Fabrication and characterization of pixelated Gd_2O_2S:Tb scintillator screens for digital X-ray imaging applications

摘要

X-ray imaging detectors in combination with scintillator screens have been widely used in digital X-ray imaging applications. Gd_2O_2S:Tb was used as scintillation material for pixelated scintillator screens based on silicon substrates (wafer) with a micropore array of various dimensions fabricated using the photolithography and deep reactive ion etching (DRIE) process. The relative light output and the modulation transfer function (MTF) of each fabricated scintillator screen were measured by a cooled CCD and compared with those of Lanex screens. The spatial resolution of our scintillator screens was higher but their light outputs were lower than those of Lanex screen probably due to the loss of light at the wall surfaces. Therefore further treatment of the wall surface, such as reflective coating, seems necessary to compensate the light loss.