DocumentCode :
1046357
Title :
Investigation of Luminescence Properties of Lu _{2} SiO _{5} :Ce (LSO) Powder Scintillator in the X
Author :
David, Stratos L. ; Michail, Christos M. ; Valais, Ioannis G. ; Toutountzis, Adrianos E. ; Liaparinos, Panagiotis F. ; Cavouras, Dionisis A. ; Kandarakis, Ioannis S. ; Panayiotakis, George S.
Author_Institution :
Dept. of Med. Phys., Univ. of Patras, Patras
Volume :
55
Issue :
6
fYear :
2008
Firstpage :
3684
Lastpage :
3691
Abstract :
This paper investigates the light emission efficiency of Lu2SiO5:Ce (LSO) powder scintillator under conditions employed in projection X-ray imaging. Although single-crystal LSO has been thoroughly studied in medical imaging energies, the efficiency of powder LSO has not been previously investigated experimentally under X-ray medical radiography conditions. For this purpose, three scintillating screens with a coating thickness of 63.4, 108.4, and 172.5 mg/cm2 were prepared by sedimentation of LSO powder. Measurements of luminescence efficiency (emitted light energy flux over incident X-ray energy flux) were performed in the radiographic X-ray tube voltages range (40-140 kVp). Parameters related to X-ray detection, i.e., quantum detection efficiency, energy absorption efficiency and probability of K-fluorescence reabsorption were calculated. A theoretical model, describing radiation and light transfer, was employed to fit luminescence experimental data and to estimate values of the intrinsic conversion efficiency and of the light attenuation coefficients of the scintillating screens. The spectral compatibility of the LSO powder scintillator to various optical detectors used in digital radiography was also determined by performing light emission spectrum measurements and by taking into account the spectral sensitivity of electronic optical detectors. Maximum values of LSO luminescence efficiency were observed within the range from 40 to 60 kVp. The 172.5 mg/cm2 thick screen was found more efficient than the two thinner screens examined in our experiments. The intrinsic conversion efficiency of LSO (0.10) was found close to that of currently employed phosphors. Spectral compatibility data of LSO screens indicates that LSO may be efficiently coupled to optical detectors used in digital radiography imaging systems.
Keywords :
X-ray detection; cerium; diagnostic radiography; fluorescence; lutetium compounds; optical sensors; phosphors; photoluminescence; sedimentation; solid scintillation detectors; K-fluorescence reabsorption; Lu2SiO5:Ce; Lu2SiO5:Ce powder scintillator; X-ray detection; X-ray medical radiography; digital radiography; electronic optical detectors; light attenuation coefficients; light emission efficiency; light emission spectrum; luminescence properties; medical imaging; phosphors; projection X-ray imaging; quantum detection efficiency; radiographic X-ray tube; sedimentation; voltage 40 kV to 140 kV; Biomedical imaging; Coatings; Energy measurement; Luminescence; Optical detectors; Performance evaluation; Powders; Radiography; X-ray detection; X-ray imaging; ${rm LSO}!!:!!{rm Ce}$; Inorganic scintillators; luminescence efficiency; powder phosphors;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2008.2006901
Filename :
4723823
Link To Document :
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