A5046852134- Nuclear Physics and Applications
- High-pressure geophysics and materials
- X-ray Diffraction in Crystallography
- Nuclear Materials and Properties
- Advancements in Battery Materials
- Atomic and Subatomic Physics Research
- Shape Memory Alloy Transformations
- Physics of Superconductivity and Magnetism
- Radiation Detection and Scintillator Technologies
- Advanced Condensed Matter Physics
- Metal and Thin Film Mechanics
- Microstructure and Mechanical Properties of Steels
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Battery Technologies Research
- Intermetallics and Advanced Alloy Properties
- Nuclear reactor physics and engineering
- Cultural Heritage Materials Analysis
- Aluminum Alloys Composites Properties
- Catalysis and Oxidation Reactions
- Fusion materials and technologies
- Advanced Battery Materials and Technologies
- Advancements in Solid Oxide Fuel Cells
- Titanium Alloys Microstructure and Properties
- High Entropy Alloys Studies
- Radiation Therapy and Dosimetry
Oak Ridge National Laboratory
2011-2024
Ormihl (France)
2015
Spallation Neutron Source
2014
University of Houston
2006
We report an in-situ neutron diffraction study of a large format pouch battery cell. The succession Li-Graphite intercalation phases was fully captured under 1C charge-discharge condition (i.e., charge to full capacity in 1 hour). However, the lithiation and dilithiation pathways are distinctively different and, unlike slowing charging experiments with which phase diagram established, no LiC24 found during at rate. Approximately 75 mol. % graphite converts LiC6 lattice dilation as 4%...
The Spallation Neutron Source at Oak Ridge National Laboratory, USA, ushered in a new era of neutron scattering experiments through the use event-based data. Tagging each event allows pump–probe experiments, measurements with parameter asynchronous to source, continuously varying parameters and novel ways testing instrument components. This contribution will focus on few examples. A pulsed magnet has been used study diffraction under extreme fields. Continuous ramping temperature is becoming...
Over the past decade, wavelength-dependent neutron radiography, also known as Bragg-edge imaging, has been employed a non-destructive bulk characterization method due to its sensitivity coherent elastic scattering that is associated with crystalline structures. Several analysis approaches have developed quantitatively determine orientation, lattice strain, and phase distribution. In this study, we report systematic investigation of crystal structures metallic materials (such selected...
On Friday June 26, 2009, the neutron beam shutter for VULCAN diffractometer at SNS was opened first time. Initial measurements to characterize instrument performance are reported. It is shown that measurement results by and large in agreement with design calculations. New research opportunities discussed.
We present the design and operating characteristics of a vacuum furnace used for inelastic neutron scattering experiments on time-of-flight chopper spectrometer. The device is an actively water cooled radiant heating capable performing up to 1873 K. Inelastic studies performed with this include phonon dynamics metallic liquids. describe design, control, characterization, limitations equipment. Further, we provide comparisons performance our commercially available options. Finally consider...
High diffraction signal-to-background ratios (SBRs), the ratio of peak integrated intensity over its background intensity, are desirable for a neutron diffractometer to acquire good statistics pattern measurements and subsequent data analysis. For given detector, while signals primarily depend on characteristics beam sample coherent scattering, largely originates from incoherent scattering instrument space. In this work, we investigated effect collimation SBRs Si powder using one high-angle...
Abstract We present the first machine learning-based autonomous hyperspectral neutron computed tomography experiment performed at Spallation Neutron Source. Hyperspectral allows characterization of samples by enabling reconstruction crystallographic information and elemental/isotopic composition objects relevant to materials science. High quality reconstructions using traditional algorithms such as filtered back projection require a high signal-to-noise ratio across wide wavelength range...
A pinhole neutron diffraction (PIND) technique was developed to enable improving the spatial resolution down 250 μm. Instead of conventional engineering method which integrates all signals on detector plane, PIND setup utilizes pattern each pixel 2D detectors. The proposed arrangement enables time-of-flight instruments and allows solving problems involving steep gradients strain or texture. phase content preferential orientation grains inside samples can be spatially resolved in 2D/3D....
A gripping capability was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading heating on the VULCAN engineering materials diffractometer at spallation source Oak Ridge National Laboratory. The proposed allowed acquisition of spectra tension, compression, torsion, and/or complex paths elevated temperatures. design consisted age-hardened, Inconel(®) 718 grips with direct attachment to existing MTS load frame having axial torsional capacities...
The tensile twinning and detwinning behaviors of a wrought magnesium alloy have been investigated during in situ four-point bending using the state-of-the-art high spatial resolution pinhole neutron diffraction (PIND) method. PIND method allowed us to resolve twinning/detwinning lattice strain distributions across sample loading-unloading sequence with 0.5 mm step size. It was found that extensive occurred near compression surface, while no behavior observed middle layer tension side sample....
TOF-ND elastic scattering of thermal neutrons offers some important advantages over X-ray diffraction (XRD), fluorescence (XRF), and metallography for the study archaeological numismatic problems. Traditional analytical methods are usually destructive often probe only surface. Neutrons deeply penetrate samples, simultaneously giving nondestructive bulk information about crystal structure, composition, texture (alignment crystallites) from which thermomechanical manufacturing processes (e.g.,...
A noncontact, nondestructive neutron diffraction technique for measuring thermal resistance of buried material interfaces in bulk samples, inaccessible to thermocouple measurements, is described. The uses spatially resolved measurements measure temperature, and analytical or numerical methods calculate the corresponding resistance. It was tested at VULCAN instrument Spallation Neutron Source, Oak Ridge National Laboratories on a stack three 6061 alloy aluminum plates (heat-source,...
Although pinning centers created by irradiation presently produce the highest Jc, it is probable that ultimately these will be emulated chemical centers. The best produced nevertheless provide guidelines for desirable morphology of structures. Jc earlier in textured HTS was obtained using isotropic high-energy ions fission 235U. This so-called U/n process produces diameter ⩽ 4.5 nm, with an effective length ∼2.7 µm. Maximum occurs center density ∼1010 cm−3. We use this as a model desired Our...
In situ neutron scattering is a powerful tool to reveal materials atomic structural response such as phase transformation, lattice straining, and texture under external stimuli. The advent of high flux source the Spallation Neutron Source (SNS) allows fast measurement in even non-equilibrium conditions, i.e., transformation steels. However, commercial heating apparatus physical simulation equipment not designed for scattering, which limits its application research by using neutrons. Here we...
Abstract Located at the Spallation Neutron Source, VENUS is an instrument optimized for wavelength-dependent neutron imaging techniques, namely Bragg edge and resonance imaging, across a broad range of energies (from meV to hundreds eV). The construction project started in Fall 2018, establishing conceptual design major components timeline purchasing, testing, installation. Completion anticipated late 2024. This comprises such as set boron carbide apertures designed both thermal/cold...
Abstract Wavelength-dependent or hyperspectral imaging is a novel nondestructive characterization technique in the field of neutron radiography and computed tomography. A dedicated facility named VENUS currently being built at Oak Ridge National Laboratory to provide these capabilities for academia, industry, other national laboratories. This feature article describes materials science engineering, provides quick overview modes access facility, illustrates measurements interpretation results.
Prevention of weld cracking is necessary for ensuring the reliability high strength steel structures. Tensile residual stress in metal one major factors causing cracking, therefore, it important to clarify distribution metal. Conventional measurement, relief method using strain gauges and X-ray diffraction technique, can only provide information surface region weld. The neutron non-destructive that measure inside [1-3]. measurement was applied 980MPa class revealed level tensile affect a...