Diffraction

Diffraction

Scientists and users at Oak Ridge National Laboratory use neutron scattering (diffraction) to observe and understand how the atomic-level magnetism and structure of materials correlates to their properties, which can lead to the development of new functional materials with highly desirable structures and properties as well as a deeper understanding of biological processes.

At ORNL, research using neutron diffraction primarily focuses on six scientific themes:

Biological materials and systems
Chemistry, catalysis, and interfaces
Computing, modeling, and data analytics
Materials and engineering
Quantum materials
Soft matter and polymers

ORNL hosts 12 diffractometers—7 at the Spallation Neutron Source and 5 at the High Flux Isotope Reactor—which are operated and maintained by the Diffraction and Materials Engineering groups. These two groups contain outstanding neutron scattering scientists with a wide range of scientific interests and expertise. The diffractometers are divided into two suites: powder diffraction instruments and single crystal instruments. More details can be found by following the links to the individual instrument and scientist pages below.

POWDER DIFFRACTION INSTRUMENTS

Instrument	Type	Methods	Applications	T (K)	P (GPa)	H (T)	Special	Resolution (∆d/d)	Q-range (Å-1)	Beam size H x V (mm)
HFIR HB-2A POWDER	constant wavelength	Rietveld	Magnetic structures	0.05 - 1800	< 0.6 gas cell < 2 clamp cell	< 7	Electric field	2 x 10-3 (variable)	0.2 - 5.1 and 0.35 - 8	30 x 60
HFIR HB-2C WAND 2	constant wavelength	Rietveld, single-crystal	General purpose powder / single-crystal	0.05 - 1800	< 0.6 gas cell < 2 clamp cell	< 6	Humidity chamber	5 x 10-3	0.1 to 8.2	30 x 40
SNS BL-11A POWGEN	t-o-f	Rietveld, PDF	General purpose powder	10 - 300 (PAC) 2 - 300 (Orange cryo & Slim Sam) 5 - 500 (JANIS) 30 - 750 (JANIS) 300 - 1450 (MICAS) 300 - 1100 (with gas insert) (MICAS)		< 5	24 position sample changer (10 - 300 K), Gas Handling with pO2 and RGA	0.8 x 10-3	0.76 - 46.9 in one frame 0.17 - 46.9 with multiple frames	10 x 40
SNS BL-1B NOMAD	t-o-f	PDF, Rietveld	Disordered materials, glasses, liquids; high flux powder	90 - 1500 (Ar cryostream) 2 - 300 (Orange cryo) 425 - 11450 (ILL furnace, limited measuring time above 1100C) 1000 - 3500 (levitator)	0.02 - 0.2 gas cell (TiZr cell, high background)		Cryostream sample changer; gas handling, batteries	5 x 10-3 to 5 x 10-2	Typical 0.2 - 31.41, low Q limited to 0.4 in furnace and Orange cryo.	Typically 6 x 6 FWHM, Gaussian beam profile, generally 2cm filling height required.
SNS BL-3 SNAP	t-o-f	Rietveld	High pressure studies powder/ single-crystal	85 - 1350 (Paris Edinburgh) 300 - 1500 Paris Edinburgh (high T insert) 2 - 350 Clamp cell (Orange cryo) 10 - 1350 Diamond Anvil Cell (DAC) (bottom loader cryo) 10 - 350 Gas cell / Clamp cell	< 20 PE cell < 6 PE cell < 2 clamp cell 0.6 Gas cell < 40 DAC			8 x 10-3 (at 2θ = 90°)	0.8-30	Typical, 1 cm2 < 1 mm2 for DACs

A suite-level review of the neutron powder diffraction instruments at Oak Ridge National Laboratory, Rev. Sci. Instrum. 89, 092701 (2018);
https://doi.org/10.1063/1.5033906

SINGLE CRYSTAL INSTRUMENTS

Instrument	Type	Applications	T (K)	P (GPa)	H (T)	Special	Q-range (Å-1)	Unit cell size (Å)	Beam size H x V (mm)
HFIR HB-3A DEMAND	constant wavelength	Magnetic / nuclear structures; small unit cells	4 - 1700 CCR 1.6 - 300 OC 0.05 - 300 DF	< 2 clamp cell < 10 DAC*	< 6	Electric current, Tunable beam divergence	0.12-12	< 100	6 mm in diameter
HFIR HB-2C WAND 2	constant wavelength	General purpose powder/single-crystal; small unit cells	0.05 - 11800	< 0.5 gas cell < 2 clamp cell < 5 Cubic anvil cell < 20 PE cell (Room T)	< 6	Humidity chamber	0.1-8.2	< 100	Variable: 10 x 40 to 30 x 60
SNS BL-12 TOPAZ	t-o-f	General purpose; small & large unit cells; diffuse scattering	90 - 1450 LN2 5-300 CCR	None	None	Electric current	0.4-25	< 75	2 , 3 and 4 in diameter
SNS BL-11B MaNDi	t-o-f	Structural biology, macromolecules, small molecules	80 - 400	None	None	Tunable beam divergence 0.12 - 0.8°	0.6 Å max resolution	10 - 300	1, 3 and 5 in diameter
HFIR CG-4D IMAGINE	quasi-Laue	Structural biology, supramolecular chemistry, magnetic / nuclear structures	4 - 1450 CCR 10 - 1300 (DAC)	< 10 DAC	None	Kappa goniometer	1.2 Å max resolution	< 150	3.2 × 2
SNS BL-9 CORELLI	t-o-f	Magnetic / nuclear diffuse scattering	6 - 750 CCR 1.6 - 300 OC 303 - 1873 (MICAS) 0.3 - 300 3He insert	< 1.8 clamp cell < 10 DAC < 4 GPa McWhan	< 5 < 30 Pulsed	Elastic discrimination			10 x 10
SNS BL-3 SNAP	t-o-f	High pressure studies powder / single-crystal	85 - 1300 (PE 10 GPa) 300 - 1500 (PE 6 GPa) 2 - 350 (gas and clamp) 10 - 350 (DAC)	< 40 DAC** < 20 PE cell < 6 PE cell < 2 clamp cell 0.7 Gas cell	None

*Note that SNAP DACs with 40 GPa capability have been successfully used on DEMAND although pressures on single crystal samples have not been demonstrated above 10 GPa. If higher pressures than 10 GPa are desired, please contact instrument team. **Note that a maximum of 20 GPa has been demonstrated for single crystal samples. The cells themselves are in principle capable of reaching 100 GPa on powders. If high pressures are of interest, please contact instrument team for discussion.

For more details of each instrument's specifics, refer to instrument home page.

A suite-level review of the neutron single crystal diffraction instruments at Oak Ridge National Laboratory, Rev. Sci. Instrum. 89, 092802 (2018);
https://doi.org/10.1063/1.5030896