X-ray space technology for focusing small-angle neutron scattering and neutron reflectometry

In Julich, a small-angle neutron scattering instrument and neutron reflecto meter will be built, both of them use a double-focusing mirror, which produ ces an one-to-one image of the entrance on the detector. This neutron focus ing technique, known since 50 years, has become practicable only recently, since very smooth mirror surfaces were produced for X-ray space telescopes. The neutron mirrors are produced by the same technique. The focusing is es pecially good for high-resolution experiments (with the momentum transfer Q < 10(-3) Angstrom(-1)). Compared to pinhole collimation, the focusing tech nique in this region has intensity advantages of several orders of magnitud e. In this contribution mainly the influence of the shape of the mirror and the influence of gravity on the quality of the image is discussed. We expl ain, how these effects can be minimized. (C) 2000 Elsevier Science B.V. All rights reserved.