Abstract
In an ideal single-carrier-type gamma ray detector, the amplitudes of the signals and the carrier drift times are correlated variables. However, if the charges produced by an incident photon are not fully collected, as is the case in CdZnTe detectors containing crystal defects, the above correlation does not hold. This permits the application of an event recognition algorithm to identify these incomplete charge collection (ICC) events, caused by the bad regions inside a detector, so that they can be removed from pulse height spectra. The ICC events primarily contribute to the Compton continuum and the low-energy tail of the photopeak. Thus, rejecting such events should not affect significantly the photopeak efficiency, but should improve the spectral response, e.g., the peak-to-Compton ratio, for a detector fabricated from material with relaxed crystal quality requirements. Such crystals are those currently available from vendors. The use of stronger ICC correlation-function rejection criteria can improve the energy resolution of these lower-quality crystals, but at the price of a loss in photoefficiency.
Original language | English |
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Pages (from-to) | 317-323 |
Number of pages | 7 |
Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
Volume | 664 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2012 Feb 1 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the US Department of Energy, Office of Nonproliferation Research and Development , Grant no. NA-22 , Defense Threat Reduction Agency , and BNL's Technology Maturation Award . The manuscript has been authored by Brookhaven Science Associates, LLC under Contract no. DE-AC02-98CH1-886 with the US Department of Energy. The United States Government retains, and the publisher, by accepting the article for publication, acknowledges, a world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes.
Keywords
- CdZnTe detectors
- Crystal defects
- Event recognition
- Virtual Frisch-grid detectors
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Instrumentation