OSL and thermally assisted OSL response in dental enamel for its possible application in retrospective dosimetry
Dental enamel was studied for its thermoluminescence (TL) and optically stimulated luminescence (OSL) defects. The TL studies showed a wide glow curve with multiple peaks. The thermally assisted OSL (TA-OSL) studies showed that the integrated TA-OSL and thus OSL signal increases with readout temperature between 100 and 250 °C, due to the temperature dependence of OSL. The thermally assisted energy E A associated with this increase is found to be 0.21 ± 0.015 eV. On the other hand, the signal intensity decreases with temperature between 260 and 450 °C. This decrease could be due to depletion of OSL active traps or possible thermal quenching. The increase of the OSL signal at increased temperature can be used to enhance the sensitivity of dental enamel for ex vivo measurements in retrospective dosimetry. The emission and excitation spectra of its luminescence centers were studied by photoluminescence and were found to be at 412 and 324 nm, respectively. It was found to possess multiple OSL active traps having closely lying photoionization cross sections characterized by continuous wave OSL and nonlinear OSL methods. The investigated dental enamel samples showed a linear OSL dose response up to 500 Gy. The dose threshold was found to be 100 mGy using a highly sensitive compact OSL reader with blue LED (470 nm) stimulation.
KeywordsDental enamel Retrospective dosimetry Photoionization cross section Thermally assisted OSL (TA-OSL)
The authors are grateful to Dr. D. N. Sharma, Director, Health Safety and Environment Group, BARC, and to Shri. D.A.R. Babu, Head, RP&AD, for the support and encouragement during the course of this work. The authors are also thankful to the editor and the referees for their suggestions and critical comments on the manuscript.
- Pass B, Godfrey-Smith DI, Scallion P (2003) Retrospective radiation dosimetry using optically stimulated luminescence in dental enamel: possibilities for in vivo dosimetry. In: Proceedings of the 36th midyear topical meeting “radiation safety aspects of homeland security and emergency response”, Health Physics Society, San Antonio, Texas, January 27–29, pp 210–217Google Scholar
- Wieser A, Darroudi F (2014) EPRBioDose 2013: EPR applications and biological dosimetry. Radiat Prot Dosim 101:217–220Google Scholar