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@INPROCEEDINGS{Schweika:1034061,
      author       = {Schweika, Werner and Vasiukov, Denis and Fabrèges, Xavier
                      and Klimk, Sergey and Soltner, Helmut and Klauser, Christine
                      and Lee, Wai Tung and Feygenson, Mikhail},
      title        = {{S}pherical neutron polarimetry at {MAG}i{C}},
      reportid     = {FZJ-2024-06882},
      year         = {2024},
      abstract     = {Spherical neutron polarimetry has been routinely
                      established using Cryopad [1], measuring in zerofieldthe
                      full polarization tensor for single Bragg peaks. This is a
                      precise tool perfectly suited formonochromatic instruments
                      at reactor sources. How to achieve this goal at ESS and at
                      pulsed sourcesin general with polychromatic beams?There are
                      two feasible solutions. Since such experiments are
                      essentially not limited by flux, a straightforwardsolution
                      for pulsed sources would be to use the Cryopad as a sample
                      environment at instrumentsthat are already equipped for
                      longitudinal polarization analysis.Here we consider an
                      alternative approach based on a precession technique [2,3]
                      that can be fullyadapted to a pulsed, polychromatic neutron
                      beam to cover a large section of the reciprocal space
                      intime-of-flight Laue diffraction. Since this method accepts
                      the non-precessing component for polarizationanalysis, it
                      applies as well to inelastic scattering. In order to make
                      use of the full wavelengthband, the π/2-flipper, which
                      initiates the precession mode, needs to be ramped in time
                      accordingto the neutron’s wavelength and its
                      time-of-flight. A common phase of the precession angle at
                      thesample is not a necessary requirement but can be
                      favorably achieved by an additional spin-echosetup. For an
                      instrument like MAGiC at ESS, spherical polarization
                      analysis can be a straightforwardextension of the existing
                      setup for longitudinal polarization analysis. We are
                      considering thispotential upgrade for the MAGiC instrument
                      and present a relatively simple scheme how to modifythe
                      magnetic field setup for the incoming beam to enable
                      spherical polarimetry. Full simulationsof the polarized
                      neutron transport not only demonstrate the feasibility of
                      spherical polarimetry butalso its excellent performance.[1]
                      Tasset, F. (1989). “Zero field neutron polarimetry”.
                      Physica B: Condensed Matter, 156, 627-630.[2] Schweika, W.
                      (2003). “Time-of-flight and vector polarization analysis
                      for diffuse neutron scattering.”Physica B: Condensed
                      Matter 335 (1 - 4), 157 -163.
                      https://doi.org/10.1016/S0921-4526(03)00229-1[3] Schweika,
                      W., Easton, S., $\&$ Neumann, K. U. (2005). “Vector
                      Polarization Analysis on DNS”. NeutronNews, 16(2), 14-17.
                      https://doi.org/10.1080/10448630500454262},
      month         = {Dec},
      date          = {2024-12-11},
      organization  = {Flipper 2024 as a satellite workshop
                       of the ILL/ESS user meeting, Institut
                       Laue-Langevin (ILL) located on the
                       European Photon and Neutron (EPN)
                       campus (France), 11 Dec 2024 - 13 Dec
                       2024},
      subtyp        = {Invited},
      cin          = {JCNS-2 / JARA-FIT / ZEA-1 / JCNS-ESS},
      cid          = {I:(DE-Juel1)JCNS-2-20110106 / $I:(DE-82)080009_20140620$ /
                      I:(DE-Juel1)ZEA-1-20090406 / I:(DE-Juel1)JCNS-ESS-20170404},
      pnm          = {632 - Materials – Quantum, Complex and Functional
                      Materials (POF4-632) / 6G4 - Jülich Centre for Neutron
                      Research (JCNS) (FZJ) (POF4-6G4)},
      pid          = {G:(DE-HGF)POF4-632 / G:(DE-HGF)POF4-6G4},
      typ          = {PUB:(DE-HGF)24},
      url          = {https://juser.fz-juelich.de/record/1034061},
}