Radiation impact on strain transfer efficiency of bonded FBGs

Radiation impact on the strain transfer for a bonded fiber Bragg grating (FBG) has been investigated. The main goal of this preliminary study is to evaluate which adhesive and which fiber are the most appropriate to design a very sensitive strain sensor able to operate in nuclear environment. We performed static and dynamic experiments on different kinds of adhesives and different optical fibers, before and after a 1 MGy(SiO2) X-ray irradiation. The results reveal that the FBG strain sensors can be as much sensitive as classic strain-gauges and that the radiation effects on adhesives can have a positive impact on the strain transfer efficiency.