Understanding kV, keV and Efficiency of Kiarmor Bi-layer in ...

kV is the voltage (Kilovolts = 1000s of volts) across the X-ray lamp that generates the keV (Kilo Electron Volts) spectrum (wavelength ... skiptoMainContent 1-805-987-5255QuoteRequestInternationalQuoteRequestContractRequest TwitterFacebookInstagramLinkedInYoutube October27,2021 InfabCorporation InfabBlog kVisthevoltage(Kilovolts=1000sofvolts)acrosstheX-raylampthatgeneratesthekeV(KiloElectronVolts)spectrum(wavelengthbandwidth)ofX-rayenergyforthemainbeam. ThekeVX-rayspectrumrangesfromapproximately15keVtothemaximumlevelofkVusedintheX-raylampexcitation.Inotherwords,ifyouuse100kV(typicalstandardX-ray)acrosstheX-raylamp,thekeVspectrumwillrangefromapproximately15keVto100keV. Ifyouuse60kV(typicalfluoroscope)thekeVspectrumwillrangefromapproximately15keVto60keV Note:ThephotoncountontheYaxisisdependentoncurrent/timeselected,sonorealscaleapplied. Scatterradiationistypically1%ofthemainbeam.Furthermore,thehigherkeVenergiesinthemainbeamdonotscatterasmuchastheypassthroughthepatient,orobject,beingX-rayed,whilstthelowerenergiesscattermoreeasilybecausetheydonothavethepenetratingpower.Therefore,ifyoulookattheresultingkeVspectrumforthescatterradiation,thetopendofthekeVspectrumisreduced. Typically,ifyougeneratedthemainbeamusing100kVonthelamp,themainbeamenergy,intermsofkeV,willrangefromapproximately15keVto100keV(Fig1),andthescatterradiationwillrangefromapproximately15keVtojustover60keV(Fig3). Ifyougeneratedthemainbeamusing60kVacrossthelamp,themainbeamenergy,intermsofkeV,willrangefromapproximately15keVto60keV(Fig2),andthescatterradiationwillrangefromapproximately15keVtojustover45keV(Fig4). Note:ThekeVscaleoftheYaxis(PhotonCount)wouldbeapproximatelya50thofthegraphsforthemainbeam. Absorbeddoseiscreatedfromradiationthatdoesnotpassthroughthebody.ThatisthelowerrangesofkeV,typically15keVtoapproximately45keV. ScatterradiationisprimarilymadeupofthisrangeofkeVandthecorematerialneedstobeatitsmostefficientandeffectiveinthisrangetobetrulyeffectiveinprotectingtheuser. Giventheprinciplesabove,andtakingtheexampleoffluoroscopy,whichtypicallyusesbetween60kVto70kVacrossthelamptogeneratetheX-rays,themainbeamwillhavekeVenergiesfrom15keVtoapproximately65keV.However,thescatterradiationwillhaveenergiesfrom15keVtoapproximately45keV.Thismeansthatthevastmajorityoftheradiationisintheabsorbeddoserangeasitlacksthepenetratingpowerandwillstayinthebodyoftherecipient. CurrentLead-freematerialsuselower-weightatomicelements,forexample,Antimony,Tin,Barium,etc.,toprovidelightermaterialsthatarejustabletopasscurrentteststandardssuchasASTMandIEC61331-1.However,theseelementshaveK-edgesinthecriticalareaofkeVintermsofabsorbeddose,whichisnotpickedupbytheteststandards.Higheratomicweightelements,suchasLeadorBismuth,haveK-edgesbeyondthekeVspectrumfortypicalscatterradiationanddonothavethesameissue. K-edgescreatefluorescenceandabreakdownoftheefficiencyoftheseelementsintermsofabsorbingphotonenergyfromanX-raysource,orthederivedscatterradiation.Infact,theseK-edgescanactuallyincreasethedosetothewearerofanX-rayprotectionapronasthefluorescencecausesanincreaseinphotonenergytothewearerofanX-rayprotectionapronmadefromtheseloweratomicweightelements(Fig5).Thesameappliestomaterialsusingacomposite(mixture)ofahigherandloweratomicweightelement,forexample,Bismuth/Antimony,oraLeadcompositematerial.Thatthisoccursrightnexttotheweareristheworstcasescenariointermsofprotectionagainstabsorbeddose. ByarrangingLead-freematerialsasaBi-layer,withaloweratomicweightelementatthetop(forexample,Antimony)andahigheratomicweightelementatthebottom(forexample,Bismuth),theK-edgeeffectisnullifiedandtheadditionalphotonscreatedbythefluorescenceoftheloweratomicweightelementisabsorbedbythehigheratomicweightelement(Fig6). IndependenttestinghasshownthatthisBi-layerconfigurationis20%moreeffectivethanLeadand40%moreeffectivethanLead-freematerialsandcompositesintermsofabsorbeddose.KiarmorBi-layerpassesallcurrentandfuturestandards,IEC61331-1,ASTMandDIN6857-1(specificallydesignedforLead-freematerialswithgeometryandbeamconditionsdesignedtocapturetheK-edgeandfluorescence). PleaseShareThis Tweet Share Share PinIt previouspost:SecureYourLeadApronswithMobileLockers nextpost:HowtoCleanyourRadiationProtectionApron Questions?ContactusordownloadtheApronBuyer'sGuide. DownloadGuide Copyright2020-AllRightsReservedVELCRO®isaregisteredtrademarkofVelcroIndustriesB.V.HealthcareMarketingAgency BackToTop Search Search Submit