1 UC Berkeley U NIVERSITY OF C ALIFORNIA, B ERKELEY Some Uses of HPGe Detectors for Nuclear Security – Developments in Berkeley Paul Barton 1, Kai Vetter 1,2 1 Applied Nuclear Physics Program, LBNL 2 Department of Nuclear Engineering, UC Berkeley  Overview of the Berkeley Applied Nuclear Physics Program  RadMAP, Nuclear Street View, and understanding the world around us  Volumetric imaging – towards multi-sensor fusion and analysis in real-time  Summary

2 Our Team 18 graduate students, 8 undergraduate students, 4 junior specialists, 6 postdocs, 12 scientists Located in B50C and B70A (… at the “heart” of LBNL) (+2 in Ge)

3 The Berkeley Applied Nuclear Physics Program Applied Nuclear Physics Program Electron-Tracking Detector Development & Fabrication Detector Readout Nuclear Street View Standoff Detection Gamma-Ray Imaging Radiation Mapping and Monitoring Compact Detection and Imaging

4 Applied Nuclear Physics Program Multi-disciplinary and multi-institutional context Applied Nuclear Physics Program Semiconductor Detector Lab LBNL G RETINA M AJORANA Biomedical Imaging Accelerator/beam diagnostics Computing N ERSC BeARING Nuclear Engineering UC Berkeley Physics EECS, IEOR NSSC LANL LLNL ORNL PNNL SNL BNL Astrophysics Gamma-ray telescopes Astrophysics Gamma-ray telescopes Nuclear Physics Particle and gamma-ray detection Nuclear Physics Particle and gamma-ray detection Biomedical imaging Cancer therapy verification Biomedical imaging Cancer therapy verification Environmental mapping Space Sciences Laboratory UC San Francisco Radiology Radiation Oncology Michigan State University Univ. Tokyo

5 Technologies vs. Applications & Science Technologies Science & Applications Modeling & Analysis Modeling & Analysis Nuclear Forensics Energy Efficiency Energy Efficiency Safeguards Astrophysics Non- Proliferation Homeland Security Cancer Diagnosis and Therapy Biological Effects of Radiation Environmental Measurements Nuclear Physics Nuclear Signatures 3D Multi-Modality Reconstruction Multi-Modality Street View Data and Signal Processing Readout Characterization Fabrication Detectors Radiation Detection Data and Algorithm’s Cloud

6 Example 1: The “Nuclear Street View” 6 1.Merge gamma-ray spectral and location information with visual and object information in 3D! 2.Create a data base of 3D radiation “backgrounds” (“clickable” objects, returning spectra on 5-10 m grid) 3.Provide ability to synthesize data from measured background to simulate operations, e.g. for moving personal or truck-mounted detection system 4.Provide guidance for operations, e.g. prior background knowledge for detection 1.Merge gamma-ray spectral and location information with visual and object information in 3D! 2.Create a data base of 3D radiation “backgrounds” (“clickable” objects, returning spectra on 5-10 m grid) 3.Provide ability to synthesize data from measured background to simulate operations, e.g. for moving personal or truck-mounted detection system 4.Provide guidance for operations, e.g. prior background knowledge for detection  Unique mobile multi-sensor platform for extensive and systematic data collection to study variations and correlations of signatures in our world  Nuclear, hyperspectral, thermal signatures, …  What is normal?  Unique mobile multi-sensor platform for extensive and systematic data collection to study variations and correlations of signatures in our world  Nuclear, hyperspectral, thermal signatures, …  What is normal?

7 Standoff Detection and Localization Enable detection, identification, and localization of radiological and nuclear materials in standoff distances ( few m – 100 m) Combine radiological (spectral and image) information with contextual and environmental data

8 Importance of Background for Detection Is there a source present, or is it just background? What is an appropriate threshold for alarming? What is the shape of the background distribution? What is the dependency on location, time, weather, …? B S+B

9 Acquire reliable and high-granularity nuclear radiation data in combination with a large range of complementary multi-sensor data to enable detailed physics models of our “natural” and “man-made” world LBNL’s HEMI gamma-ray imager in Fukushima From mapping nuclear background radiation to finding hot spots … Radiological Multisensor Acquisition Platform RadMAP: From Nuclear to Multisensor Streetview Mapping of Environmental Background Radiation Ground-based mapping of background radiation on meter-scale... to understanding “normal” Aerial mapping on 10’s meter-scale Variations of natural radiation Unique data sets being collected and made available to user communities: The Berkeley Nuclear Data Cloud Unique data sets being collected and made available to user communities: The Berkeley Nuclear Data Cloud

10 Background Measurements - RadMAP ▪Radiological Multisensor Acquisition Platform Hyperspectral cameras % HPGe

11 Spectroscopy in RadMAP – NaI vs. HPGe Energy (keV) Counts (s -1 keV -1 ) NaI[Tl] HPGe 40 K 238 U chain 232 Th chain anthropogenic cosmogenic  HPGe detectors enable un-ambiguous identification of background lines and isotopes

12 Summary of RadMAP Runs Days operated:74 days Time driven: 322 hours Distance travelled:3950 miles Data collected: 63.2 TB

13 RadMAP Data are Available ▪Gamma-Ray Data Cloud at LBNL/NERSC ▪ Mt. Diablo – 3850 ft SF Bay

14 Detection by Spectroscopy Comparing RadMAP HPGe vs NaI(Tl) NaI – no mask (100 x 10x10x5 cm 3 ) Perfect background knowledge Gross energy windowed counts Linear background estimator Trained background estimator Random 100% HPGe x {3, 7, 16} ➢ For the first time, evaluation to relevant FAR possible! ➢ Should become the standard for hardware and software developments in government agencies and elsewhere

15 Towards the Nuclear Street View Fusing coded-aperture imaging with video and LiDAR

16 Example 2: DSSD HPGe for Broad-Energy Gamma-Ray Imaging CCI-2 gamma-ray imaging prototype in a Compton imaging configuration. Compton Camera Imaging Coded Aperture Imaging CCI-2 gamma-ray imaging prototype in a coded aperture imaging configuration. MetricCompton CameraCoded Aperture Angular resolution1-2 degrees23 arcmin Energy resolution2 keV Imaging sensitivity150 keV – 4 MeV20 keV – 500 keV Field-of-view 44 0.05  – 0.25 

17 The “Compact” Compton Imager (CCI) –2 HPGe +2 Si(Li) large DSSD detectors in two cryostats & 2 nd generation digital DAQ Si(Li): Each strips w/ 2 mm pitch size; 10 mm thickness; 1.9 keV at 60 keV HPGe: Each strips w/ 2 mm pitch size; 15 mm thickness; 1.7 keV at 60 keV –Compact, high-bandwidth and resolution preamplifiers –Fully digital data acquisition system –State-of-the art graphical user interface to setup, monitor, display, and analyze data. –Realtime imaging and gating capabilities Assembled CCI-2 instrument Si+Ge detectors Photo camera Dewar 20 cm Pre- amplifiers Si-II Ge-II Ge-I Si-I

18 3D (Compton) Image Reconstruction Experimental demonstration of near-field imaging using CCI and ML-EM image reconstruction: DSSD-Si(Li) CCI 4 mm 10 mm 2 spherical 113 Sn sources (391 keV): Diameter: Each 4 mm Distance: 10 mm DSSD-HPGe

19 CCI-2 System Mock-up pipes Laser Theodolite Volumetric Imaging Concept and Initial Results Spectroscopic 3-D imaging with 3D position sensitive double-sided strip (DSSD) high-purity (HP) Ge

20 Compton 662 keV 3-D Volumetric Imaging Coded 186 keV HEU line source (pellets) Cs-137 line source, 40 mm long, 1 mm diameter

21 3-D Gamma-ray Volumetric Imaging Measurement Video Volumetric Radiation Imaging from CCI-2 Constrained to LiDAR 3D Scene

22 Real-time - volumetric gamma-ray imaging using an integrated computer vision system CCI-2 cart trajectory Compton cone axes 40uCi Cs- 137 source 3-D point cloud RT Registration Multi-sensor system Realtime reconstructed 3D scene and source identification and location (~5 m path in <1 min) Realtime reconstructed 3D scene and source identification and location (~5 m path in <1 min) Cluttered Scene Ladybug camera Coded aperture CCI-2 MS Kinect LiDAR

23 Simultaneous Scene + Gamma-Ray Image Reconstruction in Real Time Video Real-time simultaneous reconstruction of 3D scene and Compton image from a 5 m walkthrough in <1 minute

24 Summary HPGe detectors still represent the gold standard in high-resolution gamma-ray detection, providing unprecedented sensitivity for gamma-ray imaging for a broad range of energies Berkeley Applied Nuclear Physics actively pursuing: –Radiation mapping and monitoring –Volumetric, 3D gamma-ray imaging and fusion Now seeking 2 postdocs for Ge detector development and characterization

25 Acknowledgements DHS : DNDO DOE : NNSA : NA22 DOE : Office of NP LBNL Berkeley Applied Nuclear Physics Program UC Berkeley: Tim Aucott, Ross Barnowski, Joey Curtis, Andy Haefner, Victor Negut, Richard Zhang LBNL: Mark Amman, Mark Bandstra, Dan Chivers, Ren Cooper, John Kua, Lucian Mihailescu Photograph by Mark Bandstra, ANP

26 The Compton Spectrometer and Imager (COSI) Formerly known as the Nuclear Compton Telescope (NCT) Balloon-borne soft gamma-ray telescope Energy Range: MeV 12 high-purity Ge double-sided strip detectors, 2mm strip pitch Angular resolution: up to ~4° FWHM Large Field of View: ~1/4 of sky Two conventional balloon flights has been successfully flown to date. Alan Chiu, Steve Boggs, Space Science Laboratory, Berkeley

27 COSI – Performance & Scientific Goals Mapping 511 keV positron annihilation at the Galactic Center Studies of Galactic radioactivity: gamma-ray lines from supernova nucleosynthesis ( 26 Al, 60 Fe, 44 Ti) Imaging & spectroscopy of pulsars, SuperNova Remnants, X-ray binaries, and Active Galactic Nuclei Polarimetry of pulsars and Gamma-Ray Bursts COMPTEL map of 26 Al emission (1.809 MeV) (Oberlack et al. 1997) INTEGRAL/SPI Galactic center map of the positron annihilation radiation (0.511 MeV) (Bouchet et al. 2010) Alan Chiu, Steve Boggs, SSL

28 COSI – Achievements NCT’05: The 6-hour prototype flight allowed detailed characterization of the background at float altitudes (Bowen et. al., 2007), where observed background data were compared with simulations at passing altitudes. NCT’09: The Crab Nebula was clearly visible with a detection significance of ~6σ in this flight (Zoglauer et. al., 2013). It’s the first reported detection of an astrophysical source by a Compact Compton Telescope (CCT). Alan Chiu, Steve Boggs, SSL

29 COSI – Current Status After launch mishap in 2010, the instrument was reconstructed with upgraded configuration, which enhance the efficiency of polarization measurement and hard X-ray (coded mask) imaging. The instrument is being integrated and tested. Expected 50-day ULDB flight in McMurdo, Antarctica this December! Alan Chiu, Steve Boggs, SSL