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conductors with stainless-steel sheaths electrically insulated
with ceramics (magnesium oxide), as required for the
international experimental reactor ITER. However, the TIC
conductor for ASDEX Upgrade has new requirements.
Tefzel is to be used as the insulation material instead of
ceramics because it is easier to handle than the hygroscopic
magnesium oxide. The conductor qualified and produced
for ASDEX Upgrade can also be used without problems for
other fusion facilities of comparable size, i.e. with similar
coil current.
The SeaAlp consortium, based in Genoa/Italy, has the expertise
in bending conductors for coil manufacturing. However, the
experience gained with fusion devices such as ITER and Japan’s
JT-60SA had to be adapted to the specific task at ASDEX
Upgrade – bending a coil inside a vacuum vessel under limited
space conditions. While the larger coils at ITER or JT-60SA
are bent during the assembly of the fusion devices, at ASDEX
Upgrade the coils are bent for the first time directly inside the
vacuum vessel. A similar procedure is planned later for coil
assembly in the vacuum vessel of ITER.
“The work carried out for ASDEX Upgrade has allowed
us to develop a specific expertise for in-vessel coil
winding, with particular attention to optimizing the
geometry and dimensions of the winding equipment.
We are confident that this knowledge will generate new
business opportunities with other experiments in the
field of fusion energy” says the SeaAlp consortium.
For the ICAS consortium, the collaboration with IPP
also proved fruitful. Optimization of the processes
needed for the Teflon-based high-temperature
copper insulation to avoid impurities and achieve the
required tolerances, or handling the insulated copper
conductor during the steel sheathing process have
been developed. The requirements set by the project
challenged the joint team in both the development and
production phases. “The newly acquired expertise
is currently being applied in the production of the
mineral-insulated conductors with stainless steel
sheath for the ITER in-vessel coils system” says ICAS.
Tefzel-coated copper – the conductor without the sheath
Photos: ICAS