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Mass attenuation coefficients (µm), total atomic cross-sections (σt), molar extinction coefficients (), electronic cross-sections (σe), effective atomic numbers (Zeff) and electron densities (Neff) have been computed for few nylons that are polymers, namely, nylon 6 (C6H11ON), nylon 1,1 (C11H21ON), nylon 6,6 (C12H22O2N2), nylon 6,9 (C15H28O2N2), nylon 6,10 (C16H30O2N2) and nylon 6,12 (C18H34O2N2) using narrow beam good geometry set-up. In the present investigation, radio-nuclides57CO,133Ba,137Cs, Co57, Ba133, Cs137, Na22, Mn54and Co60emitting energies 122, 356, 511, 662, 840, 1170, 1275 and 1330 keV have been counted by a NaI (Tl) detector coupled with the 8 K multichannel analyzer. Values ofµm,σtandσedecrease with increasing energy of gamma photons due to the dominance of Compton scattering in the selected energy range. Effective atomic numbers of chosen samples tend to be almost constant as a function of energy. It is clearly observed from the computed results that the among the chosen samples nylon 1,1 has good absorption capability of gamma photons in the low energy region. An attempt has been made to investigate the new gamma-ray-shielding materials that can be used at a large scale and that will be available at low cost. [ABSTRACT FROM AUTHOR]

The fast neutron and gamma ray attenuation capability of the most common thermoplastic polymers used in nuclear applications has been evaluated theoretically. Monte Carlo simulation has been used to compute the gamma-ray energy absorption buildup factor in the energy range 0.015–15 MeV at penetration depths up to 40 MFP. The results of MCNPX calculations have been validated against the results derived from the Geometric Progression fitting method. To evaluate neutron attenuation performance of the polymers, the fast neutron removal cross-section has been determined using theoretical database. Despite the superior ability of polysulfone and poly (ether sulfone) in gamma ray attenuation, high-density polyethylene has been found to have the best fast neutron removal ability among all. The detailed insights into the fast neutron and gamma ray shielding properties of selected polymers in the present work might have great potential applications in nuclear systems. • The shielding properties for thermoplastic polymers were studied in mixed neutron-gamma radiation field. • EABF have been calculated using MCNPX codes and validated based on the values obtained using G.P. fitting method. • The values of macroscopic removal cross-sections for neutrons were determined. • Measured data are useful in nuclear medicine application. [ABSTRACT FROM AUTHOR]

• The photon shielding properties for some thermoplastic polymers have been studied. • The measurements have been performed in the energy range of 122-1330 keV using narrow beam good geometry set-up. • The values of μ m , μ, σ t , σ a , σ el , Z eff , N el , λ, HVL, TVL have been determined. • The experimental values have been supported with WinXCom and Monte Carlo results. • The provided data can be useful in nuclear medicine application. In this work, the γ-ray attenuation properties of some thermoplastic polymers as widely used materials in nuclear medical diagnosis and treatment have been studied. The mass attenuation coefficient (μ m) of all selected polymer samples have been measured using NaI (Tl) detector, WinXCom Program and MCNPX simulation at photon energies 122-1332 keV. Further, μ m values were used to estimate other related parameters including linear attenuation coefficient, total molecular, atomic, and electronic cross-sections, effective atomic number, effective electron density, relaxation length, HVL and TVL. Results show that the theoretical and simulation values of attenuation parameters are in satisfactory agreement with experimental results. However, the experimental values of μ m have been found to be closer to those calculated by MCNPX than the values obtained by WinXCom. In addition, the effectiveness of well-known thermoplastic polymer materials in nuclear medicine application at different photon energies has been compared and discussed. [ABSTRACT FROM AUTHOR]

The present article deals with the preparation of novel in-situ layered B 4 C and PbO reinforced solution casted layered polymer composites (SCLPC) for irradiation shielding applications. Two distinct layers of B 4 C and PbO were formed inherently in the sample owing to the difference in density of the reinforcements in the epoxy matrix. The formed layers were distinct and the interface was continuous as well. Further, the as-prepared in-situ layered sample was subjected to XRD and FTIR to confirm the particle reinforcements and chemical stability respectively. The gamma irradiation shielding studies revealed the superior efficiency in shielding of gamma irradiation at lower energy doses making it more suitable for gamma ray shielding applications. • The fabrication route is novel in-situ layered molding and curing route. • Two distinct layers of B 4 C and PbO were formed and is confirmed through microscopy. • The prepared composite was subjected thermal and gamma radiation shielding studies. • The composite was able to portray shielding with an efficiency of nearly 45% at low doses. [ABSTRACT FROM AUTHOR]