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Thermoluminescence (TL) dosimetry has emerged as an important technique for understanding the dynamics of electron trapping centers. TL glow–curve analysis methods have been applied to study the kinetics of trapped electrons and the activation energy of the corresponding\ electrons. Such methods include Chen’s Peak shape method, Initial Rise and Variable Heating Rate method. Although, the TL does prove the presence and the depth of electron trapping centres and it does not give direct information about the shallow electron trapping centres, Thermoluminescence dosimeters (TLD) are one of the most highly efficient means of characterization over a wide range of radiation doses. New materials are being introduced which allow more sensitivity and linearity in the radiation response of the TL signal output. Phosphors shows TL emission when it gets exposed to high ionizing radiation such as γ-rays, β-rays, C5+ (carbon-ion) beam etc. Energy gets stored in the material and this stored energy is emitted in the form of light when the material is heated. This phenomenon is used for measuring radiation dose. TL property of inorganic materials are decided by the factors such as crystal structure, band gap, synthesis process, crystal size, lattice imperfections and effects of impurities on solid. Lattice imperfections are described as defect centers that may occur when ions of either sign ions move away from their original sites thus leaving vacant sites that are able to interact with free charge carriers. |
