Thallium bromide is a very promising compound semiconductor for fabrication of X- and gamma-ray detectors due to its wide bandgap (2.68 eV) and higher photon stopping power than other semiconductor materials used for radiation detector fabrication such as CdTe and HgI2. Our studies made an effort to fabricate pixellated TIBr detectors with sufficient detection efficiency and good charge collection efficiency. In this study, pixellated X- and gamma-ray detectors were fabricated from TIBr crystals. The TIBr crystal was purified by the multipass zone-refining method and grown by the traveling molten zone method. The pixellated TIBr detector has a continuous cathode over one crystal surface and 3X3 pixellated anodes (0.57 X 0.57 mm2 each) surrounded by a guard ring on the opposite side. The electrodes were prepared by vacuum evaporation of palladium through a shadow mask. Typical thickness of the detectors was around 2 mm. Spectrometric performance of the pixellated TIBr detectors was tested by irradiating them with 241Am (59.5 keV), 57Co (122 keV) and 137Ts (662 keV) gamma-ray sources. Each of the anode pixels of the detector was connected to each charge sensitive preamplifier and the guard ring was grounded. Typical energy resolutions (FWHM) obtained for a pixel of the TIBr detector at -20 °C were 4 keV, 7 keV and 10 keV for 59.5 keV, 122 keV and 662 keV gamma-rays, respectively.
|IEEE Nuclear Science Symposium Conference Record
|出版済み - 2003
|2003 IEEE Nuclear Science Symposium Conference Record - Nuclear Science Symposium, Medical Imaging Conference - Portland, OR, 米国
継続期間: 2003 10月 19 → 2003 10月 25