核辐射测量方法8Methods of nuclear radiation measurement 8.docx
- 文档编号:24903421
- 上传时间:2023-06-02
- 格式:DOCX
- 页数:7
- 大小:16.88KB
核辐射测量方法8Methods of nuclear radiation measurement 8.docx
《核辐射测量方法8Methods of nuclear radiation measurement 8.docx》由会员分享,可在线阅读,更多相关《核辐射测量方法8Methods of nuclear radiation measurement 8.docx(7页珍藏版)》请在冰豆网上搜索。
核辐射测量方法8Methodsofnuclearradiationmeasurement8
核辐射测量方法8(Methodsofnuclearradiationmeasurement8)
ThisarticlebytheuniqueproductABCcontribution
PptdocumentsmayexperiencepoorbrowsingontheWAPside.ItisrecommendedthatyoufirstselectTXT,ordownloadthesourcefiletothelocalview.
Theeighthchapterisneutronmeasurement
8.1neutronsource
Maincharacteristicsof8.1.1neutronsource
1neutronsourcestrength
Neutronsourcestrengthreferstothenumberofneutronsemittedperunittime,i.e.,neutronintensity.Ifonlyoneneutronisreleasedfromeachnuclearreaction,thesourcestrengthisequaltothenumberofnuclearreactionsoccurringinthetargetmaterialperunittime.
2sourceenergy
Neutronsourceenergyistheneutronenergyemittedbyaneutronsource.Neutronenergyisusuallyreferredtoaskineticenergy
Binaryhalflifein2
Thehalf-lifeofasourcereferstothehalf-lifeofradioactiveisotopesemittedbybombardingparticles.
8.1neutronsource
Thetypeof8.1.2neutronsource
1isotopeneutronsource
1)neutronsource(alpha,n)neutronsource
Radiumberylliumsourcepoloniumberylliumneutronsourceamericiumberylliumneutronsourceofplutoniumberylliumneutronsourcespontaneousfissionneutronsource
(2)~(252Cf)))(spontaneousfissionneutronsource
8.1neutronsource
Thetypeof8.1.2neutronsource
2acceleratorneutronsource
TheenergyreleasedbytheT(D,n)4Hereactionisassignedtoneutronsandheliumnuclei
3acceleratorneutronsource
Neutronsfromthissourcecomefromachainreactioninthereactor.
8.1neutronsource
Thetypeof8.1.2neutronsource
Commonneutronsourceandclassification
8.2basicprinciplesandmethodsofneutrondetection
8.2.1nuclearreactionmethod
Neutroncrosssectionsofthreenuclearreactionsof10B,6Li,and3He,andneutroncrosssectionsofthreenuclearreactions
8.2basicprinciplesandmethodsofneutrondetection
8.2.2nuclearrecoilmethod
TheincidentenergyofEneutronsandnucleuselasticscattering,neutronmotiondirectionwillbechanged,energyhasbeenreduced,reducedneutronenergytothenucleus,thenuclearmotionatacertainspeed.Thenucleusiscalledarecoilnucleus".Therecoilnucleushasacertaincharge,whichcanberecordedaschargedparticles,andtherecoilnucleuscanberecordedtodetecttheneutron.Thismethodofdetectingneutronsiscalledthenuclearrecoilmethod".
8.2basicprinciplesandmethodsofneutrondetection
8.2.3nuclearcrackingmethod
Neutronandheavynucleicanundergofission,andfissioncrackingisthemethodofdetectingneutronsbyrecordingheavynuclearfissionfragments.Forthermalneutronsandslowneutrons,238U,239Puand233Uarealwaysusedasfissilematerials.
Characteristicsofcommonlyusedfissilethresholdenergydetectormaterials
8.2basicprinciplesandmethodsofneutrondetection
8.2.4activationmethod
Neutronseasilyenterthenucleusandformacompositenucleusintheexcitedstate,andthecompositenucleusrapidlyjumpsbacktothegroundstatebyemittingoneormorephotons.Theneutroncaptureprocess,emitgammaradiationiscalled"radiation",with(n,y)saidthatatypicalexampleistheuseof115Inastheactivematerial,letitbetheneutronexposurecanoccurfollowingreactions:
newgenerationnuclidesaregenerallynotstable,inthiscase,thegenerated116Inisbetaradiationbody,andcontinuetodecayasfollows
8.2basicprinciplesandmethodsofneutrondetection
8.2.5neutrondetector
1gasdetector
Threeboronfluoride(BF3)proportionalcounter,boronionizationchamber,fissionchamber
2scintillationdetector
ZnSfastneutronscreen,ZnSslowneutronscreen,Lithiumglassscintillator,organicscintillator
8.2basicprinciplesandmethodsofneutrondetection
8.2.5neutrondetector
3semiconductordetector
6LiFneutronspectrometer3Heneutronspectrometer
Othersandwichsemiconductordetectors
8.3neutronspectrummeasurementmethod
8.3.1slowneutronenergyspectrummeasurementmethod
1timeofflight
Iftheneutronmassisrecordedasm,theneutronenergyEcanbecalculatedwhentheneutronvelocityVisdetermined.Accordingtoandcanbeobtained:
8.3neutronspectrummeasurementmethod
8.3.
1slowneutronspectrometry
2crystaldiffractionmethod
Whentheneutronwaveissenttothecrystalsurfaceatthegrazingangletheta(nottheincidentanglealpha),thereflectedneutronwaveonthetwoadjacentcrystalfaceshasadistanceof2dsintheta(Disthedistancebetweenthetwoadjacentcrystalfaces).When2dsinthetaisequaltomultiplesofthewavelength,thetworeflectedwavesarecoherentlyenhanced,otherwisecoherent,weakened,orevencounteracted.
Thereflectionofaneutronwaveonacrystal
Theaccumulationofreflectionsonanumberofparallelcrystalsurfacesleadstocoherentconditionswhichgiverisetogreatconditions,namelytheBraggformula:
8.3neutronspectrummeasurementmethod
8.3.2fastneutronenergyspectrometry
1timeofflight
Infastneutronspectrummeasurements,theadjointparticlemethodisoftenusedasaneutronsource.
Time-of-flightspectrometer
8.3neutronspectrummeasurementmethod
8.3.2fastneutronenergyspectrometry
2hydrogenrecoilmethod
Theschematicdiagramoftherecoilnuclearmethodmeasurements(D,n)TneutronspectraoftheHereactionneutronspectrumarepresented
8.3neutronspectrummeasurementmethod
8.3.3pulsedneutronenergyspectrometry
1byanacceleratorpulsedneutronsource2pulseneutronsourceburst3
8.4neutronfluxdensitymeasurementmethod
8.4.1neutronfluxdensityandneutrondensity
Iftheuseofradioisotopeoracceleratortoproduceneutrons,generallyregardedasapointsource,andtheunitvolumeintheneutronnumberndefinitionforshootingneutrondensity(cm-3),whentheneutronemittingspeedofV(cms-1),aproductofNVneutronnumberisneutronradiationthedensityofNandVfromthespeedperunitvolumeperunittime,whichistheneutronfluxdensitywiththepointsource.WhentheneutronfluxdensityaccordingtotheenergyofEwithcontinuousdistributeddiameter(E),canbeusedtorepresenttheenergyoftheneutronfluxdensityintherangeofE+dEinE,thetotalfluxdensityattheneutron
8.4neutronfluxdensitymeasurementmethod
Thebasicmethodofmeasuringneutronfluxdensityby8.4.2
1standardsectionmethod
Sinceneutronsarenotcharged,theycannotbedetecteddirectly,andneutronsandnuclearreactionsmayproducechargedparticles(orgeneratenewradionuclides),whichcanbeusedtomeasureabsoluteenergyparticles(ornewradionuclides).Generally,aslongasthecrosssectionofnuclearreactionisknown,theneutronfluxdensitycanbedeterminedbymeasuringtheintensityofchargedparticles(ortheactivityofnewradionuclides).
2followedbyparticlemethod3followedbyparticleradioactivityand4countermeasurements
8.5applicationsofneutronmeasurements
8.5.1naturalneutronmeasurementanditsapplication
Atmosphericneutronsourceanddistributioncharacteristicsoftheairgroundinterface:
risingfastneutronflowtodeterminethegeologicalmediummoisturecontentfromtheairgroundinterfaceofnaturalneutronfluxtopredicttransientchangesinatmosphericairgroundinterfaceneutronradiationproducedbynaturalenvironment
8.5applicationsofneutronmeasurements
8.5.2neutronactivationanalysisanditsapplication
Principle:
theuseofneutronsourceirradiationsample,andmakeitbecomeactivatedradionuclides(calledinducedradionuclides),bymeasuringthesenseofthephenomenonofradioactiveradioactivitynuclideanalysisonthephysicalsample.Thegammaexposureinthetestsampleoftheinducedradionuclideratioforthepreparationofstandardsamplesofknownanalytecontent,andirradiationandmeasurementunderthesameconditionsofthesample,andthencomparingthesampleandstandardsampleofgammaspectrum,canachievethemeasuredelementscontentdetermination.
Wsisthecontentofthesampletobemeasured,andIsisthestandardamountoftheirradiatedsample.
8.5applicationsofneutronmeasurements
8.5.2neutronactivationanalysisanditsapplication
Applicationofneutronactivationanalysisinphysicsanalysis:
1)intheanalysisofhighpuritymaterialsintheanalysisoftheapplicationofhighpuritymaterials2)appliedinthesmeltingindustryinthesmeltingindustryin3)applicationinotherareasinotherareas
8.5applicationsofneutronmeasurements
8.5.
Applicationof3neutronmeasurementmethodinprospecting
1neutroninteractionwithformationmaterial
1)fastneutroninelasticscatteringoffastneutroninelasticscattering2)fastneutronactivationoffastneutronnuclearactivationofNuclearPhysics3)fastneutronelasticscatteringanddecelerationprocessinvolves3)physicalquantityoftheelasticscatteringoffastneutronanddecelerationprocessinvolving4)intherockthermalneutrondiffusionwiththecaptureofthermalneutronsintherockdiffusionandtrapping
8.5applicationsofneutronmeasurements
Applicationof8.5.3neutronmeasurementmethodinprospecting
2neutronloggingmethod
1)usingcontinuousneutronsourceloggingmethods,commoncontinuousneutronsourceloggingmethodsincludeneutrongammalogging,neutronneutronloggingandcontinuousactivationlogging.Neutronneutronlogging(neutronneutronlogging)isagroupofwellloggingmethodsthatusetheinteractionofneutronandmattertostudythepropertiesofdrillingprofiles.Accordingtotherecordedobject,itcanbedividedintoneutronthermalneutronlogging,neutronepithermalneutronloggingandneutrongammalogging.Accordingtothestructuralcharacteristicsoftheinstrument,itca
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 核辐射测量方法8Methods of nuclear radiation measurement 核辐射 测量方法 Methods
链接地址:https://www.bdocx.com/doc/24903421.html