIEORhX-rayTubeRayleighScatterX-raysfromth51ComptonScatterX-raysfromtheX-raytubeortargetstrikeatomwithoutpromotingfluorescence.Energyislostincollision.(EI>EO)Comptonscatterappearsasasourcepeakinspectra,slightlylessinenergythanRayleighScatter.AKA-“Inelastic”ScatterEIEORhX-rayTubeComptonScatterX-raysfromthe52SumPeaks2photonsstrikethedetectoratthesametime.Thefluorescenceiscapturedbythedetector,recognizedas1photontwiceitsnormalenergy.Apeakappearsinspectra,at:2X(ElementkeV).SumPeaks2photonsstrikethe53EscapePeaksX-raysstrikethesampleandpromoteelementalfluorescence.SomeSifluorescenceatthesurfaceofthedetectorescapes,andisnotcollectedbythedetector.Theresultisapeakthatappearsinspectrum,at:ElementkeV-SikeV(1.74keV).RhX-rayTube1.74keVEscapePeaksX-raysstrikethe54BrehmstrahlungBrehmstrahlung(orContinuum)Radiation:Germanfor“breakingradiation”,noisethatappearsinthespectraduetodecelerationofelectronsastheystriketheanodeoftheX-raytube.BrehmstrahlungBrehmstrahlung(55InterferencesSpectralInterferencesEnvironmentalInterferencesMatrixInterferencesInterferencesSpectralInterfer56EscapePeaksComptonScatterAniobiumfilterabsorbsClandotherhigherenergysourcex-rayswhilelettingSx-rayspass.220eVResolutionThefluorescenceiscapturedbythedetector,recognizedas1photontwiceitsnormalenergy.ΔE=Eh-Elshell.EndWindowX-RayTubesSynchrotronsSpectralInterferences较高能级的电子跃迁、补充空穴，整个原子处于低能态，即基态。ImprovedFluorescenceandlowerbackgroundThecharacteristicfluorescenceofthecustomlinesourceisusedtoexcitethesample,withthelowestpossiblebackgroundintensity.CountsRates:3,000–50,000cpsSi(Li)DetectorSamplesshouldbefreshwhenanalysedandanalysedwithshortanalysistime-ifsampleisevaporative.FilterTransmissionCurveThisconfigurationismostcommonlyusedinhigherendbenchtopEDXRFInstruments.ProportionalCounterInfluenceCoefficients,sometimescalledalphacorrectionsareusedtomathematicallycorrectforMatrixInterferencesCopperAnodeAutomatedPeakidentificationprogramsareausefulqualitativeexaminationtoolLowenergyx-raysareabsorbedSpectralInterferencesSpectralinterferencesarepeaksinthespectrumthatoverlapthespectralpeak(regionofinterest)oftheelementtobeanalyzed.Examples:K&LlineOverlap-S&Mo,Cl&Rh,As&PbAdjacentElementOverlap-Al&Si,S&Cl,K&Ca...Resolutionofdetectordeterminesextentofoverlap.220eVResolution140eVResolutionAdjacentElementOverlapEscapePeaksSpectralInterfere57EnvironmentalInterferencesLightelements(Na-Cl)emitweakX-rays,easilyattenuatedbyair.Solution:PurgeinstrumentwithHe(lessdensethanair=lessattenuation).Evacuateairfromanalysischamberviaavacuumpump.EitherofthesesolutionsalsoeliminateinterferencefromAr(spectraloverlaptoCl).Argon(Ar)isacomponentofair.AirEnvironmentHeEnvironmentAlAnalyzedwithSiTargetEnvironmentalInterferencesLig58MatrixInterferencesAbsorption:Anyelementcanabsorborscatterthefluorescenceoftheelementofinterest.Enhancement:Characteristicx-raysofoneelementexciteanotherelementinthesample,enhancingitssignal.InfluenceCoefficients,sometimescalledalphacorrectionsareusedtomathematicallycorrectforMatrixInterferencesAbsorption/EnhancementEffectsMatrixInterferencesAbsorption59Absorption-EnhancementAffectsIncomingsourceX-rayfluorescesFe.FefluorescenceissufficientinenergytofluoresceCa.Caisdetected,Feisnot.Responseisproportionaltoconcentrationsofeachelement.Red

=Fe,absorbedBlue

=Ca,enhancedSourceX-rayX-RayCapturedbythedetector.SampleAbsorption-EnhancementAffects60SoftwareQualitativeAnalysisSemi-QuantitativeAnalysis(SLFP,NBS-GSC.)QuantitativeAnalysis(MultipleintensityExtractionandRegressionmethods)Software61QualitativeScanPeakIDThisspectrumalsocontraststheresolutionofaPINdiodedetectorwithaproportionalcountertoillustratetheimportanceofdetectorresolutionwithregardtoqualitativeanalysis.AutomatedPeakidentificationprogramsareausefulqualitativeexaminationtool

ElementTagsQualitativeScanPeakIDThiss62Semi-QuantitativeAnalysisThealgorithmcomputesboththeintensitytoconcentrationrelationshipandtheabsorptionaffectsResultsaretypicallywithin10-20%ofactualvalues.SLFPStandardlessFundamentalParametersFP(withStandards)NBS-GSC,NRLXRF,Uni-Quant,TurboQuant,etc…Theconcentrationtointensityrelationshipisdeterminedwithstandards,whiletheFPhandlestheabsorptionaffects.Resultsareusuallywithin5-10%ofactualvaluesSemi-QuantitativeAnalysisThe63QuantitativeAnalysisConcentrationIntensityXRFisareferencemethod,standardsarerequiredforquantitativeresults.Standardsareanalysed,intensitiesobtained,andacalibrationplotisgenerated(intensitiesvs.concentration).XRFinstrumentscomparethespectralintensitiesofunknownsamplestothoseofknownstandards.QuantitativeAnalysisConcentra64StandardsStandards(suchascertifiedreferencematerials)arerequiredforQuantitativeAnalysis.Standardconcentrationsshouldbeknowntoabetterdegreeofprecisionandaccuracythanisrequiredfortheanalysis.Standardsshouldbeofthesamematrixassamplestobeanalyzed.Numberofstandardsrequiredforapurelyempiricalmethod,N=(E+1)2,N=#ofstandards,E=#ofElements.Standardsshouldvaryindependentlyinconcentrationwhenempiricalabsorptioncorrectionsareused.StandardsStandards(suchasce65SpectralInterferencesThissimplifiesthepulseprocessing.ENERGY(keV)SomeofthesourceX-raysstrikethesampleandarescatteredbackatthedetector.VeryhighenergyThishasbeenhistoricallythemostcommonlaboratorygradeEDXRFconfiguration.L-alphalines:Mshelle-Pre-AmplifierSampleSpinnersareusedtoaverageoutsurfacefeaturesandparticlesizeaffectspossiblyoveralargertotalsurfacearea.VeryhighenergyAdetectorfiltercansignificantlyimprovedetectionlimits.Detectorfilterscandramaticallyimprovetheelementofinterestintensity,whiledecreasingthebackground,butrequires4-10timesmoresourceflux.BackgroundReductionWindows:BeorPolymerX-raysstrikethesampleandpromoteelementalfluorescence.SynchrotronsCollimatorsTheareusedinWDXRFtorestricttheanglesthatareallowedtostrikethediffractiondevice,thusimprovingtheeffectiveresolution.Detectorcurrentpulsesaretranslatedintocounts(countspersecond,“CPS”).Standardsshouldbeofthesamematrixassamplestobeanalyzed.SollerCollimatorsElectronbeamPositronsandotherParticleBeams–Allhighenergyparticlesbeamsionizematerialssuchthattheygiveoffx-rays.ElementTagsUnfilteredTubetarget,Cl,andArInterferencePeakCollimatorsCollimatorsizesrangefrom12micronstoseveralmmTheSecondarytargetfluorescesandexcitesthesampleSeveralDevicesareusedtomodifytheshapeorintensityofthesourcespectrumorthebeamshapeSourceFiltersRhX-rayTubeFocusingopticslikepolycapillarydevicesandotherKumakhovlensdevicesweredevelopedsothatthebeamcouldberedirectedandfocusedonasmallspot.CollimatorsareusuallycircularoraslitandrestrictthesizeorshapeofthesourcebeamforexcitingsmallareasineitherEDXRForuXRFinstruments.PINDiodeDetectorSpectralinterferencesarepeaksinthespectrumthatoverlapthespectralpeak(regionofinterest)oftheelementtobeanalyzed.AutomatedPeakidentificationprogramsareausefulqualitativeexaminationtool入射X射线轰击原子的内层电子，如果能量大于它的吸收边，该内层电子被驱逐出整个原子（整个原子处于高能态，即激发态）。CollimatorsareusuallycircularoraslitandrestrictthesizeorshapeofthesourcebeamforexcitingsmallareasineitherEDXRForuXRFinstruments.Theresultisapeakthatappearsinspectrum,at:ElementkeV-SikeV(1.SamplePreparationPowders:Grinding(<400meshifpossible)canminimisescatteraffectsduetoparticlesize.Additionally,grindinginsuresthatthemeasurementismorerepresentativeoftheentiresample,vs.thesurfaceofthesample.Pressing(hydra