On the accuracy of port assembly at Wendelstein 7-X

Wendelstein 7-X uses 254 ports for diagnostic and supply purposes. Actually 176 ports are final adjusted and welded. The major number of ports meets the general position tolerances of typically 4, …, 8 mm after assembly without countermeasures. 3D metrology turned out to be an essential factor to achieve required adjustment accuracy as well as to control welding process. The measurement accuracy of typically 0.3, …, 0.6 mm proved to be appropriated for all adjustment and control processes inside the experimental hall. A consequent application of 3D metrology can substitutes trail assembly steps and saves process time. Even reduced tolerances of special ports (AEV and AEK-V2) are achieved using appropriated assembly, welding and metrology procedures.