The world’s strongest magnet for neutron experiments to be installed in Berlin

The new high field magnet, which is planned to be completed at the Hahn-Meitner-Institute Berlin (HMI) by 2011, will generate a magnetic field between 25 tesla and 30 tesla, more than half a million times stronger than the earth’s magnetic field. The National High Magnetic Field Laboratory (NHMFL), Tallahassee will build the magnet system for $8.7 million. The required infrastructure to run the magnet, including cooling facilities and power supplies will cost more than $14 million. In total, Euros 17.8 million will be financed for the entire project, primarily by the German Federal Ministry of Education and Research (BMBF).

It allows to strengthen the HMI’s leading international position with regard to experiments combining neutron research and strong magnetic fields and low temperatures. “Scientists from all over the world already come to us because we can support them explore materials by neutron scattering under extreme external conditions. With the new magnet at HMI scientists will accomplish what is not possible up to now anywhere in the world,” said Professor Michael Steiner, the scientific director of the HMI, in Berlin. Thomas Rachel, state secretary from the German BMBF, also said: “With this powerful new magnet system, the Hahn-Meitner Institute itself becomes a magnet, pulling in researchers from around the world.”

Researchers expect experiments with the magnet to yield new insight in the fields of physics, chemistry, biology, and materials science, for example experiments can contribute to the fundamental understanding of high temperature superconductivity – the ability of individual substances to conduct electric current without resistance at higher temperatures.

In order to build the magnet, the engineers at NHMFL must go to the limits of what is technically feasible. The inner part of the hybrid magnet system, the place of the highest fields, will be made up of a copper coil. The outer coil, connected in series with the resistive inner coil, will be consisting of superconducting material cooled with liquid Helium. With the aforementioned hybrid construction, the extreme fields can be produced while consuming the lowest energy input possible.

Furthermore, neutron instrumentation especially for use with a high field magnet had to be developed. This know-how is available at the HMI- another important reason why the German Helmholtz Association is supporting this project. Professor Juergen Mlynek, president of the Helmholtz Association, said in Berlin: “The Hahn-Meitner-Institute has a lot of experience in running strong magnets and in developing neutron instrumentation. On the basis of this unique expertise, HMI will lead this ambitious project to success.”