Wendelstein 7-X Trim Coils—Component Safety Aspects and Commissioning Strategy

The stellarator fusion experiment Wendelstein 7-X (W7-X) is currently under construction at the Max-Planck-Institut für Plasmaphysik in Greifswald, Germany. Five normal conducting trim coils have been designed to allow for fine tuning of the main magnetic field during plasma operation. To limit the mechanical stresses in the coil, the proper functioning of the coil cooling system must be carefully monitored. Two independent systems will monitor the coil temperature. In addition, flow monitors in the outlet hydraulic line of each coil will determine if the required cooling water flow is present. The trim coil system will be provided as a part of a collaboration program between the Princeton Plasma Physics Laboratory, Oak Ridge National Laboratory, and the Wendelstein 7-X project, and is funded by the U.S. Department of Energy.