Neutrons Sciences Directorate at ORNL

The Extended Q-Range Small-Angle Neutron Scattering Diffractometer at SNS

Extended Q-Range Small Angle Diffractometer

EQ-SANS detector array

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, high wavelength resolution (precision), and 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. The cutoff wavelength of the optics is ~1.5 Å. Above this minimum wavelength, the three bandwidth choppers on the EQ-SANS define a clean wavelength band of ~3.5 Å at 60 Hz. The choppers also allow the instrument to have a bandwidth of 3 - 4.3 Å. At present, the instrument has a 1 × 1 m low-angle detector, which will 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 10 m.

The available sample environment is a 45-cell automated sample changer than can be controlled between 5 and 80°C.

Applications

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