Potential approach of IR-analysis for high heat flux quality assessment of divertor tungsten monoblock components

•HHF performed tests with 100 cycles at 10MW/m2 on 13 components or mock-ups manufactured for ITER, for the DEMO divertor development and for the WEST project.•The IR analysis of the local temperature evolution of W blocks during the first 100 cycles at 10MW/m2 was statistically assessed.•Development of a correction algorithm of the large variability of the W emissivity in the middle- and of long-wavelength IR.•Approach of IR-analysis for HHF quality assessment of divertor tungsten monoblock components.•Discussion of a statistics based method for the application to the high heat flux testing of a large number of industrially manufactured W monoblock plasma-facing components. The paper discusses a potential approach of infrared (IR)-analysis for high heat flux quality assessment of divertor tungsten monoblock components. The aim of these activities is the development of a statistics based method for the general application to the high heat flux testing of industrially manufactured W monoblock plasma-facing components. We have performed tests with 100 cycles at 10MW/m2 on 13 components or mock-ups manufactured for ITER, for the DEMO divertor development and for the WEST project. For eight W monoblock components with grinded surfaces, the statistical high heat flux (HHF) quality assessment method originally developed for the series manufacturing of carbon fibre reinforced carbon flat tile divertor components for Wendelstein 7-X was applied. The large variability of the emissivity of W as well as the monoblock geometry require a careful emissivity correction of IR camera data. The emissivity is strongly dependent on the W surface quality and final machining and influences the apparent temperature measured by an IR camera. Therefore we have applied a pragmatic correction algorithm based on two-colour pyrometry. Finally we propose a possible HHF testing strategy of a large number of industrially manufactured W monoblock components.