SANS / WANS Diffractometer and Spectrometer (Under Design)


CENTAUR Detectors (reflection)

Instrument Description

CENTAUR will be a small- and wide-angle neutron scattering (SANS/WANS) instrument with diffraction and spectroscopic capabilities to simultaneously probe time-resolved atomic- to meso-scale structures in hierarchical systems under in situ or in operando conditions. Simultaneous SANS/WANS and diffraction capabilities will be a unique capability among neutron scattering instruments in the United States.

Its direct geometry spectrometer mode will extend inelastic measurements to low scattering angles and provide a unique capability for inelastic SANS studies.

  • High-performance, optimized SANS/WANS. The minimum Q is similar to main-stream SANS instruments ~ 0.001 Å-1. The divergence on sample is adjustable for different experiments.
  • Diffraction capability. Up to 20 Å-1 simultaneously with SANS, bridging atomic- to meso-scale structures
  • Direct geometry spectrometer capability.  A removable high-speed monochromatic chopper near the sample position provides a unique inelastic SANS capability for incident energy 0.5- 500 meV
  • Polarization neutron analysis. Up to 0.3 Å-1
  • User-friendly sample environment. Walk-in sample space, simplified sample environment device change, and a wide range of sample environments: SANS sample cells, automatic sample changers, automatic inline flow cell, liquid handling robot, temperature/pressure/humidity control, flow-through size-exclusion chromatography, stroboscopic sample environment capability, other in situ cells as needed, such as strain and shear; closed-cycle refrigerators, and low-temperature cryostats, such as helium-3 and dilution refrigerators, and magnets


The instrument will provide much needed capabilities in soft matter and polymer sciences, geology, biology, quantum condensed matter, and other materials sciences that need in situ and in operando experiments for kinetic and/or out-of-equilibrium studies. Beam polarization and a high-resolution chopper will enable detailed structural and dynamical investigations of magnetic and quantum materials. The instrument’s excellent resolution will make it ideal for low-angle diffraction studies of highly ordered large-scale structures, such as skyrmions, shear-induced ordering in colloids, and biomembranes.

Soft Matter
Examples include polymers, colloids, micelles, complex fluids, gels and blends, and microemulsions

Material Sciences
Additive manufacturing, metallurgical alloys, advanced composites, and porous materials

Soils and Earth formation rocks; planetary and meteorite geoscience

Biological Systems
Biomacromolecules such as proteins, RNA/DNA, lipids and multi-component biomembranes; intrinsically disordered proteins (IDPs) and regions (IDRs), liquid-liquid phase separations, and biopharmaceuticals

Quantum Condensed Matter
Spin texture, skyrmion, vortex lattices, Brillouin scattering, and magnetic domains


Sample size Typical radius 1–5 mm, other shapes possible with different apertures (e.g., 4×8 mm2 or smaller); minimum static solution sample in volume ~100 µL;); minimum beam size 1×1 mm2 for scanning imaging or tomography
Q range Maximum dynamic range 0.001–20 Å-1 simultaneously.
Variable Q range with different flux/divergence settings.
  • Typical solution scattering is 0.002-2.0 Å-1
  • Typical moderate-ordered sample is 0.001-6 Å-1
  • Typical diffraction samples is 0.001-20 Å-1
Detector coverage Covers the whole Q range simultaneously without repositioning
Wavelength bandwidth 7.4 Å (15 Hz), 14.8 Å (7.5 Hz)
Q resolution

Forward detectors (small- and wide-angle): < 10%
Backscattering detectors (diffraction): < 1%

Time resolution >1 second (with moderate scattering samples; integrated flux on sample up to 7.6E8 n/s/cm2 with the shortest collimation setting)
Additional capability

Inelastic SANS spectrometer (incident energy Ei: 0.5-500 meV)
Polarized analysis up to 0.3 Å-1


Conceptual Polarization Setup at CENTAUR, the SANS/WANS Instrument at the Second Target Station of SNS”. S Qian, C Jiang, F Li, A Khaplanov, Journal of Physics: Conference Series 2481 (1), 012002

"CENTAUR—The small-and wide-angle neutron scattering diffractometer/spectrometer for the Second Target Station of the Spallation Neutron Source". Shuo Qian, William Heller, Wei-Ren Chen, Andrew Christianson, Changwoo Do, Yangyang Wang, Jiao YY Lin, Thomas Huegle, Chenyang Jiang, Cristina Boone, Cameron Hart, Van Graves, Review of Scientific Instruments 93 (7), 075104 

"Optimization of neutron chopper and optics for CENTAUR, the SANS/WANS diffractometer at the spallation neutron source second target station". C. Boone, F. Ye, Y. Zhang, Nuclear Insttrument and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1063, 169253

Technical Report

SECOND TARGET STATION (STS) PROJECT CENTAUR Technical Report, S Qian, C Boone, Oak Ridge National Lab.(ORNL), Oak Ridge, TN (United States)