Single-crystal diffractometer with polarization option (Under Design)



Instrument Description

PIONEER is a time-of-flight, single-crystal diffractometer optimized for studying small-volume samples (< 1mm3) in a range of sample environments, including high/low temperature, magnetic field, and pressure. The instrument will provide world-leading capabilities by reducing sample volume requirements for single-crystal neutron diffraction experiments by more than one order of magnitude, allowing detailed atomic-scale structural characterization of materials at the earliest stages of discovery when large crystals are typically unavailable. PIONEER will be capable of measuring tiny crystals (~ 0.001 mm3) and ultra-thin epitaxial films (~10 nm thicknesses  x 25 mm2 area). It will also provide a polarized beam option to study weak magnetic scattering signals and support a high-resolution mode to probe large unit cells up to 200 Å.

PIONEER will leverage the unique Second Target Station source characteristics of high cold-neutron flux and a small beam footprint with the latest advances in neutron optics, neutron spin manipulation, instrument design, and computational techniques to enable rapid data collection despite small-volume samples and weak signals. Time-of-flight resolution will significantly reduce reflection overlap and lower the background noise. With a 4-Å wavelength band and 4.4-sr detector coverage, PIONEER will measure a broad reciprocal space at a single sample rotation. The 800-mm sample-to-detector distance will provide flexibility in using various sample environments.


Quantum Materials

  • Unconventional superconductivity
  • 4d-5d strong spin-orbital coupling systems
  • Topological materials

Functional materials for energy applications

  • Metal-organic frameworks (MOFs)
  • Polyoxometalates
  • Multiferroic oxides
  • Complex hydrides
  • Thermoelectric materials

Thin films and artificial heterostructures

  • Antiferromagnetic spintronics
  • Multiferroics

Planetary sciences and mineral physics

  • Natural mineral inclusion

Time-resolved studies

  • Spin relaxation
  • Time-resolved crystallography


Moderator Cylindrical Coupled Hydrogen (20 K)
Source frequency 15 Hz
Source-to-sample distance 60 m
Sample-to-detector distance 0.8 m
Best resolution Δ/Q < 0.3%
Average flux (n cm-2 s-1) at 0.7 MW 6.8 x 108 (1.5-5.5 Å, high flux mode)
Beam size (square) 0.5 – 5 mm, variable
Beam divergence (FWHM) 0.2°-0.6°, variable
Sample size (single crystal) 0.001 – 10 mm3
Sample size (thin film) thickness > 10 nm area, up to 25 mm2
Unit cell size up to 200 Å
Wavelength bandwidth 4.0 Å (15 Hz)
Useful wavelength range 1 – 6 Å
Q range 0.15 - 12 Å-1
Detector angular coverage -159o - 98o (horizontally)
-36o - 47o (vertically)
Detector type SiPM Anger camera
Detector resolution 0.6 x 0.6 mm2
Solid angle coverage 4.0 sr (top cylindrical)
0.4 sr (bottom planar)