DocumentCode :
1123424
Title :
Depth of γ-ray interaction within continuous crystals from the width of its scintillation light-distribution
Author :
Lerche, Christoph Werner ; Benlloch, J.M. ; Sánchez, F. ; Pavón, N. ; Escat, B. ; Gimenez, E.N. ; Fernández, M. ; Torres, I. ; Giménez, M. ; Sebastià, A. ; Martínez, J.
Author_Institution :
Inst. for Particle Phys., Univ. of Valencia, Spain
Volume :
52
Issue :
3
fYear :
2005
fDate :
6/1/2005 12:00:00 AM
Firstpage :
560
Lastpage :
572
Abstract :
We have studied a new and inexpensive method of measuring the depth of interaction (DOI) in γ-ray detectors with large-sized scintillation crystals. This method takes advantage of the strong correlation between the width of the undisturbed light-distribution in continuous crystals and the γ-ray´s DOI. In order to quantify the dependence of the distribution´s width with respect to the DOI, we first studied an analytical model of the light-distribution and tested it by means of Monte Carlo (MC) simulations of the light transport inside the crystal. Further we present an inexpensive modification of the commonly used charge division circuit that allows analog and instantaneous computation of the light-distribution´s second moment without affecting the determination of the centroid. This redesigned resistor network is based on the position-sensitive proportional counter (DPC) readout and allows, together with position sensitive photo-detectors, the additional measurement of the light-distribution´s standard-deviation σ. We tested the proposed circuit using the design-tool OrCAD and found the signal sufficiently large for digitalization. Finally, we conducted MC simulations of a realistic Positron Emission Tomography (PET) detector module setup that mimic a continuous Lu2SiO5:Ce3+ (LSO) crystal of dimensions 40×40×10 mm3 together with the new large area position-sensitive photo multiplier tube (PSPMT) H8500 from Hamamatsu. The influence of Compton scattering on the DOI determination was also estimated by MC simulations. Altogether, we obtained ≤ 5 mm DOI resolution. PACS: 87.57.Ce, 87.58.Fg, 87.62.+n, 07.85.-m.
Keywords :
Monte Carlo methods; gamma-ray detection; nuclear electronics; photodetectors; position sensitive particle detectors; positron emission tomography; readout electronics; solid scintillation detectors; Compton scattering; LSO crystal; Lu2SiO5:Ce3+ crystal; Monte Carlo simulations; OrCAD; charge division circuit; depth of interaction; gamma-ray detector; large-sized scintillation crystals; medical imaging; position sensitive photodetectors; position-sensitive photomultiplier tube; position-sensitive proportional counter readout; positron emission tomography detector module; redesigned resistor network; undisturbed light-distribution; Analytical models; Circuit simulation; Circuit testing; Computational modeling; Crystals; Gamma ray detection; Gamma ray detectors; Monte Carlo methods; Positron emission tomography; Solid scintillation detectors; Continuous scintillator; DPC readout; Positron Emission Tomography (PET); depth of interaction (DOI); gamma detector; light-distribution;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2005.851424
Filename :
1487684
Link To Document :
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