Investigation of luminescence properties of rare earth elements and transition metals doped Si and Ca based materials

Thermally stimulated luminescence materials have been an important tool in measuring the ionizing radiation dose. Due to some advantages of the thermoluminescence dosimeters in the field of personal, clinical, environmental and space applications, many studies have been carried out to produce more efficient TL dosimeters in recent years. Determination of luminescence properties and dosimetric characteristics of newly systhesized TL materials are very important in order to obtain correct results in dose assessment studies. In this thesis, luminescence properties and dosimetric characteristics of recently synthesized CaCO3:Tm, CaB4O7:Mn, CaSO4:Cu,Tm and CaSiO4:Cu materials have been investigated using beta, gamma, X-ray, UVB (312 nm) and UVC (254 nm) radiation sources. Determination of the trap parameter values of a dosimetric material such as activation energy (E), frequency factor (s) and kinetic order (b) enables one to gather more information about the traps in the lattice structure of the material. In this study, variable heating rate method, isothermal decay method and peak shape methods were used for determination of trap parameters of the dosimetric materials used. In addition, some dosimetric characteristics such as sensitivity, dose response, fading, PTTL and stability of dosimetric materials were investigated. In addition, emission spectra and crystal structure of newly synthesized dosimetric materials were investigated by Radioluminescence, Photoluminescence and X-ray diffraction techniques. The obtained results from this study showed that CaB4O7:Mn(1%) and CaSO4:Cu,Tm dosimetric materials have high sensitivity and stability, which makes them potential materials in dose measurements (0-20Gy) such as space, medical, personal dosimetry and dating. In addition, the results of studies showed that the CaCO3:Tm, CaB4O7:Mn (3%) and CaSiO4:Cu materials have very high sensitivity and stability, which make them potential dosimetry in low dose applications (~1-10µGy) such as personal dosimetry and dating. Keywords: TLD, CaCO3:Tm, CaB4O7:Mn, CaSO4:Cu,Tm, CaSiO4:Cu