Light Emission Efficiency of Gd₃Al₂Ga₃O₁₂:Ce (GAGG:Ce) Single Crystal Under X-ray Radiographic Conditions

Abstract

Inorganic scintillators, in either powder or crystal form, are used in indirect digital radiography as X-ray to light converters coupled to electronic optical sensors (photodiodes, CCDs, CMOS). A recent developed single crystal scintillator with high density, fast scintillation response and high light yield is the Ce doped Gadolinium Aluminum Gallium Garnet (Gd₃Al₂Ga₃O₁₂:Ce or GAGG:Ce). The purpose of the present study was to evaluate GAGG:Ce single crystal scintillator under general radiographic imaging conditions. The two GAGG:Ce crystals used in this study were supplied by Furukawa Co Ltd with dimensions 10×10×10 mm³ and 10×10×20 mm³. Parameters such as the Absolute Luminescence Efficiency-AE (light energy flux over exposure rate) and the light spectral compatibility to electronic optical sensors (Effective Efficiency) were investigated under X-ray excitation in the radiographic energy range from 50 to 125 kVp. Results showed that the absolute efficiency of GAGG:Ce scintillator crystals increased with X-ray tube voltage. The emission spectrum of scintillator examined in the present study is well matched with the spectral sensitivities of the optical photon detectors often employed in radiation detectors. Taking these results into account GAGG:Ce crystal scintillator could potentially be considered for further research for use in X-ray medical imaging.