Luminescence studies of various phosphors and clinical applications of newly developed BeO dosimeters

One of the purposes of this Ph.D. study is to investigate the characterization of Ce3+ and Gd3+ doped MgB4O7 powders produced by the solid-state synthesis technique. The effect of different dopant concentrations on the luminescence characteristics of MgB4O7 powders was studied. The phase composition and morphology analysis of the synthesized material were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence properties were examined by measuring the optically stimulated luminescence (OSL) decay signal, thermoluminescence (TL) and radioluminescence glow curve (RL) emission spectra,. Basic dosimetric characteristics such as linearity, reusability and fading were tested. Our findings showed a maximum luminescence efficiency when the synthesis of MgB4O7:Ce,Gd was carried out using contents of 0.1 wt% Ce3+ and 3 wt% Gd3+. All the studies of MgB4O7:Ce0.1%,Gd3% confirmed the phosphor suitability for radiation dosimetry. This Ph.D. study also aims to assess the feasibility of newly developed BeO-based ceramic pellets to be used in therapeutic dose regimes, comparing them to ionization chambers and Thermalox 995 BeO chips. The clinical measurements were performed in water-equivalent phantoms using 6 MV X-ray beams delivered by linear accelerators under different conditions of energies, dose rate, field size, depth, and incidence angle. The obtained results are sufficient to fulfill the requirements for a clinical dosimeter in radiotherapy.