Phase imaging using time-of-flight neutron diffraction

A technique that allows the spatial distribution of crystallographic phases in the interior of an object to be reconstructed from neutron time-of-flight (TOF) diffraction is described. To this end, the shift of the Bragg peaks due to the so-called `geometrical aberration' is exploited. A collimated incident white beam is used to perform a translational or rotational scan of the object whilst collecting a TOF data set for each sample position or orientation. Depending on the location of any scattering material along the line of the incident beam path through the object, the measuredd-spacings of the corresponding Bragg peaks are shifted with respect to their nominal values, which are attained only at the geometrical centre of the instrument. Using a formula that is usually employed to correct for sample offset, the phase distribution along the incident beamline can be directly reconstructed, without the need to perform a tomographic reconstruction. Results are shown from a demonstration experiment carried out on a cylindrical Al container enclosing an arrangement of Cu and Fe rods. On the basis of this formalism, an optimized experimental geometry is described and the potential and limits of this technique are explored, as are its applicability to X-ray and constant-wavelength neutron diffraction.

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Rapid Measurement of Texture of Metals by Time-of-Flight Neutron Diffraction at iMATERIA and its Applications

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.1426 ◽

2016 ◽

Vol 879 ◽

pp. 1426-1430 ◽

Cited By ~ 3

Author(s):

Yusuke Onuki ◽

Akinori Hoshikawa ◽

Shigeo Sato ◽

Toru Ishigaki

Keyword(s):

Neutron Diffraction ◽

Measurement System ◽

Life Science ◽

Time Of Flight ◽

Incident Beam ◽

High Flux ◽

Experimental Facility ◽

Texture Measurement ◽

Rapid Measurement ◽

Time Of Flight Method

The authors have developed the texture measurement system at iMATERIA, which is the neutron diffractometers built in Materials and Life Science Experimental Facility (MLF) at J-PARC, Japan. The high flux of the incident beam and Time-Of-Flight method enabled the complete texture measurement within several minutes in case of steels. Since the neutron beam can transmit most of the materials, the measured texture represents the state of whole exposed volume. The multi-histogram analysis also enables to determine phase fractions in a multiphase material as well as the texture of each phase.

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Influence of Beam Divergence on Pseudo-Strain Induced in Time-of-Flight Neutron Diffraction

Materials Science Forum ◽

10.4028/www.scientific.net/msf.777.105 ◽

2014 ◽

Vol 777 ◽

pp. 105-111 ◽

Cited By ~ 1

Author(s):

Hiroshi Suzuki ◽

Stefanus Harjo ◽

Jun Abe ◽

Koichi Akita

Keyword(s):

Neutron Diffraction ◽

Steel Plate ◽

Surface Effect ◽

Time Of Flight ◽

Incident Beam ◽

Surface Strain ◽

Beam Divergence ◽

Coarse Grain ◽

Attenuation Effect ◽

Neutron Attenuation

Effects of beam divergence on pseudo-strains observed in time-of-flight (TOF) neutron diffraction, which overlapped with the neutron attenuation effect and the surface-effect, were investigated. The through-surface strain scanning on an annealed steel plate was performed in different instrument resolutions by controlling the incident beam divergence. Typical pseudo-strain distributions were observed, but they showed different trend according to the beam divergence. Furthermore, it was demonstrated that the pseudo-strains induced in strain scanning measurements of coarse grain materials can be suppressed by controlling the incident beam divergence. Therefore, the incident beam divergence must be carefully considered to reduce pseudo-strains in time-of-flight neutron diffractometry.

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Determination of the cation distribution in Fe2Ni(PO4)2using isotopic substitution and powder neutron diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889803017515 ◽

2003 ◽

Vol 36 (6) ◽

pp. 1361-1367 ◽

Cited By ~ 12

Author(s):

Paul F. Henry ◽

Mark T. Weller ◽

Chick C. Wilson

Keyword(s):

Neutron Diffraction ◽

Time Of Flight ◽

Neutron Diffraction Study ◽

Data Set ◽

X Ray ◽

X Ray Scattering ◽

Powder Neutron Diffraction ◽

Combined Data ◽

Ray Scattering

The distribution of divalent iron and nickel over the two metal sites with differing coordination geometry in Fe2Ni(PO4)2, sarcopside, has been investigated using time-of-flight powder neutron diffraction of nickel isotopically substituted materials. Data from four separate samples were collected using HRPD at ISIS, containingnatNi,58Ni,60Ni and62Ni, under identical conditions. The occupancy of iron on theM(1) site was found to be 0.290 (1) from a combined-data-set Rietveld refinement of the three isotopically substituted samples, compared with 0.26 (4) and 0.26 (15) respectively from this and a previous time-of-flight powder neutron diffraction study using natural-abundance nickel, and 0.366 (6) and 0.376 (3) using anomalous X-ray scattering techniques. A critical comparison of isotope substitution neutron diffraction and anomalous X-ray scattering methods for distinguishing nickel and iron from powder data is presented.

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EXPERIMENTAL DATA SET NO. 25: PHASE DISTRIBUTION AND TWO-PHASE TURBULENCE FOR BUBBLY FLOWS IN PIPES

Multiphase Science and Technology ◽

10.1615/multscientechn.v6.i1-4.190 ◽

1992 ◽

Vol 6 (1-4) ◽

pp. 303-349

Author(s):

S. J. Lee

Keyword(s):

Experimental Data ◽

Phase Distribution ◽

Bubbly Flows ◽

Two Phase ◽

Data Set

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EXPERIMENTAL DATA SET NO. 24: PHASE DISTRIBUTION IN BUBBLY FLOW

Multiphase Science and Technology ◽

10.1615/multscientechn.v6.i1-4.180 ◽

1992 ◽

Vol 6 (1-4) ◽

pp. 257-301 ◽

Cited By ~ 16

Author(s):

Akimi Serizawa ◽

Isao Kataoka ◽

Itaru Michiyoshi

Keyword(s):

Experimental Data ◽

Phase Distribution ◽

Bubbly Flow ◽

Data Set

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Relaxation of Residual Stress in AISI 347 Welded Pipe: A Time-of-Flight Neutron Diffraction Study

Zeitschrift für Metallkunde ◽

10.3139/146.020033 ◽

2002 ◽

Vol 93 (1) ◽

pp. 33-41 ◽

Cited By ~ 3

Author(s):

G. Bruno

Keyword(s):

Residual Stress ◽

Neutron Diffraction ◽

Diffraction Study ◽

Time Of Flight ◽

Neutron Diffraction Study ◽

Welded Pipe

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Through-Thickness Microstructure Characterization in a Centrifugally Cast Austenitic Stainless Steel Nuclear Reactor Primary Loop Pipe Using Time-of-Flight Neutron Diffraction

Quantum Beam Science ◽

10.3390/qubs5020012 ◽

2021 ◽

Vol 5 (2) ◽

pp. 12

Author(s):

Matthew M. Schmitt ◽

Daniel J. Savage ◽

James J. Wall ◽

John D. Yeager ◽

Chanho Lee ◽

...

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Neutron Diffraction ◽

Time Of Flight ◽

Radial Distance ◽

Ultrasonic Waves ◽

Science Center ◽

Los Alamos ◽

Inspection Method ◽

Centrifugally Cast

The US code of Federal Regulations mandates regular inspection of centrifugally cast austenitic stainless steel pipe, commonly used in primary cooling loops in light-water nuclear power plants. These pipes typically have a wall thickness of ~8 cm. Unfortunately, inspection using conventional ultrasonic techniques is not reliable as the microstructure strongly attenuates ultrasonic waves. Work is ongoing to simulate the behavior of acoustic waves in this microstructure and ultimately develop an acoustic inspection method for reactor inspections. In order to account for elastic anisotropy in the material, the texture in the steel was measured as a function of radial distance though the pipe wall. Experiments were conducted on two 10 × 12.7 × 80 mm radial sections of a cast pipe using neutron diffraction scans of 2 mm slices using the HIPPO time-of-flight neutron diffractometer at the Los Alamos Neutron Science Center (LANSCE, Los Alamos, NM, USA). Strong textures dominated by a small number of austenite grains with their (100) direction aligned in the radial direction of the pipe were observed. ODF analysis indicated that up to 70% of the probed volume was occupied by just three single-grain orientations, consistent with grain sizes of almost 1 cm. Texture and phase fraction of both ferrite and austenite phases were measured along the length of the samples. These results will inform the development of a more robust diagnostic tool for regular inspection of this material.

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Design of a novel Peltier-based cooling device and its use in neutron diffraction data collection of perdeuterated yeast pyrophosphatase

Journal of Applied Crystallography ◽

10.1107/s0021889810027111 ◽

2010 ◽

Vol 43 (5) ◽

pp. 1113-1120 ◽

Cited By ~ 1

Author(s):

Esko Oksanen ◽

François Dauvergne ◽

Adrian Goldman ◽

Monika Budayova-Spano

Keyword(s):

Data Collection ◽

Neutron Diffraction ◽

Diffraction Data ◽

Catalytic Mechanism ◽

Inorganic Pyrophosphatase ◽

Neutron Diffraction Data ◽

Cooling Device ◽

Data Set ◽

X Ray ◽

X Ray Crystallography

H atoms play a central role in enzymatic mechanisms, but H-atom positions cannot generally be determined by X-ray crystallography. Neutron crystallography, on the other hand, can be used to determine H-atom positions but it is experimentally very challenging. Yeast inorganic pyrophosphatase (PPase) is an essential enzyme that has been studied extensively by X-ray crystallography, yet the details of the catalytic mechanism remain incompletely understood. The temperature instability of PPase crystals has in the past prevented the collection of a neutron diffraction data set. This paper reports how the crystal growth has been optimized in temperature-controlled conditions. To stabilize the crystals during neutron data collection a Peltier cooling device that minimizes the temperature gradient along the capillary has been developed. This device allowed the collection of a full neutron diffraction data set.

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