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Development of BaO-containing radiation-shielding glass using natural dolomite as a raw-material component
(2027-01-01)
Cheewasukhanont, W.
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Kothan, S.
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Tungjai, M.
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Intachai, N.
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Ruangtaweep, Y.
This study investigates the incorporation of dolomite (CaMg(CO<inf>3</inf>)<inf>2</inf>) as a natural substitute for synthetic CaO in the fabrication of radiation shielding glass (RSG). Dolomite samples from Kanchanaburi, Thailand, were characterized using X-ray fluorescence (XRF) to determine their chemical composition, revealing CaO (76.59-79.84 wt%) and MgO (19.13-21.54 wt%) as the primary components. These dolomites were used to synthesize borosilicate-based host glasses, where density remained stable (∼2.5 g/cm3), ensuring structural integrity. Optical transmittance measurements showed an average 80% transparency in the visible range. To enhance radiation attenuation, BaO was incorporated into the glass matrix at varying concentrations (5-35 mol%). Increasing BaO content increased the density of the glass samples, which contributed to improved radiation attenuation performance. The radiation-shielding properties, predicted using WinXCom over a wide photon energy range and experimentally evaluated at 0.662 MeV, improved with increasing BaO content. The HVL, Pb-equivalent thickness, and EABF results further supported the enhanced attenuation performance of the developed glasses, indicating that higher BaO content reduced the contribution of scattered photons to absorbed energy buildup in the intermediate-energy region. In addition, preliminary glass-forming tests of the B4 composition demonstrated the feasibility of preparing a larger glass sheet under similar melting and annealing conditions, although further optimization is still required. These findings suggest that natural dolomite can serve as a useful raw-material component for developing BaO-containing radiation-shielding glass with balanced optical transparency, density, and attenuation performance.
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Ca co-doped CsI(Tl) crystal scintillator for γ- and X-ray detecting applications
(2025-01-01)
Tariwong, Y.
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Kim, H. J.
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Quang, Nguyen Duy
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Khan, Arshad
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Daniel, D. Joseph
The vertical Bridgman method is used for the growth of single-doped CsI(Tl) and CsI(Tl:Ca) crystals, which has been evaluated for feasible applications in X-ray imaging and radiation detection. The powder XRD technique study reveals a single-crystalline phase of the grown crystal. The emission spectra show a broad emission band with a maximum of 540 nm under X-ray excitation, along with the characteristic emissions that arose from the Tl+ intra-center transition. The scintillation qualities of the grown crystal were studied via the pulse height spectra, scintillation light yield, energy resolution, and scintillation decay time. Pulse shape discrimination (PSD) was investigated under γ-rays and α-particles excitation sources. Moreover, the X-ray imaging application was investigated by an X-ray synchrotron at the Synchrotron Light Research Institute to study the performance of the grown crystal. These preliminary investigations suggest that the grown CsI(Tl:Ca) crystal can be one of the promising crystals for γ- and X-ray detecting applications.
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Structural, optical, luminescence spectroscopy and radiation shielding properties of Eu3+:borophosphotellurite glasses
(2024-10-01)
Masthanaiah, E.
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Basavapoornima, Ch
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Lokanadham, R.
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Pecharapa, Wisanu
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Kaewkhao, J.
Recently much effort is being paid to study the rare earth ions in multi component glass formers as they exhibit high enhancement in the efficiency of luminescence properties. In this direction, the present study focuses on the preparation and analysis of novel glass batches with composition of (in mol %) BPTCZEu: 40B<inf>2</inf>O<inf>3</inf>+20P<inf>2</inf>O<inf>5</inf>+15TeO<inf>2</inf>+ 10CaO+(15−x)ZnO + xEu<inf>2</inf>O<inf>3</inf>, x = 0.1, 0.5, 1.0, 1.5, 2.0 and 2.5. The important spectroscopic techniques such as optical absorption, luminescence, excitation and decay curves are taken to analyse the BPTCZEu glasses. Luminescence spectrum of BPTCZEu comprise of emission from excited (5D<inf>0</inf>) to the lower multiplets (7F<inf>J</inf> (J = 0−4)), among these, 5D<inf>0</inf> → 7F<inf>2</inf> (red luminescence) at 612 nm found to be very intense. Judd−Ofelt characteristics, Ω<inf>2</inf>, Ω<inf>4</inf> and Ω<inf>6</inf>, were derived from different constraints. To know the site symmetry around Eu3+, the fluorescence intensity ratio of 5D<inf>0</inf> → 7F<inf>2</inf> vs. 5D<inf>0</inf> → 7F<inf>1</inf> were analysed. Exciting 7F<inf>0</inf> → 5L<inf>6</inf> and monitoring 5D<inf>0</inf> → 7F<inf>2</inf>, the lifetime of 5D<inf>0</inf> level is determined to be 2 ms which is independent of Eu3+ content. The colour coordinates for all the Eu3+ concentrations are estimated to fall in the reddish−orange region. Theoretical radiation shielding results showed that substituting Eu<inf>2</inf>O<inf>3</inf> for ZnO in the glasses lowers photon number that can pass via the material, enhancing the glass system's trend to shield high energy radiation. These stimulated results are compared with experimental measurements of mass attenuation coefficient with respect to energy up to 662 KeV using Cs−137 source. All these findings obtained from title glasses are compared and discussed with respect to reported Eu3+:glasses and no systematic variation has been noticed either with single, bi− or multi−component glass formers and therefore needs further systematic work to relate Eu−radiation−ligand interaction.
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Novel Tb3+ doped borophosphate glass scintillator for X-ray imaging
(2024-10-01)
Khrongchaiyaphum, F.
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Wantana, N.
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Kaewnuam, E.
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Pakawanit, P.
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Phoovasawat, C.
In this study, we introduce an efficient green-emitting material made from Tb3+ doped borophosphate scintillating glass for X-ray imaging. An influence of Tb<inf>2</inf>O<inf>3</inf> concentration on the physical, optical, luminescent, and scintillation properties of glasses were investigated. The glass density and refractive index increase, while the molar volume and Tb3+ inter-ionic distance decreases with Tb<inf>2</inf>O<inf>3</inf> addition. These glasses absorb the photons in range of UV, Vis, and NIR. The excitations by UV and X-ray on glasses causes the strong green emission centered around 545 nm by the 5D<inf>4</inf> → 7F<inf>5</inf> transition of Tb3+. The energy transfer from Gd3+ to Tb3+ was occurred in this emission. The glass doped with 4 mol% of Tb<inf>2</inf>O<inf>3</inf> demonstrates the highest emission intensity at 545 nm due to the concentration quenching. The decay time of glasses are in few milliseconds. The integral X-ray scintillation efficiency of 4 mol% doped glass is 52% compared to that of BGO crystal. Additionally, this glass was proceeded in the X-ray imaging and yielded the image with satisfied resolution, characteristics and MTF values, compared to that obtained from YAG:Ce crystal. The developed glass has a potential for X-ray imaging applications, especially in the medical imaging, flaw detection, and security inspection.
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Eu2O3 doped silicoborate glasses for scintillation material application: Luminescence ability and X-ray imaging
(2023-12-01)
Intachai, N.
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Kothan, S.
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Wantana, N.
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Kaewjaeng, S.
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Pakawanit, P.
The glass samples were prepared by melt quenching method and changing Eu<inf>2</inf>O<inf>3</inf> concentrations following component of xEu<inf>2</inf>O<inf>3</inf> - 40Na<inf>2</inf>O - 7.5Gd<inf>2</inf>O<inf>3</inf> - 5SiO<inf>2</inf> - (47.5-x)B<inf>2</inf>O<inf>3</inf> (x = 0, 1, 2, 3 mol %). Density and molar volume tend to increase with increasing Eu<inf>2</inf>O<inf>3</inf> concentrations, corresponding to the larger non-bridging oxygen. Fourier transform infrared spectra (FTIR) results point out that the majority BO<inf>3</inf> borate group. The absorption spectra were represented in the length of UV-Vis and NIR region. The phonon energy of 3Eu:7.5Gd was 1280.54 cm−1, related to the borate glass host. The photoluminescence and X-ray-induced luminescence spectra of 3Eu:7.5Gd glass showed similar highest intensity at 613 nm (5D<inf>0</inf>→7F<inf>2</inf>). The photoluminescence quantum yield (PLQY) of 3Eu:7.5Gd glass shows the highest value at 85.70 %. The scintillation efficiency of 3Eu:7.5Gd glass was 17.51 % of bismuth germanate (BGO) crystal. The decay time owing to Eu3+ emission is 2.054 ms for 2Eu:7.5Gd glass. The highest energy transfer efficiency was 2 mol % of Eu<inf>2</inf>O<inf>3</inf> concentrations (η<inf>ET</inf> = 70 %). The CIE chromaticity coordinates of the glasses are placed in the reddish-orange area (0.65, 0.35). The spatial resolution of X-ray imaging study was 10 lp/mm. These results suggest that 3 mol % of Eu<inf>2</inf>O<inf>3</inf> doped silicoborate glass is capable of being a scintillator applied in the X-ray imaging system.

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