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Thermoluminescence and optical characteristics of lithium potassium borate glass for radiation therapy dose measurement

Alajerami, Yasser S. M. (2014) Thermoluminescence and optical characteristics of lithium potassium borate glass for radiation therapy dose measurement. PhD thesis, Universiti Teknologi Malaysia, Faculty of Science.

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Abstract

Radiosensitive glasses of lithium potassium borate (LKB) co-doped with CuO-MgO then with TiO2-MgO were prepared using melt-quenching technique. Present studies were carried out, seeking to improve upon the thermoluminescence (TL) signal of such glass systems. The overall aim of this thesis was to develop a radiosensitive glass that is suitable for thermoluminescence dosimetry (TLD). A glow curve with single prominent peak was produced at ~220 oC as a result of dopant activation (CuO/TiO2). An enhancement of about three times was shown as a result of adding MgO as a co-dopant activator (LKB: 0.1Cu, 0.1Mg and LKB: 0.5Ti, 0.25Mg- mol%). This enhancement was attributed to the ability of magnesium to create extra traps and consequently energy transfer to monovalent Cu+ and Ti3+ ions. A charge imbalance was predicted in the glass host by the addition of alkaline (Mg2+). Both LKB:Cu,Mg and LKB:Ti,Mg have low Z material (Zeff = 8.55 and 8.89, respectively), good reproducibility and low fading. The prepared glass showed 15 times less sensitive than that of LiF:Mg,Ti (TLD-100), but a promising dose response linearity was achieved over a long span of irradiation doses (up to 103 Gy). The trap parameters, including the order of kinetics (b), activation energy (E) and frequency factor (s) associated with LKB:Cu,Mg were also determined. Furthermore, a TolAnal software was used for glow curve deconvolution and analysis for the created peaks. The photoluminescence spectra (emission and excitation) for the prepared samples were studied. As new mixtures, a series of glass characterization and physical properties were discussed. The achieved results promise the use of these compositions in different dosimetric applications, particularly in medical dosimetry and high dose monitoring.

Item Type:Thesis (PhD)
Additional Information:Thesis (Ph.D (Fizik)) - Universiti Teknologi Malaysia, 2014; Supervisors : Dr. Suhairul Hashim, Prof. Dr. Ahmad Termizi Ramli, Assoc. Prof. Dr. Wan Muhamad Saridan Wan Hassan
Subjects:Q Science > QC Physics
Divisions:Science
ID Code:78094
Deposited By: Fazli Masari
Deposited On:23 Jul 2018 13:34
Last Modified:23 Jul 2018 13:34

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