Time versus monochromatic focusing on a cold neutron time-of-flight spectrometer

Abstract

In spring 99 the SINQ time-of-flight (TOF) spectrometer FOCUS became operational. The instrument can be used either in time focusing or monochromatic focusing conditions. In this contribution we want to report on recent measurements exploring the elastic and inelastic energy resolution of the instrument for the various settings. It was found that especially the usage of higher-order reflections of the double focusing pyrolitic graphite monochromator allows for energy resolutions in the order of 0.3 meV at a neutron energy loss in the order of 8–14 meV.