TY - JOUR
T1 - Photoelectron anticorrelations and sub-Poisson statistics in scintillation detectors
AU - Bousselham, Abdelkader
AU - Barrett, Harrison H.
AU - Bora, Vaibhav
AU - Shah, Kanai
PY - 2010
Y1 - 2010
N2 - The performance of scintillation detectors for X rays and gamma rays is limited fundamentally by the statistics of the scintillation light and the resulting photoelectrons. This paper presents a new experimental approach to study these statistics by observing correlations in the signals from two photodetectors. It is shown that the Fano factors (ratios of variance to mean), both for the number of photoelectrons produced on the photocathode of the photomultiplier and for the underlying number of scintillation photons, can be deduced from these correlations. For LaBr3(Ce) and 662 keV gamma rays, the photopeak signals obtained by photomultipliers on opposite faces of a thin sample are negatively correlated, and the Fano factor for the photoelectrons is significantly less than one. The inferred Fano factor for the optical photons is very small, indistinguishable from zero within experimental error.
AB - The performance of scintillation detectors for X rays and gamma rays is limited fundamentally by the statistics of the scintillation light and the resulting photoelectrons. This paper presents a new experimental approach to study these statistics by observing correlations in the signals from two photodetectors. It is shown that the Fano factors (ratios of variance to mean), both for the number of photoelectrons produced on the photocathode of the photomultiplier and for the underlying number of scintillation photons, can be deduced from these correlations. For LaBr3(Ce) and 662 keV gamma rays, the photopeak signals obtained by photomultipliers on opposite faces of a thin sample are negatively correlated, and the Fano factor for the photoelectrons is significantly less than one. The inferred Fano factor for the optical photons is very small, indistinguishable from zero within experimental error.
KW - Fano factor
KW - Photoelectron anticorrelation
KW - Sub-Poisson statistics
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U2 - 10.1016/j.nima.2010.03.152
DO - 10.1016/j.nima.2010.03.152
M3 - Article
AN - SCOPUS:77955513182
SN - 0168-9002
VL - 620
SP - 359
EP - 362
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 - 2-3
ER -