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The K α , β and L α 1,2 excitation probabilities for some elements in 56≤Z≤68 at 59.54 keV were obtained using a Si(Li) detector with a multichannel analyzer. It is the first time that the K α , β and L α 1,2 excitation probabilities were determined for the present elements. To obtain the K α , β and L α 1,2 excitation probabilities, the K and L 3 shell/sub-shell absorption jump factors and the K and L 3 shell/sub-shell fluorescence yields were determined experimentally. The measured results of absorption jump factor and fluorescence yield were compared with the theoretical and other experimental results. The determined excitation probabilities were compared only with theoretical calculated ones since there are no other experimental reports for the present elements in the literature. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The anisotropy parameter values β of the L shell fluorescent X-rays (Lι (L3-M1), Lβ6 (L3-N1), Lα1,2 (L3-M5,4) and Lβ2,15 (L3-N5,4) of Bi, Pb, Ta, Lu, and Yb excited by 22.6 keV photons were measured. These values were used to determine the kinematic coefficient ratios α(Lι/Lα1,2), α(Lι/Lβ6), and α(Lα1,2/Lβ2,15). The Lι and Lβ6 X-rays were found to be anisotropically emitted whereas Lα1,2 and Lβ2,15 X-rays showed less anisotropic spatial distributions. Also, the polarization degrees of Lι and Lα X-rays were measured for the present elements and observed that the Lι lines were found to be strongly polarized whereas the Lα lines showed less polarization. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring L3-subshell absorption jump ratios, and jump factors, for high Z elements. Jump factors and jump ratios for these elements have been determined by measuring L3 subshell fluorescence parameters such as L3 subshell X-ray production cross section , L3 subshell fluorescence yield, , total L3 subshell and higher subshells photoionization cross section . Measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation experimental geometry. Measured values for jump factors and jump ratios have been compared with theoretically calculated and other experimental values. [Copyright &y& Elsevier]

This work is part of an ongoing project to produce environmentally friendly alternative radiation shielding materials for ionizing radiation facilities such as medical and industrial areas. As a new shield, a series of Sodium Dodecatungstophosphate Hydrate (Na 3 PO 4.12WO 3.H 2 O) doped polymer composite materials with different additives have been successfully produced. The hypothesis is highlighted by the positive effect of Na 3 PO 4.12WO 3.H 2 O supplement for nuclear radiation shield efficiency. The nuclear shielding performance of the new polymer composite materials produced was calculated using the WinXcom theoretical program at different energies. The results obtained were compared with the results calculated using the MCNP-X simulation program. In addition, a wide range of shielding parameters for gamma, neutron, proton and alpha radiation. For gamma radiation, mass attenuation coefficients (μ m), half value layer (HVL), tenth value layer (TVL), mean free path (MFP), linear attenuation coefficients (LAC), effective atomic number (Z eff), exposure (EBF) and energy absorption buildup factors (EABF), dose multiplication factor (K(E,X)), the radiation protection efficiency (RPE) were evaluated; for neutron radiation, fast neutron removal cross sections (Σ R) was calculated; for proton and alpha radiation, Proton mass stopping power (Ψ P), proton projected range (PR - Φ P), alpha mass stopping power (Ψ A) and alpha projected range (PR - Φ A) have been determined. Among the mentioned shielding parameters, lower values of HVL, TVL, MFP, EBF, EABF, MSP, PR and high μ m , Z eff , Σ R imply that the composite material has better shielding properties. According to the obtained results, it is reported that the NPW20 coded sample's ability to attenuate gamma and charged particle radiation more efficiently than that of other prepared composites. NPW05 coded sample was found to be more suitable for neutron shielding capability. Image 1 • Novel polymer composite materials have been fabricated. • Nuclear shielding characterization was performed. • The experimental results were compared with MCNPX and WinXCOM data. • NPW25 sample has an excellent nuclear radiation shielding ability for charged particles and gamma ray. • NPW05 sample has better protection for neutrons. [ABSTRACT FROM AUTHOR]

Various composite shielding materials have favorable structural, mechanical, physical, and nuclear properties, besides their economic affordability. Such properties have widened the usage of composites around the globe in large-scale installations such as nuclear medical facilities, nuclear power plants, and spent nuclear fuel storage. In the current study, two groups of polymer composites have been prepared and their gamma-ray attenuation characteristics have been investigated both experimentally and theoretically. Four samples of each group have been prepared by varying the doped material (BaTiO 3 and CaWO 4) percentage between 5% and 20% with increments of 5%. To investigate the gamma-ray attenuation features, the linear attenuation coefficient, radiation protection efficiency, half value layer, mean free path, and effective atomic number parameters for these polymer composites reinforced with BaTiO 3 and CaWO 4 were obtained in the energy range between 59.5 and 1408.0 keV (at 22 different energies) using narrow beam transmission geometry. The experiments were performed with the aid of an HPGe detector and eight different radioisotope point sources. According to the experimental and theoretical results, BaTiO 3 (20%) and CaWO 4 (20%) have better gamma-ray attenuation properties than the other prepared polymer composites. Moreover, CaWO 4 (20%) has better gamma-ray attenuation features than BaTiO 3 (20%). [ABSTRACT FROM AUTHOR]

The gamma ray photon interaction parameters for different samples including calcium silicide, magnesium silicide, magnesium boride, calcium hexaboride, aluminum oxide, and titanium dioxide were investigated. For this aim, the mass attenuation coefficients for these samples were measured by the transmission geometry at 14 energies values (i.e. , E∈[81,1333] keV) and the results were compared with those acquired from the WinXCOM software. From the present samples, calcium silicide and magnesium boride have the highest and lowest effective atomic numbers, respectively. Besides, the effective atomic number values almost remain constant for magnesium silicide. The half value layer results showed that as the energy increases, the probability of photon interaction with the ceramic sample decreases, thus more gamma photons can penetrate the ceramics. • The μ/ρ, Z eff , N E , HVL and MFP parameters were obtained for six ceramic samples. • The experiments were performed using an HPGe detector and six radiation sources. • A good agreement was observed between experimental and theoretical results. • The lowest values of HVL and MFP were found for TiO 2 among the selected samples. • Mg 2 Si sample possesses the highest HVL and MFP values. [ABSTRACT FROM AUTHOR]

This paper has been focused on the a detail study on non-ionizing and ionizing electromagnetic (EM) shielding features and build-up factors of reinforced with ferrochrome (FeCr) composites. The non-inozing electromagnetic shielding performance quantities of composites have been determined in the frequency range between 12.4 and 18.0 GHz. Also, the experimental mass attenuation coefficients (MAC) have been estimated using gamma spectrometer and various radioactive point, and compared to those of theoretical and simulation (MCNPX) results. With help of the obtained linear attenuation coefficients, several attenuation quantities, i.e., effective atomic number (Z eff), half value layer (HVL), and mean free path (MFP) have been discussed. In addition, buildup factors (EBF and EABF) values have been estimated utilizing the G-P fitting method. The results showed that composite encoded FeCr(15%) is superior shielding attenuation properties among the investigated samples. • Composites reinforced with FeCr with three different ratios were produced. • Their electromagnetic shielding features were investigated between 12.4 and 18.0 GHz. • γ-ray shielding properties were investigated experimentally in a wide energy range. • EBF and EABF results of composites were calculated in the range of 0.015–15 MeV. • FeCr(15%) is the best radiation shielding material among the selected samples. [ABSTRACT FROM AUTHOR]

The shielding efficiencies of gamma and neutron radiations for ternary composites containing polyester resin, polyacrylonitrile and gadolinium (III) sulfate at different ratios were investigated in the present study. In order to investigate the gamma radiation shielding capacity of the produced ternary composites, linear and mass attenuation coefficients, half value layer, effective atomic number and radiation protection efficiency parameters were determined experimentally, theoretically and using the GEANT4 simulation code. The gamma shielding capabilities of the composites were studied in the photon energy range of 59.5–1332.5 keV. In order to investigate the neutron shielding abilities of composites, inelastic, elastic, capture and transport numbers, total macroscopic cross section and mean free path parameters were determined with the help of GEANT4 simulation code. In addition, the number of transmitted neutrons at different sample thicknesses and neutron energies were also determined. It was observed that gamma radiation shielding properties were improved due to the increasing amount of gadolinium (III) sulfate and neutron shielding properties were improved due to the increasing amount of polyacrylonitrile. While the composite coded P0Gd50 exhibits a better gamma radiation shielding ability than the others, the neutron shielding of the sample coded P50Gd0 is also more favorable than the others. • Ternary composites containing polyester, C 3 H 3 N and Gd 2 (SO 4) 3 were produced. • Their gamma shielding capacities were determined by three different methods. • Neutron shielding capacities were investigated with GEANT4. • It was observed that gamma shielding properties improved with increasing Gd 2 (SO 4) 3. • It was observed that neutron shielding properties improved with increasing C 3 H 3 N. [ABSTRACT FROM AUTHOR]