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Thin films of semiconductor Se80Ge20-xAgx (x = 0, 3, 6, 9, 12 and 15 at.%) were deposited by the thermal evaporation technology. Through optical and electrical characterization, the influence of the Ag ratio on the photoelectric parameters of Se–Ge thin film was studied. The X-ray diffraction pattern showed the amorphous nature of the deposited films as well as the polycrystalline state when the films were annealed at the maximum crystallization temperature (415 K), which was determined by the first derivative of the resistivity curve with respect to temperature. The crystallization kinetics of the film was extracted from the electrical analysis by measuring the change in resistivity with temperature. The electrical results of the thin film showed three regions; namely, amorphous, extended (crystalline) and hopping. In the extended and hopping states, the activation energy and pre-exponential factors were calculated. The optical constants, extinction coefficient and refractive index were calculated using the transmittance and reflectance of the grown Se80Ge20-xAgx films. The energy gaps of the films were estimated in the strong absorption regions. The changes in the bandgap energy of the film by thermal annealing can help to produce materials with acceptable band gaps for use as absorber layers in solar cell applications. Also, the results provide microscopic insights and studies on the structure, electr-othermal and optical properties of Ag metal-doped GeSe as a back contact of solar cells.

We fabricated pure kesterite Cu2ZnSnS4 (CZTS) nanocrystals for solar cells by solvothermal synthesis. We investigated the effects of 0.5–2 mg/mL glycine complexing agent on the nanocrystals’ properties by comprehensive spectroscopic and microscopic analysis, focusing on structural, morphological, compositional, and chemical properties. By controlling the glycine concentration, we obtained complete single-phase nanocrystals: high purity, good crystallinity, and copper-poor and Zn-rich composition. The nanocrystal diameter ranged ~50–60 nm. Thin films based on the nanocrystals were smooth, compact, free of cracks and holes, and had a grain size of up to 2.8 μm. The nanocrystals have an optical band gap between 1.51 and 2.27 eV and an absorption coefficient greater than 104 cm−1. The nanocrystal properties indicate promise for high-efficiency CZTS solar cells.

The role of Er3+ ions on the optical properties and radiation shielding features of (55-x)B2O3–10SiO2−25Gd2O3–10CaO−xEr2O3: (Er-glasses) with x = 0 (Er-0.0) to 2.5 (Er-2.5) mol% glasses was investigated. The Metallization criterion (Mcriterion) was found to vary from 0.5356 to 0.5346, while the static dielectric constant (estatic) varied from 2.7340 to 2.7406 for Er-0.0 to Er-2.5 glasses. The optical electronegativity (χ*) decreased from 0.9085 to 0.8440, the nonlinear refractive index ( n 2 o p t i c a l ) increased from 1.4075 × 10−12 to 1.4274 × 10−12 (esu), and the nonlinear optical susceptibility (χ3) increased from 6.1765 × 10−14 to 6.2714 × 10−14 (esu) with increasing Er2O3 from 0 to 2.5 mol%. The mass attenuation coefficient (MAC) for the Er-glasses has been calculated via the Phy-X/PSD program. The highest MAC was found at 0.284 MeV, and was equal to 0.197 cm2/g for Er-0.0, 0.199 cm2/g for Er-0.5, 0.200 cm2/g for Er-1.0, 0.201 cm2/g for Er-1.5, 0.202 cm2/g for Er-2.0 and 0.204 cm2/g for Er-2.5. The linear attenuation coefficient (LAC) has the following order: (Er-2.5)LAC > (Er-2.0)LAC > (Er-1.5)LAC > (Er-1.0)LAC > (Er-0.5)LAC> (Er-0.0)LAC. The RPE for the Er-2.5 glass was found to increase from 35.06% (for x = 0.5 cm) to 82.20% (for x = 2 cm) at 0.284 MeV. At the selected energies, the transmission factor (TF) decreased with the addition of Er2O3. The half value layer (HVL) of the Er-0.0-Er2.5 samples tended to decrease with the increase in Er2O3 content. The tenth value layer (TVL) decreased from 2.919 to 2.667 cm at 0.284 MeV as the Er2O3 increases from 0 to 2.5 mol%, while at 0.511 MeV it decreased from 5.771 to 5.377 cm. The results revealed that the Er-glasses can be applied for optical and radiation shielding uses.

This work aims to report the radiation shielding ability of WO3–ZnO–PbO–B2O3 glasses and to understand the effect of WO3 on the shielding behavior of this glass system. Geant4 code was applied to calculate the mass attenuation coefficient between 0.1218 and 1.458 MeV. The Phys-X software was used to validate the simulation results. Decrease in the transmission factor (TF) for the selected glasses with an increase in the thickness of the glass from 0.2 to 1 cm has been noticed and discussed. The maximum TF for the glass with composition of 20PbO-80B2O3 occurred for 0.2 cm thickness and equals to 0.44 at 0.1218 MeV and 0.966 at 1.086 MeV. Whereas, the maximum TF for 10WO3-10ZnO-20PbO-60B2O3 sample with a thickness of 0.2 cm varied between 0.256 and 0.95. The TF results emphasize the fact that the sample's power to attenuate the photons becomes weaker with the increase in the energy of the photon. The radiation protection efficiency (RPE) increases with the increase in the thickness of the glass and the amount of WO3. The replacement of 20 mol % of ZnO by 10 mol % of WO3 leads to the increase in the RPE from 8.83 to 12.03% at x = 0.4 cm, from 16.89 to 22.61% at x = 0.8 cm and from 20.64 to 27.42% at x = 1 cm. At 0.444 MeV, the linear attenuation coefficient (LAC) increases by 1.52 due to the increase in the density by 1.46, which indicated that if the density of the glass is doubled, the LAC almost doubles, and the WZPB7 glass with highest density attenuates more photons.

Six glass samples with the composition of TeO2-Li2O-ZnO were analyzed for their radiation shielding properties. The radiation shielding factors for the lithium-zinc-tellurite glasses were reported using the Geant4 code and Phy-X/PSD program. The transmission factor (TF) was determined for different thicknesses and the results revealed that the TF decreases with increasing the thickness of the glass. For TeLiZ1, increasing the thickness of the sample from 0.4 cm to 1.6 cm led to decrease the transmission of the photon from 0.84 to 0.48 at 0.5 MeV and from 0.94 to 0.76 at 4 MeV. The radiation protection efficiency (RPE) results showed that a thicker glass sample absorbs a higher number of photons, implying that lower radiation pass among the glass, increasing RPE. Also, the glass coded as TeLiZ6 has higher RPE than that of TeLiZ1 glass which suggests that at higher content of TeO2 (85 mol%), the more efficient the glass is at shielding the incoming photons. The linear attenuation coefficient (LAC) obtained by both methods (Geant4 and Phy-X/PSD showed a good agreement for all the glasses and at all investigated energies. The LAC indicates a strong energy dependence, especially at low energies. The LAC also increases as more TeO2 is added to the glasses. TeLiZ6 (85TeO2-15Li2O, ρ = 5.164 g/cm3) has the highest RPE and lowest TF, while TeLiZ1 (60TeO2-15Li2O-25ZnO, ρ = 4.976 g/cm3) has the lowest RPE and highest TF. The tenth value layer (TVL) was also determined and it was observed that TVL increases with increasing energy, reaching a maximum value at 10 MeV and varying between 12.919 and 13.808 cm. By contrast, the minimum TVL is reported at 15 keV and varies between 0.0106 and 0.0112 cm. The addition of TeO2 decreases the TVL, with TeLiZ6 having the least TVL.

In the present investigation, we successfully synthesized Cu2ZnSnS4 (CZTS) nanoparticles via solvothermal method with different sulfur sources at 240 °C for 14 h. The experimental results show that the different sulfur sources caused unique and significant changes in the material properties. The synthesized products were investigated by XRD. Raman spectroscopy revealed that the crystallinity improved and kesterite structures with no secondary phases formed. The TEM results showed that the morphological features of the prepared CZTS nanoparticles had an average particle size of 40 nm and confirmed the nanoparticles' crystallinity. The FESEM results demonstrated that the CZTS nanoparticles had thin films with dense, uniform, and smooth surfaces with grain sizes in a range of 2–4 μm. The CZTS nanoparticles’ optical band gaps were 1.51 eV. XPS was used to investigate the oxidation state of elements in a sample prepared using thiourea. Photovoltaic devices with SLG/Mo/CZTS/CdS/i-ZnO/ZnO:Al structures exhibited3.56% efficiency via CZTS thin film-based nanoparticles prepared using thiourea.

Six specimens of tellurite glass doped with rare earth with a nominal chemical composition 65TeO2–25Na2O-(10-x)NdCl3-xSm2O3: 0.0 ≤ x ≤ 2.5 mol% were fabricated. The fabrication process was conventional melt quenching. The glasses were coded as TNNS0.0 to TNNS2.5 corresponding to their x value. The glasses' non-crystalline properties were measured using X-ray diffraction. The glasses' UV–Vis data in a 300–1100 nm wavelength were calculated. Using absorption measurements, the optical energy band gap ( E Optical ) was assessed. The index of refraction (n), polarizability (αmolar), metallization criterion (Mcriterion), molar refractivity (Rmolar), static and optical dielectric constants (estatic and eoptical), reflection loss (Rloss), and optical transmission (Toptical) were calculated. Results revealed that the indirect optical energy band gap ( E I n d i r e c t O p t i c a l ) changed from 2.94 to 2.80 eV, while the direct one ( E D i r e c t O p t i c a l ) changed from 3.06 to 3.00 eV for TNNS0.0 to TNNS2.5 glasses. Refractive index varied between 2.413 and 2.453. The static dielectric constant changed from 5.824 to 6.017. To inspect the glasses’ radiation shielding characteristics, we simulated their mass attenuation coefficients (MAC) between 0.284 and 1.33 MeV using Geant4 code simulation and Phy-X/PSD software. There was good agreement between the Geant4 and Phy-X/PSD results. The linear attenuation coefficient (μ) values decreased exponentially as the energy increased, ranging from 0.229 to 0.697 cm−1 for TNNS0.0 and 0.256–0.787 cm−1 for TNNS2.5. The addition of samarium oxide (Sm2O3) increased the μ values at all of the energies investigated. The effective atomic number (Zeff) results demonstrated higher photon interactions, possibility due to the increasing Sm2O3 content. The minimum half value layer (HVL) occurred at 0.284 MeV and was 0.881 cm for TNNS2.5and 0.994 cm for TNNS0.0. The tenth value layer (TVL) decreased as the Sm2O3 concentrations increased and increased as the energy increased. TNNS2.5 had the lowest TVL of 2.927 cm at 0.284 MeV and 6.022 cm at 0.662 MeV.

Phy-X/PSD software was applied to understand the gamma photon shielding characteristics of SeO2–Ag2O–TeO2 glass systems. The highest attenuation coefficients occurred at 15 keV (between 39.576 and 48.978 cm2/g) and the lowest at 15 MeV (between 0.0369 and 0.0392 cm2/g). The results showed that the attenuation factors highly depended on the concentration of TeO2, and μ/ρ increased as TeO2 changed from 28 to 70 mol%. The maximum effective atomic number values were between 15 keV and 0.08 MeV and the values at 0.04 MeV were 45.81, 46.55, 47.23, 47.84, 48.91, and 49.38 for SeAgTe1, SeAgTe2, SeAgTe3, SeAgTe4, SeAgTe5, and SeAgTe6, respectively. From the half value thickness results, the SeAgTe6 had the lowest HVT, and thus the best attenuation. The worst attenuation was found for the SeAgTe1, which had the least amount of TeO2 and the lowest density (ρ = 5.66 g cm-3). The results also revealed that there was a rapid increase in the tenth value layer (TVL) for all of the glasses up to 1 MeV as the energy increased, and then the TVL increased at a slower rate. The TVL also confirmed that the attenuation competence of the glasses increased when the TeO2 content increased from 28 mol% to 70 mol%. The attenuation of the SeAgTe1–SeAgTe6 glasses was much better than that of ilmenite, steel-magnetite concrete, and RS-360 glass, since these glasses had lower mean free paths, whereas the attenuation properties of the RS-520 glass were comparable to the SeAgTe3.

In this work, with the help of Phy-X/PSD software, we studied the radiation shielding characteristics of 25Sb2O3–30PbO–(45−y) B2O3–yGd2O3 glasses (with y = 0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol%). The mass attenuation coefficient (μ/ρ) shows a progressive reduction with increase of energy, which denotes that the shielding efficiency of the PbSbBGd0- PbSbBGd1 glasses reduces when the energy was increased. The μ/ρ at 284 keV takes the values between 0.25988 and 0.26022 cm2/g and reduces to 0.18658 cm2/g (for PbSbBGd0) and 0.18673 (for PbSbBGd1) cm2/g at 347 keV. In addition, reasonable elevation in the linear attenuation factor (μ) values was observed with the addition of Gd2O3. This implies that, an improvement in the gamma rays shielding characteristics has occurred with the addition of Gd2O3. PbSbBGd1 sample had the largest μ values compared to all other glasses and equal to 1.418, 1.018, 0.401, 0.297 and 0.220 cm-1 at 284, 347, 826, 1275 and 2506 keV respectively. The results show that the replacement of B2O3 by Gd2O3 increases the effective atomic number (Zeff) for the PbO–Sb2O3–B2O3–Gd2O3 glass system and the Zeff of PbSbBGd1 is higher than that of PbSbBGd0- PbSbBGd0.8 samples, whereas that of PbSbBGd0 is the lowest. The mean free path (MFP) shows strong energy dependence and becomes larger at higher energies. The MFP shows gradual decrease, as the content of Gd2O3 was increased at the expense of B2O3 which implies that radiation attenuation features for the PbSbBGd0- PbSbBGd1 specimen have improved with more amount of Gd2O3. The least half value layer (HVL) is found at 284 keV for all concentrations of Gd2O3 and equals to 0.537 cm (for PbSbBGd0) and 0.489 cm (for PbSbBGd1). While, the highest HVL is registered at 2506 keV and equals to 3.456 cm for PbSbBGd0 and 3.152 cm for PbSbBGd1.

Herein we prepared five glass samples from the composition xLa2O3-(100-x)B2O3 (where x = 15, 20, 25, 30 and 35 mol%) and reported the physical, optical and gamma radiation shielding characteristics. The density of glass samples was increased from 3.1531 to 3.9443 g/cm3 with the addition of La2O3, while the molar volume is in the range of 34.2679–40.3849 cm3/mol. The refractive index of the glass samples is in the range of 1.6524–1.6541 with addition of La2O3 concentration. The optical band gap energy is found to be in the range of 3.08–3.14 eV. The transmission spectra for the La2O3 doped borate glasses in the wavelength range 200–2200 nm were reported and the results showed good transparency in visible region. This indicates that the prepared glasses are specifically showing superior transparency to visible light. The mass attenuation coefficient (μ/ρ) was simulated using MCNP code and the simulated data were compared with WinXcom data. The radiation shielding results showed that the different concentrations of La2O3 for the La2O3–B2O3 glass system have affected the μ/ρ of the glasses. Moreover, the sample with 35 mol% of La2O3 has higher μ/ρ compared with the rest of specimens especially at 0.347 MeV. The effective atomic number (Zeff) was also calculated and the highest Zeff values at all selected energies were for the sample with 35 mol% of La2O3, whereas the lowest Zeff were for the sample corresponding to 15 mol% of La2O3, which was 18.86 and 12.31 at 0.347 MeV respectively. The mean free path at 0.347 MeV and 0.511 MeV is very low for 35 mol% of La2O3 (1.88 and 2.70 cm respectively), which indicates that the sample with composition 35La2O3–65B2O3 can be used as effective and transparent photon shieling materials at low energy.

This work investigated the radiation attenuation characteristics of three series of tellurite glass systems with the following compositions: 30PbO-10ZnO-xTeO2-(60-x)B2O3 where x = 10, 30, 40, 50 and 60 mol%, xBaO–xB2O3–(100-2x)TeO2 with x = 15–40 mol% and 50ZnO–(50-x)P2O5–xTeO2, where x = 0, 10, .40 mol%. The results revealed that the attenuation parameters in all the samples decrease with increase in the energy, which implied that all the samples have better interaction with gamma photons at low energies and thus higher photon attenuating efficiency. From the three systems, the samples coded as PbZnBTe60, BaBTe70 and ZnPTe40 have the lowest half value layer values and accordingly have superior photon attenuation efficacy. The maximum effective atomic number values were found for energy less than 0.1 MeV particularly near the K-edges absorption of the heavy atomic number elements such as Te, Ba and Pb. At the lowest energy, the Zeff values are found in the range of 62.33–66.25, 49.43–50.81 and 24.99–35.83 for series 1–3 respectively. Also, we found that the density of the glass remarkably affects the photon attenuation ability of the selected glasses. The mean free path results showed that the PbO-ZnO-TeO2-B2O3 glass system has better radiation shielding efficiency than the glass samples in series 2 and 3. Keywords: Tellurite glasses, Gamma radiation, Shielding, Effective atomic number

Transparent heavy metal oxide glasses are becoming increasingly important because of their effectiveness in reducing unwanted occupational and public radiation exposure in the medical settings; and for the clear view it offers when properly used during the construction of diagnostic radiology facilities, mobile shields and eye wears. WinXCom computer program was used to determine the mass attenuation coefficients of the studied glass systems; while other shielding parameters were determined by using appropriate equations. All these shielding parameters were determined at 20 keV, 30 keV, 40 keV and 60 keV; these are the average energies of photons commonly used in diagnostic radiology. The outcome of this work shows that increment in Bi2O3 led to better MAC and HVL at 20 and 30 keV while increment in TeO2 led to better MAC and HVL at 40 and 60 keV B1, B3 and B4 showed different improved shielding properties at 20, 40 and 60 keV zBi2O3–30B2O3-(70-z) TeO2 glass system showed better shielding qualities when compared with commonly used materials in diagnostic radiology.

In the present study, series of 20BaO-10SrO-30TeO2-(40-x)B2O3-xMoO3 where (x= 0, 5, 10, & 15 mol%) was synthesized via standard melt quench technique. The XRD results affirm the amorphous nature for all glasses, while the FTIR confirms the functional group's existence for TeO2 and B2O3. Various parameters were calculated to define the physical features of the glass samples, like molar volume, density, packing density, Poisson's ratio, oxygen packing density, and oxygen molar volume. The shielding features like mass attenuation coefficient, mean free path, equivalent atomic number, half-value layer, and tenth value layer, specific gamma-ray, gamma dose rate, the specific absorbed fraction of the energy, gamma transmission factor, removal cross-section for fas neutron ( ∑ R ) were computed and determined theoretically by using Phy-X. The addition of MoO3 instead of B2O3 in glass samples improves all the structural and shielding features, indicating that glass materials can be used as a good radiation shielding absorber.

The influence of 0.25–30 kGy γ doses on the 10BaO–20ZnO–20LiF-49.3B2O3-0.7Er2O3 glass was analyzed through the density, optical absorption, thermo-, and photo luminescence. With a successive increase in the dose, the density of the glass increased, confirming radiation-induced compaction. The color of the glass deepened progressively with the increase in the γ dose, leading to the enhancement in the optical absorption. A continuous fall in the bandgap and an increase in the Urbach energy was also observed. The rise in the electron density with dose, caused a gradual upsurge in the covalency around the Er3+ ions, as inferred from the bonding parameter (δ), and the Judd-Ofelt parameters (Ω2, Ω4, Ω6). The defects produced in the glass because of irradiation were evaluated using the trap parameters deduced from the Computerized Glow Curve Deconvolution and Chen’s peak shape methods. The 30 kGy irradiated glass contained deeper traps when compared to the 0.25 kGy irradiated glass. The excitation spectrum recorded by monitoring the emission at 550 nm revealed the spectral transitions originating from the ground state 4 I15/2 of the Er3+ ion to 4 G9/2, 4 G11/2, ( 2 G,4 F)9/2, 4 F5/2, and 4 F7/2 excited states, among which the 4 I15/2 → 4 G11/2 transition at 379 nm was very intense. In the emission spectra, one violet ( 2 H9/ 2→4 I15/2) and two green emissions ( 2 H11/2→4 I15/2 and 4 S3/2→4 I15/2) were detected out of which the 4 S3/2→4 I15/2 transition was the most prominent. The decrement in the intensity of this emission with dose was attributed to the radiation-induced quenching. The laser performance parameters computed by the Fuchtbauer-Ladenburg theory validated the emission quality of the irradiated glasses. The quantum efficiency did not fall below 60% for all the doses. The color coordinates were clustered in the green region and showed not much variation with dose. The present study manifests the remarkable radiation hardness of the titled glass as a green emission device and laser.

A new glass system with a chemical formula (60-x) B2O3+20Bi2O3 +20Li2O+ xSm2O3: x = 0, 1.25, 2.5, 3.75 and 5 wt% was synthesized using the solid-state conventional approach. The density of the newly fabricated glasses was determined using the Archimedes method. The glasses’ structure was studied utilizing the X-ray diffraction spectroscopy. Moreover, some of the most effective optical features such as the refractive index (n), energy gap (Eg), and Urbach energy (Eu) were determined based on the absorbance obtained from the UV-visible spectrum. Furthermore, the radiation shielding capacity of the newly fabricated samples was assessed utilizing the Monte Carlo Modeling (MCNP 5) code and Phy-X/PSD software. The calculated mass attenuation coefficient (MAC) values at 0.015 MeV were observed to increase from 21.893 to 25.570 cm2 g−1 for glasses BBLS1 and BBLS5 respectively. Simulations demonstrated that the MAC of the fabricated glasses enhanced with the insertion of the Sm2O3 contents. Besides, the buildup factors (EBF and EABD) were calculated using the program Phy-X/PSD. The removal cross-section ƩR for the fast neutrons was theoretically calculated. The calculated results showed the ƩR varied in the range between 0.170 and 0.241 cm-1 for glasses BBLS1 and BBLS5 respectively. The recorded results depict that the insertion of Sm2O3 enhances the optical, gamma-ray, and neutron shielding capacities.

The effect of Eu3+ ions on the linear and radiation shielding factors of zinc-borate tellurite glass doped with different contents of Eu2O3 with the form (25-x)ZnO–24B2O3–51TeO2-xEu2O3: x = 0 (E1), 0.5 (E2), 1 (E3), and 3 (E4) mol% have been investigated. The linear refractive index of the E1-E4 glasses varied from 2.48 to 2.54. The (Rmolar) increased from 20.809 (cm3/mol) for E1 glass to 21.040 (cm3/mol) for E4 glass, while the (Rloss) increased from 0.180 to 0.189. The (Mcriterion) varied from 0.279 to 0.268 for the investigated E1-E4 glasses. The (estatic) varies from 6.150 to 6.451, while the (χ*) varied from 0.724 to 0.683. The mass attenuation coefficient (μ/ρ) was calculated via Phy-X/PSD program. At 0.284 MeV, the μ/ρ changes from 0.151 to 0.159 cm2/g, whereas, at 1.33 MeV, the μ/ρ increases from 0.0504 to 0.0506 cm2/g. Therefore, the (μ/ρ) obeys the trend: (μ/ρ)E1 (HVL)E2 > (HVL)E3 > (HVL)E4. Therefore, the increasing of Eu3+ ions in the investigated zinc-borate tellurite glasses leads to enhance of their linear optical and gamma-ray shielding factors. In addition, the E4 (3 mol% Eu2O3) glass sample owns better gamma ray's absorption properties compared with the rest of the investigated glasses intensively utilized in the protection against harmful gamma radiations.

A novel glass system consists of six glasses was fabricated using melt quenching process according the chemical formula (60-x) B2O3+20Na2O2+20Bi2O3 +xWO3: x = 0, 1, 2, 3, 4 and 5 wt%. Archimedes method was used to determine the density and molar volume of the fabricated glasses. Moreover, the X-ray diffraction technique was used to show the variation of the amorphous phase with the addition of WO3 contents for the fabricated glasses. The optical features such as the refractive index (n), energy gap (Eg), distribution energy (Ed) and oscillation energy (Eo) were calculated based on the absorbance obtained from the UV-visible spectrum. The electromagnetic radiation (gamma ray) shielding capacity was evaluated using Monte Carlo simulation (MCNP 5) code in addition to Phy-X program. The results showed that the highest linear attenuation coefficient (LAC) occurred at 0.015 MeV and increased from 99.532 to 138.656 cm−1 for glasses coded as W 1 and W 6 respectively. The obtained results showed an enhancement of gamma ray shielding capacity with the addition of WO3 (wt%) to the fabricated glasses. Based on the estimated LAC, other shielding properties were calculated such as the glass half value layer (HVL), mean free path (MFP) and effective atomic number (Zeff). Finally, the ability of the fabricated glasses to resist the charged particles (alpha and proton) and uncharged neutrons were also estimated using SRIM program and theoretical calculation. The obtained results refer that the insertion of WO3 contents improves the shielding capacity for alpha and protons while it reduces the effective removal cross section of the fabricated glasses.

Experimental measurements and Monte Carlo simulation were applied to simulate the mass attenuation coefficient (MAC) for five various rock samples collected from southwestern Sinai, Egypt. Also, for the same rocks we determined the MAC and exposure buildup factors (EBF and EABF) theoretically using Phy-X/PSD software. The results show that there is adequate agreement between experimental and simulated results as well as with the Phy-X/PSD data. The linear attenuation coefficient (μ) decreases as the photon energy increases. The decrease is dramatically steep for energies bellow 0.3445 MeV and then gradually decreases with further increasing in the energy. Basalt-2 has slightly higher μ than basalt-1 and both rocks have higher μ than limestone (Dike), Basalt sill, and Rhyolite. We also calculated the effective atomic number (Zeff) for the investigated rocks and the Zeff values are in the range of 18.80–23.68, 18.52–23.57, 13.98–20.49, 19.15–23.89 and 22.32–26.68 for baslat-1, basalt-2, dike, basalt-sill and rhyolite respectively. The result showed that basalt-2 possesses the lowest half value layer at all energies followed by basalt-1. The radiation protection efficiency (RPE) at 122 keV is found to be in the range of 34.295–38.982%, while at 662 keV in the range of 17.402–22.886. The obtained results of EBF and EABF showed that limestone (Dike) possess the highest EBF and EABF while samples Basalt-1 and Basalt-2 possess the lowest EBF and EABF among the studied rocks.

A series of six tungsten-based bismuth borate glasses with a xWO3- 20 Bi2O3- 20 Na2O2- (60-x) B2O3), 0≤ x ≤ 5 wt% chemical composition were synthesized by using the solid-state conventional method. The structures of the fabricated samples were studied with X-ray diffraction analysis. Optical features such as the energy gap (Eg), Urbach energy (Eu), steepness parameter (S), refractive index (n) and Fermi level energy (EF) were measured for the fabricated glasses with a UV–Vis–NIR spectrophotometer. Furthermore, a Monte Carlo simulation code (MCNP-5) was applied to estimate the gamma ray mass attenuation coefficient (MAC) for the fabricated glasses. The simulated data showed that the insertion of WO3 increases the MACs of the fabricated samples: the highest and lowest MACs were obtained for the W6 and W1 glasses, respectively. Then, the simulated MAC was used to calculate the mean free path (MFP) for all the fabricated glasses. The thinnest MFP was achieved by W6 (increasing from 0.007 to 70,560 between 0.015 and 15 MeV, respectively), while the thickest MFP was achieved by W1 (increasing from 0.0100 to 8.975 between 0.015 and 15 MeV, respectively). Moreover, new Phy-x/PD software was used to calculate MAC, MFP, equivalent atomic number (Zeq) and the exposure and energy absorption buildup factors (EBF and EABF). The simulated and calculated results showed that adding WO3 enhances the shielding properties of the synthesized glass.

In this work, we reported the gamma ray shielding factors for barium phosphate glasses with composition yCaF2–(50−y)BaO–50P2O5 (y = 0, 2, 4, 6, 8 and 10 mol%). The Phy-X/PSD software has been used to report the attenuation and penetration factors for this glass system at different energies. The linear attenuation coefficient (LAC) values are found to reduce exponentially with increasing the energy and they range from 0.176 to 0.496 cm−1 (for CaBaP1) and 0.184–0.548 cm−1 (for CaBaP6). It was found that the addition of barium oxide (BaO) causes an increase in the LAC values from 0.697 to 0.787 cm−1 at 0.284 MeV, and from 0.259 to 0.273 cm−1 at 0.662 MeV. The effective atomic number (Zeff) results revealed the higher photons interaction possibility at the higher BaO content. The maximum Zeff is reported at 0.284 MeV and equal to 18.33 for CaBaP1and 20.15 for CaBaP6. Phy-X/PSD program has been used to find the half value layer (HVL) for the glasses under evaluation between 0.284 and 1.33 MeV. The HVL results showed that more gamma rays are being shielded at 0.284 MeV, whereas the possibility of photon shielding is decreased with the increasing of the energy. The tenth value layer (TVL) values were decreased with increase in BaO concentrations and increased with increase in the energy. CaBaP6 has the minimum TVL (4.206 cm at 0.284 MeV, 8.445 cm at 0.662 MeV and 12.252 cm at 1.275 MeV).

A theoretical model discussing the environmental factors (EFs) effect of exposure time on genes, which leads to human diseases, is presented using multi-logistic model. The advantages and limitations of this model are discussed in terms of its usefulness for simulating genetic samples. It has been shown that EFs affect genes with the same degree both at high exposure level, low exposure time and at low exposure level, high exposure time.