Investigation of the asymmetric characteristics and temperature effects of CdZnTe detectors

• Published in: IEEE transactions on nuclear science Vol. 52; no. 5; pp. 2068 - 2075
• Main Authors: Sturm, B.W., Zhong He, Zurbuchen, T.H., Koehn, P.L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Anodes; Asymmetry; Cadmium zinc tellurides; CdZnTe detector; coplanar grid; Crystals; depth sensing; Detectors; Energy resolution; Gamma rays; gamma-ray spectroscopy; Instruments; Loss measurement; Orientation; Performance loss; Spectra; Spectroscopy; Temperature sensors
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2005.856728

The results of our newest depth sensing coplanar grid CdZnTe detectors will be discussed. These detectors, which utilize the third-generation coplanar anode design, were fabricated by Baltic Scientific Instruments, Ltd., using crystals acquired from Yinnel Tech, Inc., having dimensions of 1.5 cm /spl times/1.5cm/spl times/ 0.9 cm and 1.5 cm /spl times/ 1.5cm /spl times/ 0.95 cm. Employing various compensation techniques, an energy resolution of about 1.7% full width at half maximum (FWHM) was achieved for 662-keV gamma rays. We observed that the spectral performance was highly dependent upon the biasing orientation of the detector. The /spl mu//sub e//spl tau//sub e/ product for one of the crystals was measured and it was found to be a high value of 1.13 /spl times/ 10/sup -2/ cm/sup 2//V. A study of the spectroscopic performance of CdZnTe for reduced temperature operation was implemented and we observed degraded performance for temperatures below 0/spl deg/C and a complete loss of spectral information at -30/spl deg/C.