Information for DEMAND Users

An article titled "Four-circle single-crystal neutron diffractometer at the High Flux Isotope Reactor" was published in the Journal of Applied Crystallography in 2011 (44: 655-658) that details the instrument's capabilities and specifications:

Abstract

Abstract: A four-circle neutron diffractometer with a new multi-wafer 331 Si monochromator has been installed and commissioned on a thermal beamline at the High Flux Isotope Reactor at Oak Ridge National Laboratory. The instrument is well suited to studies of nuclear and magnetic structures as a function of composition and temperature, resolving symmetry changes (lattice distortions and local structural changes), mapping the evolution of complex magnetic phases, determining hydrogen bonding, analyzing nuclear and spin densities, mapping diffuse scattering, and exploring fiber diffraction. Three incident wavelengths are available, 1.003, 1.542 and 2.541 Å, with intensities of 2.5 × 106, 2.2 × 107 and 8.0 × 106 neutrons cm-2 s-1, respectively. Either high-resolution or high-intensity modes are possible by horizontal bending of the monochromator. With increased bending of the monochromator, the incident flux on the sample passes through a maximum, increasing by ×2.0 for 1.003 Å, by ×3.5 for 1.542 Å and by ×3.5 for 2.541 Å, as compared to the flat condition. The flux increases because the lattice strain in the silicon crystals increases. The ω-scan peak width increases with monochromator curvature and this width versus scattering angle flattens. Given these effects, the monochromator bending can be adjusted to deliver high intensity primarily for crystal structure refinements or high resolution for resolving symmetry changes. In addition to the traditional step-scanning mode, a more efficient continuous-scanning mode was developed, and both these are implemented through a LabView-based control program, i.e. a modified version of the SPICE software package. A 4 K closed-cycle helium refrigerator is permanently mounted on the Χ-circle of the goniometer to provide temperature control between 4 and 450 K.

Citation

Chakoumakos B. C., Cao H., Ye F., Stoica A. D., Popovici M., Sundaram M., Zhou W., Hicks J. S., Lynn G. W., Riedel R. A., "Four-circle single-crystal neutron diffractometer at the High Flux Isotope Reactor", Journal of Applied Crystallography 44, 655-658 (2011).

Shipping Addresses for Samples

For more detailed information, please visit the ORNL User Facilities Sample Handling and Shipping page.

Non-activated samples coming to HFIR:

Recipient: IPTS XXXXX, HFIR user sample
Oak Ridge National Laboratory / HFIR Site
1 Bethel Valley Road
Bldg 7972 Room 100 [Special requirements (example: freezer or inert gas)]
Oak Ridge, TN 37830
HFIR Sample Management Desk phone number: 865-576-9030

Activated samples coming to HFIR:

Recipient: IPTS XXXXX, HFIR user sample [Replace the XXXX with your IPTS number]
Oak Ridge National Laboratory / HFIR Site
1 Bethel Valley Road
Bldg 7001 [Special requirements (example: freezer or inert gas)>]
Oak Ridge, TN 37830
HFIR Sample Management Desk phone number: 865-576-9030

Users are encouraged to use a shipping provider who delivers directly to ORNL (ex. FedEx, UPS, DHL). These shipments are considered priorities and are processed through ORNL shipping facilities within 8-24 hours of delivery. Please be aware that use of the USPS may delay the processing of your shipment, due to a longer lead time for sorting.

NOTE: Replace the XXXX with your Integrated Proposal Tracking System (IPTS) number.

Access to HB-3A DATA

Experimental files are accessible on the instrument using the Spectrometer Instrument Control Environment (SPICE) data acquisition and data reduction system.

Graffiti software.

Additional Software Downloads

  • Graffiti – This program allows the user to download HFIR data to his/her own computer and browse through the scans in the experiment. It also allows combining data sets, angle calculations, spurion checks, etc.
  • FullProf and GSAS are Rietveld refinement packages for determination of nuclear and magnetic structures.
  • SaraH – contains the user friendly magnetic structure analysis programs SARAh-Representational Analysis and SARAh-Refine. SARAh uses representational analysis to calculate 'symmetry allowed magnetic structures' . The front-end SARAh-Refine facilitates analysis of magnetic diffraction data in terms of these results with GSAS and FullProf. When used with GSAS, SARAh allows reverse Monte Carlo/ Simulated Annealing refinement of the moment orientations. When used with FullProf, automatic creation and editing of the magnetic phase can be controlled by the user.
  • Mantid - Use the Mantidplot application to reduce and visualize HB-3A data.

Lecture Notes and Example Data

Please refer to the Lecture Notes page from the Magnetic Structure Determination from Neutron Diffraction Data Workshop 2014 for example data and relevant articles.