Effect of Ba co-doping on the X-ray induced afterglow of CsI(Na) crystal

Sodium-doped cesium iodide (CsI(Na)) is one of the highly effective scintillators that has been widely studied and used for several decades due to good performance. In this work, the effect of Ba co-doping on the afterglow in CsI(Na) crystal was investigated to evaluate its feasibility for applications in Computed Tomography (CT) imaging and radiation detection. We used a two-zone Bridgman furnace to grow the CsI(Na) single crystals co-doped with various concentrations of Ba. The single-doped and Ba co-doped CsI(Na) crystals demonstrate the emission at around 400 nm associated with Na-related luminescence. The scintillation performance of the grown single crystal was studied by irradiating the samples under a ¹³⁷Cs gamma source. The single-doped and Ba co-doped CsI(Na) crystals exhibit a scintillation light yield ranging from 33,000 to 44,000 ph/MeV. The reduction of afterglow observed in Ba co-doped CsI(Na) crystals is associated with electron scavenging from the traps. To summarize, the Ba co-doped CsI(Na) crystal is a promising candidate for X-ray and CT imaging.