The FlatCone multianalyzer setup for ILL's three-axis spectrometers

Abstract

Traditionally, the neutron three-axis spectrometers with their single analyzer/detector channel are associated with experiments aiming at detailed studies of the inelastic response at a few selected points in the Q , ω space. In the present contribution we report on first tests of a recently developed secondary spectrometer module consisting of an array of 31 individual channels, covering a scattering angle range of 75°. Each channel contains two elastically bent Si 1 1 1 analyzers, offering the choice between final neutron wave numbers of k f=1.5 and 3 Å −1, and a discrete 3He detector. This new device, similar to the direct geometry TOF spectrometers using large area position sensitive detectors, offers improved momentum resolution and enhanced data collection efficiency in experiments aiming at mapping of inelastic response over extended areas in the Q , ω space and, at the same time, keeps the high incident flux and most of the flexibility of up-to-date three-axis spectrometers using doubly focusing crystal optics.