Overview of plasma-facing materials and components for EAST

TLDR

EAST’s commissioning in 2006 marked the first H₂ plasma using stainless steel PFMs, and graphite has long enabled ~100‑s pulses in HT‑7 while tungsten coatings are now under development. The study aims to design divertor targets that can withstand heat loads up to ~10 MW m⁻² as heating power increases. The approach employs doped graphite tiles initially, then progressively replaces them with tungsten coatings, ultimately targeting a full tungsten plasma‑facing surface. Key findings include graphite’s contribution to long‑pulse performance in HT‑7 and the latest progress in tungsten coating development.

Abstract

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.