Construction of nano particle composite shields for radiation protection of sensitive superficial organ in computed tomography imaging

Abstract

The study of lead simulation results with Monte Carlo software and XCom code showed the confirmation of the simulation geometry. The simulation for the three composite shields shows the ability to reduce the radiation by each of used silicon metal shields as single and double metal shields. The results related to 10% of the mentioned metals with silicon matrix equal to the mass attenuation coefficient for bismuth oxide, tin oxide and tungsten oxide at 80 keV energy were equal to 0.38, 0.57 and 0.33 cm2/gr respectively. This value was equal to 0.548 for the 10% bimetallic bismuth-tungsten oxide shield at 80 keV energy, and 0.223 for the bimetallic bismuth-tin oxide composite. The results of the mass attenuation coefficient corresponding to 10% bimetallic composite with tungsten-tin oxide silicon matrix is equal to 0.412. Discussion: The main purpose of this study is to investigate and compare the shields made with bismuth, tungsten and tin metal oxides as monometallic and their bimetallic combination in the CT scan diagnostic energy range and their radiation absorption in the three desired energy ranges. The metals bismuth oxide and tungsten oxide and bimetallic compound bismuth-tungsten oxide in shields containing 10% metal, in the region between the two absorption edges (energy range 70 to 100 keV), the highest mass attenuation coefficient is related to tungsten oxide. In the comparing of the energy ranges, between 70 and 100 keV showed the appropriateness of using the combination of bimetallic and monometallic tungsten oxide with a difference of less than 5%.