Disk chopper time-of-flight spectrometer

IN5B is a high precision direct geometry Time-of-flight (ToF) spectrometer. It is used to study low-energy transfer processes as a function of momentum transfer.
Typically this instrument is used for measurements in the small energy and momentum transfer region with values of about 1 % for the energy resolution (e.g. quasi-elastic scattering in solids, liquids, molecular crystals and inelastic scattering with small energy transfers in the range 10 µeV - 100 meV).


  • local and long-range diffusion in disordered systems such as liquids, molecular crystals, amorphous solids (superionic glasses, orientational glasses, spin glasses), polymers, hydrogen-metal systems, ionic conductors.
  • dynamics of ’soft matter’, including gels, proteins and biological membranes.
  • Dynamics of quantum liquids.
  • Rotational tunnelling in molecular crystals.
  • Crystal field splitting.
  • Spin dynamics in high-TC superconductors
  • Critical scattering phenomena in dense gases and solids.

Instrument layout

This shows how the 6 choppers are distributed in the primary spectrometer and how the huge detector bench is designed.