Use of infrared light-emitting diodes to determine dosimetric characteristics of MgO:Tb,Gd,Li via the optically stimulated luminescence technique

Abstract

In this study, the temperature dependence of Infrared Stimulated Luminescence (IRSL) in MgO:Tb,Gd, Li samples were investigated and the basic dosimetric properties were examined for the radiation dosimetry. Terbium, gadolinium, and lithium doped MgO were synthesized using the solution combustion synthesis method, and the characterization of the material was performed by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The effects of the dopants were investigated by specifying the radioluminescence (RL), thermoluminescence (TL), and optically stimulated luminescence (OSL-blue stimulation/IRSL-infrared stimulation) curves of the MgO:Tb,Gd, Li phosphor. Decay curves of the light flash vs. time showed that the MgO:Tb,Gd, Li was most readily discharged by infrared stimulation. The temperature dependence of the IRSL samples was investigated between 50 and 230 °C. The optimized readout temperature was determined as 120 °C achieving the maximum IRSL intensity. It was shown that there are traps responsible for TL peaks below 200 °C which could be suggested as the source of the IRSL signals for the studied MgO:Tb,Gd, Li samples. The high-temperature TL peak nearly at 400 °C was not affected by infrared stimulation and did not contribute to the obtained IRSL signals. The dosimetric properties such as reusability, multi-readability, dose-response, and fading were examined for applicability to radiation dosimetry. The thermal stability of the sample was investigated using the isothermal annealing technique and activation energy and frequency factor of the traps responsible for IRSL signal were estimated as 0.62 eV and 106 Hz, respectively. The MgO:Tb,Gd, Li luminescent has several properties in its favor. It has been shown that the IRSL signals of the Tb, Gd, and Li doped MgO sample can be investigated and examined as a radiation dosimeter.