Fricke Dosimetry in High Energy Electron Beams

1 Page 1 NBSMeasurement Services: FrickeDosimetryin High-Energy ChristopherG.Scares EricL.Bright MargaretsEhrlich U.S.DepartmentofCommerce NationalBureauofStandards Open at page → 2 Page 2 CenterforRadiationResearch TheCenterforRadiationResearch isamajorcomponentoftheNationalMeasurementLaboratory intheNational BureauofStandards. TheCenterprovidestheNationwithstandardsandmeasurementservicesforionizing radia... Open at page → 3 Page 3 NBSMEASUREMENTSERVICES: FRICKEDOSIMETRYINHIGH-ENERGY ELECTRONBEAMS ChristopherG.Scares EricL.Bright MargareteEhrlich CenterforRadiationResearch NationalMeasurementLaboratory NationalBureauofStandards Gaithersburg,MD20899... Open at page → 4 Page 4 LibraryofCongressCatalogCardNumber:87-619834 NationalBureauofStandardsSpecialPublication250-4 Natl.Bur.Stand.(U.S ),Spec.Publ.250-4,54pages(July1987) CODEN:XNBSAV Commercialproducts—materialsandinstruments—areidentified... Open at page → 5 Page 5 PREFACE Thecalibration andrelatedmeasurement servicesoftheNationalBureau ofStandardsareintendedtoassistthemakersandusersofprecision measuringinstruments inachievingthehighestpossiblelevelsof accuracy,quality,andproductiv... Open at page → 6 Page 6 ABSTRACT TheN8SFricke-Oosimetry Service(advertised inHBSSpecial Publication 250,1986-1988andearliereditions) isdescribed in detail. Afterabriefhistoricalintroduction anddescription oftheservice,thetheoretical basis(inclu... Open at page → 7 Page 7 TAiiLEOFCOIMTENTS Abstract iv 1.Description ofService 1 1.1History 1 1.2TheService 1 2.TheoryandDesignPhilosophy 3 2.1Theory 3 2.2Design 4 2.3SystemOperation 5 2.3.1 Statistical distribution ofabsorbancegrowthintheNBS un... Open at page → 8 Page 8 TABLEOFCONTENTS,CONTINUED LISTOFTABLES Page Table1.Sample,Absorbances ofCellsBeforePre-irradiation 17 Table2.SampleofSpectrophotometry RecordofAllCellsAfterPre- irradiationwith50GyofCobalt-60GammaRadiation,Priorto Shipme... Open at page → 9 Page 9 TABLEOFCONTENTS,CONTINUED LISTOFFIGURES Figure1.DosimeterAssembly[3] 2 Figure2.MappingtheCrossSectionoftheCobalt-60Gamma-RayBeamUsed forPre-irradiation 10 Figure3,WeighingtheSulfuricAcid 12 Figure4.WeighingtheSalts 13 Fi... Open at page → 10 Page 10 i i i 1 i I I I i I J i > I j I Open at page → 11 Page 11 1.DESCRIPTION OFSERVICE 1.1History Since1967,theNationalBureauofStandards(NBS)hasbeenproviding a measurement-assurance servicefortestingthestatusofdosimetryforelectron beamsintheenergyrangefromabout5to50MeV. (Fordetailss... Open at page → 12 Page 12 phantom. Thedosimeters areshippedpre-paidbyacommercialdelivery service. Sincetheycontain acorrosiveliquidinunsealedcontainersthey cannotbesentbymail,and,ifairtransport athighaltitudes isinvolved, thepackagesmustbemarkedf... Open at page → 13 Page 13 Appendix 1containsallformsusedinwrittenexchangeswith participants. AsampleofafinalreportisshowninAppendix2. 2. THEORYANDDESIGNPHILOSOPHY 2.1Theory Theferrous-sulfate(Fricke)dosimetrysystemhasbeendiscussedexten- sivelyint... Open at page → 14 Page 14 Fe+++ Fe++++HO" ho;+H+>H2O2 Fe+++H2O2 >Fe++++OH+OH" Ferric-ionyieldisdefinedasthenumberofFe'*"'"''ionsformedinthe Frickesolutionperunitofabsorbeddosetothesolution. Itmaybedeter- minedspectrophotometri callywithhighaccura... Open at page → 15 Page 15 Analternative v^ouldbetotransferthesolutionfirstintospecially cleaned,disposableborosilicate ampoules;flame-seal theampouleswithout damagetothesolutionfromcontactwithgasesescapingfromtheheatedglass; andkeepthesolution in... Open at page → 16 Page 16 2.3.2 InternalqualitycheckonperformanceofIndividualdosimeters. I Inordertocheckontheperformance oftheFrickedosimeterspriorto j theiruse,itwasdecidedtopre-irradiateallthefreshly-filled spectro- j photometriccells,about50o... Open at page → 17 Page 17 ICRUrecentlyrecommended theuseofafixedproductofthemolarlinear absorptioncoefficient andtheferric-ionyield,[5]Thevaluerecommended fortheproductagreestowithin 1percentwiththevaluebasedonour measuredmolarlinearabsorptioncoe... Open at page → 18 Page 18 1 I Atthetimethisdocument isbeingprepared,thesetupconsistsof: ttaround150cylindrical 10-mmpathlengthquartzspectrophotometer cells withquartzwindowsandyround-glass stoppers; ®Luciteracks,builttoorderintheNBSShops,eachhold... Open at page → 19 Page 19 Initidlly, allglassware tobeusedfortheFrickesolutionwascleaned withhotconcentrated sulfuricacid,thebottleswerefilledwiththeacidand thenheatedonahot-plateuntiltheacidalmostboiled;theotheritemswere immersedinalmostboilings... Open at page → 20 Page 20 ) i COLUMNNUMBER Figure2.MappingtheCrossSectionoftheCobdlt-60Gamma-RayBeamin RoomB034,UsedforPre-Irradiation; scale: 1cm=2.5cm encirclednumbers: othernumbers: solid-lineenvelope: dashedline: correctionfactorsfromdatapoin... Open at page → 21 Page 21 3.2.1Preparingthesolutions ( a)Weighingtheingredients (samplefromDataBook837,pp .160and163) SulfuricAdd,Bakerreagentgrade,96.3percent,fresh(seefig.3) ^ graduatecylinderinbeaker,taredonMettlerbalancemodelH1200 poured~46cm... Open at page → 22 Page 22 12 Open at page → 23 Page 23 Figure4.WeighingtheSalts. Theweighedportionsaretransferredquantitatively fromthe weighingdishintothevolumetricflasksthroughaclear,dry funnel,andwasheddownwithwaterfromthewashbottle. 13 Open at page → 24 Page 24 Potassiurnnitrate,samebottleasforlasttestseries ,weighed oil MettlerbalanceH 16~^ dishalone 4.13376 g g thesalt 5.00000 g shouldbe 9.13376 g Is 9.13366 gInto500-cm3flask dishalone 4.13350 g Allflasksfilledtoneckjunctionw... Open at page → 25 Page 25 Figure5.AeratingtheSolution. Aeratingpriortofillingofindividualspectrophotometer cells ensuresthesamedegreeofinitialaerationofthedosimeters. Normally,rubberapronsarewornduringthisprocess. 15 Open at page → 26 Page 26 1 1 I Figure6.FillingtheSpectrophotometer CellswithFrickeSolution. ^ Singlydistilledwaterbathestheracksandtheoutsideofthecells. ; i 16 i Open at page → 27 Page 27 (b)Ferrous-Su1fateRinses cellssuckedoutandfilled,finished2:08p.m.;10inin.rest cellssuckedoutandfilled,finished2:32p.m.;10min.rest cellssuckedoutandfilled,finished3:00p.m.;10min.rest last(final)fill,completed atabout3:40p... Open at page → 28 Page 28 Fiyure7.Pre-irradiationwithCobalt-60GammaRadiation inRoomB034. Thesurfaceofthesupportisruled,withrowsandcolumnsmarked asinfigure2(page15).Thefixed-distance supportvisibleat shoulderheightisnotinthebeam. 18 Open at page → 29 Page 29 SampleofPre-irradiationRecord(fromDataBook856,p.39) Exposurerateondayoflastcalibration (April24,1985): 46.98R/h, Exposureratesinair,atpointofcellirradiations: OnNovember6,1985, 9.=46.98 g''^'^^^^^^^ =43.79R/h. OnNovember... Open at page → 30 Page 30 Table2.SampleofSpectrophotometry RecordofAllCellsAfterPre- irradiationwith50GyofCobalt-60GammaRadiation,Priorto Shipment.^ (FromDataBook837,p.104.) Readoul ,BeforeShipment Position d J1Ucb Average Cel1 during Cnrrpct ion... Open at page → 31 Page 31 Table.3SampleofDistribution ofPosition-Corrected Absorbances (Fromtable2;seeDataBook837,p.109.) Absorbance Interval 0216-0217M-3X-10- 2D-3 0217-0218W-1A-5B-4F-2 0218-0219A-3B-1X-5H-5 0219-0220M-4A-1A-2E-3 0220-0221G-5P-2... Open at page → 32 Page 32 Table4.Statistics, fromSampleResultsShowninTable3.(SeealsoData Book837,p.108.) Quantity All FirstHalf SecondHalf 120Cells (60Cells) (60Cells) AverageAbsorbance 0.2212 0.2205 0.2218 StandardDeviation absolute 0.0026 0.002... Open at page → 33 Page 33 relativelylarge-volume (0.02m^)thermostatically controlledcirculating waterbath. Inordertobringthetemperature ofthedosimetercellscloseto compartmenttemperaturepriortoreadout,theloadeddosimeterracksare storedforabout20min... Open at page → 34 Page 34 Figure8.Spectrophotometry Attendant isinsertingspectrophotometer cellintotemperature- controlledreadoutcompartment ofspectrophotometer. Thecircula- tingwaterbathisatright,thecomputerdisplayinthecenter. 290 294 298 302 30... Open at page → 35 Page 35 Table6.Sample,Absorbances of1g%PotassiumNitrateSolution,Obtainedas aCheckontheReproducibility ofAbsorbanceReadingsThroughoutthe RoughlySixWeeksRequiredtoCompleteOneTest.^ (FromData Book337,page163.) ReadoutSession Absor... Open at page → 36 Page 36 Table6givesasamplerecordoftheabsorbancesobtainedontwocells filledwith1g%potassium-nitrate solutionmeasuredbeforeandafterthetwo readoutsessionspriortoshipmentoftheFrickedosimeters andbeforeand afterthereadoutsessionsomesi... Open at page → 37 Page 37 Table8.SampleofSpectrophotometry RecordAfterShipmentandAssociated Absorbed-Dose Interpretation.^ (FromDataBook837,p.104and105.) Cell No. 0-1 0-2 0-3 0-4 0-5 P-1 P-2 P-3 P-4 P-5 Q-1 Q-2 Q-3 Q-4 Q-5 R-1 R-2 R-3 R-4 R-5 S-1... Open at page → 38 Page 38 ShippedControls (22) X X X X X XXXXX X X XXXXXXXXX Cut-offforAverage .0310- -.002 .002 .004 .006 .008 .010 .012 SpuriousAbsorbanceGrowth .014 .016 .018 .020 HomeControls(22 ) XXX XXXX XXXX XXXX Cut-offforAverage X XX XX... Open at page → 39 Page 39 averagesoftheplotteddata. Theaverageofthegrowthofbothshippingand homecontrolscombinedwasusedtocomputetheabsorbed-dose valuesshownin column 7oftable8,which—afterroundingtothreesignificant figures—is incorporated intothere... Open at page → 40 Page 40 Table9.Uncertainties intheDoseInterpretations Procedure FirstMethod Uncertainty indoseinterpretation derivedfromrepeated measurements inaspeciallydesignedexperiment^ Overalluncertainty SecondMethod Uncertaintyestimatedfo... Open at page → 41 Page 41 apronsarewornbythestaff;theconcentrated sulfuricacidistransported andstoredinarubber"carryingsling,"andfaceshieldsarewornbythe staffduringpouringandweighingoftheacid;acid-proofcomposites, glassor stainlesssteel,areusedas... Open at page → 42 Page 42 REFERENCES* [1]Fordefinitions oftheradiation-dosimetryquantitiesandunits(bothSI andspecial)usedinthisdocument,seeRadiationQuantities andUnits; ICRUReport19,International CommissionofRadiationUnitsand Measurements, Bethes... Open at page → 43 Page 43 Appendix 1 FormsUsedinWrittenExchangeswithParticipants 33 Open at page → 44 Page 44 NATIONALBUREAUOFSTANDARDS UNIFORMITYCHECK,DOSIMETRYOFHIGH-ENERGYELECTRON-BEAMS ToAllParticipants: Ifyouplantoparticipate intheservice,youwillneeda polystyrenephantom.Directionsforitsconstruction aregiven inthe"Protocolfo... Open at page → 45 Page 45 ANNOUNCEMENT TOALLPASTPARTICIPANTS UrJITEOSTATESDEPARTMENTOFCOMMERCE NationalBureauofScandarda GaiChersburg,MarylenaSOBgS <date> Announcement oftheNextUniformityStudyof DosimetryofHigh-EnergyElectronBeams Weplantoshipthe... Open at page → 46 Page 46 ANNOUNCEMENT TOGROUPSTHATINDICATEDTHEIRINTENTIONTOPARTICIPATE, BUTDIDNOTSUBMITAPURCHASEORDER UNITEDSTATESDEPARTMENTOFCOMMERCE Nat:ionalBureauofScandards GaitfTersburgMar/land2QB99 <date> Announcement oftheNextUniformityS... Open at page → 47 Page 47 ANNOUNCEMENTTOGROUPSTHATINDICATEDTHEIRINTENTIONTOPARTICIPATE, ANDSUBMITTEDAPURCHASEORDER UNITEDSTATESDEPARTMENTOFCOMMERCE NaclonalBureauofStsndarda GaittersburyMarylaniJ20B99 <date> Announcement oftheNextUniformityStudyo... Open at page → 48 Page 48 FERROUS-SULFATEDOSIMETERIRRADIATIONFORM Pleassecompletethisformandshipitbackwiththeexposed dosimeters Dosimeter Dose* ElectronEnergy Number (Gy ) (MeV ) control Afterirradiation, placethedosimeters inthezip-lockbagand re... Open at page → 49 Page 49 U.S.DepartmentofCommerce NATIONALBUREAUOFSTANDARDS GAITHERSBURG.MARYLAND20899 REPORTOFTEST DG<dq«/yr> <date> To:AllFarticioants inthe<stlidyname ' -Unif " q ittiity5bud/of Dosimetry _ i_nHiqh-EnergyElectronBeams Theenclo... Open at page → 50 Page 50 GrouD Dosimeter AbsorbedDose DoseDifference Irradiated No. Designation NBS Participant (Pet.of with: (6ytowater) (6y) NBSDose) 40 Open at page → 51 Page 51 Appendix2.SampleofReporttoParticipants 41 Open at page → 52 Page 52 U.S.DepartmentofCommerce NATIONALBUREAUOFSTANDARDS GAITHERSBURG,MARYLAND20899 DG8561/86 REPORTOFTEST June26,1986 To:AllParticipants intheSpring1986UniformityStudyof DosimetryinHigh-EnergyElectronBeams Theenclosedtablesan... Open at page → 53 Page 53 ReportofTest,Continued roup NO Dosimeter' Des1QDa11On Absorb MPQ ISOi_> (Gv 1nwater — edDose F'ar11c.iprAnt ) (Gv) — - • — DoseDifference •irCL.OT NBSDose) Irracliated with: 1 A-2 55.2 56.42 8MeVel A-3 62.0 63.27 +2.2 13... Open at page → 54 Page 54 ReportofTest,Continued Group Dosimeter AbsorbedDose DoseDifference Irradiated No. Desianation NBS F^artic.ipiant (F'ct.of with: (Gvinwater) (Gv) NBSDose) 13 14 V5 16 17 IS 19 L—1 ,_'r.4 \-1 1 1 (") 1 ItrV t:.1 L-2 60.9 6... Open at page → 55 Page 55 o ReportofTest,Continued — I— I— -f— 1— I— I— r CO 00 CD c CL 00 J L I I I I 1— r I I I O O o c CD O CD CL CD _^ > CD CO O Q (/) CD O O c o -I-' o *> CD Q O CX) LO O LO O |DAJ9:).UJ J9ClS^UOdlOI^JDJ J.0 J9qLUn[\| 4b Open at page → 56 Page 56 ReportofTest,Continued TZ 1 r \ \ \ o a a \ Z5 00 o c \ a \ a\ a CO 1 ' ? 00 CD c JC CO \ \ \ \ \ \ \ \ o\ \ + N \ CM o \ \ \ \ \ CD O \ \ c CD C < CD CO O tn CD -1 1 1 L \o o ^s:].UDdioi:^jDd AqpauBissy9S0Q 46 Open at page → 57 Page 57 NBS-n4A(REV.2-6CI U.S.DEPT.OFCOMM. BIBLIOGRAPHICDATA SHEET(Seeinstructions) 1.PUBLICATIONOR REPORTNO. 'BS/SP-25ri /A 2.PerformingOrgan.ReportNo.3.PublicationDate July1987 4.TITLEANDSUBTITLE NBSMeasurementServices: Fricke... Open at page → 59 Page 59 PUBLICATIONS INTHESP250SERIESFROMTHECENTERFORRADIATIONRESEARCH P250-1 SP250-2 SP250-3 SP250-4 SP250-5 SP250-6 SP250-7 SP250-8 SP250-9 SP250-10 SP250-11 NBSMeasurement Services: SpectralRadianceCalibrations J.H.Walker,R.D... Open at page → 60 Page 60 U.S.DepartmentofCommerce NationalBureauofStandards Gaithersburg,MD20899 OfficialBusiness PenaltyforPrivateUse$300 Open at page →