12
LARGE
CORPORATIONS
Plansee SE,
Reutte, Austria
Wendelstein 7-X is to demonstrate that stellarators are capable
of continuous operation. This requires a powerful divertor.
Plansee SE designed so called “target elements” for the
divertors, which must be continuously capable of withstanding
ten megawatts per square meter. A sophisticated combination of
carbon-fibre-reinforced carbon and water-cooled metal blocks,
also known as heat sinks, had to be developed. Significant steps
in this development were made in close collaboration with IPP:
Heating fusion plasmas to temperatures of roughly 100
million degrees Celsius requires very high power
outputs in the range of ten million watts. Although
the heated plasma inside the vessel will be confined by the
magnetic field, contact between the plasma boundary and
the wall segments cannot be avoided. The temperature of
the plasma decreases dramatically from its center to its outer
boundary where it is “only” about 100,000 degrees Celsius. To
protect the wall of the plasma vessel from damage, the huge
heat flow from the plasma has to be conducted through the wall.
The sections of the wall are protected by water-cooled wall
elements. The high-performance heat exchangers are known as
“divertors”. 10,000 hotplates
on one square meter
The high load
Wendelstein 7-X wall
High-performance water-cooled wall elements
Photo: IPP, Michael Herdlein