High-intensity spin-echo spectrometer

Project constructing a high-intensity spin-echo spectrometer

WASP will be a spin-echo spectrometer optimised for high signal and high momentum transfer measurements. WASP will replace the ILL spectrometer IN11. The project has received substantial financial support from Forschungszentrum Jülich.
IN11 has at present two distinct set-ups: one optimised for high data rate (IN11C) and one optimised for highest resolution (IN11A). The new spectrometer will give up to 50 times higher data rates compared to IN11 in its high signal set-up and will achieve the same resolution as available on the present high resolution / low signal set-up of IN11 for all measurements. This is achieved by a fundamental change in the magnetic coil lay out, which gives the instrument its name: wide angle spin-echo (WASP).

This instrument is beeing constructed by ILL with subtantial support from FZ Juelich.


WASP will be optimised for studying diffusion of atoms and spin excitations on atomic and molecular length scales of 0.1-10 nm. With regards to the data rate, WASP will be 10-100 better than existing spin-echo spectrometers. Typical applications for WASP will be:

  • Study of the motion of biological functional groups
  • Diffusive dynamics in incoherent scatterers
  • Dynamics in molecular magnets
  • Dynamics of 1d and 2d confined molecules
  • Development of new models for systems near the glass transition
  • Small samples (magnetic or other)

Instrument layout

This artist view (January 2010) shows the main characteristics of the new instrument. Note the small arrows which represent the neutron spin orientation.