Premium
SANS polarization analysis with nuclear spin‐polarized 3 He
Author(s) -
Gentile T.R.,
Jones G.L.,
Thompson A.K.,
Barker J.,
Glinka C.J.,
Hammouda B.,
Lynn J.W.
Publication year - 2000
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889800099817
Subject(s) - neutron scattering , neutron , polarization (electrochemistry) , small angle neutron scattering , scattering , incoherent scatter , spin polarization , optics , physics , materials science , atomic physics , nuclear physics , chemistry , electron
A neutron spin filter based on transmission through nuclear‐spin‐polarized 3 He gas has been applied to polarization analysis of small angle neutron scattering (SANS). Such spin filters, which are based on the large spin dependence of the absorption of neutrons by 3 He, make SANS polarization analysis possible because of their large angular acceptance. In the present experiment, a 3 He‐based analyzer was employed to separate nuclear scattering into its coherent and spin‐incoherent components. Polarized 3 He analyzers were prepared by two different optical pumping methods and installed on the NG3 SANS instrument at the NIST Center for Neutron Research (NCNR). Measurements were taken on cellophane tape and silica gel, for which the scattering is almost completely incoherent and coherent, respectively, and on a combined sample. For the combined sample, separation of the coherent part from the incoherent part was successfully demonstrated using polarization analysis.