Title :
Analysis of detector response using 3-D position-sensitive CZT gamma-ray spectrometers
Author :
Zhang, Feng ; He, Zhong ; Xu, Dan
Author_Institution :
Dept. of Nucl. Eng. & Radiol. Sci., Univ. of Michigan, Ann Arbor, MI, USA
Abstract :
Two 2.25-cm3 CdZnTe gamma-ray spectrometers with three-dimensional (3-D) position sensitivity were constructed and tested. By using 11 × 11 pixellated anodes and depth-sensing techniques, individual spectral data for each of ∼4800 voxels were collected throughout the detector volume. Energy resolution of 1.11% and 1.14% FWHM at 662 keV were obtained for single-pixel events from these two detectors, respectively. Spatial variations of electron mobility-lifetime product, energy resolution, photopeak efficiency, and total efficiency have been observed and analyzed. This analysis provides a direct observation on the uniformity of detector response (due to material, weighting potential, and electric field distribution) in 3-D. Possible defects in the detector are identified. The impact of the spatial variation of detector response on a CZT gamma-ray spectrometer is discussed.
Keywords :
carrier lifetime; electron mobility; electron traps; gamma-ray detection; gamma-ray spectrometers; ionisation; position sensitive particle detectors; semiconductor counters; 11 pixel; 121 pixel; 2.25 cm; 3-D position-sensitive CZT gamma-ray spectrometers; CdZnTe gamma-ray spectrometers; depth-sensing techniques; detector response; electric field distribution; electron mobility-lifetime product; electron trapping; energy resolution; individual spectral data; ionization energy; photopeak efficiency; pixellated anodes; single-pixel events; spatial variation; total efficiency; weighting potential; Anodes; Electric potential; Electron mobility; Energy resolution; Event detection; Gamma ray detection; Gamma ray detectors; Position sensitive particle detectors; Spectroscopy; Testing;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2004.839078
