• Title/Summary/Keyword: thermally stimulated luminescence

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Thermally assisted IRSL and VSL measurements of display glass from mobile phones for retrospective dosimetry

  • Discher, Michael;Kim, Hyoungtaek;Lee, Jungil
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.429-436
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    • 2022
  • Investigations of retrospective dosimetry have shown that components of mobile phones are suitable as emergency dosimeters in case of radiological incidents. For physical dosimetry, components can be read out using optically stimulated luminescence (OSL), thermoluminescence (TL) and phototransferred thermoluminescence (PTTL) methods to determine the absorbed dose. This paper deals with a feasibility study of display glass from modern mobile phones that are measured by thermally assisted (Ta) optically stimulated luminescence. Violet (VSL, 405 nm) and infrared (IRSL, 850 nm) LEDs were used for optical stimulation and two protocols (Ta-VSL and Ta-IRSL) were tested. The aim was to systematically investigate the luminescence properties, compare the results to blue stimulated Ta-BSL protocol (458 nm) and to develop a robust measurement protocol for the usage as an emergency dosimeter after an incident with ionizing radiation. First, the native signals were measured to calculate the zero dose signal. Next, the reproducibility and dose response of the luminescence signals were analyzed. Finally, the signal stability was tested after the storage of irradiated samples at room temperature. In general, the developed Ta-IRSL and Ta-VSL protocols indicate usability, however, further research is needed to test the potential of a new protocol for physical retrospective dosimetry.

A Study on Thermally Stimulated Luminescence and Exoelectron Emission Phenomena of MgO Single Crystals (MgO 단결정의 열자극 발광 및 Exo전자 방출 현상에 관한 연구)

  • Doo, Ha-Young;Sim, Sang-Hung;Kim, Hyun-Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.3
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    • pp.165-172
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    • 2006
  • On the MgO single crystals doped artificially with Cr, Cu, Fe we observed thermally stimulated luminescence(TSL) glow curves and spectra, and analyzed them in the temperatures range from at liquid nitrogen temperature(77K) to about 500K after excitation with UV or X-ray irradiation. TSL glow curves obtained from these samples show five peaks at 136.5K, 223.5K, 360K, 390K, 440K, and their estimated activation energies are 0.27eV, 0.63eV, 1.08eV, 1.08eV, 1.19eV, and 1.33eV, respectively. When we measured TSL spectrum at the range of 200nm to 650nm on the MgO single crystals. we also analyzed the peak wavelength which obtained at 345nm, 375nm, and 410nm from measurement of TSL spectrum and described their luminescence mechanisms. TSL spectrum peaks emitted from MgO:Cr, MgO:Cu, and MgO:Fe appear at the wavelengths of 345nm, 360nm, and 375nm, respectively.

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Age comparisons of coastal sand dune stratum in Chollipo, Korea by altering preheat and cut-heat, and grain size distributions by OSL dating (예열 및 cut-heat 온도와 입자의 크기에 따른 천리포 해안사구 퇴적층의 OSL 연대측정 비교)

  • Bang, Jun-Hwan;Kim, Ki-Dong;Eum, Chul-Hun
    • Analytical Science and Technology
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    • v.22 no.1
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    • pp.51-56
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    • 2009
  • The samples from coastal sand dune stratum in Chollipo were dated by Optically Stimulated Luminescence (OSL) with modified Single Aliquots Regeneration (SAR) method. It is possible to choose the OSL signals by thermal treatments such as preheat and cut-heat in SAR procedure. Preheat and cut-heat of $260^{\circ}C$ for 10 sec $-220^{\circ}C$ for 0 sec, and $270^{\circ}C$ for 10 sec $-270^{\circ}C$ for 10 sec were applied for estimation of equivalent dose of the samples. The OSL signals from different thermal treatment were used for OSL dating. Equivalent dose were estimated with 4 fractionated grain distributions with $75{\mu}m$, $150{\mu}m$ and $200{\mu}m$ sieves with above heating treatments. Consequently, the estimated dose were differently valued in sample sizes and applied heating treatments, different stratum ages were calculated. The ages from radiocarbon dating were compared with the OSL ages. The ages varying with grain sizes produce that the site sampled were formed with mixed soil sources.