Ultrasonic analysis of tungsten monoblock divertor mock-ups after high heat flux test

In this paper, a comparison is presented among the ultrasonic measures of different W-monoblock mock-ups following high heat flux tests. The DEMO reference solution for the divertor targets (ITER-like) is compared with two other concepts, in which the interlayer between monoblocks and tube has been engineered to increase the performance of the component (Thermal Break Interlayer, Thin Graded Interlayer). Ultrasonic measurements have been performed at the depths of interest. The reflected signal amplitude and time of flight at defined depths are used to determine the shape and entity of the defect, when present. For each concept, the most frequently observed defects due to thermal loading are then identified. Preliminary post-mortem analysis confirms the results from the ultrasonic tests, proving the defect imaging capability of such non-destructive technique for advanced W-monoblock concepts.