Comprehending the role of trap centers and host energy transfers in excitation density dependent kinetics of Ce doped Gd₃Ga₃Al₂O₁₂scintillator; an unresolved scintillation characteristic

Single crystal of Ce doped Gd₃Ga₃Al₂O₁₂ is one of the most studied advanced scintillators currently. The scintillation kinetics has been investigated with different excitations. The higher excitation density of alpha particles quenches the scintillation light yield but on the contrary the decay curve gets accelerated with gamma rays unlike that have been typically observed for conventionally used halide scintillators. In view of resolving this unusual behavior, a thorough investigation has been first time performed by carrying out systematic experiments on temperature dependent scintillation properties with gamma and alpha irradiation. The dependence of light yield for both radiations behaves differently with temperature with a notable early onset of quenching for charged particles. All three decay components also behave differently with temperature to indicate the various mechanisms governing the relaxation of excited charged carriers. At some temperatures the decay time components indeed behave in the similar manner as measured for halide crystals. The maximum difference in decay components carrying major amplitude occurs close to room temperatures leading to better discrimination ability. A strong correlation with thermo-luminescence properties has been observed to investigate the role of defect structure. A comprehensive model based on the prominent role of charged carriers released from trap centers along with the energy transfer and migration via Gd sub-lattice in governing the scintillation properties has been convincingly presented. It has demonstrated precisely the unusual behavior of this material but can be extended more considerably to describe various properties of other scintillators as well.