Thallium bromide (TlBr) is a compound semiconductor with wide band gap (2.68 eV) and high X- and γ-ray stopping power. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using purified material. Two types of room temperature X- and γ-ray detectors were fabricated from the TlBr crystals: TlBr detectors with high detection efficiency for positron annihilation γ-ray (511 keV) detection and TlBr detectors with high-energy resolution for low-energy X-ray detection. The detector of the former type demonstrated energy resolution of 56 keV FWHM (11%) for 511 keV γ-rays. Energy resolution of 1.81 keV FWHM for 5.9 keV was obtained from the detector of the latter type. In order to analyze noise characteristics of the detector-preamplifier assembly, the equivalent noise charge (ENC) was measured as a function of the amplifier shaping time for the high-resolution detector. This analysis shows that parallel white noise and 1/f noise were dominant noise sources in the detector system. Current-voltage characteristics of the TlBr-detector with a small Peltier cooler were also measured. Significant reduction of the detector leakage current was observed for the cooled detectors.
|Number of pages
|Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
|Published - 1999 Oct 21
|Proceedings of the 1998 7th International Conference on Solid State Detectors - Nara, Jpn
Duration: 1998 Dec 4 → 1998 Dec 6