Test results from the full size prototype test of W7-X joint

Abstract: The superconducting fusion experiment WENDELSTEIN 7-X (W7-X) is presently under construction at the Greifswald branch of the Max-Planck-Institut für Plasmaphysik (IPP). The magnet system consists of 50 non-planar and 20 planar coils which are connected by 121 bus bars in series of 10 groups of seven coils each. The connection of the bus bars will be provided by 184 joints each with a maximum allowable resistance of 5nΩ. The principle of such a joint was tested by two joints in SULTAN Test facility CRPP, Switzerland in 2003. Both joints showed resistances less than 1nΩ at 25kA in a magnetic field of 2T. In the meantime efforts to modify the design of the casing and clamping parts for the serial production of joints have been carried out and tools for the installation at W7-X and mounting procedures were developed. The essential modifications and the latest test results at the SINTEZ of the Efremov Institute in St. Petersburg, Russia will be presented. [Copyright &y& Elsevier]