The making of a ring coil—a photo story
23 Jan 2017
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R.A.
From one end to the other of the on-site manufacturing facility for poloidal field coils, the different production stations are now clearly delimited, with tooling in various stages of installation. In this 257-metre-long workshop, European contractors will carry out the winding, impregnation, and assembly phases for the four largest ring magnets, with diameters of 17 to 24 metres.
The dummy for PF Coil #5, with copper conductor instead of niobium-titanium alloy, is in the last stages of winding.
The process will require at least 18 months per coil. Series manufacturing for the "building blocks" of the coils, called double pancake windings, can begin as soon as qualification activities are validated. The first pre-dummy pancake—made with several turns of copper conductor instead of the real superconducting materials—has been wound and the manufacture of a full two-layer PF5 dummy double pancake is underway to qualify all processes.
Contractors are installing the later-phase tooling stations now. In the gallery below, you'll see progress made recently on the double pancake impregnation station in the centre of the facility and on the full coil impregnation station at the far end.
Entre les deux poutres de 43 et 48 tonnes respectivement, on installe un chariot. Photo : F4E
Les éléments du deuxième pont, composé de deux poutres de 40 tonnes et d'un chariot (que l'on voit ici au sol), seront livrés sur le site d'ITER au mois d'octobre. Photo : F4E
Ce chariot (48 tonnes), installé entre deux poutres, portera le poids du palonnier (40 tonnes) et permettra son déplacement dans le sens de la largeur du bâtiment. Photo : F4E
Following impregnation, the double pancakes are stacked together and their terminations are welded to form one single circuit. This operation is performed in a clean area near the centre of the building that is presently under construction behind the white walls in this photo. The compact assembly is now called a "winding pack" and weighs several hundred tonnes. A gantry crane with a lifting capacity of 400 tonnes will soon be installed to handle the packs and move them to the final resin impregnation station. Squeezed and compressed into the grey impregnation mould in the foreground of this photo, the winding pack will undergo a process similar to the resin impregnation of the single double pancakes. Some 18 to 24 months will have elapsed since the conductor was despooled. The final activity for each coil will be cold testing at approximately 80 K to verify the performance of the coils before their installation in the machine.