Activation Foil Irradiation by Reactor Cavity Fission Sources

1 Page 1 NBSMeasurementServices: wiiiviVe^»f'p ActivationFoil Irradiationby ReactorCavityFissionSources NBS Special Publication 250-14 GeorgeP.Lamaze JamesA.Grundl U.S.DepartmentofCommerce NationalBureauofStandards Open at page → 2 Page 2 CenterforRadiationResearch TheCenterforRadiationResearchisamajorcomponentoftheNationalMeasurementLaboratory intheNational BureauofStandards. TheCenterprovidestheNationwithstandardsandmeasurementservicesforionizing radiat... Open at page → 3 Page 3 NBSMEASUREMENTSERVICES: ACTIVATIONFOILIRRADIATIONBY REACTORCAVITYFISSIONSOURCES GeorgeP.Lamaze JamesA.Grundl CenterforRadiationResearch NationalMeasurementLaboratory NationalBureauofStandards Gaithersburg,MD20899 U.S.DEP... Open at page → 4 Page 4 LibraryofCongressCatalogCardNumber:88-600513 NationalBureauofStandardsSpecialPublication250-14 Natl.Bur.Stand.(U.S.),Spec.Publ.250-14,56pages(Mar.1988) CODEN:XNBSAV U.S.GOVERNMENTPRINTINGOFFICE WASHINGTON: 1988 Forsaleby... Open at page → 5 Page 5 PREFACE Thecalibration andrelatedmeasurement servicesoftheNationalBureau ofStandardsareintendedtoassistthemakersandusersofprecision measuringinstruments inachievingthehighestpossiblelevelsof accuracy,quality,andproductiv... Open at page → 6 Page 6 ABSTRACT ThisdocumentdescribestheNationalBureauofStandards(NBS) calibrationservice44090C(formerly8,1R)whichoperatesinthe followingway: (i)dosimetrysensors(metalfoils,nucleartrack detectors,wires,crystals,etc.,suppliedbyt... Open at page → 7 Page 7 TABLEOFCONTENTS 1.DESCRIPTION OFSERVICE 1 1.1.ConfiyurationandCharacteristics 2 2.NEUTRONFIELDCHARACTERIZATION 4 2.1.NeutronFluence 4 2.2,NeutronSpectrum 6 2.2.1. Calculation 6 2.2.2. Measurement 6 2.2.3. EvaluatedSpectr... Open at page → 8 Page 8 LISTOFTABLES Page TABLE1. EvaluatedFissionNeutronSpectrafor252Qfgpfj235u-jn 45-GroupFormat 7 TABLE2.UncertaintyEstimatesfor252cfand235uEvaluatedFission NeutronSpectra 9 TABLE3.AssignmentofUncertainties 13 vi Open at page → 9 Page 9 LISTOFFIGURES Page Fig. 1235uCavityfissionsource 3 Fig.2TheNBSevaluation ofthe ^ssy fissionneutronspectrum 8 vii Open at page → 10 Page 10 i I I 1 j j i 1 I Open at page → 11 Page 11 1.DESCRIPTION OFSERVICE TheNationalBureauofStandards(NBS)maintainsstandardfissionneutron fields(orbenchmarkfields)tosupplycalibrationirradiations andcertified fluencestandards. TheNBSCavityFissionNeutronSourceprovides a... Open at page → 12 Page 12 where:(A/aCTN) =reactionrateprobability(disintegrations per second/nucleus. ) » (|)=($/T),theeffectiveneutronfluencerateorfluxdensity (n/cm2s),and T=thelengthoftheirradiation (s)giveninthetestreport. 1.1CONFIGURATION AND... Open at page → 13 Page 13 NBSCAVITYFISSIONSOURCE Fia 1 ^^^UCavityfissionsource. Upperview: relativepositions ofneutronsensorfoils,fissiondisksandcadmiumenclosure. Lower theassemblyinthethermalcolumnoftneNBSreactor. V1ew : 3 Open at page → 14 Page 14 2.NEUTRONFIELDCHARACTERIZATION Theenergyspectraoffissionneutronsareverysimilarforallfission- ablenuclidesandbothtestandpowerreactorsexhibitfission-spectrum-like components intheMeVenergyrange. The235ufissionneutronspectr... Open at page → 15 Page 15 Thefissionneutronfluenceisperturbedbyasmallcavityreturncontri- bution,andalsobyscattering infissionsourcedisks,inencapsulations, and inthedetectorfoils. Thecorrection fortheseeffects,basedoncalcula- tion,isgivenasthefrac... Open at page → 16 Page 16 2.2.NEUTRONSPECTRUM 2.2.1. Calculation .Fissionneutronspectraaremostaccuratelydeter- minedbylaboratorymeasurementbecauseallthecalculations haveundetermined fittingparameters. (See,however,Ref.[16]andearlierworkcited ther... Open at page → 17 Page 17 TABLE1.EVALUATEDFISSIONNEUTRONSPECTRAFOR252cfAND235u IN45-GROUPFORMAT 252cf Lower Enerav Boundary (MeV) Group Fluence (() •aE Cumulative( FluencetoLower Boundary Group Fluence (j) .aE Cumulative^^) FluencetoLower Boundar... Open at page → 18 Page 18 8 Open at page → 19 Page 19 TABLE2.UNCERTAINTYESTIMATESFOR252cfand235uEVALUATED FISSIONNEUTRONSPECTRA 2 35U (Spontaneous Fission) (Thermal-Neutron-InducedFission) Energy Boundaries Group Fluence Uncertainty la (%) Uncertainty Group la Fluence (%) ^... Open at page → 20 Page 20 Theexpressionwhichgovernsthisfluencetransferis _^fcf_ . $ = ^. $ cvy D - cf ^cf ""cvy G^ a-:(>E ) \1)^{>E ) D =cf cf^ ^cf^ p^ cvy G ' o (>E ) * ijj (>E ) * D. cf cvy cvy^ p' xvy^ p' cf where$=fissionneutronfluenceand"cvy... Open at page → 21 Page 21 4.1.3. Arrangetimeatthethermalcolumnwithotherusers,principally theradiographygroupandtheactivationanalysisgroup. 4.1.4. Sourcediskassembly .Thedetectorcapsuleisnowreadyfor assemblywiththesourcedisks. Twopairsofsourcedisk... Open at page → 22 Page 22 wouldrestorethepulserresultstotheknown,truepulserrate. Thedeter- minedcountingratemustbecorrectedforlossesofeventsduetoattenuation oftheoutgoinggammarays. Thecorrectionfactor,C^,isequalto (l-e"^^)/ytwhereyisthemassattenu... Open at page → 23 Page 23 TABLE3.ASSIGNMENTOFUNCERTAINTIES (±1a) FluenceTransferMeasurements fromthe^^KfStandardFission NeutronFieldtothe235yCavityFissionSource: Percent (1)Absoluteneutronsourcestrengthofthe252cfsource 0.9 S+R (2)Distancemeasurem... Open at page → 24 Page 24 5.BENCHMARKREFERENCING Abenchmarkneutronfieldisawel 1-character!zedneutronfieldwhich willprovideanaccurateneutronfluenceforvalidationorcalibration of experimental techniquesandmethods. Forpurposesoffluencetransfertoa stu... Open at page → 25 Page 25 Inpractice, ^Q' ^^'y issimplythetimehistorycorrectedcountingrate ratioofthesampleirradiated intheunknownfieldtothatirradiated inthe 235ufield. Uncertainties duetoisotopicabundances,nuclearparameters, detectorefficiencies... Open at page → 26 Page 26 REFERENCES [1]DeJuren,J.A.,Padgett, D.W.,andCurtiss, L.F.,J.Res.NBS40,63 (1955) . [2]"NBSCalibrationServices,UsersGuide1986-1988." NBSSP250,U.S. GovernmentPrintingOffice,Washington, D.C.(1986). [3]McGarry, E.D.,Lamaze,G.... Open at page → 27 Page 27 [14]McGarry, E.D.andBoswel 1 ,E.W.,"NeutronSourceStrengthbythe ManganeseSulfateBathMethod,"NBSIR,tobepublished. [15]Eisenhauer, C.M.,privatecommunication. [16]Madland, D.G.,andNix,J.R.,"NewCalculation ofPromptFission Neu... Open at page → 29 Page 29 AppendixA DETTECTORASSEMBLYWORKSHEETFORCAVITYFISSIONSOURCE AssemblyDate:1/17/86irradiation8601 eOI:21:37:00 Jan20,1986 501:11:01:00 EST,Jan18,1986 ^AssemblyPiece DepthMeasurement S(mils) z (239-S) Ident" thk. Diecesum mi... Open at page → 30 Page 30 Piecesareassembledwithl.d.numberup (2) ErrordoesnotIncludeuncertainty inmidplaneposition. Position errorforIndiummonitorisrelativetoadjacentfoil. f-dimensionofassembledcadmiumcapsule(0.326**empty) D-sourcediskseparation:... Open at page → 31 Page 31 AppendixB IRRADIATIONLOGANDWORKSHEETFORCALCULATINGNEUTRONFLUENCE IrradiationIdentification: 8601 MaterialsIrradiated : Au ,Ni,Sc 1.SourceAssembly i.d. R/hr§ 1Ocm TopSourceDisk: BottomSourceDisk: SourceSeparationDistance:... Open at page → 32 Page 32 H.Activationdecayratefactors: T=2.10960S ^^Co A= 1.133^x10-' satfac 2.363x10-2 G=satfac/T 1.1200x10-^ C=G/A= .9881 Note:Foraconstantfluencerateirradiation, satfac= ( 1 -e 5.FissionNeutronFluenceatMidplane (z=0) : 0 i^^Au... Open at page → 33 Page 33 NOTESFORFLUENCECALCULATION (a)Diskgeometrygradient(empiricalfitofcalculationandmeasurement ) 4)(z)=neutronfluenceratepersourceneutronatz=distancefrommidplane betweencoaxialdisksadistanceDapart. =0.0470d"^ '^^ (1+21.2z^)... Open at page → 35 Page 35 AppendixC THESEARETHEINSTRUCTIONS FORRUNNINGTHEADCAMDIRECTLYFROMPRO/TOOLKIT 1 .LOADADCAMMENUBYTYPING@MENUORRUNDIRECTLYBYTYPING@STARTANDSKIP TOSTEP3.1 2.THE"A"MENUWILLBEDISPLAYED; ACARRIAGERETURNWILLCHANGETOTHE "B"MENU;AN... Open at page → 37 Page 37 Appendix D C STP2D8.FTN C MODIFIED10/1/84TOMAKEVARIABLE Y'VIRTUAL'FOR8000CHANNELS C FORMERLYSTPBG.FORFROMPDP-11RT-1 1OPERATINGSYS. C MODIFIED1984FORADCAMFILES,I.E.,.SPCFILES C MODIFIED9/25/82BYMCGARRY(HADTOCHANGEREADSTAT... Open at page → 38 Page 38 4FORMAT(II ) 5FORMATC.P') !THISISUSEDBYPGMEDPAGE TYPE8 8FORMAT(/'LOCKSHIFTKEY'/) CALLPARAMS(TEM) 10CALLGETFIL(5,IFILI,IFILO) CFORMERLYSUBROUTINEREADFI C C READANDPRINTTITLEANDCOLUMNHEADSANDINPUTSPECTRUMDATA C FROMTHEINPU... Open at page → 39 Page 39 C FORMERLY END !OFSUBROUTINEREADFI D WRITE(4,5) 21TYPE200 200FORMATC ENTERADCAMNUMBER(0OR1)') ACCEPT4,IADCAM IF(lADCAM.NE.O .AND.lADCAM.NE. 1)GOTO21 TYPE9 9FORMAT(/'THEENERGYCALIBRATIONDATASHOULDBEONKEV.DOC'// &'$D0YOUWA... Open at page → 40 Page 40 C INTHECASEOFADECAYLIKEBA,WHICHDECAYSTOLA,ONEMUST C INPUTBOTHOFTHEHALFLIVES,THELONGESTFIRST(BA).ITCALCULATES C THECASCADINGRATIOOFBAACTIVITYTOLAACTIVITYATTHEENDOF C IRRADIATION, (TA-TB)/TA. C DIMENSIONIPK(40),IWL(40) ,IW... Open at page → 41 Page 41 ACCEPT2,REPL IF(REPL.EQ.'Y')GOTO20 IF(REPL.EQ.'D')GOTO21 IF(REPL.EQ.'H')GOTO22 IF(REPL.EQ.'M')GOTO23 IF(REPL.EQ.'S')GOTO26 20TA=TA*365.25 21TA=TA*2i|, 22TA=TA*60. 23TA=TA*60. 26IF(TB.LT.1.OE-5)GOTO50 27TYPE28 28FORMAT('$... Open at page → 42 Page 42 122F0RMAT(1X,A8) 103READ(2,102,END=1 10)TOKEN IF(TOKEN.NE.KEY)GO TO103 104FORMAT(5I8,F8.0,F8.0 ,/,2E16.6) READ(2 ,104)NUM,lYRO ,IDAYO ,IHRO,MINITO,SECO,SIG,TA,TB WRITE(5,104)NUM,IYR0,IDAY0,IHR0,MINIT0,SEC0,SIG,TA,TB DO10... Open at page → 43 Page 43 c SUBROUTINECAL(Y) C C SUBROUTINEGALUSESSUBROUTINEELOCTOFINDPEAKS C ITISONLYCALLEDBYTHEMAINPROGRAM C 11 12 10 20 30 40 45 DIMENSIONX(40),E(40) VIRTUALY(8192) COMMON/PEAK/X,E,N COMMON/ADCAM/IADCAM DATASX,SX2 ,SX3,SX4,SY,S... Open at page → 44 Page 44 0PEN(UNIT=2,FILE='KEV0.D0C' ,STATUS= 'OLD ' ) GOTO201 2000PEN(UNIT=2,FILE='KEV1 .DOC,STATUS= 'OLD' ) 201WRITE(2,50)A,B,C CL0SE(2) 50FORMAT(3E17.10) TYPE55 55F0RMAT(/'FILEKEVUPDATED. '/) RETURN !TOTHEMAINPROGRAM END !OFSU... Open at page → 45 Page 45 C ANSWERNOTOTHEGAINSHIFTREQUESTINSUBROUTINEEPEAK.THEN C THEPROGRAMWILLNOTACCESSTHISSUBROUTINE. C VIRTUALY(8192) COMMON/SPEC/TIME.CLTM ISTEP=1 I=I+ISTEP IF(Y(I).LT.O.)Y(I)=-Y(I) YL=Y(I-1)+SQRT(Y(I)) YH=Y(I+1)-SQRT(Y(I)) I... Open at page → 46 Page 46 c DIMENSIONEGY(40),IPK(40),IWL(40),IWH(40),PK(40) , &IC(40),ID(MO),NL(MO),NR(40) VIRTUALY(8192) COMMON/ADCAM/IADCAM COMMON/NCHAN/ICHAN COMMON/ENEG/EGY COMMON/PKLIM/NUM,IWL,IWH,IC,ID,NL,NR,PK,IBW,SIG IFdADCAM.GT.OGOTO200... Open at page → 47 Page 47 C TOFILENAME.RES.ITWILLADJUSTTHEPEAKPARAMETERSWITHRESPECT C TOTHEPEAKFORCHANGESINGAINOFTHEPEAK.ITCALLSSUBROUTINE C CHPEAKANDLOCATE.ITISCALLEDBYTHEMAINPROGRAM. C DIMENSIONEGY(40) ,IPK(MO ),IWL(40 ),IWH(40),PK(^JO ) , &IC(... Open at page → 48 Page 48 IDAYS=0 SECS=0.0 IF(.NOT.PRMS)GOTO72 10IF(IYRO.LE.IYR)GO TO70 WRITE(5,12)IYR0,IYR 12FORMATCIYR0,',I5,', CANNOTBELARGERTHENIYR,',I5) TYPE18 18FORMATCINPUTNEWlYRO ') ACCEPT19,IYR0 19FORMAT(I6) GOTO10 70IFdYRO.EQ.IYR)GOTO71... Open at page → 49 Page 49 IF(.NOT.PRMS)GOTO15 IF(.NOT.GAIN)GOTO15 IF((PK(1 ).LT.IWL(I)).OR.(PK(I).GT.IWH(I)) )TYPE16 16FORMAT ('INPUTPEAKISOUTOFBOUNDS ') LL=IWL(I)-NL(I) ILL=LL LH=IWH(I)+NR(I) 17CALLCHPEAK(CPK,IH,IL,ILL,SIG, Y) IF(CPK.GT.5.0)GO T... Open at page → 50 Page 50 BL=BL/FLOAT(NTL) BLOW(I)=BL BH=0.0 DO66JK=1,NR(I) 66BH=BH+Y(IPLUS+JK-1 ) NTR=NR(I) XH=FLOAT (IPLUS)+(FLOAT(NTR)/2.0 ) BH=BH/FLOAT(NTR) BHIGH(I)=BH C C BACKGROUNDEQUATION C B=BL*(CPK-CC+0.5)+BH*(DD-CPK+0.5) YAA=T-B BKG(I)... Open at page → 51 Page 51 40CONTINUE TYPE9 !LINEFEED TYPE3 WRITE(4,3) WRITE(4,50) 50FORMAT(/,15XDETAILSREGARDINGTHEBACKGROUNDSUBTRACTION'/) WRITE(4,55) WRITE(4,56) 55FORMAT (2X, 'PEAKAREA LOWBKGHIGHBKG' &,' BLOW BHIGH BL/BH BKG/T%ERROR') 56F0RMAT... Open at page → 53 Page 53 Appendix E CPROGRAMSCATFOTOCALCULATESCATTERINGCORRECTIONFORACTIVATION CFOILSINCAVITYFISSIONSOURCE. DATAMAYBEENTEREDFROMADISKFILE C ORFROMTHEKEYBOARD CHARACTER*^ ANAME(50) DIMENSIONGRAD(50) DIMENSIONIT(50),P0S(50),TH(50)... Open at page → 54 Page 54 Y=-.0017+(.00356*EXP(-.08l5*X) ) Y=Y*TH(J)/10. SCAT=SCAT+Y 550CONTINUE ALSCAT=SCAT-.002+( .0017*TH(I)/10. ) GOTO800 600DO650J= 1,N IF(I.EQ.J)GO TO650 X=ABS(POS(J)-POS(I)) Y=-.oo2+(.oo2*EXP(-.^^^*x)) Y=Y*TH(J)/10. SCAT=SC... Open at page → 55 Page 55 Appendix F 10 20 30 40 50 60 70 80 90 100 110 120 125 126 130 140 150 160 170 180 190 200 REMSAT260 THEDATA SEQUENCE: X1(I ...11/21/83 VARIABLES IN COUNTER C(I)... X3(I).. T(I)... X5(I).. X6(I).. ' X7(I) . REM Fl*IS REM... Open at page → 56 Page 56 (b3U 640 650 660 670 680 NOT 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 350 860 870 880 890 900 91 0 915 916 920 218<:: 2190 220( 22IC 2240 225(: 226(: 227<: 228(: 2290 2300 23IC 233C 234(1 '-\-Tcr /... Open at page → 57 Page 57 243 244( 24^ 246( 247( 247^ 248'. 249( 254( 2560 257( 25S( 259'. 260( 261' 262( 26.3( 264( 26^ 266( 267<: 2680 269!: 270 C 271( 273 274( 2750 276C 277C L=.00000002567 i?L*="Nn-54" H'GOTO24S0 L=.0000029757 i?L*="Au" li'GO... Open at page → 59 Page 59 AppendixG TESTREPORTFORNEUTRONFLUENCESTANDARDS PRODUCEDBYANIRRADIATIONATTHENBS 23S UCAVITYFISSIONSOURCE Irradiation No. :8601 ReportDate:March6,1986 SensorMaterialsIrradiated:Nickel,Gold,andScandium (designations: Au-1,2... Open at page → 60 Page 60 Relationship ofTeatReportDatatotheMeasuredActivityatEndof Irradiation (EOI)forCavityFissionNeutronSourceIrradiations Theneutronfluenceorfluenceratestandardhasbeenexposedtoafission neutronfluencethatisperturbedbyasmallcav... Open at page → 61 Page 61 2 *=free-fieldfissionneutronfluence(n/cm )giveninthistest report. (Note:thesymbol*isrecommended byICRUandASTM E170. ) =reactionprobability Activationequationforaverageneutronfluencerate. Fordecay half-livesshortcomparedt... Open at page → 62 Page 62 RecommendedProcedureforEstablishing aCalibrationFactor (X2 s ) UseEquation (1)andeitherEquation (2)orEquation(3)toderivea free-fieldneutronfluenceoraveragefluencerate,respectively, fromthe measurement ofaparticularactivi... Open at page → 63 Page 63 ASSIGNMENT OFUNCERTAINTIES (±1a) PlusTransferMeasurements fromthe^^^cfstandardFission NeutronFieldtothe ^^Sy CavityFissionSource : Percent (1)Absoluteneutronsourcestrengthofthe252cfsource 0.9 S+R (2)Distancemeasurement 0... Open at page → 64 Page 64 NBS-n4A(REV.2-ec) U.S.DEPT.OFCOMM. BIBLIOGRAPHICDATA SHEET(Seeinstructions) 1.PUBLICATIONOR REPORTNO. NBS/SP-250/14 2.PerformingOrgan.ReportNo, 3.PublicationDate March1988 4.TITLEANDSUBTITLE NBSMEASUREMENTSERVICES: ACTIV... Open at page → 67 Page 67 THESP250SERIESONNBSMEASUREMENTSERVICES* SP250-1 SpectralRadianceCalibrations 003-003-02792 $3.50 SP250-2 FarUltravioletDetectorStandards 003-003-02810-0 $4.25 SP250-3 RadiometricStandardsInttieVacuum Ultraviolet 003-003-... Open at page → 68 Page 68 U.S.DepartmentofCommerce NationalBureauofStandards Galthersburg,MD20899 OfficialBusiness PenaltyfcxPrivateUse$300 SttmulatingAmericasProgress 1913-1988 Open at page →