Neutrons Sciences Directorate at ORNL

The General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR

Instrument scientist Ken Littrell at GP-SANS.

Instrument scientist Ken Littrell at GP-SANS.

The General-Purpose Small-Angle Neutron Scattering Diffractometer (GP-SANS) instrument is optimized for providing information about structure and interactions in materials in the size range of 0.5 – 200 nm. It has a cold neutron flux on sample and capabilities comparable to those of the best SANS instruments worldwide, including a wide range of neutron wavelengths λ 5 – 30 Å, resolution Δλ ⁄ λ 9=45%, and a 1m2 area detector with 5 × 5mm2 pixel resolution with a maximum counting capability of up to 2.5 kHz. The sample-to-detector distance can be varied from 1 to 20 m, and the detector can be offset horizontally by up to 45 cm, allowing a total accessible Q range of from <0.001 to 1 Å-1. The 2m sample environment area will accommodate large, special-purpose sample environments such as cryomagnets, furnaces, mechanical load frames, and shear cells.

CG-2 Schematic

CG-2 schematic.

Applications

Soft condensed matter: molecular self-assembly and interactions in complex fluids; intermediate order in glassy systems, polymer solutions, gels and blends, colloids, micelles, and microemulsions.

Hard condensed matter: phase separation, grain growth, and orientation in metallurgical alloys, nanocomposites, advanced ceramics, and porous catalytic and adsorbent materials.

Magnetic systems: flux lattices in superconductors, ferrofluids, and the relationship between structural and magnetic domains and ordering.