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2006 - 20102
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İndeks: Conference Proceedings Citation Index – Science (CPCI-S) × Konu: Optically stimulated luminescence ×

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Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Yayın
    Equivalent dose in quartz from young samples using the SAR protocol and the effect of preheat temperature
    (Pergamon-Elsevier Science Ltd, 2006-09) Güneç Kıyak, Nafiye; Canel, Timur
    Major concerns in the dating of samples younger than a few hundred years by the optically stimulated luminescence (OSL) technique are thermal transfer and partial bleaching. Thermal transfer during preheating enhances the OSL signal due to the charge transfer from thermally sensitive, but light-insensitive, traps to optical centres of quartz and results in an overestimate in equivalent dose, especially for very young samples. In this study, the single-aliquot regenerative-dose protocol is used to obtain values of equivalent dose (D-e) from young samples taken from various environments around Istanbul. Within this framework, we aim to investigate the effect of preheat temperature on equivalent dose from 150 to 300 degrees C, the reproducibility of De measurements for young deposits and the contribution from thermal transfer of charge to the equivalent dose estimation. It was observed that the measured dose is influenced significantly by preheat temperature and the increase in the De is clearly due to thermal transfer of charge from deep thermally sensitive traps to OSL trap during preheating of the samples prior to the main OSL measurements.
  • Küçük Resim
    Yayın
    TL/OSL properties of crystalline inclusions from heavy, barytes loaded, concrete
    (Pergamon-Elsevier Science Ltd, 2010-03) Güneç Kıyak, Nafiye; Polymeris, George S.; Kitis, George
    In the present work, we report the luminescence data obtained from heavy, barytes loaded, concrete containing many crystalline inclusions, extracted from a shielding block located at CERN. The use of both Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) signals, resulting from a specific trap at about 200 degrees C, is investigated for retrospective dosimetry purposes. By applying thermal cleaning experiments the TL signal of interest was isolated. Basic TL and OSL properties as thermal and optical stability, repeatability and mainly the linearity of the TL and OSL signals as a function of beta dose were investigated. The implications of all these luminescence properties to retrospective dosimetry are also briefly discussed.