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The present work describes the optically stimulated luminescence (OSL) of a tissue equivalent crystal, the magnesium tetraborate, doped with dysprosium or cerium and co-doped with lithium due to the lack of materials with characteristics suitable for several dosimetric applications. In the present work, MgB 4 O 7 :Dy,Li and MgB 4 O 7 :Ce,Li were characterized through their OSL and radioluminescence emissions. Our results indicate that MgB 4 O 7 :Ce,Li has a strong emission peaked at 420 nm that is connected to the Ce 3+ electronic transitions, while the emission of MgB 4 O 7 :Dy,Li has several peaks connected to the Dy 3+ transitions. The OSL decay curves from both materials are composed by two components: a slow one and a fast one. MgB 4 O 7 :Ce,Li is 10 times more sensitive than MgB 4 O 7 :Dy,Li, especially due to the wavelengths of the emission peaks. The dose response for both materials were sublinear from 0.2 Gy to 100 Gy, for MgB 4 O 7 :Ce,Li, and from 0.2 Gy to 40 Gy, for the MgB 4 O 7 :Dy,Li. The OSL signal from MgB 4 O 7 :Ce,Li showed good stability over 40 days (with a fading 4 O 7 :Dy,Li presented a complete fading of the signal after 40 days. These results suggest a clear potential of MgB 4 O7:Ce,Li for radiation dosimetry purposes using OSL technique.

The OSL characteristics of three different borate glass matrices containing magnesia (LMB), quicklime (LCB) or potassium carbonate (LKB) were examined. Five different formulations for each composition were produced using a melt-quenching method and analyzed in terms of both dose-response curves and OSL shape decay. The samples were irradiated using a 90Sr/90Y beta source with doses up to 30 Gy. Dose-response curves were plotted using the initial OSL intensity as the chosen parameter. The OSL analysis showed that LKB glasses are the most sensitive to beta irradiation. For the most sensitive LKB composition, the irradiation process was also done using a 60Co gamma source in a dose range from 200 to 800 Gy. In all cases, no saturation was observed. A fitting process using a three-term exponential function was performed for the most sensitive formulations of each composition, which suggested a similar behavior in the OSL decay.