Insulation of the Coil and Bus Bar Ends During Assemblyof W7-X

The superconducting magnet system of the WENDELSTEIN 7-X (W7-X) experiment consists of 50 nonplanar and 20 planar coils which are connected by 121 bus bars in series in seven groups of ten coils each. The terminal ends of the coils and bus bars are not insulated by the manufacturers and will be insulated during assembly. The insulation has to withstand a voltage of 13 kV dc for 1 min at Paschen conditions. Furthermore it has to be considered that the quench detection wires which were fed inside the insulation along the coil and bus bar ends have to be fed through the insulation near the joints