MS44-P04 HEIMDAL@ESS – Fast neutron powder diffraction for material science Jürg Schefer (Paul Scherrer Insitut, Villigen PSi, Switzerland) Jonas Birk (Nanosicience Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark) Sonja L. Holm (Nanosicience Center, Niels Bohr Institute, University of Copenhagen & Danish ESS Update Program, Copenhagen, Denmark) Dan Mannix (Departement of Chemistry & iNano, University of Aarhus, Lund and Aarhus, Sweden) Kåre Iversen (Departement of Chemistry & iNano, University of Aarhus, Aarhus and Lund, Denmark) Rodion Kolevatov & Bjørn Hauback (IFE, Institute for Energy Technology, Kjeller, Norway) Kim Lefmann (Nanosicience Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark) Lukas Keller (Paul Scherrer Institut, Villigen PSI, Switzerland) Mogens Christensen (Departement of Chemistry & iNano, University of Aarhus, Aarhus, Denmark)email: jurg.schefer@alumni.ethz.ch

New functional materials are in the focus for cutting-edge materials as demanded for example to minimize energy consumption, reducing waste and optimizing recycling processes. Such new materials must be probed under working conditions by a wide range of methods including neutron diffraction, covering a length scale from millimeters down to atomic distances below <1 nm.

 

The HEIMDAL [1,2] instrument at the new spallation neutron source ESS is exactly covering these needs, combining powder diffraction (NPD), small angle scattering (SANS) and neutron imaging (NI) in a single instrumental setup. It is essential to have time dependent information from the sample using different probes to give access to all length scales. In a first stage, we will complete the powder diffraction part, later upgrade the instrument by the SANS and imaging option.

 

A key component of the instrument is a double guide delivering thermal and cold neutrons. Extracting neutrons through two separated guides was a consequence of the different optics needed for the transport of cold and thermal neutrons, respectively. Our solution allows the optimization of the flux-sensitive NPD using thermal neutrons down to 0.5Å. The NPD takes full advantage of the long pulse of ESS: HEIMDAL can deliver high flux as well as high resolution by adjusting the pulse width within seconds. We can adapt exactly to the need for the materials science community, where phase transitions and structural parameters can be envisaged.

 

As we expect a less trained user community in this field, we and the Data management and software center (DMSC) in Copenhagen will make a big effort to offer a wide range of easy-to-operate software packages, such as 2D Rietveld refinement.
 

Figure 1:

The layout of the new HEIMDAL instrument at the European Spallation Neutron Source ESS in Lund, Sweden: A dedicated instrument for in-situ and in-operandi studies for materials science in the long experimental hall.

References:

[1] S.L. Holm et al., Nuclear Instrument and Methods (2016) 782, 1-8.

[2] K. Anderson and Instrument Groups , Instrument park at ESS, in preparation (to be submitted to NIM)
Keywords: Neutron Diffraction, In-Operandi, In-Situ