Mission Statement

Study of a large variety of samples ranging from liquids, solutions, glasses, polymers, and nanocrystalline materials to long-range-ordered crystals.

Instrument Description

NOMAD is a high-flux, medium-resolution diffractometer that uses a large bandwidth of neutron energies and extensive detector coverage to carry out structural determinations of local order in crystalline and amorphous materials. It enables studies of a large variety of samples ranging from liquids, solutions, glasses, polymers, and nanocrystalline materials to long-range-ordered crystals. The enhanced neutron flux at SNS, coupled with the advanced neutron optics and detector features of NOMAD, allows for unprecedented access to high-resolution pair distribution functions, small-contrast isotope substitution experiments, small sample sizes, and parametric studies.

Applications

  • Environmental (e.g., solvent) effects on and direction of nanoscale structure formation
  • In situ structural changes in nanoscale oxide catalysts used in automobile catalytic converters
  • Structure of hydrogen storage materials under in situ conditions
  • Transient structures of materials under extreme conditions (e.g., at high temperature or high pressure under the influence of transient fields or in metastable states)

Specifications

Beam line1B
Moderatordecoupled poisoned supercritical hydrogen
Moderator-to-sample distance19.5 m
Sample-to-detector distance0.5 – 3 m
Wavelength range0.1 – 3 Å
Momentum transfer range0.04 – 100 Å-1
Detector angular range3 – 175° scattering angle
Initial coverage4.0 steradian
Full detector complement8.2 steradian
Flux on sample~1 × 108 neutrons cm-2 sec-1

Sample Environment

Automated Sample Changer with Cobra Cryostream90-500K, vanadium sample cans, quartz capillaries, NMR & kapton tubes
Orange Cryostat2-310K, vanadium sample cans
ILL furnaceRoom temperature -1200C, vanadium sample cans (Compatibility of sample with vanadium at high temperatures required)
Aerodynamic levitator800-3000K, container-less solid samples
High Voltage Stick+-10kV at room temperature, no temperature control, ceramic solids
Gas Handling Panel2-310K in Cryostat + gas handling, vanadium sample cans

More information can be found in this NOMAD overview presentation or "The Nanoscale Ordered Materials Diffractometer NOMAD at the Spallation Neutron Source SNS," published in Nucl. Inst. and Meth. B.