First results and surface analysis strategy for plasma-facing components after JET operation with the ITER-like wall

During the carbon wall operations of JET since 2001, an extensive post-mortem analysis programme has been carried out under the JET Task Force Fusion Technology and a similar analysis programme is underway for the JET-ILW tiles removed during the 2012 shutdown. The first post-mortem results from the JET ITER-like wall tiles have shown that the overall amount of deposition on the divertor tiles and on remote divertor areas has been reduced by more than an order of magnitude with respect to JET-C. In addition, the obtained data indicate a possible interaction between Be and W such as the formation of mixed Be-W layers. This could be due to the surface roughness of the tiles, or could be caused by diffusion or even alloying. Ion-beam analyses and secondary ion mass spectrometry techniques give only elemental information, so other techniques such as x-ray diffraction, x-ray photoelectron spectroscopy, secondary electron microscopy/energy dispersive x-ray spectroscopy and nuclear microprobing are required. Since the nature of deposition and erosion has changed during the JET-ILW operations, a change in the post-mortem analysis programme is needed. For example, no cross-sectional samples from the sloping parts of tiles 4 and 6 are required. A strategy for post-mortem analyses of the marker-coated tiles will be presented in this paper