Abstract
Abstract Thermoluminescence (TL)is a well-known phenomenon amongst thermally stimulated processes and has been largely recognized as an ideal technique for obtaining information of the distribution of naturally occurring or artificially created defects. In this work, the characteristic glow curves of natural salt collected from soil surface has been studied and the TL properties including the kinetic parameters of the soil salt have been determined. Soil salt samples were crushed and pressed carefully to form of circular disc pellets before irradiated with a calibrated 90Sr- 90Y source-β-particles emission source 1Gy.The sensitivity of its main dosimetric peaks is strongly affected by thermal treatments, such that the optimum annealing condition was determined by varying the annealing temperature from room temperature (RT) up to 700 oC/1h. The glow curves are subjected to Computerized GL-Curve Deconvolution (CGD) within the general order kinetic formalism and the natural salt characterizing the GL-curves shows two prominent glow peaks ~175°C and 235°C. By increasing the annealing temperature, the glow curve shows a single sharp peak at about 225 oC and a broad shoulder at high temperature. The fading results gave evidence that TL emission is due to a redistribution of trapping levels and indicate that the prominent TL-peak near 235oCis useful for TL-dosimetric applications. The increase of intensity has been correlated and linked to the inclusion of impurity defect pairs, or larger complex groups associated and coupled to intrinsic defects and localized distortions as a variations in the probabilities of electrons in the conduction band falling into different empty energy levels, there being one type of level for each TL-peak. The examination was extended to include the phase crystalline structure of the soil salt through the measurements and analysis using X-ray Diffraction (XRD) spectroscopy technique to validate the results and conclusions.