Coating impact and radiation effects on optical frequency domain reflectometry fiber-based temperature sensors

Abstract

International audienceTemperature response of radiation-tolerant OFDR-based sensors is here investigated, with particular attention on the impact of coating on OFS. By performing consecutive thermal treatments we developed a controlled system to evaluate the performances of our distributed temperature sensor and to estimate the radiation impact. We show an important evolution of the temperature coefficient measurements with thermal treatments for non-irradiated fiber and that the amplitude of this change decreases increasing radiation dose. As final results, we demonstrate that sensor performances are improved if we performed a pre-thermal treatment on the fiber-based system permitting to monitor temperature with an error of 0.05°C

Evaluation of Distributed OFDR-Based Sensing Performance in Mixed Neutron/Gamma Radiation Environments

“…We have indeed observed a change in the C T of 5% at the highest dose. Comparing these results with those obtained in only γ -irradiated samples [14] we notice that the coefficient value corresponding to the highest fluences is similar to the 1 MGy irradiated sample (values are (6.59± 0.02)·10 −6 • C −1 for the 1 MGy irradiated sample of reference [14] and (6.58± 0.01)·10 −6 • C −1 in 10 17 n/cm 2 irradiated sample) thus suggesting that both mixed neutron and γ -radiation at these fluences and doses can change the fiber response. As a first approximation, the radiation, by acting on the coating stabilization, changes the coating/fiber configuration according to the studies on thermic and mechanical properties on acrylate coated optical fibers of [21].…”

“…In this section we report the results on OFDR distributed sensors to investigate their response to mixed exposure. The comparison with only-γ irradiated samples, investigated in [14], will be discussed later.…”

Investigation of Coating Impact on OFDR Optical Remote Fiber-Based Sensors Performances for Their Integration in High Temperature and Radiation Environments

“…To investigate this packaging related error sources an accurate study on double acrylate coated fibers was carried out in [9] and [11] showing that both temperature and radiation affect the temperature sensor response influencing the calibration coefficients of the fiber under test. The results showed also that a pre-thermal treatment up to 80°C and/or a pre-irradiation up to 3 MGy reduce the coating linked error on C T and C ɛ variations from 5% to 0.5% improving the performances of fiber sensors for operation in harsh environments.…”