Fibre Bragg grating sensors for fusion diagnostics: Temperature monitoring of a tungsten mono-block mock-up under high heat flux

This necessitates the development of a component monitoring system for its operationstatus including temperature and strain. This study introduces a promising technique for monitoring temperatureand strain sensor systems based on the fibre Bragg grating (FBG).

It was used to monitor the temperature of a W/Cu mono-block mock-up during a high heat flux (HHF) test for the first time, demonstrating its suitability as atemperature monitoring system for the tungsten divertor. Temperatures up to 1000 °C were measured underHHF using five femtosecond FBG sensors inscribed in an optic fibre encapsulated in a stainless-steel capillarytube. The FBG sensors exhibit higher sensitivity to temperature variation while maintaining the same measurementaccuracy relative to the five thermocouples (TCs) in symmetrical locations.