Examination of W7-X target elements after high heat flux testing

The reception tests performed on the pre-series high heat flux elements of WENDELSTEIN 7-X (W7-X) divertor by means of infrared thermography inspection and high heat flux thermal cycling tests, exhibited some tiles with thermal inhomogenities, which developed during high heat flux testing. To assess damage detection and to understand the behaviour of pre-series elements under heat loading, post-testing investigations were undertaken to discriminate the tiles with insufficient bonding. Metallographic studies showed a good correlation with the surface temperature rise measured during the thermal cycling tests and the results of non destructive post-examination.