Another year of successful collaboration between ITER and CERN

The 4th meeting of the Steering Committee of the CERN-ITER Collaboration Agreement was held on 19 November at CERN. It marked the end of a second year of successful collaboration between ITER and CERN on superconducting magnets and associated technologies and the establishment of CERN as the ITER “reference laboratory” for superconducting strand testing for the next five years.


From left to right: Luca Bottura, Head of the CERN Superconductor and Devices Section, Neil Mitchell, Head of the ITER Magnet Division, Frederick Bordry, Head of the CERN Technology Department, Arnaud Devred, Head of the ITER Superconductor Systems and Auxiliaries Section, and Lucio Rossi, Head of the CERN Magnet, Superconductors and Cryostats Group, standing in front of a sample holder used for critical current measurements of Nb3Sn strands in the Superconductor Laboratory (bldg 163) at CERN.

The implementation agreement for 2009 encompassed a wide range of topics ranging from expertise in stainless steel and welding, high voltage engineering, high temperature superconductor current lead design, and testing and consultancy in cryogenics and vacuum.

The main role of CERN as the ITER reference laboratory will be to carry out yearly benchmarking of the acceptance test facilities at the six domestic agencies involved in superconducting strand production, to help in the training of the personnel involved in these tests around the world, and to carry out third-party inspection and expertise in case of problems during production. To this end CERN will use the facilities that were set up for the LHC strand qualification, however with an important modification: the upgrade of magnetic fields from 10 T to 15 T in order to properly test samples of Nb3Sn superconductors. This program has a considerable synergy with the CERN study for high gradient quadrupoles in Nb3Sn that is underway to prepare new technology for the LHC luminosity upgrade (see also CERN Courier). Nb3Sn is a material with superior performance with respect to the Nb-Ti employed for the LHC. However its brittleness and the need for high temperature heat treatments mean that much R&D is still required. ITER will be the first massive use of Nb3Sn: some 400 tonnes of the conductor will be used for the toroidal field coils and the central solenoid.

by Lucio Rossi and Frederick Bordry