Cryotechnology for Wendelstein 7-X

For the underlying task to cool the Wendelstein 7-X (W7-X) superconducting coil conductors and the divertor cryo-pumps, an extended cryo-system is required. Besides the magnet coils and cryo-pumps proper, the coil housings and supports, the thermal shields of the cryostat and cryo-pumps, and the current leads (CL) have to be cooled. This is achieved by a refrigeration plant including coolant transfer lines and distribution boxes, and a widespread pipework within the cryostat. All these components are finally defined, and purchase actions are under way.