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

In spring 99 the SINQ time-of-flight (TOF) spectrometer FOCUS became operat ional. The instrument can be used either in time focusing or monochromatic focusing conditions. In this contribution we want to report on recent measu rements exploring the elastic and inelastic energy resolution of the instru ment for the various settings. It was found that especially the usage of hi gher-order reflections of the double focusing pyrolitic graphite monochroma tor allows for energy resolutions in the order of 0.3 meV at a neutron ener gy loss in the order of 8-14 meV. (C) 2000 Elsevier Science B.V. All rights reserved.