Simulation of an anomalous behavior of thermoluminescence glow peak of quartz from Nigeria

Mechanism of the experimentally observed anomalous shift of a thermoluminescence (TL) glow peak that varied with irradiation dose is yet to be fully established. A theory that the anomalous peak must have contained more than one first order composite peak each with different TL dose characteristics has been one major explanation proposed to explain this observation. This work was undertaken to simulate the anomalous glow peak by using a modified version of a previously proposed model and numerically solving sets of simultaneous differential equations governing the stages of TL phenomena (excitation, relaxation and heating). In the modified model, two additional electron trapping centers were incorporated in order to simulate accurately this glow curve. Computerized curve deconvolution (CGCD) analyses was carried out on the simulated  glow peak in attempt to retrieve back the electron trapping center energies and to identify their respective peak positions. The outcome of this confirmed the peak to be possibly composite in nature comprising three overlapping glow peaks at 288, 300 and 317^oC with respective energy gaps of 1.70, 1.73 and 1.75eV. It is therefore further substantiated that this kind of temperature shift of peak with dose resulting from composite glow peaks is possible.