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Description
Digital flat-panel detectors based on the indirect detection scheme commonly employ amorphous silicon TFT or silicon CMOS matrix arrays combined with a variety of scintillators and they are widely used in medical imaging, security screening, and nondestructive testing. Scintillators are essential components in indirect X-ray detectors, as they convert high-energy ionizing radiation, such as X-rays or gamma rays, into visible light. Significant research efforts have been devoted to developing high-performance scintillator materials, leading to the commercialization of various types. Nevertheless, there remains a strong demand for new scintillators that are cost-effective, exhibit high light-output, and possess fast decay times to meet the requirements of high-speed radiation detection technologies.
Nowadays, gadolinium oxysulfide (Gd2O2S:Tb) and new gadolinium aluminum gallium garnet (GAGG:Ce) materials are considered as the most efficient scintillator for X-ray detection and imaging. In this work, thin powder typed scintillator screens with different coating thickness(30-100um) on polymer substrate were designed for digital X-ray imaging with high spatial-resolution and high-speed. The dynaminc CMOS flat panel detector with high-resolution is consisted of silicon photodiode array with 1,200 × 1,072 matrix size and 50μm pixel pitch(theoretical resolution limit: 10lp/mm).
The scintillation properties such as emission spectrum and light intensity by radiation luminescence(RL) were measured and characterized. The imaging performance of CMOS flat panel imagers in combination with diffferent thin powder scintillating screens were investigated in terms of the relative light response to given X-ray irradiation, modulation transfer function (MTF), noise power spectrum and X-ray phantom imaging. These results suggest promising applicability for high-speed, high-resolution digital X-ray imaging in both medical and industrial domains.