Optical fibers for distributed sensing in harsh environments

Author(s):  
Jie Li ◽  
Xiaoguang Sun ◽  
Lei Huang ◽  
Andrei A. Stolov
2015 ◽  
Vol 2015 (1) ◽  
pp. 000609-000615 ◽  
Author(s):  
John Mazurowski

Present fiber optic connections need to align two or more optical fibers to accuracies of microns (multimode fiber) and tenths of a micron (single more fiber). For connections in rugged applications, consisting of wide temperature ranges, substantial vibration, or in the presence of contaminants, the alignment of normal physical contact connections becomes even more difficult. New expanded beam connectors make fiber optic connections more durable, and help stabilize the transmission of high speed optical signals between systems, boxes, boards, and devices in these harsh environments.


2014 ◽  
Vol 43 (12) ◽  
pp. 1206002 ◽  
Author(s):  
吕安强 Lv An-qianga ◽  
李永倩 LI Yong-qiana ◽  
李静 LI Jingb ◽  
陈永 CHEN Yonga

2020 ◽  
Vol 225 ◽  
pp. 08006
Author(s):  
G. Cheymol ◽  
L. Maurin ◽  
L. Remy ◽  
V. Arounassalame ◽  
H. Maskrot ◽  
...  

The DISCOMS project, which stands for “DIstributed Sensing for COrium Monitoring and Safety”, considers the potential of distributed sensing technologies, based on remote instrumentations and Optical Fiber Sensing cables embedded into the concrete floor under the reactor vessel, to monitor the status of this third barrier of confinement. This paper focuses on the selection and testing of singlemode (SM) optical fibers with limited RIA (Radiation Induced Attenuation) to be compliant with remote distributed instruments optical budgets, the ionizing radiation doses to sustain, and their reduction provided by the concrete basemat shielding. The tests aimed at exposing these fibers and the corresponding sensitive optical cables, to the irradiation doses expected during the normal operation of the reactor (up to 60 years for the European Pressurized Reactor), followed by a severe accident. Several gamma and mixed (neutron-gamma) irradiations were performed at CEA Saclay facilities: POSÉÏDON irradiator and ISIS reactor, up to a gamma cumulated dose of about 2 MGy and fast neutron fluence (E > 1 MeV) of 6 x 1015 n/cm2. The first gamma test permitted to assess the RIA at various optical wavelengths, and to select three radiation tolerant singlemode fibers (RIA < 5 dB/100 m, at 1550 nm operating wavelength). The second one was performed on voluminous strands of sensitive cables encapsulating the selected optical fibers, up to approximately the same accumulated dose, at two temperatures: 30°C and 80°C. A significant increase of the RIA, without any saturation tendency, appeared for fibers inserted into cables, correlated with the increase of the hydroxyl attenuation peak at 1380 nm. Molecular hydrogen generated by the radiolysis of compounds of the cable is at the origin of this phenomenon. A third gamma irradiation run permitted to measure the radiolytic hydrogen production yield of some compounds of a dedicated temperature cable sample. The efficiency of a carbon coating layer over the silica cladding, acting as a barrier against hydrogen diffusion, was also successfully confirmed. Finally, the efficiency of this carbon coating layer has also been tested under neutron irradiation, then qualified as a protection barrier against hydrogen diffusion in the optical fiber cores.


2013 ◽  
Author(s):  
Peter D. Dragic ◽  
John Ballato ◽  
Stephanie Morris ◽  
Alex Evert ◽  
Robert R. Rice ◽  
...  

Author(s):  
C. Vazquez ◽  
A. Tapetado ◽  
P. J. Pinzon ◽  
D. S. Montero ◽  
J. D. Lopez-Cardona ◽  
...  

1987 ◽  
Author(s):  
B. J. Skutnik ◽  
M. H. Hodge ◽  
J. P. Clarkin

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