Scintillator study for improving material separation ability in x-rays computed tomography imaging

Different scintillators have different x-rays attenuation characteristics. Many researchers are committed to developing scintillators with strong x-rays stopping power for industrial x-rays computed tomography (CT) imaging. But scintillators with strong x-rays stopping power may not always be the best choice. In this paper, we study the scintillator selection for improving material separation ability of low attenuation samples in x-rays imaging. Digital radiography (DR) experiments using cerium-doped lutetium yttrium oxyorthosilicate (LYSO: Ce, strong x-rays stopping power), cerium-doped gadolinium aluminum gallium garnet (GAGG: Ce, medium x-rays stopping power) and aluminum-doped zinc selenide (ZnSe: Al, weak x-rays stopping power) scintillators are implemented based on an optical coupling detection system. Material separation ability using DR images at 40-130 kVp x-rays sources are compared. Besides, CT imaging experiments of a Chinese herbal medicine using the three scintillators are completed. Material separation results of images obtained using ZnSe: Al is better than that using GAGG: Ce and LYSO: Ce. Thus ZnSe: Al is the best choice for material separation in x-rays CT imaging of low attenuation samples among the three scintillators.