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Ce3+,Pr3+-codoped SiO2-Al2O3-B2O3-Gd2O3 glasses (SABG:Ce,Pr) were prepared by melt quenching under a CO reducing atmosphere. Luminescence properties were investigated under UV and X-ray excitations. A dominant emission band at 430 nm belonging to the Ce3+:5d1 → 4f transition was observed in the photo- and radio-luminescence spectra. The energy transfer occurs from this Ce3+ band toward the 3PJ levels of Pr3+ with an efficiency of up to 24%, followed by the reduction of integrated luminescence intensity with an increasing Pr3+ concentration. This result is attributed to the increase in the reabsorption of Ce3+ luminescence and the non-radiative energy transfer toward the 3PJ levels of Pr3+. The cross-relaxation process within the Pr3+ pairs can further diminish the total luminescence yield at high Pr3+ concentrations. The integral scintillation efficiency and light yield measurements were carried out and compared to the reference Bi4Ge3O12 (BGO) crystal. [ABSTRACT FROM AUTHOR]

Luminescence and scintillation properties of Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,Mg (0.02, 0.05 %) garnet crystals grown by the micro-pulling down method were investigated. The onset temperature for luminescence quenching at ∼365 K is determined from the temperature dependence of photoluminescence decay time. At room temperature, the Mg (0.05 %) sample exhibits high integral scintillation efficiency of ∼445 % of BGO crystal, light yield value of 23,500 photons/MeV, and fast scintillation decay times of 20 ns (15 %) + 54 ns (85 %). The higher radioluminescence intensity of the Mg (0.05 %) sample correlates with an appearance of its lower themally-stimulated luminescence intensity in 77–500 K range. • Luminescence and scintillation properties of Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,Mg (Mg = 0.02 %, 0.05 %) crystals are investigated. • Both crystals show onset of luminescence quenching at 365 K. • Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,0.05%Mg shows light yield of 23,500 photons/MeV. • Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,0.05%Mg shows scintillation decay time of 20 ns (14 %) + 54 ns (86 %). • Thermoluminescence characteristics are investigated. [ABSTRACT FROM AUTHOR]

Optical and scintillation characteristics of Mg2+-codoped Lu 2 Y(Al 5-x Ga x)O 12 :Ce (x = 2, 3) multicomponent garnet crystals grown by the micro-pulling down method were investigated. At RT, the shortening of scintillation decay time and a decrease of light yield (LY) value measured for a higher Ga containing samples can be explained by thermal ionization of the Ce3+ 5d 1 excited state. At 662 keV γ-rays, Lu 2 YAl 3 Ga 2 O 12 : Ce, 0.05%Mg exhibits high LY value of 29,000 ph/MeV along with scintillation decay times of 50 ns (86%) + 73 ns (14%). Co-doping with larger Mg2+ content leads to a decrease of LY value, scintillation decay time, and afterglow level. Radioluminescence quenching observed at low temperature region in correlation with large thermoluminescence peaks can be caused by trapping of electrons at intrinsic shallow traps. • Luminescence and scintillation properties of Lu 2 Y(Al 5-x Ga x)O 12 :Ce,Mg (x = 2, 3) crystals are investigated. • Temperature dependencies of photo-and radioluminescence are presented. • Lu 2 YAl 3 Ga 2 O 12 :Ce,0.05%Mg shows high light yield of 29,000 photons/MeV. • Lu 2 YAl 3 Ga 2 O 12 :Ce,0.05%Mg shows quenching temperature at 435 K due to thermal ionization. • Afterglow and thermoluminescence characteristics are investigated. [ABSTRACT FROM AUTHOR]

The optical and scintillation properties of Ce 3+ -doped YGd 2 Al 5− x Ga x O 12 ( x =2,3,4) single crystals were investigated. With increasing Ga content in the garnet host, the 5d 1 absorption and emission bands shift toward higher energy due to the decrease in the crystal field splitting of the 5d levels. Temperature dependences of absorption and emission spectra and of photoluminescence decays of both prompt and delayed components were measured. Light yield (LY) and its dependence on an amplifier shaping time were measured under excitation with γ-rays. High LY value of 38,000 photons/MeV was obtained for a YGd 2 Al 2 Ga 3 O 12 :Ce sample. Scintillation decay was measured with an extended dynamical and temporal scale under the nanosecond-pulsed soft X-ray excitation. The relative content of the fastest component in the scintillation response increases with increasing Ga content. [ABSTRACT FROM AUTHOR]

Mg2+-codoped Y 0.6 Gd 2.4 Al 2 Ga 3 O 12 :Ce (YGAGG:Ce,Mg) single crystal was grown by the Czochralski method and its luminescence and scintillation properties were investigated. Temperature dependence of radioluminescence (RL) yield and photoluminescence (PL) decay time was measured, and activation energy of thermal ionization process was determined from temperature-dependent PL decay time measurement. YGAGG:Ce,Mg exhibited high X-ray excited RL yield almost 5 times higher than BGO reference scintillator. Its light yield of 41,500 ph/MeV and scintillation decay times of 12 ns (2%) + 52 ns (65%) + 207 ns (33%) were measured under excitation with 662 keV γ rays from 137Cs source. Afterglow and thermally stimulated luminescence characteristics are also investigated. • Luminescence and scintillation properties of Y 0.6 Gd 2.4 Al 2 Ga 3 O 12 :Ce,Mg crystal are investigated. • Temperature dependence of photo-and radioluminescence are presented. • Y 0.6 Gd 2.4 Al 2 Ga 3 O 12 :Ce,Mg shows high light yield of 41,500 photons/MeV. • Luminescence quenching above RT can be caused by thermal ionization. • Afterglow and thermoluminescence characteristics are investigated. [ABSTRACT FROM AUTHOR]