When DREAMs Come True
After two years, from the initial planning stage, the central component of the DREAM instrument was completed at ZEA-1 in collaboration with the Laboratoire Léon Brillouin (France) and was sent to the European Spallation Source (ESS).
DREAM (Diffraction Resolved by Energy and Angle Measurements) is a neutron spectrometer with a resolution improved by a factor of 10 compared to existing spectrometers. The unique design of the powder diffractometer, in combination with the beam brilliance of the ESS, will enable scientists to gain previously unattainable insights into the structures of complex materials. And in situ, quickly and from small samples. The scientific community hopes to gain new insights into physical and chemical issues in the fields of nanoscience, energy and battery materials as well as complex magnetic structures.
In a neutron time-of-flight powder diffractometer, pulsed neutron beams are shot onto a sample. The incident beam is either reflected at the surface or enters the sample where it is diffracted, i.e. deflected. This creates a diffraction pattern to be analysed, quickly and without destroying the sample. In a diffractometer, the central sample location is a sphere surrounded by detectors.
Technical challenge
The unique feature of the hollow sphere planned, designed and manufactured at the FZJ is that it was milled from a single piece of aluminium with a diameter of 1 m and a wall thickness of only approx. 2 mm. This is less than the thickness of a 1 euro coin. In addition, the sample in the sphere is under vacuum, so the neutron scattering radiation between the sample and the neutron detector must be influenced as little as possible by the thickness of the sphere wall.
This was possible thanks to the interdisciplinary, holistic approach at ZEA-1 - many experts worked together closely and in partnership to optimise the thin-walled sample vessel in particular so that it could withstand all loads. After successfully passing the tests, everything is ready for transport to Sweden - an engineering masterpiece worth millions. It is one of the first instruments to be assembled at the ESS. The total length is 80 metres and the costs will be 13 million euros in total.
More informations: https://europeanspallationsource.se/instruments/dream