Dosimetry for High Dose Applications

1 Page 1 NBSMeasurementServices: Dosimetryfor HighDose Applications U.S.DepartmentofCommerce NationalBureauofStandards Open at page → 2 Page 2 CenterforRadiationResearch TheCenterforRadiationResearchisamajorcomponentoftheNationalMeasurementLaboratory intheNational BureauofStandards. TheCenterprovidestheNationwithstandardsandmeasurementservicesforionizing radiat... Open at page → 3 Page 3 NBSMEASUREMENTSERVICES: DOSIMETRYFORHIGHDOSE APPLICATIONS JimmyC.Humphreys DeneHocken WilliamL.McLaughlin CenterforRadiationResearch NationalMeasurementLaboratory NationalBureauofStandards Gaithersburg,MD20899 U.S.DEPART... Open at page → 4 Page 4 LibraryofCongressCatalogCardNumber:88-600506 NationalBureauofStandardsSpecialPublication250-1 1 Natl.Bur.Stand.(U.S.),Spec.Publ.250-11,49pages(Mar.1988) CODEN:XNBSAV Certaincommercialequipment,instruments,ormaterialsarei... Open at page → 5 Page 5 PREFACE Thecalibration andrelatedmeasurement servicesoftheNationalBureau ofStandardsareintendedtoassistthemakersandusersofprecision measuringinstruments inachievingthehighestpossiblelevelsof accuracy,quality,andproductiv... Open at page → 6 Page 6 ABSTRACT ThisdocumentdescribescalibrationservicesavailableattheNationalBureau ofStandardsforthestandardization ofhighabsorbeddosemeasurements of ionizingradiation. Theareasofapplicationofsuchmeasurements include medicalp... Open at page → 7 Page 7 TABLEOFCONTENTS Page 1 .DescriptionofService 1 2.DesignPhilosophyandTheory 2 3.DescriptionofSystem 3 3.1 60 CoIrradiationFacilities 3 3.2TransferStandardDosimeters 9 3.3Spectrophotometer 9 3.4ThicknessGauge 9 4.Operating... Open at page → 8 Page 8 LISTOFTABLES Page Table 1 60 CoDecayCorrectionsFactors(C d ) 13 Table2VariousDosimetersTypes 17 Table3Uncertainties inAbsorbedDoseValuesforIrradiationswith PoolSource . 21 Table4Uncertainties inAbsorbedDoseValuesforIrrad... Open at page → 9 Page 9 LISTOFFIGURES Page Fig.1.PhotographofmodelofNBS 60 CoPoolSource 4 Fig.2.SchematicdrawingofGammacell220self-shielded 60 Coirradiator inthechamberloadposition 6 Fig.3.SchematicDrawingofGammacell220irradiatorintheirradiate... Open at page → 11 Page 11 NATIONALBUREAUOFSTANDARDS MEASUREMENTSERVICES: DOSIMETRYFORHIGH-DOSEAPPLICATIONS 1.DescriptionofService 1.1TheNationalBureauofStandards,IonizingRadiationDivision,provides dosimetryservicesforindividualusersofintenseradia... Open at page → 12 Page 12 2.DesignPhilosophyandTheory 2.1Thereisaneedforthestandardization ofhigh-absorbed-dose measurements usedintheradiationprocessingindustryinordertoprovidemeasurement assuranceandtraceability tonationalstandards. Someareasof... Open at page → 13 Page 13 2.5Theabsorbed-dose ratesencountered inradiationprocessingcancoveran extremelywiderange. For 6 0 Cosources,theratesmaybeasiowasafewgrays perminute;forelectronbeams,ratesashighas10 10 grayspersecondarenot uncommon. Theref... Open at page → 14 Page 14 4 Open at page → 15 Page 15 3.1.2TheGammacell220irradiator, illustrated inFigures 2and3isa commerciallysuppliedunit(manufacturedbyAECLofCanada),with24 50 Co sourcerodsofabout20kCitotalactivityinastationaryannulararray. The sourcerodsarelocatedinsid... Open at page → 16 Page 16 FRONTVIEWSHOWINGDRAWERUP Figure2-SchematicdrawingofGammacell220self-shielded Co irradiator inthechamberloadposition 6 Open at page → 17 Page 17 REMOVABLE E»EBOLT fOnLIFTINGUNIT TimerRANGE SELECTOR SWITCHES 0R*wER'uP~push3UTTQN ORAwER"DOWNPUSHBUTTON KEYSWITCH CROSSARMSUPPORTS cavityronlitt*ucx t'hiGH X32'wiOC FRONTVIEWSHOWINGDRAWERDOWN Figure 3-SchematicDrawingof... Open at page → 18 Page 18 o o u o u cti •H CO ^ J-i •H O U o to CO 0) I T3 0) tH CD •H C/) CD Oh 4-1 CO u 0) 4= U 01 rH cu 4-1 00 C •H cl M CJ •H 4-1 CO e CU ,fl o en 0) J-i •H 8 Open at page → 19 Page 19 3.2TransferStandardDosimeters Thesedosimetersareradiochromic dyefilms,purchasedinlargebatchesfrom FarWestTechnology, thathavebeencarefullyandthoroughlycharacterized by NBSastotheirresponsereproducibility, stability,absor... Open at page → 20 Page 20 4.1.3Randomdosimetersamplesaretakenfromthebatchtobecalibrated. Thesesamplesareirradiatedtospecificabsorbeddoselevelsandtheir responsesareassumedtobeindicativeoftheexpectedresponsesofthe unirradiateddosimetersintherestoft... Open at page → 21 Page 21 -1- M-|-r •— ! _-o .._> ~< -. 4_| ill i . : . v- j— f--— c. FIGURE5ExamplesofFWTA Q scans,from610nmdownto600nm , showingvariousoscillations, fordifferentorientations. NOTE: Spectrophotometer settings: RANGE: 0.1ABS ;S.B.... Open at page → 22 Page 22 4.1.8Beforethecalibrationirradiations, thedosimeterfilmsarestoredat roomtemperature (~24°C)inacontrolledhumidityenvironment (withinthe rangeof40to50%R.H.)foratleast24hours[7].Afterthisperiod,the dosimetersarepackagedinap... Open at page → 23 Page 23 «—•O(O COI—Io Ov£>mo cr>Oncr>on on*o<rco—<<r»o >jno •-• o\ ONCOCOO "~»OWN— • OO"-O -O - -7 vOr-~>O CO"~<c^O r-JOoO \0«j«n< tocooor~-r^r-« r^v£>v£> \£)>x>\ss^>/>y\ Nf-i— •r-| i/"> »-« <T <ni—«.— « Or-»r~)O r-»-<r•-' oocr\... Open at page → 24 Page 24 intersectsthevertical"10"columncorresponding to110days. Thisfactoris 0.9611. Thefactorfor"3",theremainingnumberofdays,inthefirstrowis 0.9989. Multiplythesetwofactorstogivethecorrectionfor113days: 0.9600. Multiplythisfact... Open at page → 25 Page 25 Q) \ C \ Q) \ £_ \ > \ -- -P \ W \ > \ i—1 \ o \ 0. \ C \ -H N c -- o •H 4-> to^ JDH 1— 1 fOrH O(0 •H -- OE oo 1c o> "" tOrH 1o h-CL U.Q) <D -- NO) D £1 USZ CDw J 1 1 1 — — J- 1 1 1 ^ i -N> -8 -9 -_o _-o n CD ro 0) o D "... Open at page → 26 Page 26 c o •H -p CO . L. n•H •HLl roi— i u(D •H oE oO ic o> CD 1O CL Ll0) 0) c_ rHQ) Q H uH -p4-> (D CD s •8 +8 8 .© i t > CD XL ro c •H 0) CO o Q TD CD m £_ O W < 03 U 03 4-1 0) I 03 O H IH 03 a •H B o o o •H cd 03 > U a a o •... Open at page → 27 Page 27 Table2 VARIOUSDOSIMETERTYPES DosimeterType AbsorbedDoseRange kGyinH 2 0 FWT-60-00dyefilm 3 1-50 HarwellRedPerspex b 5-50 HarwellAmberPerspex b 1-20 HarwellHXPerspexandRadix clearPMMA b 3-100 Ceric-cerous sulfatesolutions... Open at page → 28 Page 28 poolsource)duringirradiation. Thiscontainermaybeintheformofsquare blocksforFWT-60-00thindyefilmsasusedintheinternalNBScalibration, or intheformofacylindricalcupforRedPerspexorsimilartypedosimeters. Thesecontainerssupplyt... Open at page → 29 Page 29 oCD cn CO O c E COCDC TDCO C If) CO O a CD COu Q at II COCD CD TD n o"E tDo (D L. i_J CDo aCO E 1 COH ^ U. CO •rl Ll •ri E O c > r-i O - CO CO L cn CO Q n -p t u cn CO CO L O) CO Q CO c_ D +J c_ CO a E CO c •H CO O T3 T3... Open at page → 30 Page 30 dyefilmdosimeters, theproceduresareidenticaltothosediscussedin4.1. Forothertypesofdosimeters, thespectrophotometric analysisistailoredto meettheirparticularrequirements. Forexample,RedPerspexdosimetersare readatonlyonewa... Open at page → 31 Page 31 Table3 UNCERTAINTIES INABSORBEDDOSEVALUES FORIRRADIATIONSWITHPOOLSOURCE SourceofUncertainty TypeA(%)TypeB(%) (random) (other) Graphitecalorimeter/ion chamber 0.14 measurementofpoolsourcedoserate Sourcedecay,halflife 0.01... Open at page → 32 Page 32 Thesourcesoftheuncertainties areasfollows: (1) Thecalorimeter/ion chambermeasurements ofthepoolsourceabsorbed doseratewereanalyzedinreference [3]forallpossiblesourcesoferror contributions suchascoremass,electricalpower,a... Open at page → 33 Page 33 3%ata95%confidencelevelforuseofthesedosimeters. Theuncertainty corresponding toonestandarddeviationwouldbe1.5%.Otherdosimetry methods(suchascalorimetry) arebeingdevelopedtoimprovetheaccuracyof thedetermination ofthisabso... Open at page → 34 Page 34 Table4 UNCERTAINTIES INABSORBEDDOSEVALUES FORIRRADIATIONSWITHGAMMACELL220 TypeA(%) TypeB(%) SourceofUncertainty (random) (other) NPLdichromatereference 1.50 dosimetermeasurementofdoserate Sourcedecay,halflife 0.01 Timing... Open at page → 35 Page 35 Table5 UNCERTAINTIES INABSORBEDDOSEVALUES FORIRRADIATIONSWITHVERTICALBEAMSOURCE SourceofUncertainty Graphiteionchamber measurementofexposurerate Conversionofexposurerate toabsorbeddoserateinwater TypeA(%) (random) TypeB(... Open at page → 36 Page 36 Table6 UNCERTAINTIES INABSORBEDDOSEVALUES EMPLOYINGTRANSFERSTANDARDDOSIMETERS SourceofUncertainty TypeA(%) TypeB(%) (random') (other) Combined(inquadrature)from Table3 0.34 1.05 Transferstandarddosimeter response 1 .00 D... Open at page → 37 Page 37 6.InternalQualityControl 6.1Measurementassuranceprogram(MAP)typetechniquesareusedtoensure thatcalibrationirradiations areperformedcorrectlyandtheprocessisina stateofstatisticalcontrol[16]. 6.2Anumber,n,ofcheckstandards,... Open at page → 38 Page 38 6.3Controllimitsmaybechosenforfuturecheckstandarddosimeter observations (whereeachobservation isthemeanofn=5readings)usingthe following: Uppercontrollimit=A c +— — 7n 3sc 7n Lowercontrollimit=A c Inthiscase,asafetyfactor... Open at page → 39 Page 39 checkallcalibrationreports. Theconditionofeachgroupoftestdosimeters tobeirradiated isevaluatedwhentheyarereceivedtoensuretheyareofhigh quality. Anyunusualconditionorappearance ischeckedbyconsultingwiththe requestingcusto... Open at page → 40 Page 40 References 1.Uriano,G.A.Garner,E.L.Kirby,R.K. ,andReed,W.P.,Editors.NBS CalibrationServicesUsersGuide1986-1988Edition.NBSSpecialPublication 250 andFeeScheduleforSP250,OfficeofPhysicalMeasurementServices,National Bureauof... Open at page → 41 Page 41 13.McLaughlin, W.L.,"ANationalStandardization ProgrammeforHigh-Dose Measurements", High-DoseMeasurements inIndustrialRadiationProcessing, IAEA Tech.ReportNo.205,IAEA,Vienna,pp.17-32(1981). 14.Loftus,T.P.,andWeaver,J.T.,"... Open at page → 43 Page 43 U.S.DEPARTMENTOfCOMMERCE KATKWAlIURIAUOfSTANDARD* OAiTMiRiiURO.marvianoio«M Test536/111111-86 NBSDB100/100 XRG-322 December26,1985 REPORTOFCALIBRATION of FarWestTechnology, Inc.Type60-00Rad1ochron1c Dosimeters for Kilora... Open at page → 44 Page 44 Test536/HHU-86 NBSDB100/100 XRG-322 December26,1985 Page2of2pages Theattachedpagedescribesuncertainties andrelatedfactorsInhigh-dose calibrations, suchastheonecoveredbythisReportofCalibration. Anyquestions regardingenvir... Open at page → 45 Page 45 UNCERTAINTIES ANDRELATEDFACTORSINHIGH-DOSECALIBRATIONS StandardHigh-DoseGamma-RayIrradiations atNBS (Estimateduncertainty: ±3.3%ata99%confidencelevel) Thehigh-dosecalibrations atNBS(schedule49010S)involvethe administrati... Open at page → 47 Page 47 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalBureauofStandards Gaithersburg.Maryland2QB99 June27,1986 FEDERALEXPRESSPRIORITY 1 Mr.JohnDoe SeniorEngineer GammaRadiations, Inc. 123UniversityAvenue Chicago, IL60606 DearMr.Doe:... Open at page → 49 Page 49 U.S.DEPARTMENTOFCOMMERCE NATIONALBURCAUOfSTANDARD! QAITHERSBURQ.MARYLAND20SSS REPORTOFCALIBRATION of Gammacell220Irradiator for Gammaray,Inc. 999CobaltStreet Miami,FL32111 Attention: JamesDoe Ref.P.O.No.:32123 Transferdo... Open at page → 50 Page 50 Test.536/222222-86 NBSDB100/001 XRG-321 October10,1985 Page2of5pages Thedosimeterswereread1ntermsofopticalabsorbancebefore(A 0 )andafter(A*) Irradiation, usingaCaryModel219spectrophotometer (3.5nmS.B.W.),attwo opticalwav... Open at page → 51 Page 51 Test536/222222-86 NBSDB100/001 XRG-321 October10,1985 Page3of5pages Date, Dosimeter Time No. Aq ofAj Aj Thickness aA/mm (605nm)(510nmjReading(605nm)(510nmj (mm) (605nm)(510nm) tCI U.10**3 n07fift7/7/OJ 161030?5?*i 005? ?... Open at page → 52 Page 52 Test536/222222-86 NBSDB100/001 XR6-321 October10,1985 Page4of5pages Analysisofthedosimeterresponseconsistsofdetermining themeanaA/mmforeach groupoffivedosimetersirradiatedtogetherandthestandarddeviationofeach groupasshow... Open at page → 53 Page 53 Test536/222222-86 NBSDB100/001 XRG-321 October10,1985 Page5of5pages Theattachedpagedescribesuncertainties andrelatedfactorsInhigh-dose calibrations, suchastheonecoveredbythisReportofCalibration. Anyquestions regardingenv... Open at page → 54 Page 54 UNCERTAINTIES ANDRELATEDFACTORSINHIGH-DOSECALIBRATIONS StandardHigh-DoseGamma-RayIrradiations atNBS (Estimateduncertainty: ±3.3%ata99%confidencelevel) Thehigh-dosecalibrations atNBS(schedule49010S)involvetheadministratio... Open at page → 55 Page 55 NBS-114A(REV.2-80) U.S.DEPT.OFCOMM. BIBLIOGRAPHICDATA SHEET(Seeinstructions) 1.PUBLICATIONOR REPORTNO. NBS/SP-250/11 2.PerformingOrgan.ReportNo.3.PublicationDate March1988 4.TITLEANDSUBTITLE NBSMeasurementServices: Natio... Open at page → 59 Page 59 THESP250SERIESONNBSMEASUREMENTSERVICES* SP250-1 SpectralRadianceCalibrations 003-003-02792 $3.50 SP250-2 FarUltravioletDetectorStandards 003-003-02810-0 $4.25 SP250-3 RadiometricStandardsIntheVacuum Ultraviolet 003-003-0... Open at page → 60 Page 60 U.S.DepartmentofCommerce NationalBureauofStandards Gaithersburg,MD20899 OfficialBusiness PenaltyforPrivateUse$300 Open at page →