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| Home > Publications database > New polarized neutron diffraction setup with 8 T magnet on POLI |
| Conference Presentation (After Call) | FZJ-2021-03615 |
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2020
Abstract: The polarized single-crystal diffractometer POLI offers two types of polarized neutron diffraction experiments:spherical neutron polarimetry (SNP), also known as full three-dimensional polarization analysis in zero mag-netic field, and classical polarized neutron diffraction, also called flipping-ratio (FR) method, in high appliedmagnetic fields. Recently, the available sample environment of POLI has been extended by an asymmetric fieldmagnet of 8 T. Although this new magnet is actively shielded, its stray fields are still too large to be used withthe sensitive 3He polarizer of the original SNP setup. To overcome this issue, a new, large-beam-cross-sectionsolid-state supermirror (SM) bender polarizer has been developed for POLI. An existing shielded Mezei-typeflipper is used between the magnet and SM polarizer. A dedicated guide field construction was numericallysimulated, optimized and built to link the magnetic field of the polarizer to the flipper and to the stray field ofthe magnet. An almost loss-free spin transport within the instrument in the complete field range of the newmagnet was achieved. The new setup was successfully implemented and tested. A high polarization efficiencyof above 99% for short wavelength neutrons could be experimentally reached with the new solid-state bender.The new high–field FR setup is now available for POLI’s user community.
Keyword(s): Magnetic Materials (1st) ; Instrument and Method Development (1st) ; Magnetism (2nd)
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