Multi-energy X-ray curved surface imaging-with multi-layer in-situ grown scintillators

As a promising technology, multi-energy X-ray imaging technology is expected to be applied for many key fields such as distinguishing the subtle differences in material composition and density, like showing biological skeleton and muscle defects. However, the current multi-energy X-ray imaging technology usually has a high threshold in material selection and device design. To ensure that the imaging resolution reaches the expected level, it is necessary to efficiently couple the multi-layer scintillators with specific energy X-ray response characteristics. At the same time, each layer of scintillators must always maintain high uniformity and radiation stability in the long-term application process.

Prof. Menglu Chen's group from Beijing Institute of Technology innovatively proposes a general vitamin B1 (VmB1) assisted in-situ growth method. The VmB1 assisted in-situ grown perovskite polymer-ceramic (PC) scintillator film of multiple systems all able maintain high uniformity and radiation stability for long-term use. By calculating the charge distribution difference of polymer functional groups and the adsorption energy with perovskite by density functional theory (DFT), as shown in Figure 1. DFT calculation demonstrates that the larger energy interaction between the PVA and the perovskite benefits the optical properties. This work provides effective guidance for the rational selection of polymer host in situ growth process.

To pursue reasonable device design, the different energy X-ray absorbed distribution probability at multilayer scintillator films is calculated in Figure 2. On this basis, the rational design of the type, thickness and stacking sequence of each layer of scintillator films is realized.

Finally, a four-channel multi-energy X-ray imaging system across the 10 keV to 60 keV energy range is successfully constructed by hetero-stacking. As shown in Figure 3, the multi- energy X-ray imaging with four energy channels can clearly distinguish the differences between various objects (metal and plastic) by a single X-ray shoot. In addition, with the excellent flexibility of the polymer-ceramic scintillator film, the multi-energy X-ray imaging technology can be realized high-resolution and informative X-ray imaging for curved objects.

The related results are published in PhotoniX with the title of “In-situ grown polymer-ceramic scintillator and applications on X-ray multi-energy curved surface imaging.”