DocumentCode :
3473270
Title :
Scintillator crystal optimization by Monte Carlo simulation for photodiode matrix detector
Author :
Chavanelle, J. ; Pousse, A. ; Fagot, L. ; Parmentier, M. ; Kastler, B.
Author_Institution :
Lab. d´´Imagerie et d´´Ingenerie pour la Sante, Univ. de Franche Comte, Besancon, France
Volume :
3
fYear :
2000
fDate :
2000
Abstract :
The design of gamma ray imaging probes based on silicon photodiodes and on a CsI(Tl) monocrystal is delicate and complex. Electronic and statistical noise deteriorate energy and spatial resolution. A Monte Carlo simulation is used to set the probe´s parameters in order to obtain the best compromise between spatial uniformity energy uniformity, spatial linearity and energy collection. The output distribution of light depends on the physical properties of crystal edges, crystal thickness and refractive index of the coupling grease. A 75×75 mm2 squared CsI(Tl) crystal coupled to a 5 by 5 array of photodiodes (15×15 mm2) has been simulated. Energy and spatial characteristics of the probe were determined for crystal thickness varying from 2 mm and 20 mm and refractive index of coupling grease varying from 1.5 and 2.5. The influence of the aspect of the surfaces has also been studied. The best results were obtained with a crystal thickness of 8 mm, a grease refractive index of 1.9, and a crystal with polished edges and diffusing entrance face. These parameters minimize the statistic fluctuations of the light distribution on the array of photodiode leading to the best compromise between spatial linearity and energy collection
Keywords :
Monte Carlo methods; biomedical electronics; gamma-ray detection; photodiodes; radioisotope imaging; solid scintillation detectors; 2 to 20 mm; CsI:Tl; Monte Carlo simulation; coupling grease refractive index; crystal edges; crystal thickness; energy collection; light distribution; medical diagnostic imaging; nuclear medicine; polished edges; spatial linearity; spatial resolution; spatial uniformity energy uniformity; statistical fluctuations minimization; Fluctuations; Linearity; Nuclear imaging; Optical coupling; Photodiodes; Probes; Refractive index; Silicon; Spatial resolution; Statistical distributions;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium Conference Record, 2000 IEEE
Conference_Location :
Lyon
ISSN :
1082-3654
Print_ISBN :
0-7803-6503-8
Type :
conf
DOI :
10.1109/NSSMIC.2000.949304
Filename :
949304
Link To Document :
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