Development of a Stron/um Iodide Coded Aperture Instrument
Transcript of Development of a Stron/um Iodide Coded Aperture Instrument
NRL
DevelopmentofaStron/umIodideCodedApertureInstrument
byLeeMitchell,EricGrove,BernardPhlips
PresentedatNASAFutureGamma-rayMissionWorkshop3/2016
NRL
Introduc/on• DevelopmenttowardsCodedApertureSystemforshortgamma-rayburst
(sGRB)detec/onandlocaliza/on– WideFieldofView(90deg-fullycoded)– Imagingenergyregime20-600keV– Detec/onupto1MeV– ReducedSWAPtoincreasemissionopportuni/es
• SpaceTestProgram(STP)-istheprimaryproviderofspaceflightDODspacescienceandtechnologycommunity.– Interna/onalSpaceSta/on– Secondarypayloads– Dedicatedlaunchservices.
• Stron/umIodideRadia/onInstrument(SIRI)• ProposedDevelopmentofPrototypeStron/umIodideCodedAperture
(SICA)array• Full-sizedInstrument(SICADA)
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Stron&umIodideRadia&onInstrument(SIRI)Detector
SBC
UnpopulatedElectronics/COMBoard
HousingSIRI1of5instruments
STPSat5
ExplodedView
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Stron&umIodideRadia&onInstrument(SIRI)
• InstrumentDescrip/on– SingleRMDSrI2:Eudetector(17x17x40)mm3– SensL2x2J-seriesSiPMarray– lowpowerCOTSMCA(Kromek)andSBC(BeagleBoneBlack)– /mestampedeventdata
• Objec/ves– Studytheinternalac/va/onoftheSrI2:Euinaspaceenvironment(al/tude~500km)
– SiPMperformanceanddegrada/onover1yrmissionlife• CurrentSchedule
– InstrumentassemblyandGEVStes/ng(nextfewmonths)– Spacecradintegra/onbeginsummer2016– Launchsummer2017,Falcon9,ESPAring
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Stron/umIodideCodedAperture
TestdetectorCrystalandSiPM
27Ucube
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SICAprototype
• Objec/ves– sGRBdetec/onandimaging– intheFCFOVRate2-3/yr– SmallinstrumentincreaseslikelihoodofSTPselec/on– 3yearsfromstarttolaunch– Reasonableposi/onaccuracy– Imagingregime(20–600keV)
• Descrip/on– DetectorPlane–8x8arrayofSrI2:Eu3.2%@662keV(pitch1.0cm)– EachDetector-0.8cmx0.8cmx5cm– Mask–Tantalum30x30eachelement(1cmx1cmx0.5cm)– COTSelectronics,withsomecustommainboards– Mask20cmfromdetectorplane– FullyCodedFieldofView(FCFOV)=58o– AngularResolu/on(AR)=2.9o– Power=13W
Note:Posi/onaccuracy=AR/SNR
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Stron/umIodideCodedApertureDetectorArray(SICADA)
• FullSizedversionof(SICA)• Objec/ves
– IncreasedsGRBdetec/onrate(~8/yr)overtheprototype– Improvedposi/onalaccuracy– Energyregime20keV–600keV– Largerinstrumentwithbackgroundrejec/on– SWAPandcostsstartlimitmissionop/ons
• Descrip/on– DetectorPlane-40x40arraypitch=1cmthickness5cm– MaskTitanium108cmx108cmx0.5cm(pitch1cm)– Largernumberofchannels(morecustomelectronicsrequired)– FCFOV=90o– AR=~2.0o(20arcminfora6sigmadetec/on)– Mass~300kg– Power20-30W– Ac/veBGOshieldonbackandsidesofdetectorplane
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Stron/umIodideCodedApertureDetec/onArray(SICADA)
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SICADASimula/ons
• Simulated1photon/cm2sGRB5ooffaxis
• Addedinternalbackground(duetoac/va/on)
• Needtoaddgalac/cdiffuseandalbedobackgroundcontribu/ons
Withoutinternalbackground
Withinternalbackground
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Conclusion
• Thedura/onofsGRBs(T90<2s)associatedwithLIGOtypeeventsrequireswideFOVfordetec/on.
• AsmallinstrumentsuchasSICAwouldallowustorapidlygetsomethingintotheSTPqueue
• Alargermoresensi/veinstrument(SICADA)isidealbutlargerSWAPlimitsmissionopportuni/esandincreasescost