Overview of the EAST in-vessel components upgrade

Highlights: • Molybdenum PFM reduce ratio of H/(H + D) significantly. • Tungsten divertor with monoblock technology was developed. • Modular tungsten divertor was designed and fabricated. • Mineral material (MgO) insulation in-vessel coils were developed. • VS coils location optimized to obtain more effective instability control. - Abstract: In-vessel components of the EAST superconducting tokamak upgraded from full carbon plasma facing material (PFM) to carbon PFM for upper and lower divertor, and molybdenum PFM for other surface in 2011. Carbon tiles were mechanical connected to CuCrZr heat sink can handle heat flux ∼3 MW/m². EAST was planned to update plasma heating power to 36 MW. After that heat flux to divertor will be up to 10 MW/m² for steady state operation and 15 MW/m² for transient. Upgrading divertor accommodate high performance plasma operation requirement is necessary. Tungsten PFM with ITER-like monoblock and flat tungsten technology was developed for EAST upper divertor to handle the high heat flux. To meet tungsten divertor pumping requirement an in-vessel cryo-pump was designed to install in upper divertor area. Type-I edge localized mode (ELM) was observed during EAST plasma operation in 2012. Resonant Magnetic Perturbation (RMP) coils with ITER in vessel coils like insulation technology were developed for the ELM mitigation. Vertical Stability (VS) control coils are also upgrade to ITER-like insulation technology, and coils locations were optimized to obtain more effective instability control.