Research on medical X-ray shielding mechanism and functional materials

Abstract: [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]: Develop lightweight, lead-free flexible X-ray protective materials for commonly used medical diagnostic X-ray tubes within the voltage range of 150 kV. [Methods]: Firstly, focusing on studying the X-ray energy spectrum characteristics under 80, 100, and 120 kV tube voltages, and analyzing their bremsstrahlung and characteristic radiation characteristics; Secondly, using the Xcom program to calculate the photon absorption cross-sections of different elements and using the MCNP program to simulate and predict shielding performance; Finally, the shielding performance of the flexible X-ray protection material prepared is tested and verified by experiments. [Results]: The W+Bi based composite material combined with Gd has excellent shielding performance, with a highest shielding efficiency of 82.98% at 120 kV tube voltage, a mass attenuation coefficient of 6.47 cm2·g-1, a linear attenuation coefficient of 10.12 cm-1, and a half value layer of 0.07 cm. [Conclusions]: Theoretical prediction indicates that the absorption cross section tends to decay with energy, but there is a significant K-absorption edge effect in the low-energy region. Not only W, Bi, and Gd elements all have high mass absorption coefficients for X-rays, but also thier K-absorption edges have complementary advantages, which can effectively shield both bremsstrahlung and characteristic radiation in the energy spectrum. This study can deepen our understanding of medical X-ray shielding strategies and provide guidance for the development of lightweight, lead-free flexible X-ray protective materials.