Multi-Energy X-Ray Imaging Technology for Security Check

Conventional grayscale single-energy X-ray imaging technology (SEXIT) often struggles to accomplish outstanding material-specific functions. While dual-energy X-ray imaging technology (DEXIT) partially compensates the limitation, its implementation typically demands dual detectors or twice X-ray exposures. Besides, valuable spectral photon information is abandoned by both SEXIT and DEXIT.¹^,2 Herein, we have developed an inventive multi-energy X-ray imaging technique (MEXIT) designed by multiple scintillators with a ΔE-E telescope structure. Specifically, three distinct scintillators convert and assign X-rays from different energy bins into individual visible light information in an energy sequence. Emerging scintillation materials of metal halides were employed.³ The carefully selected filters were inserted into them, enabling the combined radioluminescence (RL) to span the entire visible range (350 nm to 800 nm) devoid of any overlap. Consequently, substances with different CT numbers can be readily discriminated through their corresponding emission colors. Moreover, notable spatial imaging resolutions that exceeds 22 lp mm^-1 across all X-ray energy were achieved by MEXIT. The conceptual demonstration was conducted in a scenario for the inspection of various substances with complicated composition, where the ΔE-E telescopic scintillator allows effective screening of different substances based on X-ray energy bins. Dirffrent ROIs ( region of interests) are avaliable to be extracted by the orginal images. Our study presents a promising avenue for achieving MEXIT and extends it to trichromatic vision, introducing innovative perspectives for various scientific and practical fields. To the best of our knowledge, no prior reports exist of a similar design capable of translating X-ray energy into an ultrabroad RL spectra using three distinct scintillation materials to achieve multi-energy X-ray imaging.<br/><br/>1. Ran, P.<i> et al.</i> Multispectral Large-Panel X-ray Imaging Enabled by Stacked Metal Halide Scintillators. <i>Advanced Materials</i> <b>34</b>, 2205458 (2022).<br/>2. Shao, W.<i> et al.</i> Transparent Organic and Metal Halide Tandem Scintillators for High-Resolution Dual-Energy X-ray Imaging. <i>ACS Energy Letters</i> <b>8</b>, 2505-2512 (2023).<br/>3. Zhou, Y., Chen, J., Bakr, O. M. & Mohammed, O. F. Metal Halide Perovskites for X-ray Imaging Scintillators and Detectors. <i>ACS Energy Lett.</i> <b>6</b>, 739-768 (2021).