【英文标准名称】:StandardGuideforX-RayComptonScatterTomography
【原文标准名称】:X射线康普顿散射断层摄影的标准指南
【标准号】:ASTME1931-2009
【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】:E07.01
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:
【英文主题词】:back-scatter;comptonscattertomography;computedtomography;CST;radiologic;radioscopic;sliceimage;tomography;CST(Comptonscattertomography);Imageanalysis;Radioisotopes;Radiologicalexamination;Sliceimage;Tomography;X-rayComptonscatter
【摘要】:PrincipalAdvantageofComptonScatterTomography8212;TheprincipaladvantageofCSTistheabilitytoperformthree-dimensionalX-rayexaminationwithouttherequirementforaccesstothebacksideoftheexaminationobject.CSToffersthepossibilitytoperformX-rayexaminationthatisnotpossiblebyanyothermethod.TheCSTsub-surfacesliceimageisminimallyaffectedbyexaminationobjectfeaturesoutsidetheplaneofexamination.Theresultisaradioscopicimagethatcontainsinformationprimarilyfromthesliceplane.Scatteredradiationlimitsimagequalityinnormalradiographicandradioscopicimaging.ScatterradiationdoesnothavethesamedetrimentaleffectuponCSTbecausescatterradiationisusedtoformtheimage.Infact,themoreradiationtheexaminationobjectscatters,thebettertheCSTresult.LowsubjectcontrastmaterialsthatcannotbeimagedwellbyconventionalradiographicandradioscopicmeansareoftenexcellentcandidatesforCST.VeryhighcontrastsensitivitiesandexcellentspatialresolutionarepossiblewithCSTtomography.Limitations8212;Aswithanynondestructivetestingmethod,CSThasitslimitations.Thetechniqueisusefulonreasonablythicksectionsoflow-densitymaterials.Whilea25mm(1in.)depthinaluminumor50mm(2in.)inplasticisachievable,theexaminationdepthisdecreaseddramaticallyasthematerialdensityincreases.Properimageinterpretationrequirestheuseofstandardsandexaminationobjectswithknowninternalconditionsorrepresentativequalityindicators(RQIs).Theexaminationvolumeistypicallysmall,ontheorderofafewcubicinchesandmayrequireafewminutestoimage.Therefore,completelyexamininglargestructureswithCSTrequiresintensivere-positioningoftheexaminationvolumethatcanbetime-consuming.Aswithotherpenetratingradiationmethods,theradiationhazardmustbeproperlyaddressed.1.1Purpose8212;ThisguidecoversatutorialintroductiontofamiliarizethereaderwiththeoperationalcapabilitiesandlimitationsinherentinX-rayComptonScatterTomography(CST).AlsoincludedisabriefdescriptionofthephysicsandtypicalhardwareconfigurationforCST.1.2Advantages8212;X-rayComptonScatterTomography(CST)isaradiologicnondestructiveexaminationmethodwithseveraladvantagesthatinclude:1.2.1TheabilitytoperformX-rayexaminationwithoutaccesstotheoppositesideoftheexaminationobject;1.2.2TheX-raybeamneednotcompletelypenetratetheexaminationobjectallowingthickobjectstobepartiallyexamined.Thickexaminationobjectsbecomepartoftheradiationshieldingtherebyreducingtheradiationhazard;1.2.3Theabilitytoexamineandimageobjectsubsurfacefeatureswithminimalinfluencefromsurfacefeatures;1.2.4Theabilitytoobtainhigh-contrastimagesfromlowsubjectcontrastmaterialsthatnormallyproducelow-contrastimageswhenusingtraditionaltransmittedbeamX-rayimagingmethods;and1.2.5Theabilitytoobtaindepthinformationofobjectfeaturestherebyprovidingathree-dimensionalexamination.Theabilitytoobtaindepthinformationpresupposestheuseofahighlycollimateddetectorsystemhavinganarrowangleofacceptance.1.3Applications8212;Thisguidedoesnotspecifywhichexaminationobjectsaresuitable,orunsuitable,forCST.Aswithmostnondestructiveexaminationtechniques,CSTishighlyapplicationspecifictherebyrequiringthesuitabilityofthemethodtobefirstdemonstratedintheapplicationlabor......
【中国标准分类号】:N78
【国际标准分类号】:35_240_80
【页数】:13P.;A4
【正文语种】:英语