OSL characteristics of MGO:TB and MGO:TB,CO

In this paper O.S.L. characteristics are presented of a newly synthesized materials Mg O:Tb and Mg O:Tb,Co developed and produced at the Institute of Nuclear Sciences, Vinca, Belgrade. These materials show a bright luminescent signal both under thermal and optical stimulation. A thermally stimulated emission spectrum showed the characteristics lines of Tb3+ in a wide range of wavelengths. Mg O:Tb shows the glow curve with the main temperature peak at about 220 Celsius degrees and Mg O;Tb,Co shows the dominant T.L. peak at about 300 Celsius degrees and a small temperature peak at about 190 Celsius degrees. The T.L. sensitivity of optimally prepared magnesium oxide luminescent materials are about 4 times higher than that of Al2O3:C. The highest O.S.L. sensitivity was obtained under green lamp (500 - 570 nm) stimulation. The fast component in the O.S.L. decay curve is 2.4 times faster than that of Al2O3:C. The O.S.L. signal is comparable with that of Al2O3:C. The O.S.L. signal is liner with dose up to 10 Gy. The lower limit of O.S.L. detection was found to be lower of 10 Φ Gy. The O.S.L. signal is even possible to be measured with a very small mass of a grain of about 0.5 Φ g, down of 0.1 mGy. This gives the possibility for application in the radiotherapy. The presented results show that these materials have very promising O.S.L. properties for the application in radiation dosimetry. (authors)