The effect of adding multiple nanoparticles on the radiation properties of silicon shields in the energy range of diagnostic imaging

Abstract

Nowadays, Due to the extensive applications of X-rays in the diagnosis and treatment of various diseases, as well as the relevance of radiation protection in medical imaging modalities, the development and implementation of more effective radiation shielding materials to protect against harmful radiation exposure seems necessary. The aim of this study is to introduce a new nanocomposite to reduce the exposure of patients and staff while using ionizing radiation. In the present study, the protective properties of silicon nanocomposites in the diagnostic energy range were investigated based on the K absorption edge overlap. The composites were designed as single nanoparticles and multi-nanoparticles and their attenuation coefficients were compared with each other. Method and materials: The narrow beam geometry and silicon-based nanocomposites were simulated using Monte Carlo method. The diameter of nanoparticles used in this study had diameters of 50 and 100 nm. The nanoparticles were designed at concentrations of 5, 15 and 30 mg / ml. Using the photon flux reached to the detector, attenuation coefficients were first calculated for single nanoparticle nanocomposites and then for multi-nanoparticle nanocomposites. The obtained data was compared with the data of WinXCom. The photon flux passing through three different multi nanocomposites with a thickness of 1 mm was calculated and compared with pure lead with a thickness of 0.25 mm. Based on the results, the most optimal nanocomposite was selected among the other combinations. Results: The obtained results from the simulations showed that single nanoparticle composites containing samarium, gadolinium, tungsten, bismuth and lead nanoparticles have better radiation attenuation in the energy range of their K absorption edge. Three multi nanocomposites were designed using these nanoparticles. Multi-nanoparticle composites including samarium, bismuth and tungsten showed better attenuation than the other two composites. Also, the comparison between single-nanoparticle and multi-nanoparticle nanocomposites showed that multi-nanoparticle composites provided almost 8% superior attenuation in the whole investigated energy range. Based on the comparison of attenuation of multi nanocomposites and pure lead, 5 mm of these nanocomposites with a concentration of 30% were equivalent to 0.25 mm of pure lead.