Reproducibility of Dose Rate Measurements with Radioluminescent Nitrogen-doped Optical Fibers

We studied the reproducibility of X-ray dose rate measurements using radioluminescent (RL) single-mode and multi-mode N-doped silica based optical fibers in the [22 mGy(SiO 2 )/s - 6.6 Gy(SiO 2 )/s] range. The influence of the probe manufacturing parameters on the dispersion of the RL sensitivity coefficient (χ in counts∙mGy -1 ∙s) is discussed for 20 manufactured probes. In particular, we demonstrated how the quality control of the splice between the N-doped sample and its transport fiber can efficiently reduce the dispersion of those coefficients. In addition, also the impact of measuring the RL fiber length was studied. Thanks to this study, we could estimate the achievable performances of this potential fiber-based dosimeter, avoiding individual calibration procedure of each probe. The good performances in terms of χ dispersion (17% for the multi-mode optical and of 3.8% for the single-mode optical fibers) demonstrate the high potential of this technology for implementation in harsh environments.