Analysis of alpha-alumina by variable dose and T_m -T_STOP methods and simulations of the whole process

The T_m -T_STOP and the variable dose methods were applied to alumina experimentally, and then all the steps of the methods were simulated numerically. The T_m -T_STOP experiments were performed between 70 and 300°C, and results showed that the glow curve of the used alumina had six distinct peaks between 40 and 400°C. The glow curves were analyzed using computerized glow curve fitting programs, the analytical equations were also fitted to the experimental data, and the trapping parameters of the peaks were measured. The samples were irradiated above the saturation level to ensure the complete filling of the electron traps and, therefore, the concentrations of traps were measured experimentally. Short-term anomalous fading behaviours of the peaks were investigated, and a new equation was proposed to compute the anomalous fading rate. In addition, the variable dose and T_m -T_STOP methods were simulated using the six trap-one recombination centre (6T1C) model and the experimental trapping parameters. Results showed that there was good harmony between numerical and experimental glow curves. After all the simulations were performed with acceptable accuracy, an estimate was made for the trapping coefficients (A_i = 1-6 ) that could not be measured directly from thermoluminescence experiments. Results showed that the trapping coefficients were affected by the applied dose.