NF T30-212-1981 涂料和清漆.可溶金属含量的测定.可溶锑含量的测定

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【英文标准名称】:StandardTestMethodforMeasuringNeutronFluenceandAverageEnergyfrom3H(d,n)4HeNeutronGeneratorsbyRadioactivationTechniques1
【原文标准名称】:用放射性技术测定H3(d,n)He4中子发生器所产生的中子注量和平均能量的标准试验方法
【标准号】:ASTME496-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:E10.07
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:14-MeV;DT;neutronactivation;neutrongenerator;neutronmetrology;Neutronactivationreactions;Neutronflux/fluence;Radioactivation--fastneutronflux;Thresholddetectors--14MeV;Fastneutronflux/fluence;Fluence
【摘要】:RefertoPracticeE261forageneraldiscussionofthemeasurementoffast-neutronfluencerateswiththresholddetectors.RefertoTestMethodE265forageneraldiscussionofthemeasurementoffast-neutronfluenceratesbyradioactivationofsulfur-32.Reactionsusedfortheactivitymeasurementscanbechosentoprovideaconvenientmeansfordeterminingtheabsolutefluenceratesof14-MeVneutronsobtainedwith3H(d,n)4Heneutrongeneratorsoverarangeofirradiationtimesfromsecondstoapproximately100days.Highpuritythresholdsensorsreferencedinthistestmethodarereadilyavailable.Theneutron-energyspectrummustbeknowninordertomeasurefast-neutronfluenceusingasinglethresholddetector.Neutronsproducedbybombardingatritiatedtargetwithdeuteronsarecommonlyreferredtoas14-MeVneutrons;however,theycanhavearangeofenergiesdependingon:(1)theangleofneutronemissionwithrespecttothedeuteronbeam,(2)thekineticenergyofthedeuterons,and(3)thetargetthickness.InmostavailableneutrongeneratorsoftheCockroft-Waltontype,athicktargetisusedtoobtainhigh-neutronyields.Asdeuteronspenetratethroughthesurfaceandmoveintothebulkofthethicktarget,theyloseenergy,andinteractionsoccurringdeeperwithinthetargetproduceneutronswithcorrespondinglylowerenergy.WidevariationsinneutronenergyarenotgenerallyencounteredincommerciallyavailableneutrongeneratorsoftheCockroft-Waltontype.Figs.1and2(1)showthevariationofthezerodegree3H(d,n)4Heneutronproductioncrosssectionwithenergy,andclearlyindicatethatmaximumneutronyieldisobtainedwithdeuteronshavingenergiesnearthe107keVresonance.Sincemostgeneratorsaredesignedforhighyield,thedeuteronenergyistypicallyabout200keV,givingarangeofneutronenergiesfromapproximately14to15MeV.Thedifferentialcenter-of-masscrosssectionistypicallyparameterizedasasummationofLegendrepolynomials.Figs.3and4(1,2)showhowtheneutronyieldvarieswiththeemissionangleinthelaboratorysystem.TheinsertinFig.4showshowthemagnitude,A1,oftheP1(x03B8;)term,andhencetheasymmetryinthedifferentialcrosssectiongrowswithincreasingenergyoftheincidentdeuteron.Thenonrelativistickinematics(validforEdx003C;20MeV)forthe3H(d,n)4Hereactionshowthat:where:En

【中国标准分类号】:A58
【国际标准分类号】:17_240
【页数】:12P.;A4
【正文语种】:英语

标准名称：	主轴油
中标分类：	石油 >> 石油产品 >> 润滑油
替代情况：	被SH 0017-90代替
发布日期：
实施日期：	2000-10-01
首发日期：
作废日期：
出版日期：

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