Development of a cold neutron polarizer working under a low external magnetic field less than 0.5 mT

A magnetically very soft neutron polarizing mirror which consists of Supers endust (Fe58Ni32Si6Al4; 10.5 nm)/germanium (Ce; 8 nm) [30 bilayers] has bee n developed. Since the potential energy of the Supersendust layers for down arrow spin neutron is almost equal to that of germanium, a high efficiency of neutron polarization is expected. The mirror has been evaporated on a p olished silicon wafer in an applied magnetic field of 14 mT in order to sat urate the film in a lower magnetic held. The neutron polarizing efficiency was 95% in the low magnetic held of 0.5 mT and the coercive force was estim ated to be 1 mT, (C) 1999 Elsevier Science B.V. All rights reserved.