Ce/Gd-codoped sol-gel silica glasses: towards temperature-independent radiation dosimeters

We explored the potential of solgel-derived silica rods to monitor X-ray beams in real time, even in environments prone to temperature variations. These materials consist of silica glasses doped with either Gd ³⁺ or Ce ³⁺ ions, or co-doped with Ce ³⁺ /Gd ³⁺ . These doped or co-doped 1 cm-long rods were spliced to 5 m-long radiation-hard multi-mode optical fibres to evaluate their RadioLuminescence (RL) properties at different temperatures ranging from 153 to 353 K. Our ultimate aim is to design a fibred temperature-independent radiation sensor. In this paper, we have investigated the dependence of the RL response on the temperature and on the dose of single-doped and co-doped silica rods under X-ray. We demonstrated that, while the single-doped rods exhibit opposite trends of the RL signal versus the temperature, the co-doped rods show a constant RL response in a certain temperature range after a pre-irradiation under an accumulated dose of about 20 kGy. For an appropriate co-doping concentration, this temperature range extends from 273 K to 353 K. The obtained results highlight the potential of these fibred systems for the development of temperature-independent dosimetry, which can be suitable for real-time applications in several areas such as radiotherapy (in vivo dosimetry, brachytherapy, diagnosis).