Qualification activities to start on ITER's "ring" magnets
26 Oct 2015
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K.D.
A short video on in-factory equipment testing is available on the European Domestic Agency website.
The clean area on the south side of the building will host two winding tables, where lengths of niobium-titanium conductor will be fed from two spools simultaneously ("two-in-hand" winding), insulated, and wound into double pancakes. Dummy conductor for tooling qualification is stored in the crates, at left.
In ITER's largest on-site manufacturing facility, work has begun to prepare for the start of industrial activities.
The Poloidal Field Coils Winding Facility, a 257-metre-long facility on the ITER platform inaugurated in 2012, will house the fabrication and assembly activities for the largest ring-shaped magnets. Since July, two clean areas have been framed out for coil winding activities and the first crates of equipment have been delivered and stored in preparation for the installation of full winding tooling in November.
Six poloidal field coils will encircle the ITER vacuum chamber like so many parallels of latitude to shape the plasma and contribute to its stability by "pinching" it away from the walls. The smallest poloidal field coil (PF1) situated at the top of the machine will be supplied by Russia; the five others are under the procurement responsibility of Europe.
Due to the impressive size and weight of the middle coils (24 metres in diameter for the largest, 400 tonnes for the heaviest), Europe will carry out the successive stages of coil manufacture—winding and insulation, resin impregnation, stacking and assembly—on-site. PF6 (at the bottom of the machine) will be manufactured in China, according to the terms of an agreement concluded with the European Domestic Agency.
Overhead cranes will travel the length of the 257-metre building to transport the double pancake windings from station to station. The complete process, from winding to finished coil, will take between two and three years per coil.
The European agency has divided the manufacturing process for poloidal field coils 2-5 into a number of work packages to cover overall engineering integration, tooling equipment, site and infrastructure, manufacturing and cold testing. Four of six contracts have now been signed, including those for winding tooling (SEA ALP, Italy), site and infrastructure (Dalkia-Veolia, France), and engineering integration (ASG Superconductors, Italy).
At the SEA ALP factory in Italy, the winding table and associated auxiliary equipment has been manufactured, assembled and tested, and the first batch of equipment is now on its way to the ITER site. The winding contractor will now be responsible for the installation and commissioning of the equipment in the winding facility as well as for training personnel in its use.
The first activity on the winding line will be to use "dummy" conductor made of copper (instead of the real superconducting materials) to commission the winding line; China has delivered two batches of dummy conductor for this purpose that are currently stored in the Poloidal Field Coils Winding Facility. Following this qualification phase, the series production of double pancakes (flat, spiralled coils that are stacked in up to nine layers to form the coil winding packs) can begin.
A short video on in-factory equipment testing is available on the European Domestic Agency website.