Discussion on data correction for Polarization Analysis with a 3He spin filter analyzer

International Conference on Polarised Neutrons for Condensed Matter Investigations

Babcock, Earl^1 ; Salhi, Zahir^1 ; Kentzinger, Emmanuel^2 ; Mattauch, Stefan^1 ; Ioffe, Alexander^1

Jülich Centre for Neutron Science (JCNS), Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jlich GmbH, Garching

85747, Germany^1

Jülich Centre for Neutron Science JCNS, Peter Grünberg Institut PGI, JARA-FITForschungszentrum Jülich GmbH, Jlich

52425, Germany^2

关键词: 3He neutron spin filters;    Adiabatic fast passages;    Conceptual understanding;    Grazing incidence small angle neutron scatterings;    Neutron polarization;    Polarization analysis;    Polarized neutron reflectometry;    Polarized neutron scattering;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/862/1/012001/pdf
DOI  :  10.1088/1742-6596/862/1/012001

来源: IOP

【 摘 要 】

Fully polarized neutron reflectometry and grazing incidence small angle neutron scattering are effective methods to explore magnetic structures on the nm to μm length scales. This paper is an outline of how to fully correct for the polarization analysis (PA) inefficiencies of such an instrument and to determine the error contributions of the neutron polarizer and analyzer. This discussion considers the exact case of the polarization analysis instrumentation used on the MARIA neutron reflectometer at the MLZ or for a general polarized neutron scattering instrument using at least one3He neutron spin filter that has the capability for adiabatic fast passage nuclear magnetic resonance flipping of the3He polarization. This paper will work to build a conceptual understanding of how the inefficiencies of neutron polarization elements affect measured data in order to stress and encourage the application of PA corrections and to help perform successful measurements. Then, using data from a fully polarized neutron reflectometer test measurement we show how it is possible to recover signals on the order of, or even smaller than, the inefficiencies, or bleed-through, of the neutron polarization devices used.