Scintillator-based X-ray imaging detectors are pivotal in
numerous scientific and practical domains, including medical
imaging, food and device inspection, and security monitoring. Recent
advancements have spurred interest in 4D X-ray imaging using
synchrotron radiation, necessitating higher temporal
resolutions. Consequently, this places stringent demands on X-ray
detector technology, especially when X-ray energy exceeds 20 keV.
The selection of a suitable scintillator material is crucial for
achieving optimal timing resolution, yet it poses a significant
challenge in dynamic X-ray imaging. This study delves into the
optimization of scintillator properties and their impact on spatial
resolution and light output, elucidating the performance of Ce-doped
Gd3Ga3Al2O12 (GAGG:Ce) scintillators for X-ray imaging
applications. We developed a micro X-ray imaging detector using a
100 μm-thick GAGG:Ce scintillator plate and conducted
X-ray imaging tests at the Aichi SR facility. The results
demonstrated that the resolution, quantified as the chart slit width
at a contrast transfer function (CTF) value of 10%, reached
2 ∼ 3 μm with a 4× lens,
0.52 μm± 0.03 μm with a 20×
lens, and 0.42 μm± 0.01 μm with a
40× lens. Although the results of this study did not achieve
a spatial resolution nearing the effective pixel size of the
40× lens, the text also elucidates the underlying reasons for
this limitation. Furthermore, we compared the X-ray sensitivity of
our GAGG:Ce scintillator plate with that of a commercial LuAG:Ce
scintillator, revealing an approximately 1.5-fold increase in light
output. As a demonstration, transmission images of dried small fish
were captured using the GAGG:Ce scintillator plate and the developed
X-ray imaging system. These findings highlight the potential of the
X-ray imaging detector devised in this study for future generations
of X-ray imaging applications.
