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85748 Garching

RESEDA

Resonance spin echo spectrometer

RESEDA RESEDA


RESEDA (resonance spin echo for diverse applications) is a high-resolution resonance spin-echo spectrometer installed at the cold neutron guide NL5-S in the Neutron Guide Hall West. The instrument gives access to a large time and scattering vector range for quasi-elastic measurements.

RESEDA supports longitudinal neutron resonance spin echo (LNRSE, time range from 0.001 to 20 ns for λ = 8 Å) and modulation of intensity with zero-effort (MIEZE, time range from 0.001 to 20 ns for λ = 8 Å) experiments. At RESEDA, the analysis of S(Q,τ) provides characteristic parameters, e.g. relaxation time and amplitude of the dynamic processes in the sample investigated. The determination of S(Q,τ) is feasible for different Q-values and/ or different temperatures and pressures.

NRSE experiments require non-depolarising sample environment conditions. For MIEZE experiments (and in contrast to NRSE) the spin manipulation and analysis is realised solely before the sample. Therefore, the MIEZE method enables high-resolution study of depolarising samples, under magnetic field and/ or within depolarising sample environments. However, as a consequence of the polarisation analysis before the sample, MIEZE experiments are limited to a smaller Q-range than NRSE measurements.
Next to 3He detectors, a 2D CASCADE detector with an active area of 20 cm x 20 cm characterised by a spatial resolution of 2.6 mm2 and a time dynamics of the order of a few MHz is available [1, 2].

Hence, RESEDA is in addition suited to (polarised) small angle neutron scattering (SANS) applications.

[1] Schmidt, C.J. et al., Journal of Physics: Conf. Ser. 251, 012067 (2010).
[2] Häußler, W. et al., Rev. Sci. Instr. 82, 045101 (2011).

Typical Applications
  • Quasi-elastic measurements:
    • e.g. to determine the dynamics of water in porous media, polymer melts, diffusion processes in ionic liquids as well as magnetic fluctuations in single crystals, powder samples and thin films
  • (Polarised) Small Angle Neutron Scattering (SANS):
    • e.g. to investigate the diffraction pattern of magnetic structures and vortex lattices to choose suited reflections for a line-width determination
  • Spherical polarisation analysis
Sample Environment

At RESEDA the whole sample environment of the MLZ is applicable. Depolarising conditions are limited to MIEZE experiments.

  • Available temperature range: 50 mK (dilution insert, see below) up to more than 1300 K (high temperature furnace, non-depolarising)
  • Maximal pressure: 7 GPa
  • Maximal magnetic field: 7.5 T
  • Available cryostats:
    • Closed cycle cryostat: (3 K < T < 300 K)
    • 3He insert: (450 mK < T < 300 K)
    • Dilution insert: (50 mK < T < 6 K)
Technical Data

Primary beam

  • Neutron guide: NL5-S
  • Guide cross section: 29 × 34 mm2
  • Wavelength selection: Velocity selector (max. 28000 rpm)
  • Wavelength range: λ = 3 – 12 Å
  • Wavelength bandwidth at sample position: Δλ/λ = 9 – 20%
  • Polariser: V-cavity (length: 2 m, coating: m = 3)

Spectrometer

  • Optional polariser before sample: V-cavity (length: 30 cm, coating: m = 4)
  • Length of the spectrometer arms: 2.6 m
  • Two secondary spectrometer arms: SANS (MIEZE) arm and LNRSE arm
  • For polarisation analysis available: V-cavity, Bender
  • Detectors: 3He counter or 2D detector (CASCADE)

Characteristic parameters

  • Flux at sample position: φ ≥ 106 n cm-2 s-1 (at λ = 5.3 Å)
  • Frequency range of RF coils: 35 kHz – 1.7 MHz
  • Maximum scattering angle: 2θ = 93°
  • Maximum scattering vector: Q = 2.5 Å-1 (at λ = 3 Å)
  • Spin echo time range: τ = 0.001 – 20 ns for λ = 8 Å
  • Energy resolution: 0.03 µeV – 0.1 meV

Instrument Scientists

Dr. Christian Franz
Phone: +49 (0)89 289-14760
E-Mail:

Dr. Olaf Soltwedel
Phone: +49 (0)89 289-14769
E-Mail:

RESEDA
Phone: +49 (0)89 289-14874

Operated by

TUM

Publications

Find the latest publications regarding RESEDA in our publication database iMPULSE:

impulse.mlz-garching.de

Citation of the instrument

Heinz Maier-Leibnitz Zentrum. (2015). RESEDA: Resonance spin echo spectrometer. Journal of large-scale research facilities, 1, A14. http://dx.doi.org/10.17815/jlsrf-1-37

For citation please always include the DOI.

Gallery

RESEDA
RESEDA
© W. Schürmann, TUM
Dynamics of TBABr solution
Dynamics of TBABr solution

Figure 1: Dynamics of TBABr solution in heavy water (D. Bhowmik et al., Eur. Phys. J. – Special Topics 213, 303 – 312 (2012)).

Temperature dependence of the spin dynamics
Temperature dependence of the spin dynamics

Figure 2: Temperature dependence of the spin dynamics in MnSi above TC as seen by NRSE (left) and MIEZE (right)

MLZ is a cooperation between:

Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Geesthacht> Helmholtz-Zentrum GeesthachtForschungszentrum Jülich> Forschungszentrum Jülich