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In this paper, the role of TeO 2 in radiation attenuating characteristics of xTeO 2 -10CaF 2 -(60–0.6x) B 2 O 3 -(30–0.4x) CaO glass system with x = 20, 25, 30, 35 and 40 wt% was investigated. The gamma radiation studies were carried out by utilizing Geant4 simulations and the newly developed Phy-X/PSD program. The gamma-shielding characteristics of the present glass samples were examined in terms of mass attenuation coefficient (μ/ρ), and some other related factors such as the effective atomic number (Z eff), and mean free path (MFP). The electron radiation-shielding characteristics were tested by determining the stopping power (ψ e) and CSDA range for each glass specimen. The neutron radiation-shielding characteristics were explored by evaluating the removal cross section (RCS) for the tested glasses. Moreover, the G-P method was employed to investigate the exposure buildup factor (EBF) for photon energies up to 15 MeV. The results showed that the TeO 2 content had a significant influence on the shielding ability of the investigated glasses against gamma and neutron radiations. In contrast, the TeO 2 content had an insignificant influence on the electron radiation-shielding capacity of the glasses involved. Additionally, the nuclear-shielding properties of the studied samples were compared with those of standard nuclear radiation shields. It can be concluded that the present calcium boro-tellurite glasses have a promising future to be used as a shielding material against gamma, electron and neutron radiation, wherein the TeO 2 concentration can be balanced according to the desired application. [ABSTRACT FROM AUTHOR]

In this research paper, we studied the optical and nuclear shielding efficiency of newly developed BGO glasses with the following compositions (in wt%): 32Bi 2 O 3 –68GeO 2 , 42Bi 2 O 3 –58GeO 2 , 47Bi 2 O 3 –53GeO 2 , 52Bi 2 O–48GeO 2 , 62Bi 2 O 3 –38GeO 2. BGO glasses were prepared by traditional melt quenching method. To obtain the band gap values of fabricated BGO glasses, optical absorption spectra were used for evaluation of optical properties. The mass attenuation coefficients (μ/ρ) were achieved for prepared glasses at 0.015–15 MeV photon energies employing MCNPX Monte Carlo code and WinXcom program. Moreover, broad-range of nuclear shielding parameters for gamma ray, neutrons and charged particles such as mass attenuation coefficient, half value layer, effective atomic number, buildup factors, mass stopping powers, projected ranges, fast neutron removal cross sections and damage factors were calculated. The refractive index is calculated from E opt , As Bi 2 O 3 concentration is enhanced, E opt is also increased as well as the optical electronegativity and consequently the refractive index. In addition, the results showed that BIGE5 glass sample with highest Bi 2 O 3 contribution has excellent nuclear radiation shielding ability among the other fabricated glass samples. [ABSTRACT FROM AUTHOR]

This paper evaluates the γ-radiation shielding traits of some new types of borate glasses of composition (70–x)B 2 O 3 –10Bi 2 O 3 –10BaO–10CdO–xPbO (where 0 ≤ x ≤ 20 mol%) prepared using melt quenching method. As-quenched samples were characterized to determine the effects of various PbO contents on their γ-radiation shielding properties. XRD patterns of the samples verified their amorphous nature. The Phy-X and XCOM was used to compute the mass attenuation coefficients of the glasses and then compared with the experimental data. The γ-radiation shielding performance of the proposed glasses were evaluated in terms of diverse attenuation parameters like mean free path, half and tenth value layer, atomic cross-section, electronic cross-section, effective atomic number and effective electron density. The γ-radiation shielding performance of the glasses were significantly improved with the increase of PbO contents. This new borate glass system is established to be advantageous for the radiation shielding applications. • The borate glass samples with different PbO content were prepared by the standard melt-quenching method. • The μ/ρ values of the glasses were increased with the increase of the PbO content. • The relatively higher Zeff at lower energies due to the dominance of PE effect. • Promising HVT and TVL achieved with the new prepared glasses. • The proposed glass improves the efficiency of IR shielding material. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a biodegradable organic acid of polymeric chain that has as chemical structure the monomer C 3 H 4 O 2 and it is one of the most used materials in rapid prototyping among 3D printers. Due to the ease of manufacturing PLA parts and because of its low atomic number, PLA can be used as holder to radiation source and detectors to establish fixed geometries in experiments using gamma radiation, hence the importance in knowing more about PLA characteristics. In this way, the novelty of this paper is to determine the mass attenuation coefficient of 3D printed PLA samples using gamma densitometry. A mathematical model was developed using MCNPX code and consisted of a PLA sample, a NaI(Tl) detector and gamma rays of 661.6 keV as radiation source (narrow beam). The mathematical model was experimentally validated using the same geometry and a lead collimator. Besides that, PLA weight fractions and density were also determined in order to use this information as input data in the MCNPX code. The obtained mass attenuation coefficients were in good agreement with the NIST theoretical reference value, presenting relative errors of 0.99% (MCNPX) and 2.00% (experimental). The proposed methodology was repeated replacing PLA for aluminum samples and comparing its results with NIST. In addition, the mass attenuation coefficient for some polymers was calculated using this model aiming to validate the geometry developed with MCNPX code. • Simulation of mass attenuation coefficients using MCNPX code. • Absorber material are 3D printed polylactic acid samples. • Experimental validation of the methodology using gamma densitometry. • Simulation of others absorber materials. [ABSTRACT FROM AUTHOR]

This paper focuses on the role of antimony oxide (up to 15 wt%) in the physical, structural, optical, and radiation attenuating characteristics of boro-bismuth glasses within B 2 O 3 -20Bi 2 O 3 - 20Na 2 O 2 - Sb 2 O 3 system. This glass system was prepared by melting at 1250°C and quenching into water. The physical properties were studied by measuring the density, molar volume, and x-ray diffraction for the prepared glass system. The structural features were investigated by determining packing density, passion ratio, oxygen packing density, and oxygen molar volume. The optical attributes were explored by evaluating bandgap, Urbach energy, refractive index, and other related parameters such as dielectric constant, reflection loss, molar polarizability, molar refractivity, optical dielectric constant, optical electronegativity, electron polarizability, optical basicity, metallization, and cut-off wavelength. On the other hand, the shielding properties of the prepared glasses were studied against different types of radiation such as gamma, electron, proton, and neutron beams. The radiation studies were carried out by utilizing Geant4 simulations and the newly developed Phy-X/PSD program. The radiation-shielding characteristics of the present samples were examined in terms of mass attenuation coefficient, stopping power, half value layer, removal cross section, mean free path, and effective atomic number of gamma, electron, and proton beams. The results showed that antimony oxide content had an important influence on the shielding ability against all of the types of radiations. Additionally, the obtained results were compared with those of standard radiation shields. It can be concluded that the present glasses have a promising future to be used as radiation shielding material, wherein the antimony oxide concentration can be balanced according to the desired application. [ABSTRACT FROM AUTHOR]