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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]

The transparent thermoluminescent aluminum oxide-based glass of 15Al2O3-35P2O5-25CaO-25Na2CO3, abbreviated as APCN (all in mol%) doped with different concentrations of SiO2 from 0.0-500 ppm was prepared using a conventional melt-quenching technique. The TL sensitivities of the prepared glasses were investigated at 3 Gy γ-dose using a 60Co source and measured at a heating rate 10 C/sec. The highest TL intensity of the material doped with SiO2 was found at a concentration of 500 ppm (APCNSi5). Deconvolution of the glow curve from APCNSi5 resulted in four peaks at about 161, 194, 237 and 293 C with a Figure Of Merit (FOM) of 1.28%. The APCNSi5 specimen had the best dosimetric properties when compared with the other samples. Reproducibility, repeatability, dose-response curve and fading effect were checked for peak 3, which appeared at about 237 C. The results displayed that the APCNSi5 glass system was a low-Z material (Zeff ≈ 10), and had good reproducibility and good repeatability. Peak 3 showed good linearity over a dose range up to 20 Gy (R2 = 0.999) and sublinearity behaviour was found. The signal from APCNSi5 faded by about 11% after 2 days post irradiation, therefore it showed almost no significant loss. Such properties make the newly prepared glasses suitable for and highly recommended for use in γ-dosimeters. Copyright © 2016 John Wiley & Sons, Ltd. [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]

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]

In this study, the effect of high γ-doses on the track parameters, structure as well as optical properties of pristine and γ-irradiation CR-39 nuclear track detector (NTD) were investigated. CR-39 detectors were exposed to γ-doses from 50 up to 500 kGy and then irradiated by fission ions (F.F) of fluence from 252 CF source. The track diameter (D), bulk etch rate (V B ), etch induction time (EIT), cut-off or saturated time (t cut-off ) for saturated diameters and projected track length (L o ) of normally and inclined incident fission tracks were estimated for different removal layers (h). A linear relationship between D and γ-doses (D γ ) up to 500 k Gy was obtained. The V B for pristine and for γ-irradiated CR-39 was determined. A linear behaviour of V B was obtained up to 300 kGy. Etch induction time (EIT) and saturated time (t cut-off ) of pristine and γ-irradiated detectors for normal and inclined fission ions tracks were evaluated respectively up to 500 kGy. Each EIT and t cut-off decreased exponentially fast with increasing γ-doses but the inclined incidence appeared earlier than normal case. Pristine and γ-irradiated CR-39 detectors were examined using FTIR and UV-Vis spectrophotometer. From this study, a linear relation of band gap energies (E gap ) as a function of γ-doses, Dγ, was obtained. The value of (E gap ) decreased when increasing γ-doses for direct and indirect transitions, respectively. In addition, a systematic increase of Urbach energy (E U ) was recorded together with the D γ increase. Moreover, a linear behavior of the refractive index (n) along with γ-irradiated CR-39 plastic detector was observed via direct and indirect methods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)