#STELLA GLOW CARTESIA UPGRADE#
#STELLA GLOW CARTESIA WINDOWS#

Spin-Echo Modulated Small Angle Neutron Scattering (SEMSANS) in Time-of-Flight (ToF) mode has been shown to be a promising technique for measuring (very) small angle neutron scattering (SANS) signals and performing quantitative Dark-Field Imaging (DFI), i.e., SANS with 2D spatial resolution. Sales, Morten, E-mail: Plomp, Jeroen Bouwman, Wim Wavelength-independent constant period spin-echo modulated small angle neutron scattering The experimental characterization of the instrument components demonstrates the reliable performance of the new neutron resonance spin-echo option, now available for the scientific community at FLEXX.Â«Â less The improved performance extends the range of feasible experiments, both for inelastic scattering on excitation lifetimes in single crystals, and for high-resolution Larmor diffraction.

In combination with the redesigned components of the FLEXX spectrometer, including the guide, the S-bender polarizer, the double focusing monochromator, and a Heusler crystal analyzer, the count rate increased by a factor of 15.5, and the neutron beam polarization is enhanced. Due tomoreÂ Â» the compact design of the spin-echo units in combination with the increased coil tilt angles, the accessible momentum-range in the Larmor diffraction mode is substantially enlarged. The larger beam cross sections permit higher coil inclination angles and enable measurements on dispersive excitations with a larger slope of the dispersion.

#STELLA GLOW CARTESIA WINDOWS#

The RF-flippers with larger beam windows allow for an improved neutron flux transfer from the source to the sample and further to the analyzer. The parameters of redesigned key components are discussed, including the radio frequency (RF) spin-flip coils, the magnetic shield, and the zero field coupling coils.

#STELLA GLOW CARTESIA UPGRADE#

We describe the upgrade of the neutron resonance spin-echo setup at the cold neutron triple-axis spectrometer FLEXX at the BER II neutron source at the Helmholtz-Zentrum Berlin.

Neutron resonance spin-echo upgrade at the three-axis spectrometer FLEXX Here we present the results of numerical optimization of the coil geometry and first data from the prototype instrument. In addition, it also incorporates the MIEZE technique, which allows to achieve spin echo resolution for spin depolarizing samples and sample environments. The LNRSE technique is a future alternative for high-resolution spectroscopy of quasi-elastic excitations. One pair of RF flippers at a distance of 2 m generates a field integral of Ëœ0.5 Tm. The DC fields are generated by B0 coils, based on resistive split-pair solenoids with an active shielding for low stray fields along the beam path. Our prototype LNRSE spectrometer described here was implemented at the resonance spin echo for diverse applications (RESEDA) beamline at the MLZ in Garching, Germany. As the precision and the current density of the correction coils are the limiting factors for the resolution of both NSE and LNRSE, the latter has the intrinsic potential to surpass the energy resolution of present NSE instruments. Due to the good intrinsic homogeneity of the B0 coils, the current densities required for the correction coils are at least a factor of three less than in conventional NSE. The residual inhomogeneity can be reduced by Fresnel- or Pythagoras-coils as in the case of conventional spin echo instruments ( neutron spin echo (NSE)). In the center of the RF coils, the sign of the spin precession phase is inverted by a Ï€ flip of the neutron spins, such that non-uniform spin precession at the boundaries of the RF flippers is canceled. The advantage of the longitudinal configuration is the inherent homogeneity of the effective magnetic path integrals. We report on the design, construction, and performance of a neutron resonance spin echo (NRSE) instrument employing radio frequency (RF) spin flippers combining RF fields with DC fields, the latter oriented parallel (longitudinal) to the neutron propagation direction (longitudinal NRSE (LNRSE)). Krautloher, Maximilian Kindervater, Jonas Keller, Thomas HÃ¤uÃŸler, Wolfgang

Neutron resonance spin echo with longitudinal DC fields

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