Extended Q-Range Small-Angle Neutron Scattering Diffractometer


Mission Statement

Enable nanoscale characterization of materials from physics, chemistry, biology and the materials sciences to better understand the relationship between structure and function.

Instrument Description

The EQ-SANS Diffractometer is designed to study non-crystalline, nano-sized materials in solid, liquid, or gas forms such as polymers, micelles, proteins, and other large biological molecular complexes in solution. It offers high neutron flux, broad dynamic Q-range, and overall wide Q-coverage.

EQSANS is located on beam line 6, viewing the top-downstream, coupled supercritical hydrogen moderator. It has a curved multichannel beam bender to avoid the direct line of sight of the moderator, which cleans out the background from the prompt neutron pulse quite effectively. Three bandwidth choppers on the EQ-SANS define a clean wavelength band 3 - 4.3 Å wide at 60 Hz depending on the detector distance being employed. The instrument can operate at 30 Hz to produce two neutron wavelength bands, which provides a wider dynamic Q-range at a single detector distance setting. At present, the instrument has a 1 × 1 m low-angle detector, which could be expanded to 1 × 1.4 m. The low-angle detector can travel along the beam inside the scattering tank, giving a variable sample to detector distances of 1.3 to 9 m.

The available sample environment is an automated sample changer that can be controlled between 5 and 60°C and can accommodate 15 banjo cells or 10 demountable titanium cells. An extended temperature range of 5°C to 130°C can be achieved with improved precision and ramp rates via Peltier units capable to accommodate 12 banjo cells. A furnace is available that can provide temperatures up to 330 °C. A sample tumbler for studying colloids that settle out of solution, and a relative humidity generator that can interface with a goniometer for performing GI-SANS measurements are also available.


Polymer and colloidal systems

  • Block copolymers and dendrimers
  • Micelles and emulsions
  • Polyelectrolytes and ion distribution at solid-liquid interfaces

Materials science

  • Simultaneous study of domain and crystalline structures
  • Crystallization and precipitation
  • Nanoparticles

Life science

  • Solution structures of proteins, DNA, and other biological molecules and molecular complexes
  • Protein-protein and protein-ligand interactions, kinase regulation
  • Protein-membrane interaction
  • Materials for drug delivery

Earth and Environmental Sciences

  • Pore structure in soils
  • Structure of geologic materials


Moderator Coupled supercritical hydrogen
Source-to-sample distance 14m
Sample –to-detector distance 1.3 ~ 9m
Detector size 1m x 1m
Bandwidth 3-4.3A
Integrated flux on sample ~ 10^7 – 10^9 n/cm2/s
Q range 0.002 < q < 1.4 A-1
Detector resolution 5.5 x 4.3 mm


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