Listemann delivers vacuum brazed assemblies for nuclear fusion reactor ITER

Manfred Boretius, 14. October 2020

Recently we had the opportunity to support the ITER project in France. The ITER Tokamak is a machine meant to produce energy from the nuclear fusion, same nuclear reaction, which powers the sun and the stars.

The sun as a blueprint - nuclear fusion as the energy source of the future

It will rely on three sources of external heating to bring the plasma to the temperature necessary for fusion: neutral beam injection and two sources of high-frequency electromagnetic waves, ion and electron cyclotron heating. By generating waves at a frequency that matches the oscillation of specific ion species in the plasma, the ion cyclotron resonance heating (ICRH) system transfers energy to the plasma (see Figure 1).

Das ICRH-System -Ion Cyclotron Resonance Heating

Figure 1: Ion cyclotron resonance heating (ICRH) system transfers energy to the plasma [source: ]


A generator, transmission lines and an antenna are necessary for ion cyclotron heating. A generator produces high-power radio frequency waves that are carried along a transmission line to an antenna located in the vacuum vessel, sending the waves into the plasma.


Vacuum brazed steel / copper assemblies for a tight connection

The company Mairold-Mechanik AG,, cooperating with Stäubli Electrical Connectors AG, asked Listemann AG to supply vacuum brazed steel / copper assemblies to be integrated in a RF Antenna of the ICRH (see Figure 2). The main requirement for the joint was tightness since the parts are predestined for vacuum. A silver based brazing alloy, suitable for vacuum applications, was selected and successfully implemented.


vakuumlöten-Ion Cyclotron Resonance Heating

Figure 2: The vacuum brazed components to be integrated in the antenna
[source: Company Stäubli]





Topics: Vakuumlöten