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SIS300 magnet prototype at GSI



A superconducting magnet prototype for the ring accelerator SIS300 has arrived at GSI. The dipole magnet was delivered from Italy and can now be tested at GSI. The SIS300 accelerator is part of the future facility FAIR which is currently being built in an international effort and will be connected to the existing GSI facility. The magnet was developed and constructed by scientists of the Italian research institute INFN (Instituto Nazionale di Fisica Nucleare) and the company ASG Superconductors in Genua and Mailand in cooperation with GSI. Dipole magnets are used in ring accelerators to keep the beam on the curved flight path.

In total 60 such magnets are necessary for the SIS300 accelerator. The prototype is five meters long and weighs six tons. It has an especially small radius of curvature of 66,7 meters and a magnetic field of 4,5 tesla. It is cooled to its working temperature of 4,7 kelvin (that is minus 268,5 degrees celsius) with liquid helium. The scientists have developed a special new superconductor for the magent: a copper-manganese alloy between the filaments of the superconductor prevents coupling and reduces unwanted AC losses. These innovations lead to an improved ramping rate that is up to a factor 50 higher compared to customary magnets.

In the upcoming months the magnet will be tested at GSI. Apart from measuring its magnetic properties also the maximum ramping rates and the AC losses during ramping will be examined. The next generation of dipoles is already under development in Italy in cooperation with the INFN and the European nuclear research center CERN.

The SIS300 accelerator is destined to be built in the second construction stage of the modularised FAIR facility and aims at an efficient parallel operation of several parts of the facility and a further increase of the beam energy. It could for example be used in the experimental setup for research on compressed nuclear matter CBM.

SIS300 dipol in Italy
Delivery of the dipole at GSI
Photo: H. Müller, GSI Helmholtzzentrum für Schwerionenforschung
Photo: E. Fischer, GSI Helmholtzzentrum für Schwerionenforschung