Temperature Impact on a Radioluminescent Silica-Based Optical Fiber Dosimeter for Space Applications

Dosimetry holds significant importance across various applications such as radiotherapy, nuclear power plants, accelerators, and space research domains. Indeed, ensuring accurate dosimetry calibration is crucial for radioprotection or operations. In the context of challenging environments such as space, temperature calibration of radiation sensors plays an important role in ensuring their performance. This article discusses the temperature calibration of cerium (Ce)-doped silica (SiO₂)-based optical fiber (OF). The calibration covers a temperature range, during 40-keV X-ray irradiation, varying from $- 80~^{\circ }$ C to $+ 100~^{\circ }$ C, meeting the requirements for space applications and allowing for the determination of the temperature dependence of the radiation-induced luminescence (RIL). The tests were repeated on three identical 1-cm-long Ce-doped OFs. Our experiments reveal a temperature dependence of the RIL, particularly noticeable at low temperatures, where RIL decreases significantly as the temperature drops. Consequently, a temperature sensitivity curve for RIL is proposed, to calibrate the variations in RIL responses across the investigated temperature range. However, in complex operation conditions, with varying dose rates and temperatures, other phenomena could alter the detector performances, in particular the thermoluminescence (TL) observed during strong positive temperature gradients. This work contributes to highlight the potential of RIL-based sensors under varying temperature conditions, crucial for improving reliability and accuracy, especially in a harsh environment such as space.