New possibilities of TOF spectroscopy with NEAT at BENSC

Complete text of publication follows. NEAT is a very flexible multichopper spectrometer for inelastic neutron scattering experiments in the region of medium to very small energy and momentum transfers, including inelastic small-angle scattering. Large-angle inelastic scattering is analysed with an array of 388 3He single detectors (SD) mounted at a fixed distance from the sample (2.50 m). An additional particularity of NEAT is a 3He 2D position-sensitive detector (MD) comprising 64 x 64 detector elements, which can be used to analyse inelastic small-angle scattering with an improved energy and momentum resolution, as the distance from the sample to the MD can be varied from 4 to 7.3 m. Furthermore, the MD chamber can also be used for inelastic large-angle scattering to ensure an appreciable increase of energy and momentum resolution in a solid angle of special interest. Some examples of the new possibilities given by the MD are presented together with new results already obtained in different fields of condensed matter physics: analysis of the central peak critical dynamics in a molecular single crystal near an incommensurate structural phase transition, diffuse scattering in a single crystalline inclusion compound, which is due to the motions of the guest molecules. (author)