Timing characteristics of the scintillation response of Gd3Al2Ga3O12:Ce and Gd3Al2.6Ga2.4O12:Ce single crystal scintillators

• Scintillation time response of GAGG:Ce crystals was studied.
• Gd3Al2Ga3O12:Ce exhibited superior timing characteristics.
• Energy resolution of 5.6% @662 keV was obtained for Gd3Al2.6Ga2.4O12:Ce.
• Coincidence time resolution of 345 ps was obtained for Gd3Al2Ga3O12:Ce.

The timing characteristics of scintillation response of Czochralski-grown Gd3Al2Ga3O12:Ce and Gd3Al2.6Ga2.4O12:Ce single crystals were compared. The photoelectron yield, scintillation decay times, and coincidence time resolution were measured. At 662 keV γ-rays, the photoelectron yield of 6200 phe MeV−1 obtained for Gd3Al2Ga3O12:Ce is higher than that of 4970 phe MeV−1 obtained for Gd3Al2.6Ga2.4O12:Ce, while an inferior energy resolution of the former (7.2% vs. 5.6%) is observed. Scintillation decays are approximated by sum of exponentials with the dominant fast component decay time and its relative intensity of 89 ns (73%) for Gd3Al2Ga3O12:Ce and 136 ns (69%) for Gd3Al2.6Ga2.4O12:Ce. The coincidence time resolution obtained for Gd3Al2Ga3O12:Ce is superior than that of Gd3Al2.6Ga2.4O12:Ce. The normalized time resolution was also discussed in terms of a number of photoelectrons and decay characteristics of the light pulse.