Neutrons are a powerful, non-destructive probe for the investigation of structure and dynamics in matter in a broad space and time domain. They provide indispensable tools for the investigation of magnetism, for micro-structural studies in materials relevant to engineering and materials science as well as for soft- and bio-matter. Earth and environmental science and cultural heritage are increasingly relying on research with neutrons. Neutron sources are also used for neutron activation analysis, in particular for environmental studies, for radiography and tomography as well as for the production of isotopes and doping of semiconductors.

Major progress in neutron optics, detectors, sample environment and methods have revolutionized neutron scattering. The next generation MW spallation sources provide a peak flux exceeding the flux of research reactors by at least two orders of magnitude. These gains make neutrons a tool for space and time resolved studies of micro- and nano-structured materials, in vivo studies of bio-molecular complexes and multi-component soft matter systems, in situ studies of catalysts, studies of quantum phase transitions under extreme conditions or of spin fluctuations in highly correlated electron systems.

The image shows the spin structure of the {Mo72Fe30} Keplerate molecular magnet with high geometrical frustration. Neutron scattering is the only method to determine such complex spin structures and the corresponding spin fluctuations.

The programme topic 'Neutrons' is characterized by an intensified involvement in FRM II, operation of the Berlin neutron-source BER II and the extreme sample environments available there, and intense utilization of the foreign site at SNS in Oak Ridge, USA.