Nowadays researchers tend to use fusion as a safe energy source at power plants. Nevertheless, this process is dangerous. It requires reliable fiber optic technology for structural health monitoring at power plants. Novel fiber optic sensors offer robust operation in the harsh conditions of a commercial fusion power plant.
To be more precise, these fiber sensors provide temperature sensing applying optical fibers with written fiber Bragg gratings (FBGs). The FBG operating principle is based on broadband light that is directed on it. Although most of the light goes through, one wavelength is reflected. Herewith, the reflected wavelength changes with both temperature and strain.
Therefore, the installation of several fiber Bragg gratings enables performing independent temperature sensing of each location. Standard FBGs are widely used in various industries for strain and temperature sensing. Herewith, compact superconducting cables use these optical fibers based on fiber optic technology.
Novel FBG sensors can maintain “the intense electrical, mechanical, and electromagnetic stresses of a fusion magnet’s environment.” The novel fiber optic technology supposes ultra-long fiber Bragg gratings of 9-millimeter located 1 mm apart. The FBG sensors operate as conventional long quasi-continuous systems.
Compared to standard systems, FBG sensors include such benefits as long grating length (meters instead of millimeters). Ultra-long FBGs allow for sensing simultaneously occurring temperature changes along their entire length. Thus, it is possible to determine fastly temperature variation, irrespective of the location of the heat source.
Additionally, it is possible to combine ultra-long FBGs and traditional FBGs to produce both spatial and temporal resolution. The fiber optic technology has been developed by a team of researchers from Switzerland. According to them, such a combination can be used on bigger cables.
These FBG sensors detect quickly and accurately even the smallest temperature changes under realistic operation conditions. Moreover, they demonstrate a better signal-to-noise ratio thanks to their high level of sensitivity and the opportunity to adjust the optical fiber response.
Thus, the fiber optic sensors locate quench events tens of seconds faster than voltage taps. Herewith, the application of FBG sensors for HTS magnets quenches detection is very potential. It allows for overcoming the current problem of HTS coils from damage during quenches.
Finally, such a fiber optic technology plays a crucial role in compact fusion processes, where practical, high-field, high-temperature superconducting magnets are important. FBG sensors are still under development and need some improvements to be used in new applications.
Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com