TY - JOUR
T1 - Rejecting incomplete charge-collection events in CdZnTe and other semiconductor detectors
AU - Bolotnikov, A. E.
AU - Camarda, G. S.
AU - Cui, Y.
AU - De Geronimo, G.
AU - Fried, J.
AU - Gul, R.
AU - Hossain, A.
AU - Kim, K.
AU - Yang, G.
AU - Vernon, E.
AU - James, R. B.
N1 - 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.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - 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.
AB - 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.
KW - CdZnTe detectors
KW - Crystal defects
KW - Event recognition
KW - Virtual Frisch-grid detectors
UR - http://www.scopus.com/inward/record.url?scp=84555196013&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2011.10.066
DO - 10.1016/j.nima.2011.10.066
M3 - Article
AN - SCOPUS:84555196013
SN - 0168-9002
VL - 664
SP - 317
EP - 323
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1
ER -