TY - JOUR
T1 - Pixellated thallium bromide detectors for gamma-ray spectroscopy and imaging
AU - Onodera, T.
AU - Hitomi, K.
AU - Shoji, T.
AU - Hiratate, Y.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/6/1
Y1 - 2004/6/1
N2 - Recently, pixellated semiconductor detectors exhibit high-energy resolution, which have been studied actively and fabricated from CdTe, CZT and HgI2. Thallium bromide (TlBr) is a compound semiconductor characterized with its high atomic numbers (Tl=81, Br=35) and high density (7.56g/cm3). Thus, TlBr exhibits higher photon stopping power than other semiconductor materials used for radiation detector fabrication such as CdTe, CZT and HgI2. The wide band gap of TlBr (2.68eV) permits the detectors low-noise operation at around room temperature. Our studies made an effort to fabricate pixellated TlBr detectors had sufficient detection efficiency and good charge collection efficiency. In this study, pixellated TlBr detectors were fabricated from the crystals purified by the multipass zone-refining method and grown by the horizontal traveling molten zone (TMZ) method. The TlBr detector has a continuous cathode over one crystal surface and 3×3 pixellated anodes (0.57×0.57mm2 each) surrounded by a guard ring on the opposite surface. The electrodes were realized by vacuum evaporation of palladium through a shadow mask. Typical thickness of the detector was 2mm. Spectrometric performance of the TlBr detectors was tested by irradiating them with 241Am (59.5keV), 57Co (122keV) and 137Cs (662keV) gamma-ray sources at temperature of -20°C. Energy resolutions (FWHM) were measured to be 4.0, 6.0 and 9.7keV for 59.5, 122 and 662keV gamma-rays, respectively.
AB - Recently, pixellated semiconductor detectors exhibit high-energy resolution, which have been studied actively and fabricated from CdTe, CZT and HgI2. Thallium bromide (TlBr) is a compound semiconductor characterized with its high atomic numbers (Tl=81, Br=35) and high density (7.56g/cm3). Thus, TlBr exhibits higher photon stopping power than other semiconductor materials used for radiation detector fabrication such as CdTe, CZT and HgI2. The wide band gap of TlBr (2.68eV) permits the detectors low-noise operation at around room temperature. Our studies made an effort to fabricate pixellated TlBr detectors had sufficient detection efficiency and good charge collection efficiency. In this study, pixellated TlBr detectors were fabricated from the crystals purified by the multipass zone-refining method and grown by the horizontal traveling molten zone (TMZ) method. The TlBr detector has a continuous cathode over one crystal surface and 3×3 pixellated anodes (0.57×0.57mm2 each) surrounded by a guard ring on the opposite surface. The electrodes were realized by vacuum evaporation of palladium through a shadow mask. Typical thickness of the detector was 2mm. Spectrometric performance of the TlBr detectors was tested by irradiating them with 241Am (59.5keV), 57Co (122keV) and 137Cs (662keV) gamma-ray sources at temperature of -20°C. Energy resolutions (FWHM) were measured to be 4.0, 6.0 and 9.7keV for 59.5, 122 and 662keV gamma-rays, respectively.
KW - Imaging detector
KW - Pixellated detector
KW - Thallium bromide
KW - X- and γ-ray detector
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U2 - 10.1016/j.nima.2004.03.046
DO - 10.1016/j.nima.2004.03.046
M3 - Conference article
AN - SCOPUS:3342887980
SN - 0168-9002
VL - 525
SP - 199
EP - 204
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1-2
T2 - Proceedings of the International Conference on Imaging Technique
Y2 - 24 June 2003 through 27 June 2003
ER -