MLZ is a cooperation between:

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MLZ (eng)

Lichtenbergstr.1
85748 Garching

SANS-1

Small angle neutron scattering

SANS-1 SANS-1

The new small angle scattering instrument SANS-1, a joint project of TUM and HZG is in regular user service [1]. SANS-1 is located at the end of neutron guide NL4a in the Neutron Guide Hall West.

SANS-1 is a standard pinhole SANS instrument with both 20 m collimation distance and 20 m sample detector distance, respectively. SANS-1 has been optimised by Monte-Carlo simulations to fit the restrictions in both available space and optimal usage of the provided neutron beam [2,3]. A vertical S-shaped neutron guide with extreme suppression of fast background neutrons is optimised for complementary wavelength packages, followed by the selector tower with two selectors for high and low resolution, respectively. Adjacent to the selector tower, a collimation system with four parallel horizontal tracks provides vast flexibility: The first track is occupied by a neutron guide system, the second track carries the collimation system with additional background apertures on track three. One track remains empty for various future applications such as focussing lenses or a longitudinal spin echo option. Two Fe/Si transmission polarisers have been optimised to cover the whole wavelength band from 4.5–30 Å. A TISANE double disk chopper is available which allows to perform kinetic neutron scattering experiments in the µs regime.

The acentric mounting of the detector tube with around 2.4 m inner diameter allows to use a primary detector of 1 × 1 m2 with lateral movement of more than 0.5 m, significantly expanding the accessible Q-range to around Qmax ≈ 1 Å-1. The primary detector is made up of an array of 128 position sensitive tubes to provide 8 mm × 8 mm spatial resolution. A second high resolution (3 mm) detector, installed downstream of the primary detector is foreseen for 2016.

A thorough characterization of the key features of SANS-1 at MLZ is given in [1]. Measurements of the neutron beam profile, divergence and flux are given for various positions along the instrument including the sample position, and agree well with Monte Carlo simulations of SANS-1 using the program McStas [2,3]. Secondly, the polarization option of SANS-1 is characterized for a broad wavelength band. A key feature of SANS-1 is the large accessible Q-range facilitated by the sideways movement of the detector. Particular attention is hence paid to the effects that arise due to large scattering angles on the detector where a standard cos3 solid angle correction is no longer applicable. Finally the performance of the instrument is characterized by a set of standard samples.

[1] Mühlbauer, S. et al., NIMA 832, 297-305 (2016).
[2] Gilles, R. et al., Physica B 385-386, 1174-1176 (2006).
[3] Gilles, R. et al., J. Appl. Cryst. 40, s428-s432 (2007).

Typical Applications

The instrument SANS-1 is dedicated to study the structure of materials on length scales of 10 to 3000 Å. With its polarised beam option, the flexible sample goniometer, the wide non-magnetic sample space and the specialised set of sample environment, SANS-1 is particularly adapted for the needs of materials research and magnetism. The precise sample goniometer carries various loads up to 750 kg and fulfills the rising demand on diffraction experiments at low scattering angles, for instance for studies of superconducting vortex lattices and other large magnetically ordered systems.

  • Precipitates and segregation in alloys
  • Chemical aggregation
  • Defects in materials, surfactants, colloids
  • Ferromagnetic correlations in magnetism
  • Magnetic domains
  • Polymers, proteins, biological membranes, viruses, ribosomes and macromolecules
  • Superconducting vortex lattices
  • Large magnetic structures such as helical magnets and skyrmion lattices
Sample Environment
  • Standard sample changer with 22 positions
  • Different types of high temperature furnaces up to 1900°C
  • Deformation-rig with heating
  • Set of magnets (5 T horizontal, parallel and perpendicular access, 7.5 T vertical)
  • Sample changer with thermostat (-20 +200°C), 11 positions
  • Different cryostats with optional 3He insert (460 mK base temp. with 5 T magnet, 50 mK with 7.5 T magnet)
  • Polarisation analysis with 3He cell
Technical Data

Primary beam

  • S-shaped neutron guide (NL 4a), 50 × 50 mm2
  • Mechanical velocity selectors with variable speed
    • 1) ∆λ/λ = 10% medium resolution
    • 2) ∆λ/λ = 6% high resolution
  • Wavelength range: 4.5 Å – 30 Å
  • TISANE chopper setup with µs time resolution

Polarisation

  • Two V-shaped polarisers

Collimation system (source-to-sample distance)

  • 1 m, 2 m, 4 m, 8 m, 12 m, 16 m to 20 m in steps via insertion of neutron guide sections

Sample size

  • 0 – 50 mm diameter

Q-range

  • 0.0005 Å-1 < Q < 1 Å-1 with primary detector
  • Qmin= 0.0001 Å-1 with secondary high resolution detector

Detectors

  • Primary detector: Array of 128 3He position­ sensitive tubes with an active area of 1000 × 1020 mm2 and 8 mm resolution. Lateral detector movement up to 0.5 m, counting rate capability up 1 MHz.
  • Secondary high resolution detector (3 mm) and an active area of 500 x 500 mm2 to be installed 2016.

Instrument Scientists

Dr. André Heinemann
Phone: +49 (0)89 289-14534
E-Mail:

Dr. Sebastian Mühlbauer
Phone: +49 (0)89 289-10784
E-Mail:

SANS-1
Phone: +49 (0)89 289-12818 /-14992

Operated by

TUM
GEMS

Publications

Find the latest publications regarding SANS-1 in our publication database iMPULSE:

impulse.mlz-garching.de

Citation of the instrument

Heinz Maier-Leibnitz Zentrum. (2015). SANS-1: Small angle neutron scattering. Journal of large-scale research facilities, 1, A10. http://dx.doi.org/10.17815/jlsrf-1-32

For citation please always include the DOI.

Gallery

SANS-1
SANS-1
© W. Schürmann, TUM
Collimation chamber
Collimation chamber

View into the collimation chamber of the SANS-1

MLZ is a cooperation between:

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