TY - GEN
T1 - A compact scintillator-based coded aperture imager for localizing illicit nuclear materials
AU - Vaska, P.
AU - Vanier, P. E.
AU - Junnarkar, S.
AU - Krishnamoorthy, S.
AU - Pratte, J. F.
AU - Stoll, S.
PY - 2007
Y1 - 2007
N2 - Efficient detection, localization, and identification of illicit nuclear materials is a critical need for national security. Gamma-ray signatures can be exploited for these purposes, but very high detection efficiency is needed in addition to a practical design that can be effective in the field. Modern, dense scintillators with low intrinsic background provide the highest detection efficiency (albeit at somewhat lower energy resolution than semiconductor detectors), and solid-state photodetector readout of the scintillation light can enable a compact and robust design compared to conventional photomultiplier tubes. We explore the feasibility of a coded aperture gamma-ray imager which combines gadolinium oxyorthosilicate scintillator (GSO) and avalanche photodiode (APD) readout. Each GSO crystal is 5×5 mm in cross-section and 25 mm long, and is coupled to a Hamamatsu S8664-55 APD with matching active area. 225 detectors are arrayed in a 15 × 15 matrix within a tungsten shield box. Readout is effected with a custom PC board which includes multiple 32-channel ASICs to handle preamplification, shaping, and energy and time discrimination. The output is fed to a compact data acquisition system originally designed for medical imaging with the RatCAP PET system. Various coded aperture designs are being evaluated for optimal imaging performance. Detector design and performance are presented.
AB - Efficient detection, localization, and identification of illicit nuclear materials is a critical need for national security. Gamma-ray signatures can be exploited for these purposes, but very high detection efficiency is needed in addition to a practical design that can be effective in the field. Modern, dense scintillators with low intrinsic background provide the highest detection efficiency (albeit at somewhat lower energy resolution than semiconductor detectors), and solid-state photodetector readout of the scintillation light can enable a compact and robust design compared to conventional photomultiplier tubes. We explore the feasibility of a coded aperture gamma-ray imager which combines gadolinium oxyorthosilicate scintillator (GSO) and avalanche photodiode (APD) readout. Each GSO crystal is 5×5 mm in cross-section and 25 mm long, and is coupled to a Hamamatsu S8664-55 APD with matching active area. 225 detectors are arrayed in a 15 × 15 matrix within a tungsten shield box. Readout is effected with a custom PC board which includes multiple 32-channel ASICs to handle preamplification, shaping, and energy and time discrimination. The output is fed to a compact data acquisition system originally designed for medical imaging with the RatCAP PET system. Various coded aperture designs are being evaluated for optimal imaging performance. Detector design and performance are presented.
UR - https://www.scopus.com/pages/publications/48349114069
U2 - 10.1109/NSSMIC.2007.4437220
DO - 10.1109/NSSMIC.2007.4437220
M3 - Conference contribution
AN - SCOPUS:48349114069
SN - 1424409233
SN - 9781424409235
T3 - IEEE Nuclear Science Symposium Conference Record
SP - 1195
EP - 1197
BT - 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC
T2 - 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC
Y2 - 27 October 2007 through 3 November 2007
ER -