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ABSTRACT: In this communication, we investigate the scintillation properties of LaBr<sub>3</sub>:Ce as a function of Ce concentration. We have studied crystals nominally doped with 0.5%, 5%, 10%, 20%, and 30%Ce (by mole). Previous reports suggest that as the Ce content increases, there is a decrease in light output and little or no change in decay time constants. These results show that the light output does not change with Ce concentration up to 30% and depends mostly on the crystal quality. On the other hand we have found the timing properties to be a strong function of Ce concentration. As the Ce content increases, the principal decay time constant of scintillation decreases from ∼26 ns for 0.5%Ce to ∼17 ns for crystals with >5% Ce. Moreover, there is a significant change in rise time constants. The rise time measured for a sample doped with 0.5%Ce is up to 9 ns, whereas for samples doped with >10% Ce it is less than 0.5 ns. The change of rise time has a major effect on the timing properties of this scintillator, with timing resolution improving from 361 ps to less than 100 ps (full width at half maximum).
IEEE Transactions on Nuclear Science 11/2005; · 1.45 Impact Factor
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ABSTRACT: In this paper, we report on cerium doped scintillator-LaBr<sub>3</sub> : Ce for gamma ray spectroscopy. Crystals of this scintillator have been grown using the Bridgman process. This material when doped with cerium has high light output (>60 000 photons/MeV) and fast principal decay constant (<30 ns). The peak of LaBr<sub>3</sub> : Ce emission is at 360 nm. LaBr<sub>3</sub> : Ce shows excellent energy resolution for gamma ray detection. For 662 keV gamma rays (<sup>137</sup>Cs source), energy resolution of 2.6% (full-width at half-maximum) has been recorded at room temperature for LaBr<sub>3</sub> : Ce crystals coupled to a photomultiplier. This energy resolution is over two times better than that of NaI(Tl) scintillators. Analysis of the energy resolution of LaBr<sub>3</sub> : Ce scintillators is presented. Energy resolution of LaBr<sub>3</sub> : Ce crystals coupled to silicon avalanche photodiodes is also discussed.
IEEE Transactions on Nuclear Science 11/2004; · 1.45 Impact Factor
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ABSTRACT: We report on cerium doped scintillator - LaBr<sub>3</sub>:Ce for gamma ray spectroscopy. Crystals of this scintillator have been grown using the Bridgman process. This material when doped with cerium has high light output (>60,000 photons/MeV) and fast principal decay constant (<30 ns). The peak of LaBr<sub>3</sub>:Ce emission is at 360 nm. LaBr<sub>3</sub>:Ce shows excellent energy resolution for gamma ray detection. For 662 keV gamma rays (<sup>137</sup>Cs source), energy resolution of 2.7% (FWHM) has been recorded at room temperature for LaBr<sub>3</sub>:Ce crystals coupled to a photomultiplier. This energy resolution is over two times better than that of NaI(TI) scintillators. Analysis of the energy resolution of LaBr<sub>3</sub>:Ce scintillators is presented and the performance of this scintillator at other gamma ray energies is covered. Energy resolution of LaBr<sub>3</sub>:Ce crystals coupled to silicon avalanche photodiodes is discussed. Potential applications of this material are addressed.
Nuclear Science Symposium Conference Record, 2003 IEEE; 11/2003
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ABSTRACT: In this paper, we report on a new cerium doped, high atomic number scintillator - LuI<sub>3</sub>:Ce for gamma ray spectroscopy. Crystals of this material have been grown using Bridgman process. LuI<sub>3</sub> crystals doped with 0.5 and 5% Ce<sup>3+</sup> show high light output (∼50,000 photons/MeV) and fast principal decay constant (23 to 31 ns). The Ce<sup>3+</sup> emission peaks at 474 nm. Energy resolution of LuI<sub>3</sub>:Ce coupled to photomultiplier (PMT) and measured at 662 keV was ∼10% (FWHM). Timing resolution of LuI<sub>3</sub>-PMT and BaF<sub>2</sub>-PMT detectors operating in coincidence mode was measured to be 210 ps (FWHM). Potential applications of this scintillator are discussed.
Nuclear Science Symposium Conference Record, 2003 IEEE; 11/2003
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ABSTRACT: Lutetium iodide (LuI3) is a new addition to the family of Ce-doped lanthanide trihalide scintillating materials. Crystals of this material show hexagonal structure with density of 5.6 g/cm3 and have been grown by the Bridgman method. Under X-ray excitation this material exhibits broad, cerium based emission that peaks at 475 and 520 nm. The fastest and major component of scintillation time profile of LuI3:Ce emission decays with a 31 ns time constant. The light yield of LuI3:Ce for thin samples (∼0.2 mm) was estimated to be ∼50,000 photons/MeV.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
