الفهرس 
Radiation Shielding MaterialsOnly 14 pages are availabe for public view
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Abstract
In the present work, the radiation shielding properties such as linear attenuation coefficient and mass attenuation coefficient for silicone rubber composites filled with different concentrations of lead oxide were evaluated and compared with the theoretical calculations. A good agreement has been found between the experimental values and the theoretical values calculated by WinXcom program (version 3.1). The linear attenuation coefficients and the mass attenuation coefficients were found to be increased with the increase of lead oxide content.
The effect of lead oxide content on the mechanical properties (tensile strength (σR), elongation at break (εR), Young’s modulus (E) and hardness (H)) has been studied and discussed. from the obtained results it is found that the mechanical properties (tensile strength (σR), elongation at break (εR), Young’s modulus (E) and hardness (H)) increase with the increase of filler content up to 35 wt. % by weight and then decrease except the hardness. The hardness of silicone rubber composites increases as the lead oxide concentration increase because the addition of filler in rubber compounds leads to an increase in the materials hardness linearly. The present work shows a strong advantage of rubber composite shield for its low weight and elasticity compared with the standard shielding concrete.
The thesis of this work is divided into five chapters, which are summarized as follows:
CHAPTER 1 includes a general introduction and a literature survey concerning all works that were interested in the field under study i.e. shielding materials and their shielding and physical properties. The study is concentrated for silicone rubber shields.
CHAPTER 2 contains information about different radiation shielding materials associated with their advantages or disadvantages for different types of radiation. Additionally this chapter includes details about different types of rubber.
CHAPTER 3 presents the main fundamental basis of the interaction of radiation with matter; the attenuation properties have been also described. Furthermore, this chapter includes the different types of radiation detectors. A description of the different physical parameters such as tensile strength (σR), elongation at break (εR), Young’s modulus (E), hardness (H) and the dielectric properties has been included.
CHAPTER 4 deals with the experimental procedures through this study according to samples preparation and the experimental setup for the apparatus used for gamma ray attenuation measurements and also the equipments used for measuring the mechanical parameters (tensile strength (σR), elongation at break (εR), Young’s modulus (E) and hardness (H). The apparatus used in dielectric measurements were also described in details in this chapter.
CHAPTER 5 contains all the obtained results concerning determination of density, mass attenuation coefficient, half value layer and the mean free path. Furthermore, the experimental results concerning the different mechanical properties of silicone rubber composites (tensile strength (σR), elongation at break (εR), Young’s modulus (E) and hardness (H)) have been also included. The effect of both lead oxide concentration and dose on the different physical properties have nicely presented and carefully discussed. The results concerning the dependence of the real part of the dielectric constant ε′ and the imaginary part ε″ on both lead oxide concentration and frequency has been experimentally performed and carefully discussed.