JT-60 is planned to be modified to a fully superconducting coil tokamak (JT-60SC) to establish scientific and technological bases for an attractive DEMO reactor. A divertor geometry for JT-60SC is designed to achieve enough exhaust capability for high triangularity configuration, which is essential to obtain high plasma pressure and type II ELMs. For the improvement of detachment control capability, vertical targets are applied with baffle plates into which 3 cm SOL flux surface on the outer midplane can be led. Cryopanels are installed under both a private dome and an outer divertor to allow separated pressure control for inner and outer divertor legs, which is important for the detachment control. The preliminary results of the numerical simulation with SOLDOR/NEUT2D code show that the pumping speed of ⩽60 m3 s-1 at an outer pumping slot would be enough to control the detachment at the outer divertor without an X-point MARFE under the condition of the edge density of 3.2×1019 m-3 and the SOL power flow of qi = qe = 6 MW.
JET with a pumped divertor: design, construction, commissioning and first operation