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Thermoluminescence (TL) response of newly synthetic silicon-activated Ca9AlP7O28 nanophosphor doped with different concentrations (0.3–10 mol%) (abbreviated as CAP: Six) were prepared by the sol–gel method. The optimum concentration of Si ions for the best TL response was found to be 0.3 mol% (CAP: Si0.3), which was selected for subsequent dosimetric measurements. Phase purity and the crystal structure of the CAP: Si0.3 sample were identified and verified using X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis, where results obtained confirmed the successful synthetic method used in the preparation of the nanophosphor samples. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) mapping revealed the localization of constituent elements and indicated the homogeneous distribution of Si-ions as well as the feasibility of dopants in the herein sample. The dosimetric properties of the CAP: Si0.3 sample, including glow curve structure, reproducibility, repeatability, dose–response and fading effect, were extensively investigated. The gamma irradiated CAP: Si0.3 sample exhibited a simple glow curve of a single prominent peak centred at 222 ± 1.33°C with considerably high TL intensity (1.22 relative to MTS-700 TLD detector). The relative standard deviation (RSD) of peak areas of CAP: Si0.3 were 5.25 and 2.7% for reproducibility and repeatability studies, respectively. These values of RSD were <10%, so they were acceptable internationally. A good linear dose–response relationship was achieved over a dose range of up to 20 Gy with an excellent correlation coefficient of R2 = 0.9969 and a calibration factor of F = 51.75 × 107 a.u./Gy. Almost no fading was registered from the studied CAP: Si0.3 sample after irradiation. Zeff values were found to be in the range 11.62 to 11.61, which are closely related to that of natural bone (11.3 to 11.8). Minimum detectable dose of CAP: Si0.3 had a value of 11 μGy. The outstanding features of this herein-prepared sample make it a good TLD nanophosphor, very suitable for personnel and environmental dosimetry of γ-radiation within the studied dose range. [ABSTRACT FROM AUTHOR]

In this study, new PVC (polyvinyl chloride) polymers doped with different contents of basalt nanoparticles have been prepared. The PVC was mixed with concentrations (0, 5, 10, 15, 20, and 50 wt%) of basalt nanoparticles utilizing the casting method. The samples coded as PB0.0, PB5.0, PB10.0, PB15.0, PB20.0, and PB50.0. The density of the casted samples increased from 1.38 to 2.18 g/cm3 with increasing basalt nanoparticle concentrations. Scanning electron microscope (SEM) of the prepared samples showed a good dispersion with small basalt concentrations in the while some agglomerations were found with the highest basalt concentrations in the mixture. The values of the direct optical energy gap varied from 3.0 to 3.5 eV, while the refractive index values changed from 2.39 to 2.27. The gamma-ray shielding parameters were evaluated using the Phy-X/PSD software program as well as the MCNP – code. The most critical results showed that the linear-attenuation coefficient (μ) increased from 14.421 to 23.862 cm−1 (at 0.015 MeV), and from 0.030 to 0.048 cm−1 (at 15 MeV) for PB0.0 and PB50.0 samples, respectively. Moreover, the evaluation of other gamma - ray shielding characteristics showed an enhancement with the addition of the basalt nanoparticles. Besides, neutron cross section was also calculated, and results revealed that PB0.0 is 0.086 cm−1 and PB50.0 is 0.104 cm−1. Finally, the obtained results concluded that the γ -ray, and neutron shielding capacities were enhanced with the increase in basalt nanocomposites amount in the fabricated composites. • New polymeric materials based on PVC doped with basalt were prepared. • TEM proved that the used materials are Nano composites. • The radiation shielding capacity of the prepared samples has been investigated through Phy-X and MCNP code. • Optical band gap and refractive index were calculated. [ABSTRACT FROM AUTHOR]

Transparent thermoluminescent alumino-phosphate‑sodium glass system of 15Al 2 O 3 -35P 2 O 5 -25CaO-25Na 2 CO 3 (all in mol%) doped with different concentrations of SiO 2 were prepared by conventional melt quenching technique. X-ray diffraction (XRD) studies checked the amorphous nature of the prepared glass. Fourier Transform Infrared (FTIR) of the glass system was investigated to find the effect of SiO 2 -dopant concentrations on the absorption spectra in comparison with that of bulk sample (without dopants). Direct and indirect energy band gaps (E opt ) were determined and found to be in the range of 2.47–3.65 eV for m = ½ and 2.24–3.3 eV for m = 2. Refractive index (n) for each E opt value vary from 2.42 to 2.55 and from 2.32 to 2.63 for the direct and indirect transition, respectively. Urbach energy values of the newly prepared glasses are found to be from 0.57 to 0.98 eV. In addition, effect of UV exposure on thermoluminescence (TL) sensitivity was also examined for APCNSi 5 (contains 500 ppm SiO 2 concentration) and a linear response to dose was obtained, indicating that this type of glass is promising as a TL dosimeter within the UV range. [ABSTRACT FROM AUTHOR]

A study of photon attenuation and optical properties was performed for (20Bi2O3–60B2O3–(20-y)PbO–yTiO2), where y = 0.0, 1.0, 2.5, 5.0, 7.5, and 10.0 wt%) glassy system. UV–Vis absorption measurements for the glasses in the range of 90–1100 nm wavelengths have been recorded. Based on the absorption spectra, the band gap of optical energy for each glass sample has been evaluated using absorbance spectrum fitting ( E Optical ASF ) and derivative absorbance spectrum fitting ( E Optical DASF ) models and compared with those obtained by Tauc's method. E Optical ASF varies from 2.405 to 2.008 eV, while E Optical DASF takes values from 3.000 to 2.914 eV. Indeed, different optical parameters such as refractive index, molar polarizability, molar refractivity, metallization criterion, dielectric constants, optical transmission, reflection loss, band gap of optical energy-based metallization criterion, and refractive index-based metallization criterion have been evaluated. Moreover, several shielding parameters such as mass attenuation coefficients, linear attenuation coefficient, half-value layer, tenth-value layer, mean free path, effective atomic numbers, and effective electron densities have been evaluated using the WinXCOM program in the energy range 0.010–15 MeV for the prepared glass system. At 1 MeV photon energy, the half value layer for the investigated glasses takes values from 2.03 to 2.15 cm. The results showed that the studied glasses can be applied as candidate for radiation shielding materials according to their coefficients of mass attenuation and HVL values, especially the composition with the highest value of PbO (20 wt%), which introduced good nuclear radiation shielding. [ABSTRACT FROM AUTHOR]