Thin substrate powder scintillator screens for use in digital X-ray medical imaging applications

The aim of the present study is to investigate the absolute luminescence efficiency (AE) and the effective luminescence efficiency (EE) of thin substrate Gd
₂
O
₂
S:Eu powder scintillating screens, for possible use in digital radiography detectors. To this aim two relatively thin screens with thicknesses (coating density) 32.1 mg/cm
²
and 64.9 mg/cm
²
were prepared on Borosilicate glass substrate 22×22 mm
²
. For the determination of the AE, X-ray tube voltages ranging from 50 to 133 kVp were used. The effective efficiency was examined for four optical sensors, currently adapted in diagnostic medical systems, namely S100AB SITe, passivated a-Si:H photodiode, CMOS hybrid with blue AR coating and CMOS RadEye photodiode array. The absolute luminescence efficiency of the thin substrate Gd
₂
O
₂
S:Eu powder phosphors was relatively high. The spectral compatibility and the overall efficiency (effective efficiency) with the optical detectors examined in our study was higher than that of a corresponding thickness Gd
₂
O
₂
S:Tb powder phosphors. Our preliminary results indicate that thin substrate Gd
₂
O
₂
S:Eu powder phosphors can be used adequately with detectors for digital X-ray Imaging.