16 Oct 2008



MAPS has changed the way the neutron community thinks about inelastic neutron scattering.

​​​​​View of MAPS from above

MAPS has been in operation since 2000. It was the first chopper spectrometer to employ a large array of position sensitive detectors, and the first to be designed solely for the purpose of measuring excitations in single crystals. It was originally envisaged that MAPS would be used predominantly for studies of high-energy excitations, using neutrons with incident energies in the epithermal range. Its use has evolved over time, and now a significant proportion of the beam time is devoted to single crystal excitation experiments involving the use of thermal neutrons, measuring excitations with energies as low as a few meV. In addition a recent trend has seen about one quarter of the beam time become devoted to catalysis and molecular spectroscopy experiments.​

Further technical information about MAPS is provided in the link on the right hand side of this page.

​The MAPS upgrade, which involved installation of a neutron guide and new choppers,​ has now been completed. The gain in flux on the upgraded instrument exceeded expectations and is now between a factor 2 and 20 higher (energy dependent) than in the past, making it essentially the same as that available on MERLIN.​


Recent proposal rounds have seen significant number of beamtime proposals rejected by the panel for similar reasons. The Excitations group and Facility Access Panel wish to help users to submit good proposals so would point out the following reoccurring issues of missing information in proposals that is detrimental to their scores, together with straightforward remedies:

  • Lack of evidence that a large single crystals exists or that a sufficient number of co-aligned crystals can be aligned for the experiment. This can be resolved by including a picture (with scale bars)
  • Lack or unclear presentation of relevant structural and physical property characterisation of the materials to be studied. This can be resolved by presenting diffraction and physical properties characterisation of your samples in the proposal.
  • Lack of details regarding what will be measured during the experiment which makes it challenging or in some cases impossible for the viability and merit of th