Brussels, 24 Jan 2006
The Max Planck Institute of Plasma Physics (IPP) has received its first parts for the Wendelstein 7-X plasma chamber fusion reactor. The 35-ton device is constructed from hundreds of separate components in 20 sectors. The installation is expected to be complete in six years.
Fusion power has the potential to provide clean and almost limitless fuel for the world. The problem with fusion power is that the heat required - 100 million degrees - is simply too hot to contain with current technology. To overcome this problem, the fusion reaction needs to be contained within magnetic fields.
To maximise the chances of achieving a fusion reaction, the plasma chamber has an unusual, asymmetrical design that required a very high degree of accuracy in its manufacture. 'The asymmetric shape in conjunction with the high precision required to make all this is a feat of construction bordering on the technically feasible,' said Bernd Hein, IPP's engineer responsible for the ring.
The components had to be brought together and placed in precise spots 2mm apart. The joins were completed by hand, using brazing wire and then the final seal checked by a laser for accuracy. More than 1,600 metres of brazing has been used to complete the seals.
Once the construction is complete, the plasma chamber will be surrounded by 70 super-conducting magnetic coils, keeping the plasma away from the walls of the vessel, which would otherwise be immediately vaporised. The area outside the plasma chamber will be separated with a vacuum and supercooled with liquid helium, giving the magnetic coils superconductive properties.
The project is supported under the Sixth Framework Programme (FP6) under Euratom.