Title :
Study of detection efficiency of Cd1-xZnxTe detectors for digital radiography
Author :
Giakos, George C. ; Vedantham, Srinivasan ; Chowdhury, Samir ; Odogba, Jibril ; Dasgupta, Amlan ; Pillai, B. ; Sheffer, Daniel B. ; Nemer, Richard E. ; Guntupalli, Ravi Kumar ; Suryanarayanan, Sankararaman ; Vega-Lozada, Victor A. ; Endorf, Robert J. ; Pa
Author_Institution :
Dept. of Biomed. Eng., Akron Univ., OH, USA
fDate :
2/1/1998 12:00:00 AM
Abstract :
In this paper, the signal-to-noise ratio (S/N) of resistive Cd1-xZnxTe semiconductor detectors, at different directions of irradiation, within the X-ray diagnostic energy range, has been experimentally studied. In addition, the dependence of the spatial resolution of a planar Cd1-xZnxTe substrate both on the applied bias voltage and thickness has been experimentally determined. The detection efficiency of semiconductor detectors depend upon the energy absorption efficiency as well as the collection efficiency. This study suggests that high signal-to-noise ratios can be obtained by optimally choosing which polarizing electrode is directly exposed to the incident X-ray beam, as well as on both the detector thickness and applied bias voltage. In addition, the experimental results on the temporal system MTF indicate a spatial resolution of >6 cy/mm. Besides the intrinsic charge transport characteristics of the semiconductor sample, by decreasing the collector size and optimizing the X-ray digital system geometry and temporal response, the temporal system MTF can be improved significantly. The research imaging detector system allows one to investigate methods to improve the detection and imaging performance parameters as part of the development of a digital radiographic system
Keywords :
II-VI semiconductors; X-ray applications; X-ray detection; cadmium compounds; diagnostic radiography; optical transfer function; semiconductor counters; Cd1-xZnxTe detectors; CdZnTe; X-ray diagnostic energy range; X-ray digital system geometry; bias voltage; collection efficiency; detection efficiency; detector thickness; digital radiographic system; digital radiography; energy absorption efficiency; imaging performance parameters; incident X-ray beam; intrinsic charge transport characteristics; polarizing electrode; research imaging detector; semiconductor detectors; semiconductor sample; signal-to-noise ratio; signal-to-noise ratios; spatial resolution; temporal response; temporal system MTF; thickness; Electromagnetic wave absorption; Optical imaging; Signal to noise ratio; Spatial resolution; Substrates; Tellurium; Voltage; X-ray detection; X-ray detectors; Zinc;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
