Omnidirectional 3D Gamma-ray Imaging with a Free-moving ...

Omnidirectional3DGamma-rayImagingwithaFree-movingSphericalActiveCodedAperture

D.Hellfeld Omnidirectional3DSphericalCodedAperture 10.24.171

D.Hellfeld1,P.Barton2,A.Haefner2,D.Gunter2,L.Mihailescu2,andK.Vetter1,2

1UniversityofCalifornia,BerkeleyDepartmentofNuclearEngineering

2LawrenceBerkeleyNationalLaboratoryAppliedNuclearPhysics– NuclearScienceDivision

IEEENuclearScienceSymposiumandMedicalImagingConferenceAtlanta,Georgia

21-28October2017

Outline

• Introduction• Activesphericalcodedaperture– PRISM• 2Dimaging

• 3Dimaging

• Experimentalresults

• GPUacceleration• Conclusionsandfuturework


Introduction


MotivationDetect,locate,andidentifyweakradioactivesourcesincomplexenvironmentsandefficientlymapradiationfields.Applicationsinastrophysics,nuclearsecurityandsafeguards,nuclearcontaminationremediation,medicalimaging

NeedPortable(hand-held)2D/3Dimagingsystemwithhighefficiency,widefield-of-view,highenergyresolution,andbroadenergysensitivity

ApproachMultipleroom-temperatureoperatedcm3CdZnTe (CZT)coplanargird(CPG)detectorsarrangedtofacilitatecodedaperture(40– 400keV)andComptonimaging(300keV– 2MeV)modalities

CrabnebulawithNCT

Bandstra etal,TheAstrophysicalJournal,738(1),2011

137CscontaminationinFukushimahome

CourtesyofA.Haefner,LBNL,2016

ActivePlanarArrangement- HEMI


HighEfficiencyMulti-modalImager(HEMI)• 96CZTCPGdetectors(1cm3,<2%FWHMat662keV)• 32inactivecodedfrontplane,64infullypopulatedbackplane• Codedaperture(50keVto350keV)andComptonimaging

(300keVto3MeV)• 10° resolutionat662keV(Compton)and186keV(CA)• <10lbs

137Cs8μCi

22Na10μCi

88Y20μCi

50cm

88Y22Na

137Cs

Comptonmode

-80° 80°

0°180°

Φ

θ

1 2 3

2

3

1

Codedaperturemode

-30°

30°

-30° -30° -30°30° 30° 30°

133Ba(81keV)

θ

Φ Φ Φ

M.Galloway,Ph.D.Thesis,UCBerkeley,2014

ActiveSphericalCodedAperture


• PlanararrangementofHEMIsuffersfromalimitedandanisotropicfield-of-viewinthecodedaperturemodality

• Mask-detectorgeometryhaspartialcodingexcepton-axis

FC-FOV

15cm

7.5cm

• Arrangedetectorsintoasphericalactivecodedconfigurationtofacilitateomnidirectionalimaging

HEMI

4𝝅 CodedApertureFieldofView

Spherical

15cm

PRISM


PortableRadiationImagingSpectroscopyandMapping(PRISM)• Hand-held,free-moving,CZTCPG-based,spherical

activecodedaperture• 1cm3 crystalsinmodularLexancasings• 6modular(identical)faces• 192totalavailabledetectorlocations• <2%FWHMat662keV• <10° resolutionat186(CAI)and662keV(Compton)• <10lbs,<10Wpower

èHardwarespecifictalkintheNSS/RTSDjointsession(next)inCentennialIIbyPaulBarton

2DFar-fieldCodedApertureImagingin4𝜋


• 93/192detectorspopulatedo Pseudo-random(notoptimized†)o 74/93detectorsfunctional

• 10-mindwell,20𝜇Ci241Am(60keV)

†Foroptimization,see D.Hellfeldetal,IEEETNS,2017.DOI: 10.1109/TNS.2017.2755982

𝟐𝟎∘1

3

4

𝟓𝟎∘

2

1 2

3 4

MLEMreconstruction(50iterations)

2Dto3DImaging


• 2Dimagingprovidesaccuratereconstructionsofthesourcedirectioninspace,thoughpositionalongdirectionisambiguous

Static2Dimagewith3Doverlay Multi-location3Dreconstruction

Barnowski,Ph.D.Thesis,UCBerkeley,2016

• Datafromdifferentperspectivescanbecombinedtocreate3Dimages

Free-movingTrackingandSceneDataFusion


• Auxiliarycontextualsensors(visualcamera,LiDAR,IMU)usedwithSimultaneouslyLocalizationandMapping(SLAM)algorithmstotrackthepositionandorientationofthesystemasitmovesfreelythroughanenvironment

• 3Dscenedatafusedwith3Dradiationimagetoprovidevisualcontext,increaseimageaccuracy,reducenoise,and decreasereconstructioncomputationaltime

Systempath

Topdownview

Free-moving3DComptonImagingwithHEMI


• Equippedwithauxiliarycontextualsensors(visualcamera,LiDAR,andIMU)

• Demonstrated137CsmappinginFukushimawithComptonimagingo Hand-heldandUAVoperation

HEMI

LiDAR

Camera,IMU

<5min

27min

PRISMSystemSetup


LiDARandIMU PRISM

Backpackcontainsbatteriesandlaptopforcontextualdataprocessing

Hand-heldtabletforgamma-rayreconstructionandvisualization

ExperimentalMeasurementSetup


20𝜇Ci241Am(60keV)

Results


Measurementtime:120sTotalcounts(60keVROI):7982Occupiedvoxels:33340 (14%oftotal)Voxelsize:10cmPoses:927Operatingdetectors:74

MLEM(20iterations)Topdownview

20𝜇Ci241Am(60keV)

ZoomedIsometricview

10 0.25 0.5 0.75

Head-onboxes

GPUAcceleration


• Asthevoxelized spacegrowslarger,imagereconstructioncanbecomeverycomputationallyexpensive

• SignificantspeedupswhencomputationparallelizedonGPUvs.CPUusingOpenCL

Hardware Sensitivity(s)

MLEM iteration(s)

Total(20iterations)(s)

2.7GHz Intelquad-corei7-6820HQ 6.1 29.0 586 -

IntelHDGraphics530(integrated) 4.4 9.5 173 3.4x

AMDRadeonPro455(dedicated) 2.6 4.3 89 6.6x

• Furtherworkisnecessarytoimproveefficiencyandovercomememorymanagementissues

• However,resultsarepromisingtowardsareal-timeon-boardimagereconstruction

Conclusions


• Developingasphericalactivecodedaperturegamma-rayimagingsystemtoovercomethelimitedandanisotropicfield-of-viewissuesintraditionalplanarsystems

• Firstexperimentaldemonstrationofsphericalcodedapertureomnidirectional2Dimaging

• Firstsuccessfulfree-moving3Dcodedapertureimagereconstruction

• SignificantspeedupsobservedinreconstructiontimewithGPUparallelization

Futurework• Continueexploringthe3Dcodedapertureimagingcapabilities/limitationsofPRISM• Real-timeimaging• 3Dimagingimprovementswithdepth-of-interactionreadout• Near-field3Dimaging

AcknowledgementsandDisclaimer


NuclearScienceDivision,LBNLLucianMihailescu,PaulBarton,AndyHaefner,DonGunter,RossBarnowski,MarcosTurqueti,VictorNegut,RyanPavlovsky

Dept.ofNuclearEngineering,UCBerkeleyKaiVetter

EngineeringDivision,LBNLPaulLuke,MarkAmman,JulieLee

DefenseThreatReductionAgency,DODHankZhu,MarcBlack

This material is based on work supported in part by the Department of Energy National Nuclear Security Administration through the Nuclear Scienceand Security Consortium under Award Number DE-NA-0003180 and the Defense Threat Reduction Agency under Contract Number DTRA10027-19346.

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government norany agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for theaccuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringeprivately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwisedoes not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Theviews and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.


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