Sensitivity Study of Mechanical Behavior of Busbar System Designed for Wendelstein 7-X Stellarator

The Wendelstein 7-X stellarator is now under construction in Greifswald, Germany. The superconducting busbar system for the stellarator coils is designed and manufactured at the Forschungszentrum Jiilich, Germany. The electromagnetic forces on the long busbars, considerable relative tilting of the coils carrying the busbar supports, lack of available space required for the robust design of these supports, collisions with other systems during operation as well as the cooling down process had to be taken into account during design phase. Having a complex layout and complying with different, often contradictory requirements, the busbar system turned out to be sensitive to the manufacture and assembly tolerances. The modular structure of the magnet system implied the modular sequence of the busbar system production. The mechanical behavior of the busbar system has been numerically simulated for the module 5. The developed global model reflects main important features of the complex system in a relatively simple way. It proved to be useful tool for frequent iterations during design period and for numerous tolerance studies. The paper describes the main features of the numerical model and some results of the sensitivity study of the busbar system.