8
LARGE
CORPORATIONS
“Have you ever tried
to wrap up a hedgehog?”
The thermal insulation
of the Wendelstein 7-X
Here are a few significant features for the manufacturing of the
thermal insulation:
▶ Actively cooled cover elements, so-called shields, had to be
manufactured for the thermal insulation of the plasma vessel.
Due to the unconventional shape of the vessel and the extremely
confined working environment, the precisely shaped shields
had to be made with very high accuracy. Despite advanced
shaping technology, attempts using steel, brass, and copper
were unsuccessful. A fiberglass-reinforced plastic shield was
the solution.
▶ Not only did the plastic shields have to be formed exactely
to the unusual shape ot the vessel, they also had to be suitable
for conducting heat. A technology based on laminated copper
meshes, which has led to a joint patent, proved to be the
solution. The result is a heat-conducting composite that is
suitable for use at extremely low temperatures.
▶ Assembly of the thermal insulation by MAN Energy
Solutions meant that the company was taking a risk. Unlike
the situation at normal construction sites, Wendelstein 7-X
represented a complex scientific environment, where the
contractor had to react quickly to adjustments and changed
requirements. This is typical for a “first of its kind” facility.
Inner and outer view of the Wendelstein 7-X plasma vessel
Photo: IPP, Beate Kemnitz Photo: IPP, Wolfgang Filser