Twelve years after the award of contract for delivery of 50 non-planar coils for the Wendelstein 7-X (W7-X) fusion experiment of the Max Planck Institute for Plasma Physics (IPP), the signing of the acceptance certificate marks the successful completion of the project. The contract with a volume of more than 50 million euros has been the biggest individual order awarded in this sector. It was carried out under the lead of Babcock Noell GmbH (BNG), based in Würzburg, Germany, one of the leading manufacturers of superconducting magnet systems in Europe.

On 31 March 2010, the final acceptance certificate was signed in the course of a small celebration of members of the IPP directorate and project management as well as of the BNG management and project management in Greifswald. [Picture 1]

In his words of welcome, Prof. Dr. Hasinger, Chair of the IPP directorate, expressed his thanks again to Babcock Noell for the successful delivery of the core piece of the Wendelstein experiment and wished BNG lots of success with all their further projects, in particular with nuclear fusion projects.

The objective of the W7-X fusion device which is being built at Greifswald is to demonstrate the physical feasibility of nuclear fusion based on the stellarator principle. The 50 stellar non-planar coils are the key component of this unique experiment. They form the magnetic cage for confining the plasma, heated to 100 million degrees Celsius, where the fusion reaction takes place.

The 50 coils had already been successfully delivered in March 2008, however, before being assembled all coils were subjected to a cold test carried out at the test rig of the technological research institute CEA (Commissariat à l´Energie Atomique) in Saclay near Paris. In the test, the coils were cooled to 4 K, -269° C, in a cryostat and charged with a current greater than 17 kA to prove the coils’ capability as superconducting coils. By the end of 2009, all coils had successfully passed the test; and the installation of the coils at IPP was completed in early 2010. [Picture 2]

On passing all the tests at the CEA and at IPP and with the final documentation issued, the contract’s successful completion was finally sealed with the formal signing of the acceptance certificate.

Dr. Ronald Hepper, Managing Director of BNG, described this project as an important milestone with regard to the next project of nuclear fusion: the ITER.

The ITER project is aimed at demonstrating the physical-technological feasibility of fusion based on the TOKAMAK principle and is expected to produce 10 times as much energy as is put into the experiment. BNG have applied for constructing these coils as well and hope to continue cooperating as a reliable partner in research.

BNG have extensive experience and have established an excellent reputation as a reliable partner, among others for large-scale research projects. In December 2005, e.g. BNG was awarded the CERN Golden Hadron Award in recognition of their outstanding achievement in constructing one third of the 1200 superconducting magnets of the Large Hadron Collider at CERN, which achieved the greatest success so far in particle acceleration on 30 March 2010.

Picture 2: Signing of the final acceptance certificate at IPP in
front of the last module with 5 superconducting non-planar coils.
From left: Monika Hammer (Head of Purchase, IPP), Peter Stephan (Managing Director, BNG), Kathrin Heyn (Project
Manager W7-X, BNG), Konrad Risse (Project Manager, IPP),
Dr. Rummel (Section Head Magnets and Cryostats, IPP)

Picture 1: Assembly of a non-planar coil at IPP Greifswald