Material properties and consequences on the quality of tore supra plasma facing components

In the frame of the CIEL project, which is an upgrade of the in-vessel system of the Tore Supra tokamak, a toroidal pump limiter is under fabrication. The elementary components are made of N11 carbon fibre composite (CFC), CuCrZr alloy, OFHC copper (for compliant layer), low cobalt stainless steel and Ni (as an interlayer between CuCrZr and stainless steel). The properties of the materials were carefully analysed at the beginning of the fabrication as they can have consequences on the final quality of the actively cooled high heat flux components. However: (1) during the manufacture, an abnormal phase was detected in the stainless steel with a risk of cracks at installation welding, (2) the properties of CuCrZr material were rather scattered, at the reception, among the different batches, (3) a low percentage (3–6%) of CFC tiles were faulty suggesting the CFC physical properties scattered significantly to fall out of the margins.