Search results for "Distributed temperature"
showing 4 items of 4 documents
Effects of radiation and hydrogen-loading on the performances of raman-distributed temperature fiber sensors
2015
International audience; The integration of Raman-distributed temperature fiber-based sensors (RDTS) into the envisioned French deep geological repository for nuclear wastes, called Cigéo requires evaluating how the performances of RDTS evolve in harsh environments, more precisely in presence of H2 or γ-rays. Both H2 and radiations are shown to affect the temperature measurements made with the single-ended RDTS technology. The amplitudes of the observed effects depend on the different classes of multimode fibers varying in terms of composition and coatings. By selecting the most tolerant fiber structure for the sensing, we could maintain the RDTS performances for such application. A hardeni…
Steady state γ-ray radiation effects on Brillouin fiber sensors
2015
International audience; Brillouin optical time-domain analysis (BOTDA) sensors offer remarkable advantages for the surveillance of the planned French deep geological radioactive wastes repository, called Cigéo1,2. In this work we study the performances of Brillouin distributed sensors in harsh environment. We evaluate the radiation tolerance of different sensor classes and their responses evolution during γ-ray exposition with 1kGy/h dose rate (to reach ~0.2MGy) and after 1, 3, 6 and 10 MGy accumulated doses. Measurements on strained Ge-doped SMF are reported to highlight the variation on Brillouin scattering proprieties, both intrinsic frequency position of Brillouin shift and its dependen…
Hydrogen and radiation induced effects on performances of Raman fiber-based temperature sensors
2014
International audience; Raman Distributed Temperature Sensors (RDTS) offer exceptional advantages for the monitoring of the envisioned French deep geological repository for nuclear wastes, called Cigéo. Here, we present experimental studies on how the performances of RDTS evolve in harsh environments like those associated with H2 or g-rays. Both of them are shown to strongly affect the temperature measurements made with RDTS. We showed that by adapting the characteristics of the used fiber for the sensing, we could limit its degradation but that additional hardening by system studies will have to be developed before integration of RDTS in Cigéo.
Radiation and Hydrogen-Loading effects on Raman fiber-based temperature sensors
2013
We present experimental studies on how Raman based temperature sensors undergone two different treatments: gamma-radiation and H-loading. Unfortunately, gamma radiation and hydrogen release in harsh nuclear environment can affect the temperature measurements based on this technology of sensor, limiting the sensor performances. Moreover, the Raman device response in both cases changes with the different classes of multimode fibers that are used by the engineers.