An ultra-compact in-situ 3He polarizer for high Q-range SANS: on-beam test and future upgrades

International Conference on Polarised Neutrons for Condensed Matter Investigations

Salhi, Zahir^1,2 ; Babcock, Earl^1,2 ; Bingöl, Kendal^1,2 ; Starostin, Denis^1,2 ; Pistel, Patrick^1,2 ; Lumma, Nils^1,2 ; Radulescu, Aurel^1,2 ; Ioffe, Alexander^1,2

Julich Centre for Neutron Science (JCNS), Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstaße. 1, Garching

85747, Germany^1

Forschungszentrum Julich GmbH ZEA-1, Leo-Brandt-Straße, Julich

52425, Germany^2

关键词: Diode laser array;    Incoherent background;    Magnetic cavity;    Neutron wavelengths;    Polarization analyzers;    Small angle scattering;    Soft matter;    Volume Bragg gratings;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/862/1/012022/pdf
DOI  :  10.1088/1742-6596/862/1/012022

来源: IOP

【 摘 要 】

We present an ultra-compact3He polarizer to be used as a polarization analyzer for separation of incoherent background for soft matter research. The3He will be polarized in-situ within a very compact, 18 cm long, magnetic cavity that can be placed between the sample and the detector tank of small-angle scattering diffractometer KWS2 at MLZ [1]. This allows for the angular coverage of 38°, that corresponds to the maximal momentum transfer Qmaxλ=0.85 Å-1for neutrons with wavelength λ=4.5Å. The Qmaxcan be extended to 1.28 Å-1following the recent upgrade of KWS2 for neutron wavelength λ=3Å. The optical pumping will be done by the diode laser array bar frequency narrowed by the ultra-compact volume Bragg grating. The full system will be readily hand transportable and thus useful as an instrument add-on.