The analysis of thermoluminescent glow peaks of CaF2 : Dy (TLD-200) after ß-irradiation

Variable dose (VD), Tm-Tstop, initial rise (IR), variable heating rate (VHR), peak shape (PS) and computerized glow curve deconvolution (CGCD) methods are used to determine the number of peaks, the order of kinetics (b), the activation energy (Ea) and attempt-to-escape frequency (s) associated with the glow peaks in CaF2 : Dy (TLD-200) after ß-irradiation between the dose level 0.1 and 110 Gy. The Tm-Tstop procedure indicates that the glow curve of this crystal consists of at least nine glow peaks. The dose variation experiment indicates that seven of them, namely peaks 1-6 and 8, are of first-order kinetics and peaks 7 and 9 are of general-order kinetics. However, the Tm-Tstop procedure and the CGCD method have indicated that peak 6 has general-order kinetics too. The activation energy found with the IR, VHR, PS and CGCD methods for peak 4 yield very close values. For all other peaks, there is no agreement between the results of all the applied methods. This work also indicates that the post-irradiation annealing and the heating rate have pronounced effects on the evaluated kinetic parameters of all glow peaks

Thermoluminescence glow curve analysis of natural onyx from Turkey

In this study, the thermoluminesce (TL) properties of natural onyx were determined after ß-irradiation (90Sr/90Y) at room temperature. The effect of the additive dose and variable heating rate for TL glow peaks of the sample were investigated. Computerized glow curve deconvolution (CGCD) methods were used to determine the number of peaks and kinetic parameters related to the TL glow peaks in natural onyx from Turkey. It was also determined kinetic parameters of onyx by means of the variable heating rate (VHR) method. The sample was exposed to ß-irradiation between 2.4Gy and 2.457kGy. The CGCD methods showed that the glow curve of sample is the superposition of at least six first order components which were ascribed as P1-P6. The dose responses of some peaks have similar patterns and they follow linearity. The effect of heating rates on the response of dosimetric glow peaks of sample was studied. The maximum TL peak intensities of glow curve are decreasing with increasing heating rate and maximum TL peak intensities at 1°C/s drops to 20% of the initial value when the sample is read at 6°C/s. © 2014 Elsevier Ltd.Firat University Scientific Research Projects Management Unit: İMYO2012BAP3 National Council for Scientific ResearchThe authors are grateful for the financial support from the Scientific Research Projects of Cukurova University İMYO2012BAP3 project. The authors are also grateful to Gaziantep University and Turkish Scientific and Technology Research Council (TUBITAK)