Optimization of thermoluminescence response of copper doped zinc lithium borate glass co-doped with Na2O

Establishing the basic procedures that will influence the enhancement of the TL yield of a phosphor is paramount in the issue of dosimetry. Melt quenching method was adopted in synthesizing lithium borate glass modified with ZnO, doped with CuO and codoped with Na2O. The structural and optical properties of zinc lithium borate and some TL properties of copper doped zinc lithium borate were reported in our previous works. The amorphous nature of the prepared glasses was confirmed by x-ray diffraction analysis (XRD). Physical properties of the glass were obtained via Archimedes principle. The copper doped zinc lithium borate was co-doped with different concentration of Na2O (0.025 mol % to 0.1 mol %). The glasses were irradiated with 4 Gy dose of gamma rays using 60Co gamma cell. The highest TL response was recorded against 0.05 mol% concentration of Na2O. The best settings for TLD reading of the proposed TLD were determined. The optimal annealing temperature and time for this composition was found to be 300 oC and 50 min respectively. The best heating rate at which the new TLD can be readout was 3 oC S-1

Glow curve analysis of glassy system dosimeter subjected to photon and electron irradiations

The current paper illustrates glow curve analysis of newly developed Borate glass dosimeters. A series of dosimetric properties including dose response for photons and electrons, energy response, optical fading, and precision were determined. Glow curve deconvolution based on the general order kinetics equation was applied to extract the trapping parameters. Excellent fitting was obtained with the superposition of three-second order glow peaks. The quality of fitting was monitored through the r2 value which is always in excess of 0.9998. Thermoluminescence (TL) measurements showed that the material exhibits good linear dose–response over the delivered range of absorbed dose from 0.5 to 4 Gy for photons and electrons irradiation with low energy dependence. The material exhibits large signal loss when exposed to direct sunlight and moderate signal loss when exposed to fluorescent light. Therefore, it is recommended to use the current dosimeters indoor and to avoid prolonged direct exposure to fluorescent light. This combination of properties makes the material suitable for radiation dosimetry

Investigation of photon, neutron and proton shielding features of H3BO3–ZnO–Na2O–BaO glass system

The current study aims to explore the shielding properties of multi-component borate-based glass series. Seven glass-samples with composition of (80-y)H3BO3–10ZnO–10Na2O–yBaO where (y = 0, 5, 10, 15, 20, 25 and 30 mol.%) were synthesized by melt-quench method. Various shielding features for photons, neutrons, and protons were determined for all prepared samples. XCOM, Phy-X program, and SRIM code were performed to determine and explain several shielding properties such as equivalent atomic number, exposure build-up factor, specific gamma-ray constants, effective removal cross-section (SR), neutron scattering and absorption, Mass Stopping Power (MSP) and projected range. The energy ranges for photons and protons were 0.015–15 MeV and 0.01–10 MeV, respectively. The mass attenuation coefficient (µ/?) was also determined experimentally by utilizing two radioactive sources (166Ho and 137Cs). Consistent results were obtained between experimental and XCOM values in determining µ/? of the new glasses. The addition of BaO to the glass matrix led to enhance the µ/? and specific gamma-ray constants of glasses. Whereas the remarkable reductions in SR, MSP, and projected range values were reported with increasing BaO concentrations. The acquired results nominate the use of these glasses in different radiation shielding purposes

Optical and erbium ion concentration correlation in lithium magnesium borate glass

Tuning the optical response of lithium magnesium borate glass via controlled doping of rare earth ions is the key issue in photonic devices. Glasses with composition 30Li2O-(60-x)B2O3-10MgO-xEr2O3, where 0 ≤ x ≤ 1 are prepared by conventional melt-quenching technique. The X-ray diffraction (XRD) pattern confirms the amorphous nature of all samples. Fourier transform infrared (FTIR) spectra reveal the presence of BO3 and BO4 local structure unit. The physical parameters, such as the direct and indirect optical energy band gap, oscillator strength, refractive index, ion concentration, Polaron radius, molar volume and inter-nuclear distance are calculated and analyzed. The room temperature UV-vis-IR spectra comprised of ten absorption bands centered at 1523, 973, 796, 650, 550, 522, 486, 447, 406, 373 nm corresponding to the transitions from the ground state to 4I13/2, 4I11/2, 4I9/2, 4F9/2, 4S3/2, 2H11/2, 4F7/2, (4F5/2 + 4F3/2), 2G(1)9/2, 4G11/2 excited states, respectively. The peak evidenced at 522 nm is due to hypersensitive transition. The up-conversion spectra exhibits three emission peaks centered at 509, 547 and 656 nm. All the emission bands (green and red) at 0.5 mol% of Er3+ shows a significant enhancement in the intensity attributed to the energy transfer from Mg2+ to the Er3+ ion. Our results suggest that these glasses can be nominated for solid state lasers

Luminescence features of dysprosium and phosphorus oxide co-doped lithium magnesium borate glass

Lithium magnesium borate (LMB) glass system co-doped with the oxides of dysprosium (Dy2O3) and phosphorus (P2O5) were synthesized using melt-quenching method. Prepared samples were characterized using various techniques to determine the effects of co-dopants concentration variation on their thermoluminescence (TL) and photoluminescence (PL) properties. TL glow curves of LMB:0.5Dy sample revealed a single prominent peak at Tm=190 °C, where TL intensity was enhanced by a factor of 2.5 with the increase of P2O5 concentration up to 1 mol%. This enhancement was accompanied by a shift in Tm towards higher temperature. Good linearity in the range of 1–100 Gy with linear correlation coefficient of 0.998 was achieved. PL spectra displayed two significant peaks centred at 481 nm and 573 nm. These attractive luminescence features of the proposed glass system may be useful for the development of radiation dosimetry

Impact of Eu3+ ions on physical and optical properties of Li2O-Na2O-B2O3 glass

The lithium sodium borate glasses doped with Eu3+ ion are prepared using melt quenching technique, their structural and optical properties have been evaluated. The density of prepared glasses exhibits an inverse behavior to the molar volume ranging from 2.26 g/cm3 to 2.43 g/cm3 and 26.95 cm3/mol to 26.20 cm3/mol, respectively. The absence of sharp peaks in XRD patterns confirms the amorphous nature of the prepared glasses. The absorption spectra yield four transitions centered at 391 nm (7F0→5L6), 463 nm (7F0→5D2), 531 nm (7F0→5D1), and 582 nm (7F0→5D0). The most intense red luminescence is observed at 612 nm corresponding to 5D0→7F2 transition under 390 nm laser excitations

The optical properties of trivalent rare earth ions (Er3+) doped borotellurite glass

Erbium doped borotellurite glass has been fabricated by using conventional melting method. The density and molar volume have been calculated and analyzed while their optical properties were studied by measuring the optical absorption and luminescence spectra at room temperature. From the XRD results, since the patterns do not exhibit any diffraction line thus it confirms their amorphous nature. It is found that the density of the glass samples increased and the molar volume decreased with respect to Er ions content. Meanwhile, the upconversion emissions centered at 487, 523, 558, 642, 695 and 782 nm have been observed under the 650 nm excitation in the 4F9/2 level. Some other results will be analysed and discussed in details

Dosimetric features and kinetic parameters of a glass system dosimeter

Lithium borate (LB) glasses doped with dysprosium oxide (Dy2O3) have been prepared by utilizing the conventional melt-quench technique. The prepared glass samples were exposed to 60Co to check their dosimetric features and kinetic parameters. These features involve glow curves, annealing, fading, reproducibility, minimum detectable dose (MDD), and effective atomic number (Zeff). Kinetic parameters including the frequency factors and activation energy were also determined using three methods (glow curve analysis, initial rise, and peak shape method) and were thoroughly interpreted. In addition, the incorporation of Dy impurities into LB enhanced the thermoluminescence sensitivity ~170 times. The glow from LB:Dy appeared as a single prominent peak at 190°C. The best annealing proceeding was obtained at 300°C for 30 min. Signal stability was reported for a period of 1 and 3 months with a reduction of 26% and 31%, respectively. The proposed glass samples showed promising dosimeter properties that can be recommended for personal radiation monitoring

Natural environmental radioactivity and the corresponding health risk in Johor Bahru District, Johor, Malaysia

This study aims to obtain the baseline data on environmental terrestrial radiation and to assess the corresponding health risk in Johor Bahru District, Johor, Malaysia. The mean activity concentrations of 232Th, 226Ra and 40K were 119 ± 6, 51 ± 4 and 158 ± 21 Bq kg−1, respectively. Primordial radionuclide 232Th is the main contributor to gamma dose rate and the mean found to be 135 nGy h−1. Gross alpha and gross beta activity concentrations in water were 0.012 ± 0.003 and 0.234 ± 0.018 Bq L−1, respectively