Research on medical X-ray shielding mechanism and functional materials

[Background]: With the continuous development of nuclear technology, the demand for radiation protection is increasing, and the optimization research of protective materials is receiving more and more attention. [Purpose]: This study aims to develop lightweight, lead-free, and flexible X-ray protective materials suitable for commonly used medical diagnostic X-ray tubes operating within a voltage range of 150 kV. [Methods]: Firstly, the X-ray energy spectrum characteristics under 80 kV, 100 kV, and 120 kV tube voltages were studied, and their bremsstrahlung and characteristic radiation properties were analyzed. Secondly, the XCOM program was used to calculate the mass attenuation coefficients of different elements, and the Monte Carlo program was employed to simulate and predict shielding performance. Finally, the shielding performance of the prepared flexible X-ray protection material was tested and verified through experiments. [Results]: The W+Bi based composite material combined with Gd has an excellent shielding performance, with the highest shielding efficiency of 82.98%, the mass attenuation coefficient of 5.86 cm2·g-1, the linear attenuation coefficient of 9.16 cm-1, and the half value layer of 0.08 cm under the 120 kV tube voltage with a 2.7 mm Al filter. [Conclusions]: This study demonstrates that elements such as W, Bi and Gd exhibit high mass attenuation coefficients for X-rays, and their K-edge absorption edges are complementary to each other. It therefore enhances our understanding of medical X-ray shielding strategies and provides guidance for the development of lightweight, lead-free flexible X-ray protective materials.