ASTM E666-2003 γ或X辐射吸收剂量计算的标准实施规范

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【英文标准名称】:StandardPracticeforCalculatingAbsorbedDoseFromGammaorXRadiation
【原文标准名称】:γ或X辐射吸收剂量计算的标准实施规范
【标准号】:ASTME666-2003
【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(ASTM)
【起草单位】:E10.07
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:吸收;数量估计;工艺;核能;γ辐射;X射线;剂量
【英文主题词】:calculationofabsorbeddose;chargedparticleequilibrium;radiationdosimetry
【摘要】:Theabsorbeddoseisamoremeaningfulparameterthanexposureforuseinrelatingtheeffectsofradiationonmaterials.Itexpressestheenergyabsorbedbytheirradiatedmaterialperunitmass,whereasexposureisrelatedtotheamountofchargeproducedinairperunitmass.Absorbeddose,asreferredtohere,impliesthatthemeasurementismadeunderconditionsofchargedparticle(electron)equilibrium(seeAppendixX1).Inpractice,suchconditionsarenotrigorouslyachievablebut,undersomecircumstances,canbeapproximatedclosely.Differentmaterials,whenexposedtothesameradiationfield,absorbdifferentamountsofenergy.Usingthetechniquesofthisstandard,chargedparticleequilibriummustexistinordertorelatetheabsorbeddoseinonematerialtotheabsorbeddoseinanother.Also,iftheradiationisattenuatedbyasignificantthicknessofanabsorber,theenergyspectrumoftheradiationwillbechanged,anditwillbenecessarytocorrectforthis.Note18212;Forcomprehensivediscussionsofvariousdosimetrymethodsapplicabletotheradiationtypesandenergiesandabsorbeddoseraterangesdiscussedinthismethod,seeICRUReports14,21,and34.1.1Thispracticepresentsatechniqueforcalculatingtheabsorbeddoseinamaterialfromknowledgeoftheradiationfield,thecompositionofthematerial,(1-5)andarelatedmeasurement.TheprocedureisapplicableforXandgammaradiationprovidedtheenergyofthephotonsfallwithintherangefrom0.01to20MeV.1.2Amethodisgivenforcalculatingtheabsorbeddoseinamaterialfromtheknowledgeoftheabsorbeddoseinanothermaterialexposedtothesameradiationfield.Theprocedureisrestrictedtohomogeneousmaterialscomposedoftheelementsforwhichabsorptioncoefficientshavebeentabulated(2).Italsorequiressomeknowledgeoftheenergyspectrumoftheradiationfieldproducedbythesourceunderconsideration.Generally,theaccuracyofthismethodislimitedbytheaccuracytowhichtheenergyspectrumoftheradiationfieldisknown.1.3Theresultsofthispracticeareonlyvalidifchargedparticleequilibriumexistsinthematerialandatthedepthofinterest.Thus,thispracticeisnotapplicablefordeterminingabsorbeddoseintheimmediatevicinityofboundariesbetweenmaterialsofwidelydifferingatomicnumbers.Formoreinformationonthistopic,seePracticeE1249.1.4Energytransportcomputercodesexistthatareformulatedtocalculateabsorbeddoseinmaterialsmorepreciselythanthismethod.Tousethesecodes,moreeffort,time,andexpensearerequired.Ifthesituationwarrants,suchcalculationsshouldbeusedratherthanthemethoddescribedhere.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A58
【国际标准分类号】:
【页数】:9P.;A4
【正文语种】: