The Superconducting Bus-Bar System for Wendelstein 7-X - A Challenge to Engineering

Abstract

Forschungszentrum Julich is contributing to the Wendelstein 7-X project among others with the superconducting bus-bar system. The scope is the design, qualification, manufacturing, and assembly of the superconducting bus bars and its appropriate supports. An overall concept of the bus-bar manufacturing was developed with the goal to optimize the process, to simplify the system assembly, and to provide easy transportation. A suitable insulation set up fulfilling all specifications was developed. For the qualification of the insulation and the fabrication process different samples have been fabricated and tested. The bus-bar support system has to take considerable loads due to cool down shrinkage, electromagnetic forces, and displacements imposed by the magnet system. General considerations led to the choice of a system of standardized components which allows assembly of specific adjustable supports for each position. The complexity of the system geometry and its loading required an iterative approach of support design and stress analysis. Finally, an assembly sequence for the bus-bar system was found matching the technological requirements of the bus itself with all geometric and other constraints of the assembly facility.