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	∆ d d	Q-range	sample size
HFIR HB-2A Powder Diffractometer	constant wavelength	Rietveld	Magnetic structures	0.05 - 1800	< 5 gas cell < 2 clamp cell	< 7	Electric field	2.2e-3 (variable)	0.2-5.1 and 0.35-8	Beam size 60 x 30 mm
HFIR HB-2C WAND ²	constant wavelength	Rietveld, single-crystal	General purpose powder/single-crystal	0.05 - 1800	< 5 gas cell < 2 clamp cell	< 6	Humidity chamber	0.016 for Q = 5 Å^-1	0.1 to 8.2 Å^-1	Standard 6, 8, 10 mm cans, maximum volume 3cc, ideally 1g
SNS BL-11A POWGEN	t-o-f	Rietveld, PDF	General purpose powder	10 - 300 2 - 300 5 - 700 525 - 1450, 525-1100 (with gas insert)		< 5	24 position sample changer (10 – 300 K), Gas Handling with pO ₂ and RGA	0.001-0.025	0.7-50 in one frame, 0.15-50 with multiple frames	Standard 6,8,10 mm cans maximum volume is 1, 2 and 3cc. Smallest sample measured ~150 mg
SNS BL-1B NOMAD	t-o-f	PDF, Rietveld	Disordered materials, glasses, liquids; high flux powder	100 - 500 2 - 310 525 – 1450 1000 - 3500	0.02 – 0.2 gas cell		+/- 10kV applied electric field; sample changer; gas handling	5e-3 to 5e-2	0.2-50
SNS BL-3 SNAP	t-o-f	Rietveld	High pressure studies powder/ single-crystal	85 - 350 300-1500 2 - 350 10 – 350 10-350	< 20 PE cell < 6 PE cell < 2 clamp cell 0.6 Gas cell < 40 DAC
HFIR HB-2B NRSF2	constant wavelength	Single peak fitting / Rietveld	engineering / stress mapping
SNS BL-7 VULCAN	t-o-f	Rietveld	engineering				Load-frame

SINGLE CRYSTAL INSTRUMENTS

instrument	type	applications	T (K)	p (GPa)	H (T)	special	Q-range	Unit cell size range (Å)	Beam size
HFIR HB-3A Four-circle Diffractometer	constant wavelength	Magnetic / nuclear structures; small unit cells	4 – 700 CCR 1.6 - 300 orange cryostat 303 – 1773 Vacuum furnace	< 2 clamp cell < 40 DAC (in development)		Electric field			Beam size 5 mm
HFIR HB-2C WAND ²	constant wavelength	General purpose powder/single-crystal; small unit cells	0.05 – 1800	< 5 gas cell < 2 clamp cell	< 6	Humidity chamber	0.1-8.2		Variable up to 9.6mm x 40 mm; up to 30mm x 60 mm
SNS BL-12 TOPAZ	t-o-f	General purpose; diffuse scattering; small and large unit cells	100 - 800						beam size 1 cm
SNS BL-11B MaNDi	t-o-f	Structural biology, macromolecules, small molecules	80 - 300	None	None	Tunable beam divergence 0.12-0.8°	0.6 Å Max Resolution	10-300	Variable 0.5 to 7mm
HFIR CG-4D IMAGINE	quasi-Laue	Structural biology, supramolecular chemistry, magnetic / nuclear structures	4 - 450	< 40 DAC (in development)	None	Kappa goniometer	> 1.0 Å resolution	< 150	3.2 × 2 mm
SNS BL-9 CORELLI	t-o-f	Magnetic / nuclear diffuse scattering, elastic discrimination	6 - 750 CCR 1.6 - 300 orange cryostat 0.3 - 300 ³He insert	< 1.8 clamp cell < 40 DAC	< 5 < 30 Pulsed				1 cm ²
SNS BL-3 SNAP	t-o-f	High pressure studies powder/ single-crystal	85 - 350 300-1500 2 - 350 10 – 350 10-350	< 20 PE cell < 6 PE cell < 2 clamp cell 0.6 Gas cell < 40 DAC