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Gamma-ray detection and studying its interactions with matter is very important and serves in many fields of research. Besides, investigation of new shielding materials against gamma-ray will provide a lot of solutions for several problems accompanied by the presence of radiation sources in wide areas of applications, such as industry, medicine, agriculture, research laboratories, and nuclear power plants. In the present work, different gamma-ray attenuation parameters will be calculated theoretically using different metal chlorides mixed with epoxy resin polymers at different weight ratios. These attenuation parameters were calculated in a wide energy range started from 0.05 up to 3 MeV. This wide energy range covers almost the most known radionuclide gamma-ray energies. The obtained results were compared with pure epoxy resin polymer to show how well the modification of polymer properties was when mixed with other materials. Also, all mixture's attenuation parameters results were compared with lead metal results to check its validity as a gamma-ray shielding material. The obtained results found to be promising and the presented materials can be used instead of lead metal as an effective material in radiation protection.

In the present work we investigated the gamma radiation parameters as mass attenuation coefficients μ/ρ, the total atomic scattering cross-sections σν, the electronic scattering cross-sections se, the effective atomic numbers Zeff, and the effective electron densities Neff for some polymers such as polyoxymethylene (CH2O), poly acrylonitrile (C3H3N), natural rubber (C5H8), poly ethyl acrylate (C5H8O2), polyphenyl methacrylate (C10H10O2), and polyethylene tetraphthalate (C10H8O4). The gamma ray photons were detected by NaI(Tl) detector with resolution of 8.2 % at 662 keV, using radioactive gamma ray sources 57Co, 133Ba, 137Cs, 54Mn, 60Co, and 22Na at energies 122, 356, 511, 662, 840, 1170, 1275, and 1330 keV. Values of μ/ρ for the chosen polymers decrease with increasing energy. The results of investigated data are useful in plastic industry, building materials, agriculture fields radiation shielding, accelerator centers, polymer industry, medical field, etc.

The present study portrays the development of lightweight epoxy laminates filled with boron carbide (B4C) and lead (Pb) particles through a novel layered molding and curing route. Six different laminates of single and tri-layers were prepared with varying compositions and were subjected to thermal, radiation shielding, and dielectric studies. Radiation shielding test were done using a narrow beam setup with six different sources such as Cobalt-57 (Co57-122 keV), Barium-133 (Ba133-356 keV), Sodium-22 (Na22-511 and 1275 keV), Cesium-137 (Cs137-662 keV), Manganese-54 (Mn54-840 keV), and Cobalt-60 (Co60-1170 and 1330 keV). The dielectric studies were done to understand the dielectric constant, dielectric loss factor, and AC conductivity at different temperature and frequency ranges. From the characterizations, it was found that the thermal stability of the single-layered sample increased with respect to the addition of B4C and Pb particles, which may be due to the thermally stable nature of the particles. The radiation shielding study of the samples witnessed the superior characteristics and radiation shielding ability of sample D (40% Pb) and sample E with Pb cladding at incident gamma radiation energy of 662 keV. The dielectric constant of the samples increased significantly at higher temperatures and the dielectric loss factor increased with an increase in temperature and decreased with an increase in frequency. The AC conductivity of the samples increased with respect to an increase in temperature and frequency. [ABSTRACT FROM AUTHOR]

We have computed radiological parameters of some C- H- N- O based amine group bio material in the energy range 122–1330 keV with the gamma ray count by narrow beam geometry. The NaI(Tl) detector with 8 K multichannel analyser was used having resolution 6.8% at 663 keV. The energy absorption buildup factor (EABF) was determined by using Geometric Progression (G-P) fitting method up to penetration depth of 40 mfp at energy 0.015–15 MeV. The NIST XCOM data were compared with the experimental value and we observed (3–5%) difference. The comparative study of effective atomic number and effective electron density in the energy range 122–1330 keV using Gaussian fit for accuracy were performed. The amino acid has the highest EABF value at 0.1 MeV and the variation in EABF with penetration depth up to 1–40 mean free path (mfp). The calculated radiological data of biological material are applicable in medical physics and dosimetry. [ABSTRACT FROM AUTHOR]

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]

Photon attenuation coefficient calculation methods have been widely used to accurately study the properties of amino acids such as n-acetyl- l -tryptophan, n-acetyl- l -tyrosine, d -tryptophan, n-acetyl- l -glutamic acid, d -phenylalanine, and d -threonine. In this study, mass attenuation coefficients ( µ m ) of these amino acids for 0.122-, 0.356-, 0.511-, 0.662-, 0.884-, 1.170, 1.275-, 1.330-MeV photons are determined using the radio-nuclides Co 57 , Ba 133 , Cs 137 , Na 22 , Mn 54 , and Co 60 . NaI (Tl) scintillation detection system was used to detect gamma rays with a resolution of 8.2% at 0.662 MeV. The calculated attenuation coefficient values were then used to determine total atomic cross sections ( σ t ), molar extinction coefficients ( ε ), electronic cross sections ( σ e ), effective atomic numbers ( Z eff ), and effective electron densities ( N eff ) of the amino acids. Theoretical values were calculated based on the XCOM data. Theoretical and experimental values are found to be in a good agreement (error<5%). The variations of µ m , σ t , ε , σ e , Z eff , and N eff with energy are shown graphically. The values of µ m , σ t , ε , σ e are higher at lower energies, and they decrease sharply as energy increases; by contrast, Z eff and N eff were found to be almost constant. [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]