Overview of plasma-facing materials and components for EAST

By the end of September 2006, the engineering commissioning of the Experimental Advanced Superconducting Tokamak (EAST) was completed and the first H₂ plasma was achieved with stainless steel as the plasma-facing material (PFM). In the following phases, with gradual increase in the heating power, the EAST divertor targets have to handle expected heat loads up to ∼10 MW m^-2. The PFMs to be employed include doped graphite and W coatings. The former will be used to cover the whole plasma-facing surface in the first phase, and then the latter applied to replace the graphite tiles gradually in the second phase, and finally a whole W plasma-facing surface will be expected. Graphite has been studied for many years and contributed greatly to the HT-7 to achieve long pulses of some 100 s. The W coatings are being developed and the latest R&D development is reported in the paper.