Activation Foil Irradiation with Californium Fission Sources

1 Page 1 NBSMeasurement Services: ActivationFoil GeorgeP.Lamaze JamesA.Grundl U.S.DepartmentofCommerce NationalBureauofStandards Open at page → 2 Page 2 CenterforRadiationResearch TheCenterforRadiationResearchisamajorcomponentoftheNationalMeasurementLaboratoryintheNational BureauofStandards. TheCenterprovidestheNationwithstandardsandmeasurementservicesforionizing radiati... Open at page → 3 Page 3 NBSMEASUREMENTSERVICES: ACTIVATIONFOILIRRADIATIONWITH CALIFORNIUMFISSIONSOURCES GeorgeP.Lamaze JamesA.Grundl CenterforRadiationResearch NationalMeasurementLaboratory j NationalBureauofStandards Gaithersburg,MD20899 I U.S... Open at page → 4 Page 4 LibraryofCongressCatalogCardNumber:88-600508 NationalBureauofStandardsSpecialPublication250-13 Natl.Bur.Stand.(U.S.),Spec.Publ.250-13,38pages(Mar.1988) CODEN:XNBSAV Commercialproducts—materialsandinstruments-areIdentifie... Open at page → 5 Page 5 PREFACE Thecalibration andrelatedmeasurement servicesoftheNationalBureau ofStandards areintendedtoassistthemakersandusersofprecision measuringinstruments inachievingthehighestpossiblelevelsof accuracy,quality,andproducti... Open at page → 6 Page 6 ABSTRACT ThisdocumentdescribestheNBScalibrationservice440800 (formerly8.1Q),whichoperatesinthefollowingway: (i)dosimetry sensors(metalfoils,nucleartrackdetectors,wires,crystals, etc.,suppliedbythecustomerorbyNBS)areirrad... Open at page → 7 Page 7 TABLEOFCONTENTS I.DESCRIPTION OFSERVICESANDFACILITIES 1 I.a.GenericDescription 2 I.b.AvailableFissionNeutronExposures 2 I.e.Corrections forNeutronScattering at5cmPosition 2 I.d.Configuration andCharacteristics 2 II.NEUTR... Open at page → 8 Page 8 LISTOFTABLES Page TABLE1.252cfFissionNeutronFieldParametersandUncertainty Components 5 TABLE2,TypicalNeutronFluenceandSensorResponsePerturbations duetoNeutronScattering 8 TABLE3.EvaluatedFissionNeutronSpectrafor252cf 235... Open at page → 9 Page 9 LISTOFFIGURES Page Fig. 1TheNBSevaluation ofthe252Qffissionneutronspectrum 3 Fig.2Typicalarrangement ofsixactivationsensorsaroundthe 252cfsource 4 Fig.3Scatteringmaterialsinthelow-mass252cffissionneutron sourcecapsule 6... Open at page → 11 Page 11 I.DESCRIPTION OFSERVICESANDFACILITIES NBSmaintainsstandardfissionneutronfieldstosupplycalibration irradiations andcertifiedfluenceandfluenceratestandards. TheNBS252cf FissionNeutronSource(typicalmaximumfluenceof1.0x10^^n... Open at page → 12 Page 12 I.a.GENERICDESCRIPTION Astandard 252(;fneutronfieldconsistsofneutronsfromthespontaneous fissionof252Qfy^j^hlittleornoenergydegradation. Themedianenergyof thespectrumis1.68MeV,with98%oftheneutronsbetween0.1MeVand8MeV (see... Open at page → 13 Page 13 CS/2->«-*tN3/N> C3>IHd 3 Open at page → 15 Page 15 Thecaliforniumsourcecapsule,showninfiyure3,ismadeupofadisk- shaped252Qfdepositinanaluminumpelletencapsulated inathin-walled stainlesssteelcylinder. Thepositionofthecaliforniumdepositrelativeto thecapsulesurfaceisknowntoa... Open at page → 16 Page 16 7.9mm 1.7mm -0.50mm 7.6mm SOURCE GUIDE TUBE STAINLESSSTEEL CAPSULELID(0.59g) CfDEPOSIT(-3mg) OgSO^DISI 1.4mm^ ) (CfgOgSO^DISPLACEMENT ALUMINUMPELLET (6.4mmdio.x5.7mm LONG :0.48g ) STAINLESSSTEELCAPSULE (TYPE304 i76mmdio... Open at page → 17 Page 17 free-fieldfissionneutronfluence. Theirradiationgeometryshownin figure2istermedcompensated-beam geometryandreferstotheexperimental practiceofplacingsensorsofsimilarsensitivity inpairsonoppositesides ofthesource,andnearlye... Open at page → 18 Page 18 TABLE2.TYPICALNEUTRONFLUENCEANDSENSORRESPONSEPERTURBATIONS DUETO NEUTRONSCATTERING(5-cmDISTANCE) Neutronfluenceperturbations: (above0.4eV) roomreturn 0.1% sourcecapsulescattering 0.8% supportstructurescattering 0.4% airs... Open at page → 19 Page 19 wherep =fractionoftheneutronspectraaboveE ;andinacoarseseven- groupdisplay, (|)(E)aE,asfollows: ^ Elimits: 0 0.25 0.8 1.5 2.3 3.7 8 12fleV (|)(E)dE (252cf) 0.047 0.184 0.220 0.194 0.200 0.146 0.009 (|)(E)dE(235U) 0.054 0... Open at page → 20 Page 20 Asmallanisotropyresultsfromthecylindrical shapeofthefission sourcecapsule. Theratioofthefluencerateaveragedoveralldirectionsto thefluenceratealongadirectionperpendicular tothecapsuleaxisis0.992 whenthesensorsdonotsubtend... Open at page → 21 Page 21 TABLE3.EVALUATEDFISSIONNEUTRONSPECTRAFOR252cfAND235u IN45-6R0UPFORMAT 252cf 2 35U Lower Energy Boundary (MeV) Group Fluence ({) •aE Cumulat!ve^^) FluencetoLower Boundary Group Fluence 4) •aE Cumulat !ve^^^ FluencetoLower... Open at page → 22 Page 22 Spectrumuncertainties intheevaluationarebasedonstandarddeviations fromthemeanofsubsetsofmeasureddatafromthefinaladjustedMaxwellian, Thisestimate,carriedoutinasevengroupstructure, hasbeenmadeforala uncertainty. Resultsare... Open at page → 23 Page 23 3)Havetheshopsmeasuretheseparationdistanceofthesensorpairsonthe coordinatemeasuringmachine. Thisshouldbeadirectmeasurement of face-to-face separationwhenpossible. Recordallparameters, sothata finalcenter-to-center separa... Open at page → 24 Page 24 2)Thefluencerate, (j),averagedoverthesurfaceofthesensorisobtained fromtheequation: whereRistheaveragesourcetosensordistanceandpistheradiusof thesensor,typically6.35mm. Thisequationhasbeenprogrammed onaTISR-52deskcalculat... Open at page → 25 Page 25 V.BENCHMARKREFERENCING Abenchmarkneutronfieldisawel 1-character izedneutronfieldwhich willprovideanaccurateneutronfluenceforvalidation orcalibration of experimental techniquesandmethods. Forpurposesoffluencetransfertoa s... Open at page → 26 Page 26 VI.SAFETY Theneutronsourcesusedfortheseirradiationservicesrangeinsource strengthfrom 1to5x10^n/s.Whilethesesourcesarenotlethal, mishandling canresultinradiationexposureswelloverthelegallimitfor radiationexposures. Thesou... Open at page → 27 Page 27 REFERENCES [1]Grundl ,J.,andEisenhauer,C,"CompendiumofBenchmarkNeutronFieldsfor ReactorDosimetry," NBSIR85-3151(January,1986). [2]Grundl,J.A.,Spiegel,V.,Eisenhauer, C.M.,HeatonII,H.T. , Gilliam, D.M.NBS;andBigelow,J.,ORN... Open at page → 29 Page 29 APPENDIXA C CFYLD--CALIFORNIUM YIELD6/26/82. DIMENSIONKC0M(66) CHARACTERAlREP CHARACTERA4A C THISPROGRAMUSES2.645YRHALFLIFEFOR252CFANDNU=3.766. C FOR250CFITUSES13.2YRSAND3.53.FOR254CFITUSES61.9DAYS C AND3.93.NURATIOSAREF... Open at page → 30 Page 30 READ(5 ,1)X050,X052,X054 C NORMALIZETHENEUTRONEMMITTERSTO1. SN=X050+X052+X054 X50=X050/SN X52=X052/SN X54=X054/SN WRITE(7,6) READ(5,3)ID,M,IYR1 CALLIDAYS(ID,M,IYR1,IDAY1) CALLLPDAYS(IYR1,IYR0,ITL) WRITE(7,9) READ(5,1)CA... Open at page → 31 Page 31 READ(5,3)ID,M,IYR3 CALLIDAYS(ID,M,IYR3,IDAY3) CALLLPDAYS(IYR3,IYR2,ITL) N=(IYR3-IYR2)A365+IDAY3-IDAY2+ITL+1 GOTO80 70N=l WRITE(7,23) READ(5,3)ID,M,IYR2 IF(ID.EQ.0)G0 TO200 CALLIDAYS(ID,M,IYR2,IDAY2) 80CALLLPDAYS(IYR2,IYR... Open at page → 32 Page 32 1 I C FORJANUARYANDFEBRUARY IF(M.LE.2)X=0.0 C FORMONTHSAFTERFEBRUARYINLEAPYEARS IF(M.GT.2.AND.IY.EQ.0)X=1.0 Y=(M-l)A30.57+0.5+ID-X ' IDAY=INT(Y) RETURN END C : c I SUBROUTINELPDAYS (I2YR,IIYR,ITL) ' C i C THISSUBROUTINEC... Open at page → 33 Page 33 GOTO1000 60IF(IMOD.EO.O)IDAY=IDAY-1 C AAAAAAAAAA>;?kAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA C IDAYATTHISLINEOFTHEPROGRAMMUSTBE60ORGREATER. C THISSECTIONOFTHEPROGRAMDECIDESWHERETHEPROGRAM C SHOULDCONTINEINORDERTOAV... Open at page → 35 Page 35 APPENDIXB A THISVERSIONOFCFGFACISDATEDNOVEMBER5,1985 DOUBLEPRECISIONTMI(20 ),CMI (20 ) DOUBLEPRECISIONTOUT,DE,HE,TE,DS,HS,TS,TDI,THI,CDI,CHI,T , +FLU rPFLU rALCF,TAU ,ALAM,SATFR ,B,GFAC ,CFAC,BLAM 1FORMATdS) 2FORMAT(D16.... Open at page → 36 Page 36 READ(7 ,2)TDI,THI,TMI (I ) GOTO102 101WRITE(7,7) READ(7,2)TDI,THI,TMI(I ) 102WRITE(7,13) READ(7 ,2)GDI,CHI,CMI(I ) TMKI)=TMI{I)+(TDIA24.D0+THI) A60.D0-TS GMKI)=GMI(I)+(GDI^24.D0+GHI) A60.D0-TS 100TOUT=GMI(I)-TMI(I)+TOUT... Open at page → 37 Page 37 APPENDIX C TESTREPORTFORNEUTRONFLUENCESTANDARDS PRODUCEDBYANIRRADIATION ATTHENBS^^^CfFISSIONNEUTRONSOURCE Irradiation No.: ReportDate: NeutronSource: SensorMaterialsIrradiated: (designations : EndofIrradiation (EOI): REP... Open at page → 38 Page 38 TESTREPORTFORNEUTRONFLUENCERATESTANDARDS PRODUCEDBYANIRRADIATIONATTHENBS^^^CfFISSIONNEUTRONSOURCE Irradiation No.: ReportDate NeutronSource: SensorMaterialsIrradiated: (designations : EndofIrradiation (EOI): REPORTFOR: F... Open at page → 39 Page 39 Comments ; 1)ThisserviceisofferedasSPNo.44080C. Adocumentdescribing the serviceisinpreparationandwillbeforwardedwhenavailable. 2)ReferenceDocoument: "CompendiumofBenchmarkNeutronFieldsfor ReactorDosimetry,"NBSDocumentNBS... Open at page → 40 Page 40 Relationship ofTestReportDatatotheMeasuredActivityatEndof 252 Irradiation (EOI)for CfFissionNeutronIrradiations Compensatedbeamgeometry . Neutronfluencestandardsareirradiated in pairsonoppositesidesandequidistantfromthes... Open at page → 41 Page 41 C=decaycorrectionfactorgivenintestreport. Foran uninterrupted irradiation oflengthTataconstantfluence rate,Cisequalto[( 1 -exp(-AT ))/AT] .(Whenitis appropriate toreportaverageneutronfluencerate,thedecay correctionfactor... Open at page → 42 Page 42 RecommendedProcedureforEstablishing aCalibrationFactor (x^^) UseEquations (2)or(3)toderiveafree-fieldneutronfluenceoraverage fluencerate,respectively, fromthemeasurement ofaparticularactivity oftheneutronsensor. Defineac... Open at page → 43 Page 43 NBS-114AiREv.2.BC) U.S.DEPT.OFCOMM. BIBLIOGRAPHICDATA SHEET(Seeinstructions) 1.PUBLICATIONOR REPORTNO. NBS/SP-250/13 2.PerformingOrgan.ReportNo.3.PublicatlonDate March1988 4.TITLEANDSUBTITLE NBSMeasurementServices: Activ... Open at page → 45 Page 45 1 ] I I i I j I i i j I ! I ! I i Open at page → 47 Page 47 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 → 48 Page 48 U.S.DepartmentofCommerce NationalBureauofStandards Gaithersburg,MD20899 OfficialBusiness PenaltyforPrivateUse$300 75YearsSlimulalingAmerica'sProgress 19U-19S8 Open at page →