Accuracy of the construction of the superconducting coils for WENDELSTEIN 7-X

WENDELSTEIN 7-X, a superconducting fusion experiment, is presently under construction at the Greifswald branch of the Max-Planck-Institut fur Plasmaphysik (IPP). The magnetic confinement of the plasma is achieved by 70 coils. The accuracy of the magnet system plays an important role in order to achieve the technical and scientific goals. The accuracy of the coil system is determined by the accuracy of the shape of the winding packs, the accuracy of the final machining of the casings and the accuracy of the assembly of the stellarator. The contribution gives an overview about the accuracy requirements for the coils and presents a strategy to control the geometrical shape of the winding packs as well as of the casings. The achieved accuracy of the winding packs is in full agreement to the requirements. It can be postulated that the complicated shape of the nonplanar coils does not lead to an insufficient accuracy.