ASTM E481-2003 用钴和银的放射性测定中子积分通量率的标准试验方法

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【英文标准名称】:StandardTestMethodforMeasuringNeutronFluenceRatebyRadioactivationofCobaltandSilver
【原文标准名称】:用钴和银的放射性测定中子积分通量率的标准试验方法
【标准号】:ASTME481-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E10.05
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测量;试验;钴;中子注量;银;核能;放射性;核技术
【英文主题词】:activation;cobalt;dosimetry;foil;silver;thermalneutron
【摘要】:1.1Thistestmethodcoversasuitablemeansofobtainingthethermalneutronfluencerate,orfluence,inwellmoderatednuclearreactorenvironmentswheretheuseofcadmium,asathermalneutronshieldasdescribedinMethodE262,isundesirablebecauseofpotentialspectrumperturbationsoroftemperaturesabovethemeltingpointofcadmium.1.2ThistestmethoddescribesameansofmeasuringaWestcottneutronfluencerate(Note1)byactivationofcobalt-andsilver-foilmonitors(SeeTerminologyE170).Thereaction59Co(n,)60Coresultsinawell-definedgammaemitterhavingahalf-lifeof1925.5days(1).Thereaction109Ag(n,)110mAgresultsinanuclidewithacomplexdecayschemewhichiswellknownandhavingahalf-lifeof249.76days(14).Bothcobaltandsilverareavailableeitherinverypureformoralloyedwithothermetalssuchasaluminum.AreferencesourceofcobaltinaluminumalloytoserveasaneutronfluenceratemonitorwirestandardisavailablefromtheNationalInstituteofStandardsandTechnology(NIST)asStandardReferenceMaterial953.Thecompetingactivitiesfromneutronactivationofotherisotopesareeliminated,forthemostpart,bywaitingfortheshort-livedproductstodieoutbeforecounting.Withsuitabletechniques,thermalneutronfluencerateintherangefrom109cm2s1to31015cm2s1canbemeasured.Forthismethodtobeapplicable,thereactormustbewellmoderatedandbewellrepresentedbyaMaxwellianlow-energydistributionandan(1/E)epithermaldistribution.Theseconditionsareusuallymetinpositionssurroundedbyhydrogenousmoderatorwithoutnearbystronglyabsorbingmaterials.Otherwisethetruespectrummustbecalculatedtoobtaineffectiveactivationcrosssectionsoverallenergies.Note0Westcottfluencerate=Equation1-v00n(v)dv.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:F04
【国际标准分类号】:17_240;27_120_30
【页数】:6P.;A4
【正文语种】: