R&D of a strain monitoring system for the EAST tungsten divertor

The tungsten divertor of the Experimental Advanced Superconducting Tokamak (EAST) device operates atvarying temperatures and strong electromagnetic fields during plasma operation. In order to monitor thethermomechanical and electromagnetic responses of the structural components, a strain sensor system has beenproposed to be applied in the EAST device. To develop this technology, two initial experiments on the thermalstrain measurement of a tungsten divertor module of the EAST have been carried out using electrical strain gagesand optical strain sensors. However, some engineering issues were exposed during the experiments. Under thiscondition, all these issues are summarized and discussed this time. Moreover, a comparison between the twotechniques has been made when applied in the tungsten divertor. To make them more suitable for the applicationin the tungsten divertor of the EAST, several activities including a thermomechanical simulation, thewelding technologies for the sensors’ installation and a thermal stability test on the optical strain sensors wereconducted. Based on these progresses, it is expected that the strain monitoring system will be established in theEAST device in the near future.