Thermoluminescence characteristics of X-ray induced kyanite mineral and its thermal quenching parameters

Thermoluminescence (TL) glow curves of X-ray irradiated micro-grain natural kyanite have been recorded under annealed and un-annealed condition at various heating rates (2, 4, 6, 8 and 10 K s⁻¹). TL parameters such as activation energy, order of kinetic and pre-exponential frequency factor have been investigated from the glow peak by a computerized glow curve deconvolution technique. Variation of peak integrals, peak maximum temperatures, FWHM and activation energy with heating rates have been investigated and the glow curves at higher rates have been found to be influenced by presence of thermal quenching. For annealed sample value of thermal quenching activation energy (W) and pre-exponential factor (C) are found to be 0.86 ± 0.02 eV and 2.5 × 10⁹ s⁻¹ respectively and for un-annealed sample these values are 1.68 ± 0.03 eV and 3.1 × 10¹⁰ s⁻¹ respectively. Experimentally measured value of W and C have been verified by estimating thermal quenching efficiencies η(T) with the help of calculated value of W and C; quenched glow curves have been successfully reconstructed for each heating rate. The dose sensitivity of both types of samples is also reported. Annealed sample shows improved dose response than un-annealed sample. (author)