The Neutron Spin Echo Spectrometer at SNS

NSE

NSE is funded and operated by the Jülich Centre for Neutron Science.

The SNS NSE instrument provides ultrahigh resolution spectroscopy with a Fourier time range that covers τ = 1 ps to a nominal 350 ns with a high effective neutron flux, aiming to be the best of its class in both resolution and dynamic range (please refer to the instrument fact sheet for a detailed current status). Researchers use this instrument to investigate soft condensed matter and complex fluids applications in a variety of fields. The planned optional ferromagnetic and intensity-modulated modes will allow for detailed investigation of magnetic samples and phenomena.

The design of the NSE spectrometer takes full advantage of recent progress in neutron optics and polarizing supermirror microbenders,1,2 resulting in considerable gains in polarized neutron flux over a wide wavelength range.

For the future, plans are to develop novel field correction elements3 to extend the maximum achievable Fourier time (i.e., the resolution) up to 1 µs. Using wavelengths of 2 Å < λ < 14 Å, an unprecedented dynamical range of up to 1:106 can be achieved in theory.

References

  1. Th. Krist and F. Mezei, "Compact neutron optical elements," Physica B: Condensed Matter  208, 276-278 (2000).
  2. B. Farago, “Neutron Spin Echo Spectroscopy,” Lecture Notes in Physics 601, F. Mezei, C. Pappas, and T. Gutberlet, eds, Springer-Verlag, Heidelberg (2003).
  3. M. Monkenbusch, “Neutron Spin Echo Spectroscopy,” Lecture Notes in Physics 601, F. Mezei, C. Pappas, and T. Gutberlet, eds, Springer-Verlag, Heidelberg (2003).

Applications

Although the NSE spectrometer is designed primarily for soft-matter research, its capabilities also make it useful for all fields of modern condensed matter physics, materials science, and biophysics. This instrument is especially suited for analyzing slow dynamical processes and thereby unraveling molecular motions and mobilities at nanoscopic and mesoscopic levels. This feature is highly relevant to soft-matter problems in research on the molecular rheology of polymer melts, related phenomena in networks and rubbers, interface fluctuations in complex fluids and polyelectrolytes, and transport in polymeric electrolytes and gel systems. NSE could also aid studies in magnetism.