V4

Small Angle Scattering Instrument
(SANS)

Instrument description

V4 allows for the measurement of density composition and magnetization fluctuations in materials on a length scale from 0.5 nm to 400 nm. At short distance the 2D-detector can be moved vertically by 0.17 m, extending the Q range to even higher values. A large sample chamber is connected to the vacuum system with the detector and collimator tubes. Automatic sample changers (both T and B controlled) are available.

A high transmission supermirror polarizer can be introduced by remote control in front of the 12 m collimation without any modification of the instrument alignement. The polarization direction can be reversed by a RF gradient spin-flipper in front of the sample. The SANSPOL option is characterized by a high neutron flux of more than 30% of the non-polarized beam (wavelength dependent), a high degree of polarisation ( > 90%) and high efficiency of the spin-flipper ( > 95%) for λ< 1.8 nm without any additional background.
Using the list mode data acquisition time-stamped measurements can be performed. Stroboscopic measurements by using a trigger signal allow to investigate the kinetics of periodic processes. The chopper system based on TISANE technique allows for studies of microsecond dynamics. 

Applications

  • Nanoscaled materials
  • Phase separation in alloys and glasses
  • Morphologies of superalloys
  • Magnetic correlations
  • Microporosity in ceramics
  • Interfaces and surfaces of catalysts
  • Biological macromolecules
  • Polymers and membranes 
  • Flux line lattices in superconductors

Selected examples

Time resolved SANSPOL investigations in concentrate Co-ferrofluids

Instrument layout



List of publications
Instrument Data
Neutron guide NL 3A
Collimation Entrance window: 50x30 mm2
Collimator length: 2m, 4m , 8m, 12m (all also for SANSPOL), and 16m
Monochromator Mechanical velocity selector
Wave length 0.45 < λ < 2 nm
Wave length resolution 8% < Δλ/λ < 18% FWHM
Flux 4.6·106n/cm2 at λ=0.5 nm, Δλ/λ = 10% and collimation 2m
Q range 0.01 nm-1 < Q < 8.5 nm-1
Q resolution
Detector ca. 1 m diameter, 112 Reuter-Stokes tubes, 1000 mm / 850 mm / 600 mm
Sample-to-detector distance Horizontal: 1 to 16m continuously
Vertical offset: 0.17 m at short distance
Polarized neutrons no longer supported
Instrument options • Stroboscopic SANS
• TISANE
Sample environment • T-controlled automatic sample changer (5°C-80°C)
Software BerSANS

Data reduction software

The "BerSANS" data reduction software package has been developed by Uwe Keiderling, and is constantly being expanded to offer new options and data treatment tools. It contains a set of programs for automated two-dimensional and one-dimensional reduction of large amounts of data files, and a set of graphical tools for data analysis, documentation, and publication.