E. Jericha, G. Badurek, M. Trinker:
"Ultra-small-angle scattering with polarized neutrons";
Physica B: Condensed Matter,
Ultra-small-angle neutron scattering (USANS) has been established as an effective technique for the study of structures in the
micrometre range in recent years. Consequentially this method has been extended to magnetic structures of corresponding size. We
present the instrument arrangement and first experimental results. The instrument itself is a double crystal diffractometer in Bonse-Hart
configuration which takes advantage of the narrow angular width of the perfect crystal reflection to obtain an extremely high angular
resolution of the scattering vector. The neutrons are loss-free polarized by permanent magnetic prisms located between the
monochromator crystal and the sample. Neutrons with opposite polarization are separated to a large extent and their different scattering
behaviour may be studied in a single measurement without additional manipulation of the neutron spin. In this manner we are able to
separate the magnetic and nuclear contribution to the scattering. We present first exemplifying measurements on ferromagnetic rods and
wires, and on soft-magnetic ribbons. Related experiments were performed at the USANS facility of the TRIGA reactor at the Vienna
University of Technology and at the combined neutron interferometer/USANS instrument S18 at the ILL, Grenoble.
Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.