Design and performance evaluation of a CsI(Tl)–CMOS camera-based large-area high-speed X-ray imaging system

Molten fuel-coolant interaction (MFCI) studies are conducted at IGCAR, Kalpakkam, India to investigate molten fuel relocation in sodium. The MFCI process occurs within a few milliseconds (∼10 ms), high speed X-ray imaging with a large field of view is essential for resolving the transient phenomena. To address this requirement, a high speed X-ray imaging system (HSXIS) was developed using multiple CsI(Tl) scintillator screens coupled with an optical camera operating at100 fps. The imaging system comprises four 100 × 100 mm² CsI(Tl) screens, mirrors, lead shielding, and a fixed-focus optical camera. The performance of the HSXIS was experimentally evaluated in terms of spatial resolution, measurement accuracy, and imaging reliability using a 6 mm stainless steel ball drop experiment. The acquired images were analyzed to determineball velocity and circularity, thereby assessing the system's measurement capability and associated uncertainties. This paper presents the HSXIS design and its experimental performance evaluation methodology.