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 line | 1B |
|---|---|
| Moderator | decoupled poisoned supercritical hydrogen |
| Moderator-to-sample distance | 19.5 m |
| Sample-to-detector distance | 0.5 - 3 m |
| Wavelength range | 0.1 - 3Å |
| Momentum transfer range | 0.04 - 100Å-1 |
| Detector angular range | 3 - 175 ° scattering angle |
| Current Coverage | 4.0 steradian |
| Full detector complement | 8.2 steradian |
| Flux on sample | ~1 x 108 neutrons cm-2 sec-1 |
Sample Environment
| Automated Sample Changer with Cobra Cryostream | 90-500K, vanadium sample cans, quartz capillaries, NMR & kapton tubes |
|---|---|
| Orange Cryostat | 2-310K, vanadium sample cans |
| ILL furnace | Room temperature -1200C, vanadium sample cans (Compatibility of sample with vanadium at high temperatures required) |
| Aerodynamic levitator | 800-3000K, container-less solid samples |
| High Voltage Stick | +-10kV at room temperature, no temperature control, ceramic solids |
| Gas Handling Panel | 2 - 310K in cryostat + gas loading, vanadium sample cans, Room Temperature + gas flow, quartz U-Tube, Room Temperature - 800 C in ILL furnace + gas flow, quartz U-Tube |
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.