Analyzing the structure of inhomogeneities, from minerals to biological tissues.
USANS is designed for the study of hierarchical structures in natural and artificial materials. It can be considered an advanced version of the classical Bonse-Hart double-crystal diffractometer (DCD), which in contrast with its single-wavelength reactor-based analog, will operate with the discrete multiwavelength spectrum of Bragg reflections.The optical scheme of the USANS instrument is similar to that of the conventional Bonse-Hart DCD; however, the pulsed nature of SNS offers an opportunity to separate the orders of Bragg reflection in time space using the time-of-flight technique. Thus, the concept of the USANS technique allows optimization of the neutron flux and the Q resolution, following the principles of dynamical diffraction theory.
Ultra-small-angle neutron scattering provides a new way to solve a broad range of scientific problems such as:
Supramolecular structure of polymer blends
Macroscale self-similarity of rocks
Structure of colloidal crystals and alloys
Hydration of cement pastes
Aggregation in colloidal dispersions
Self-assembling of polymers
Mesoscopic structure of natural composites
Structure of granular powders
Morphology of colloidal reinforcing fillers
Structure and morphology of complex fluids
Rheology and morphology of hydrogels
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 – 3 Å
Momentum transfer range
0.04 – 100 Å-1
Detector angular range
3 – 175° scattering angle
Initial coverage
4.0 steradian
Full detector complement
8.2 steradian
Flux on sample
~1 × 108 neutrons cm-2 sec-1
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 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.