Neutron and charged particle attenuation properties of volcanic rocks

Radiation Shielding efficiency of lead-tungsten-boron glasses with Sb, Al, and Bi against gamma, neutron and charge particles

We report on newly developed nuclear shielding glass system based on lead-tungsten-boron (PWB) for radiation applications against photon, neutron and charge particles. This newly developed system contains also different additions, in low concentrations, such as Sb, Al and Bi. The gamma/photon shielding performance was tested by using FLUKA Monte Carlo. Moreover, the shielding efficiency of the present system is examined against charged particles (light and heavy ones) and neutrons. The highest gamma/photons attenuation is observed in the lowest incident energy and this is at the region of the photoelectric absorption. We also observe that the values of effective atomic number (Zeff) show a peak at 100 keV incident energy. The reduction of these values is higher for photon energy range 0.1-1 MeV than below 80 keV energies. The lowest half value layer (d1/2), reflecting the best shielding efficiency, is recorded for the PWB-Bi system. The PWB-Bi system demonstrates promising performance better than many of commercial and standard systems and heavy concretes.

Examinations of mechanical, and shielding properties of CeO2 reinforced B2O3-ZnF2-Er2O3-ZnO glasses for gamma-ray shield and neutron applications

The glass system 75B2O3 - 4.5ZnF2 - 0.5 Er2O3- ( 20 - x ) ZnO- x CeO2, x = (0 ≤  x  ≤ 1 mol. %) was manufactured using a melt quenching process, with CeO2 substituted for ZnO in the glass matrix in concentrations ranging from 0 to 1 mol %. The Makishima-Mackenzie model and sound wave velocity measurements were used to evaluate the mechanical parameters and elastic characteristics of the examined glass system, respectively. The results showed that increasing CeO2 doping ratio from 0 to 1 mol% increased density, sound velocities, elastic properties, and microhardness from 5.80 to 9.01 GPa. Phy-X/PSD software was employed to assess the effect of replacing ZnO with CeO2 on shielding capacity. The obtained results revealed that replacing ZnO with CeO2 enhances shielding characteristics and the manufactured glass may be useful in shielding applications.

Radiation shielding ability and optical features of La2O3+TiO2+Nb2O5+WO3+X2O3 (X=B, Ga, and In) glass system containing high-entropy oxides

Three high entropy materials (La₂O₃+TiO₂+Nb₂O₅+WO₃+X₂O₃ coded as LTNWM1, LTNWM2, and LTNWM3 for X = B, Ga, and In) produced by aerodynamic containerless processing were evaluated for optical attributes, and their gamma-radiation absorption abilities were investigated in this report. Optical related parameters such as the molar refractivity ( R m ), optical transmission ( T ), molar polarizability ( α m ), metallization criterion ( M ), reflection loss ( R L ), static ( ε s t a t i c ), and optical ( ε o p t i c a l ) dielectric constants were estimated through standard expressions, while photon attenuation parameters were estimated from data from photon transmission simulations in FLUKA code and XCOM software. The attenuation parameters were calculated for a wide energy photon spectrum (15 keV-15 MeV). LTNWM1, LTNWM2, and LTNWM3 had R m values of 18.94 cm³/mol, 21.45 cm³/mol, and 26.09 cm³/mol respectively. The α m has a value of 7.52 × 10^-24 cm³ for LTNWM1, 8.51 × 10^-24 cm³ for LTNWM2, and 10.35 × 10^-24 cm³ for LTNWM3. The photon shielding parameters evaluated by FLUKA and XCOM are compatible. The mass attenuation coefficient for the glasses was between 0.0338 and 52.8261 cm²/g, 0.0336-58.0237 cm²/g, and 0.0344-52.1560 cm²/g for LTNWM1, LTNWM2 and LTNWM3, respectively. The effective atomic number at 1.5 MeV was 18.718, 20.857, and 22.440 for LTNWM1, LTNWM2, and LTNWM3, respectively. The shielding parameters of the HMOs compared to traditional gamma radiation absorbers are exceptional and highlight the potential of using them as optically transparent gamma-shields.

Radiation Attenuation Assessment of Serpentinite Rocks from a Geological Perspective

Serpentinites are metamorphic rocks that are widely applied as aggregates in the production of radiation-shielding concrete. Different varieties of massive serpentinite mountains located in Egypt exist without real investment. Hence, this study aims to evaluate the radiation shielding efficacy of three varieties of serpentinite rocks from different geological perspectives: mineralogical, geochemical, and morphological characteristics. X-ray diffraction, transmitted-light microscopy, and thermal analysis were required to characterize their mineralogical composition, while X-ray fluorescence was necessary to investigate their geochemical features. Moreover, scanning electron microscopy was used to detect their morphological characteristics. On the other hand, the PuBe source and stilbene detector were employed for the experimental determination of fast neutrons and γ-ray attenuations, which were conducted at energy ranges of 0.8−11 and 0.4−8.3 MeV, respectively. Based on the mineralogical, geochemical, and morphological characteristics of these rocks, the radiation attenuation capacity of lizardite > antigorite > chrysotile. However, these serpentinites can be applied as a natural alternative to some radiation-shielding concrete in radiotherapy centers and other counterpart facilities.

Recycling potential of cathode ray tubes (CRTs) waste glasses based on Bi2O3 addition strategies

Cathode-ray tubes (CRTs) from computer monitors and television sets are considered as one of the main sources of waste materials worldwide. Therefore, a new application for such out of use materials is required to solve the relatively huge amount of this waste. In this paper, the popular melt-quench technique was used to synthesis glass samples with the structure: xBi₂O₃-(100-x) waste CRTs (where x = 0, 10 & 20 wt%) and designated as CRT-Bi0, CRT-Bi10, and CRT-Bi20 accordingly. The physical, structural, optical and radiation absorption competence of the glasses were investigated. The XRD analysis of the glasses reveals an amorphous structure while the mass density increased linearly with the Bi₂O₃ content of the glasses from 2.86 to 3.08 g/cm³. The optical absorbance of the glasses initially increased and later declined in the visible region as the weight fraction of Bi₂O₃ increased. The direct optical bandgap E_g values were found to be 3.26, 2.72, and 2.64 eV whereas the indirect E_g values were equal to 3.15, 2.30, and 2.26 eV for CRT-Bi0, CRT-Bi10, and CRT-Bi20, respectively. The gamma-ray interaction parameters of the glasses obtained through FLUKA simulations and XCOM computation showed that mass attenuation falls within the range 0.6991-0.0256, 1.1426-0.0276, 1.5860-0.0301 cm²/g for photon energy range 0.1-10 MeV. Generally, the computed gamma ray interaction quantities show that the gamma ray shielding ability of the CRT-Bi glasses follows the order: CRT-Bi0 < CRT-Bi10 < CRT-Bi20. This order is conserved in the computed interaction cross sections for thermal (25 meV) neutrons. On the other hand the fast neutron removal cross section follows a reverse order with values of 0.0891 cm^-1, 0.0867 cm^-1, and 0.0850 cm^-1 for weight fraction of Bi₂O₃ from 0 to 20 wt%. The comparison of the gamma-ray attenuation capacity of the CRT-Bi20 with common shielding materials reveals good potential for shielding application. Out of use CRT glasses may thus be recycled for use as radiation shielding glasses as described in this study for gamma radiation protection applications.

Experimental and Numerical Investigation of the Damage Characteristics of Rocks under Ballistic Penetration

Rock penetration is an inevitable problem in the study of drilling and projectile penetration. The penetration resistance of red sandstone and limestone was investigated at projectile speeds ranging from 600–1200 m/s. The damage characteristics of these rocks were studied via experimental tests and numerical simulations. The damage condition of the target surface, internal damage state and crack distribution were obtained. It was concluded that the maximum error of the numerical simulation and experimental results was not more than 10%. The penetration resistance of limestone was approximately 23.8% stronger than that of red sandstone. However, the energy absorption effect of limestone was weaker than that of red sandstone, and large cracks can be more easily formed. The compaction area of red sandstone was softer, with obvious crack compaction in the crater area, and particle detachment can more easily occur. Red sandstone was more sensitive to the impact angle of the projectile. With oblique penetration, the projectile was more likely to deflect inside the red sandstone target.