Scientific Review: Polarized³He Spin Filters for Hot Neutrons at the FRM II

Abstract

Gaseous 3He neutron spin filters (NSF) are simple transmission devices, with predictable characteristics, that do not require any special optical adjustments on a neutron beam. Since polarized nuclei of 3He possess very high spin-dependent neutron absorption efficiency over a wide range of energies, the 3He NSF can be used as a broadband neutron polarizer or analyzer, with the possibility to optimize its efficiency for nearly all neutron wavelengths. In 2005 the facility for large-scale production of highly polarized 3He gas, HELIOS, was put into operation at FRM-II.