Winding is over for ITER’s sixth Poloidal Field coil
Group photo of ASIPP team celebrating the completion of the conductor winding for Poloidal Field coil six
Six massive superconducting magnets, known as Poloidal Field (PF)
coils, will embrace the ITER machine from top to bottom to shape and contribute
to the stability of the superhot plasma. Europe is responsible for the
production of five of these coils. One
of Europe’s coils, however, the heaviest and lowest of all PF coils, is
manufactured in China. Following an agreement between F4E and The Institute of
Plasma Physics of the Chinese Academy of Sciences (ASIPP), and in line with the
ITER project’s spirit of collaboration, ASIPP and F4E have joined forces to
manufacture the sixth PF coil, in Hefei (China).
At the end of June, ASIPP celebrated a major milestone by completing
the winding of the conductor lengths needed for the coil. The sixth PF coil
consists of nine pairs of windings, known as Double Pancakes (DPs). It has been
a long journey since the fabrication of the first pre-dummy DP in February
2016, followed by a dummy Double Pancake, before going ahead with the
production of the first DP in February 2017.
The winding of each DP took around one month. Basically, it involved
winding two superconducting cable lengths which eventually take the form of a spiral.
Each turn of superconductor had to be electrically insulated from the adjacent
turn with a combination of Kapton and fibre glass tapes.
and insulating with Kapton and fiber and glass tapes the conductor of the sixth
Poloidal Field coil
Furthermore two helium inlets had to be carefully fabricated to allow
cold helium to flow inside the coil. The whole process was rigorously
controlled to ensure the DP is fabricated in line with the technical requirements
by a dedicated team of specialist technicians and engineers.
“ASIPP have been very collaborative with F4E and have reached this
milestone due to the hard work, professionalism and attention to detail of
their teams” explain Carlo Sborchia and Peter Readman, F4E Technical Officers following
the production in China.
the helium inlet of the Poloidal Filed coil’s first double pancake
It is expected that by the end of September all nine DPs will be fully
impregnated paving the way for stacking, an activity where they will be placed
one of top of each other, connected electrically and hydraulically. Then the
nine DPs will become one solid component, known as the “Winding Pack” (WP), it will
be ground insulated and impregnated. The final assembly of the WP will take
place before shipment to the ITER site
in France, which is expected before mid-2019.