Abstract
The goal of this work was to investigate the relevant dosimetric and luminescent properties of MgO:Li3%,Ce0.03%,Sm0.03%, a newly-developed, high sensitivity Optically Stimulated Luminescence (OSL) material of low effective atomic number (Zeff = 10.8) and potential interest for medical and personal dosimetry. We characterized the thermoluminescence (TL), OSL, radioluminescence (RL), and OSL emission spectrum of this new material and carried out a preliminary investigation on the OSL signal stability. MgO:Li,Ce,Sm has a main TL peak at ~180 °C (at a heating rate of 5 °C/s) associated with Ce3+ and Sm3+ emission. The results indicate that the infrared (870 nm) stimulated OSL from MgO:Li,Ce,Sm has suitable properties for dosimetry, including high sensitivity to ionizing radiation (20 times that of Al2O3:C, under the measurement conditions) and wide dynamic range (7 μGy–30 Gy). The OSL associated with Ce3+ emission is correlated with a dominant, practically isolated peak at 180 °C. Fading of ~15% was observed in the first hour, probably due to shallow traps, followed by subsequent fading of 6–7% over the next 35 days. These properties, together with the characteristically fast luminescence from Ce3+, make this material also a strong candidate for 2D OSL dose mapping.
Highlights
Stimulated Luminescence (OSL) technique is becoming a widespread method for personal and medical dosimetry since the development of Al2O3:C1,2
The combination of Ce and Sm gave rise to a new TL curve, characterized by an almost isolated TL peak at 180 °C, that is different from the TL curves reported for other lanthanide-doped MgO samples[30,31,32] or MgO doped with transitions metals[36,37]
When comparing the TL curves from different studies, one should keep in mind that the TL curves and peak positions can be affected by the detection window and heating rate used in each study.) It was found that 3% Li co-doping increases the TL peak intensity at least 30 times, making the TL of this material about 10 times more intense than the already sensitive MgO:Li,Ce
Summary
Stimulated Luminescence (OSL) technique is becoming a widespread method for personal and medical dosimetry since the development of Al2O3:C1,2. One-dimensional dose mapping using Al2O3:C has been demonstrated and used commercially in computed tomography[13], but the luminescence lifetime of ~35 ms from the main luminescence centers in this material (F-centers) is too long for 2D dosimetry readout by spot-scanning laser. This problem has been overcome by detecting the OSL signal originated from the fast (~7 ns) F+-center present in Al2O3 samples[14] and using an algorithm to correct for the pixel-bleeding caused by the F-center emission[9]. A dosimetric OSL material which does not require the so-called “pixel-bleeding correction”, caused by the long luminescence lifetime of the F-centers in Al2O3:C, could further simplify the development of this technology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
