MAST upgrade closed pumped divertor design and analysis

The design of the Mega Amp Spherical Tokamak (MAST) Upgrade project provides an excellent opportunity for advancements in tokamak physics in support of ITER and DEMO as well as CTF. One of the main areas of contribution is the divertor. MAST Upgrade will be capable of operating with the outer leg of the divertor being either conventional or with the novel Super-X Divertor (SXD) configuration, in which additional shaping of the magnetic field takes the divertor leg out to large radius. A region of low poloidal field in the chamber of the divertor allows the outer leg to traverse a considerable distance toroidally, reaching a large major radius. Cryopumps outboard the divertor targets will provide density control. This paper describes the current design and layout of the closed pumped divertor geometry to meet the configurations envisaged. The assembly supports symmetrical plasmas with both the upper and lower divertor assemblies able to accommodate either the conventional or SXD.