Ce/Gd-Codoped Sol–Gel Silica Glasses: Toward Temperature-Independent Radiation Dosimeters

We explored the potential of sol–gel-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 Gd3+ or Ce3+ ions, or codoped with Ce3+/Gd3+. These doped or codoped 1 cm-long rods were spliced to 5 m-long radiation-hard multimode optical fibers 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 article, we have investigated the dependence of the RL response on the temperature and on the dose of single-doped and codoped silica rods under X-ray. We demonstrated that, while the single-doped rods exhibit opposite trends of the RL signal versus the temperature, the codoped rods show a constant RL response in a certain temperature range after a preirradiation under an accumulated dose of about 20 kGy. For an appropriate codoping concentration, this temperature range extends from 273 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, and diagnosis).