DocumentCode :
1033296
Title :
Thermoluminescence and scintillation properties of rare earth oxyorthosilicate scintillators
Author :
Szupryczynski, Piotr ; Melcher, Charles L. ; Spurrier, Merry A. ; Maskarinec, Michael P. ; Carey, A. Andrew ; Wojtowicz, Andrzej J. ; Drozdowski, Winicjusz ; Wisniewski, Darek ; Nutt, Ron
Author_Institution :
CTI Molecular Imaging Inc., Knoxville, TN, USA
Volume :
51
Issue :
3
fYear :
2004
fDate :
6/1/2004 12:00:00 AM
Firstpage :
1103
Lastpage :
1110
Abstract :
In recent years, the scintillation properties of several cerium-doped rare earth oxyorthosilicate scintillators, Ln2SiO5:Ce where Ln=Y,La-Lu, have been reported and, in some cases, extensively studied . In addition, binary and ternary compounds such as (Lu,Y)2SiO5:Ce, (Lu,Gd)2SiO5 and (Lu,Y,Gd)2SiO5:Ce have been reported . All of these crystals have either monoclinic P or C structures with characteristic SiO4 tetrahedra and trivalent cations occupying two unique crystallographic positions , . The trivalent cerium activator ions are assumed to occupy the cation lattice sites and possibly interstitial positions as well. The excited 5d state of Ce3+ is split into three observable levels with luminescence emission occurring only from the lowest 5d level to the 4f ground state (∼3 eV) with a Stokes shift of ∼0.5 eV. The bandgap is about 6 eV, and the index of refraction is close to 1.8, with some variation according to crystallographic direction. Despite these similarities, in some cases, differences in scintillation efficiency, decay time, rise time, and phosphorescence time profiles have been observed. In this paper, we combine thermoluminescence measurements with the temperature characteristic of scintillation efficiency between 10 and 350 K to determine the trapping levels that may influence the scintillation and phosphorescence properties of crystals of various compositions.
Keywords :
crystal structure; phosphorescence; solid scintillation detectors; thermoluminescence; (LuGd)2SiO5:Ce; (LuY)2SiO5:Ce; (LuYGd)2SiO5:Ce; 10 K; 350 K; 4f ground state; Ce3+; LGSO; LSO; LYGSO; LYSO; Lu2SiO5:Ce; SiO4 tetrahedra cations; Stokes shift; binary compounds; cation lattice sites; cerium-doped rare earth oxyorthosilicate scintillators; decay time; excited 5d state; interstitial positions; lowest 5d level state; luminescence emission; monoclinic C structures; monoclinic P structures; phosphorescence properties; phosphorescence time profiles; temperature characteristics; ternary compounds; thermoluminescence; trapping levels; trivalent cations; trivalent cerium activator ions; unique crystallographic positions; Atmosphere; Atmospheric measurements; Cerium; Charge carriers; Crystalline materials; Crystallography; Crystals; Nitrogen; Phosphorescence; Temperature measurement; $_2$SiO $_5$; $_2$SiO$_5$:Ce; LGSO; LSO; LYGSO; LYSO; Lu,Gd; Lu,Y; Lu,Y,Gd; Lu$_2$SiO$_5$ :Ce; oxyorthosilicate; scintillators; thermoluminescence;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2004.829388
Filename :
1312025
Link To Document :
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