Determination of the Attenuation Coefficients of Epoxy Resin with Carbopol Polymer as a Breast Phantom Material at Low Photon Energy Range

Abstract

Six different composites of epoxy resin and Carbopol 974p polymer were prepared based on Carbopol 974p polymer concentrations of 0%, 5%, 10%, 15%, 20%, and 25%. The linear and mass attenuation coefficients, Half Value Layer (HVL), and mean free path (MFP) of these composites were determined using single-beam photon transmission in the energy range between 16.65 keV and 25.21 keV. This was carried out by determining the attenuation of ka1 X-ray fluorescent (XRF) photons from niobium, molybdenum, palladium, silver, and tin targets. The results were compared with theoretical values of three types of breast material (Breast 1, Breast 2, Breast 3) and Perspex, which was calculated using a XCOM computer program. The results show that there were no significant differences in the attenuation coefficient values after the consequent Carbopol additions. Moreover, it was found that the mass attenuation coefficients of all tested composites were close to those of Perspex and the values for Breast 3. The HVL and MFP results showed that the E25 sample is closer to the results of the Perspex material with differences of (0.53–1.15%) and (0.51–1.20%), respectively. In addition, the densities of the fabricated samples were in the range of 1.102–1.170 g/cm3, which is in the range of human breast density. A computed tomography (CT) scanner was used to investigate the CT number values for the fabricated samples. The CT numbers of all samples were in the range of human breast tissue (24.53–40.28 HU). Based on these findings, the fabricated epoxy–Carbopol polymer is a good candidate for use as a breast phantom material.

Detailed Analysis of Gamma-Shielding Characteristics of Ternary Composites Using Experimental, Theoretical and Monte Carlo Simulation Methods

“…Nagaraja et al have investigated the gamma-shielding performances of polymers such as polystyrene, polypropylene, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), and polychlorotrifluoroethylene (PCTFE) up to an energy of 1.330 MeV and found that PCTFE's radiation shielding property is superior to the others [11]. In another study, the photon absorption properties of epoxy resin with carbopol polymers, used in breast phantoms of different densities, were examined at low energies, and it was found that the density differences did not significantly affect the radiation permeability [12]. The radiation permeabilities of synthetic polymers, including polyethylene (PE), polystyrene (PS), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyvinylpyrrolidone (PVP), polytetrafluoroethylene (PTFE), polypropylene (PP), and polymethyl methacrylate (PMMA), were investigated by Mirji et al between the energies of 14.4 and 1332 keV [13].…”