Synthesis, Characterization And Evaluation Of Zinc Doped MgB4O7 Based Glass Thermoluminescence Dosimeter For Radiotherapy And Industrial Applications
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Date
2018-04
Authors
Bakhsh, Muhammad
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
The present study is aimed to develop a highly sensitive and tissue equivalent thermoluminescent dosimeter for quality assurance in modern radiotherapy techniques and industrial applications. Series of MgB4O7 glasses, of compositions X(MgO) - 100-X(B2O3) where 35 ≤ X ≤ 45 mol%, Magnesium Borate (MB), X(ZnO) - 35-X(MgO) - 65(B2O3) where 0.1 ≤ X ≤ 1 mol%, Zinc doped Magnesium Borate (MB:Zn) and X(Li2O) - 0.4(ZnO) - 35- X (MgO) - 65(B2O3) where 0.01 ≤ X ≤ 0.1 mol%, Lithium co-doped Zinc doped Magnesium Borate (MB:Zn, Li) are synthesized using conventional melt-quenching method. The amorphous nature of synthesized samples is analysed through X-ray diffraction (XRD) and further confirmed with Field Emission Scanning Electron Microscopy (FESEM). The selected glass compositions demonstrated good glass forming abilities, MgB4O7 glass, 0.56, MgB4O7:ZnO glass, 0.61 and MgB4O7:ZnO,Li2O glass, 0.56. Moreover, the synthesized glass series are found to have good glass stabilities, MgB4O7 glass, 1.73, MgB4O7:ZnO glass, 1.62 and MgB4O7:ZnO,Li2O glass, 0.76. The glow curve of MB glass with 35 mol% of MgO revealed a single prominent dosimetric peak at a maximum peak temperature (Tm) of 200 oC. An enhancement in TL response by a factor of 1.46, with a shift in dosimetric peak towards higher temperature at 240 oC, is observed with introduction of ZnO (0.4%) as a dopant in MB glass matrix forming MB:Zn. Further enhancement in TL response is observed by a factor of 1.16 with a shift in dosimetric peak towards higher temperature at 250 oC by adding Li2O as co-dopant in MB glass matrix forming MB:Zn,Li. MB:Zn,Li having nearly tissue equivalent effective atomic number, Zeff = 8.87, showed excellent linearity up to 5 kGy with higher TL response as compared to MB as well as MB:Zn. MB:Zn,Li has good signal stability with 10% fading over a period of two weeks for as compared to 15% for MB:Zn and 20% for MB.
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Keywords
Highly sensitive and tissue equivalent thermoluminescent dosimeter , quality assurance in modern radiotherapy techniques