Polaris Cd Zn Te GammaRay Imaging Spectrometer Systems

Polaris Cd. Zn. Te Gamma-Ray Imaging Spectrometer Systems Zhong He On behalf of the Orion group ISOE International ALARA Symposium Tokyo, Japan, 27 -29 August, 2013

Polaris Systems Eighteen 2 2 1. 5 cm 3 Cd. Zn. Te detectors (108 cm 3, 648 grams = 1. 43 lb) Performance Goals E/E 1% FWHM (at 662 ke. V) Real-time Imaging + isotope I. D. E 1 E 2 Number of photons: 97 18 2033 4 3 2 1

Polaris 1. 1 (GMI ASIC) – August 2010

137 Cs Energy Spectra of the 1 st Polaris system #1. 1 (From all 18 detectors of Polaris, 24 o. C, uncollimated 137 Cs) - 1 -pixel events - 2 -pixel events - 3 -pixel events - 4 -pixel events Counts 662 ke. V 1. 44% All FWHM events Energy (ke. V)

2 nd-Generation Polaris System #2. 1 (BNL ASIC) (From all 18 detectors, room-temperature, uncollimated 137 Cs) 662 ke. V Single-pixel events 0. 61% (4. 0 ke. V) FWHM

2 nd-Generation Polaris System #2. 1 (BNL ASIC) (From all 18 detectors, room-temperature, uncollimated 137 Cs) 662 ke. V All events – no selection July 2012 0. 86% (5. 7 ke. V) FWHM Peak-to-Compton ratio 20. 5

Next-Generation digital 3 -D Cd. Zn. Te detectors (VAD_UM digital ASIC, Room-temperature, uncollimated 137 Cs) Counts Energy resolutions (FWHM) of all events measured on best detectors Detector # 4 E-1 4 R-169 Entire volume 0. 56% 0. 61% From better ~50% volume 0. 46% 0. 51% E/E is still limited by ASIC noise ! Peak-to-Compton ratio 22. 5 ( 25. 1 if no event selection) Energy (ke. V) 662 ke. V 0. 46% FWHM

Counts 228 Th Energy Spectra Polaris-2 D. E. Energy (ke. V) S. E. 2614 ke. V

Weiyi Wang Yuefeng Zu Willy Kaye He 60 Co 22 Na Chris Wahl 137 Cs Polar Angle Target specific -Spec. 23 min. data EIID Azimuthal Angle

Real-Time Combined Coded Aperture and Compton Imaging for Locating Sources From all 18 detectors Isotope selected: 57 Co, 22 Na, 137 Cs 122 ke. V 662 ke. V 511 ke. V 1275 ke. V

Detection Sensitivity of Polaris Image of 650 E 674 ke. V SBP with 2 – 4 pixel events 208 Tl 583. 2 Source Present 214 Bi 609. 3 -Background - 137 Cs present 40 K 1461 All events A 30 Ci Cs-137 source behind a wall at ~4 m A 12 -hour “background” Measurement

Today and Tomorrow