Mission Statement

Looking at tiny structures 

SANS (small-angle neutron scattering) gathers information about the structure and interactions in materials between 0.5–200nm. Among the many things SANS is used to study are molecules called dendrimers, which are used in drug casings, and research with SANS is helping scientists develop cancer-fighting drugs that target particular locations in the body. Doing so would increase both drug efficiency and cancer survival rates.

Instrument Description

The General-Purpose Small-Angle Neutron Scattering Diffractometer (GP-SANS) CG-2 instrument is optimized for providing information about structure and interactions in materials in the 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(5–20 Å), a resolution Δλ ⁄ λ 9-45%, and a 1-square-meter area detector with 5.2 × 4 mm2 pixel resolution with a maximum counting capability of up to 200 kHz. The sample-to-detector distance can be varied from 1–20 m, and the detector can be offset horizontally by up to 45 cm, allowing a total accessible Q range from 0.0007 to 1 Å-1. The 2-meter sample environment area will accommodate large, special-purpose sample environments such as cryomagnets, furnaces, mechanical load frames, and shear cells.


  • 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


Beam SpectrumCold
MonochromatorsHelical slot selects
Incident wavelength4 < λ < 20 Å
Resolution RangeΔλ ⁄ λ= 9 – 45%
CollimationEight removable guide sections, each 4 x 4 cm2 and 2 m long; 2-meter open area at sample stage to mount automatic changers, furnaces, magnets, cryostats, pressure cells, etc.
Q range (Å-1)
1.5-m collimation
20 m collimation

0.038 < Q < 1.0 Å-1 (5 Å); 0.019 < Q < 0.50 Å-1 (10 Å)
0.004 < Q < 0.074 Å-1 (5 Å); 0.002 < Q < 0.037 Å-1 (10 Å)
Sample detector distances1 - 20 m
Detector2D (3He) position-sensitive detector with detector resolution/pixels 192x256
Max counting rate200 kHz