Thermoluminescence properties and kinetic parameters of β-irradiated Turkish slate stone

Abstract

The current study includes a detailed investigation of the thermoluminescence (TL) characteristics and kinetic analysis of beta-irradiated slate stone from Muğla, Turkey. The heating treatment above 400 °C enhanced the visible TL intensity of the maxima, but the trap system is significantly modified with thermal annealing at temperatures higher than 700 °C. The structural, morphological, and chemical analyses of the samples were verified by X-ray diffraction, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and atomic absorption spectroscopy techniques, respectively. The TL dosimetric parameters of annealed slate stone including TL glow curves, reusability, fading characteristics, dose response, and heating rate behavior have been studied in detail. There are four apparent TL maxima in the glow curves for both non-annealed and annealed powdered samples, while the natural emission has shown a presence of 395 °C TL maximum as a form of spurious signal that was observed within a few hours during the storage time analysis as well. The material has proven to have very good reusability within the confidence interval (less than ± 5%). A linear response in the dose range of 0.1–103 Gy was achieved when the peak maximum at 258 °C is examined. The kinetic analysis was achieved using TM-Tstop, initial rise, and computing glow curve deconvolution methods. The TL glow curve of the beta-irradiated slate stone annealed at 700 °C consisted of twelve overlapping TL peaks by following first- and general order kinetics.