and the W7-X Team

The new American-German collaboration on the W7-X stellarator in Greifswald, Germany, is in its first year as an ICC project. Los Alamos, Princeton, and Oak Ridge have organized an effort centered on applications of 3D magnetic fields to improve the performance and design of toroidal confinement devices. In particular, presently we have three focus areas: providing copper trim coils to be mounted externally on the W7-X cryostat, developing a scraper element for the divertor, and working control issues under the theme of 3D Diverted Plasmas. The trim coils must be designed and built on a fast schedule, to meet assembly timelines. The LANL effort involves theoretical modeling of whether the stellarator bootstrap current depends on the radial electric field, and an experimental investigation (IR imaging) of the heat loading and wall interactions in the W7-X 3-dimensional divertor. W7-X is a modular niobium-titanium superconducting stellarator of the helias type, with 5-fold symmetry, and the outer vessel is 16 meters in diameter, not including port extensions. It is presently 4/5 assembled, with the last module being moved into place this year. There are more than 250 ports (being insulated and welded into place now), although only ~150 are available for diagnostics...i.e., 30 per sector. Completion of construction is scheduled for late 2014. Other opportunities for increased collaboration scope abound. We report on the establishment of a new collaboration which began in FY11, between the US and German fusion research programs, under the auspices of the recently recompeted OFES Innovative Confinement Concepts program, formally known as SC Program Announcemen