From 2014 to 2016 SEA-ALP designed, manufactured and supplied to Fusion For Energy the plant for the ITER PF coils winding. The superconducting conductor has a square section 51.9 x 51.9 mm, the jacket made of AISI 316L stainless steel. The coil is formed through a continuous CNC bending, and wound according to the double pancake technique. The turn-to-turn transition is shaped using the ‘smooth transition’ solution, so bending only in one direction, in such a way that the transition is formed by the rolling machine as a continuous bending, without the need of any stop for a local forming.
The CNC movement of the individual WM parts (with a couple of exceptions) is driven on the base of the conductor forwarding coordinate, precisely measured by a patented measuring carriage designed for overcoming inaccuracies due to any residual curvature of the straightened conductor and incoming line oscillation. A second measuring carriage placed after bending as a redundancy measure can take into consideration any conductor elongation during bending and provides the additional measure of the local curvature.
This Winding Machine is the first one using the two-in-hand technique, two incoming lines feeding conductor to the coil resting on a large rotating table. This is made possible by a patented solution which allows to form the turn-to-turn transition without moving the winding table in the plane, as it was necessary in the previous winding machines having just one feeding line.
The machine completed the production of the PF5-PF2 Double Panckes (~ 17m dia.) and in 2020 has been re-configured for PF3-PF4 (~ 24m dia.). In its wider configuration, the plant footprint is about 45x30m. The plant includes the in-line ultrasonic cleaning of straightened conductor and the conductor sandblasting and taping after bending.
A second rotating table, with the same dimension of the Winding Table, has been supplied for off-line operations on the Double Pancakes.