Suspension of the W7-X coils

A large steady state plasma fusion experimental device WENDELSTEIN-7X (W7-X) of the stellarator type is presently being built at the Max-Planck-Institute for Plasmaphysics (IPP). The aim of the experiment is to prove the reactor validity of the stellarator research line in addition to the tokamak research line. The magnet coil system of the main and ancillary coils is carried by a central support structure and kept in a position strongly predefined in space. The central support structure together with the additional lateral stiffening elements between the coil housings represent a complex 3D-framework system. This system is responsible to balance the considerable electromagnetic forces which are typically in the range of 1–4 MN at a nonplanar field coil and 20 MN per period as residual force in the centripetal direction. This paper shows FE-results of the main components inside the structure. Especially the central support elements, so-called extensions, which connect the coil housings with the support ring, are loaded by very high forces and moments.