A5028725133- Nuclear Physics and Applications
- High-pressure geophysics and materials
- X-ray Diffraction in Crystallography
- Additive Manufacturing Materials and Processes
- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Crystallization and Solubility Studies
- Medical Imaging Techniques and Applications
- Microstructure and Mechanical Properties of Steels
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- Advanced X-ray Imaging Techniques
- Welding Techniques and Residual Stresses
- Laser Material Processing Techniques
- Ion-surface interactions and analysis
- Microstructure and mechanical properties
- Thermography and Photoacoustic Techniques
- Non-Destructive Testing Techniques
- Cold Fusion and Nuclear Reactions
- Electron and X-Ray Spectroscopy Techniques
- NMR spectroscopy and applications
- Crystallography and molecular interactions
- Particle accelerators and beam dynamics
- Advanced Sensor Technologies Research
- Magnetic Properties and Applications
Paul Scherrer Institute
2020-2025
Technical University of Denmark
2017-2022
Lawrence Livermore National Laboratory
2019
Abstract Many neutron techniques can greatly benefit from enhanced lenses for focusing and imaging. In this work, we revisit the potential of diffractive optics beams, building on advanced high-resolution nano-lithography developed fabrication X-ray used at synchrotron facilities. We demonstrate state-of-the-art nickel silicon Fresnel zone plates report proof-of-concept experiments full-field microscopy small angle scattering. The advancement will open new opportunities techniques, improving...
Laser powder bed fusion is an efficient technique for additive manufacturing of metallic materials. The quality the material produced depends on optimization a large range build parameters and complex thermo-mechanical process prone to inducing detrimental features such as porosity residual stresses negatively affecting fatigue resistance lifetime. Here we apply neutron Bragg edge radiography in parametric study printing 316L steel. concerned are laser scanning speed strategy well optional...
Abstract Neutron Bragg edge imaging enables spatially resolved studies of crystalline features through the exploitation and analysis edges in transmission spectra recorded each pixel an detector. Studies with high spectral resolutions, as is required e.g. for high-resolution strain mapping, large wavelength ranges have been largely reserved to pulsed neutron sources. This due fact, that efficiency resolution measurements significantly higher at short pulse At continuous sources a fraction...
A key aim of the HighNESS project for European Spallation Source is to enable cutting-edge particle physics experiments. This volume presents a conceptual design report NNBAR experiment. would exploit new cold lower moderator make first search in over thirty years free neutrons converting anti-neutrons. The observation such baryon-number-violating signature be fundamental significance and tackle open questions modern physics, including origin matter-antimatter asymmetry. shows beamline,...
Layer-wise laser-based additive manufacturing techniques offer immense versatility and flexibility in fabricating metallic composites with complex shapes. Interest producing new multi-materials advanced characteristics outpaces the available methods that provide insights into bulk material formation, which turn enables process optimisation. While some operando studies enable highly local observations established layers, effect of intrinsic heat treatment inherent is generally beyond reach...
In this work we perform a neutron Bragg edge tomography of stainless steel 316L additive manufacturing samples, one as built via standard laser powder bed fusion, and using the novel three-dimensional (3D) shock peening technique. First, consider conventional attenuation two samples by integrating signal for wavelengths beyond last edge, to analyze bulk density properties material. This is used map defects, such porosities or cracks, which yield lower density. Second, obtain strain maps each...
Neutron dark-field imaging is a powerful technique for investigating the microstructural properties of materials through high-resolution full-field mapping small-angle scattering. However, conventional neutron utilizing Talbot-Lau interferometers limited to probing only one scattering direction at time. Here, we introduce novel multi-directional approach that utilizes single absorption grating with two-dimensional pattern simultaneously probe multiple directions. The method demonstrated...
Scattering studies of milk and products, which are highly relevant food products on the global market, often utilized reported in literature to investigate understand subtle microscopic structural differences between dairy samples. These features determine physical properties ultimately texture and, thus, also influence consumer’s experience. Small-angle neutron scattering is a prominent example, enables observations length scales, convey proteins fat globules food-grade milk. In addition,...
Compared to the dual-energy scintillator detectors widely used today, energy-resolved photon-counting x-ray show potential improve material identification in various radiography and tomography applications for industrial security purposes. However, detector effects, such as charge sharing photon pileup, distort measured spectra pixelated, operating under high flux. These effects result a significant performance degradation of when where accurate spectral measurements are required. We have...
Spectral X-ray computed tomography (SCT) is an emerging method for non-destructive imaging of the inner structure materials. Compared with conventional CT, this technique provides spectral photon energy resolution in a finite number channels, adding new dimension to reconstructed volumes and images. While mitigates energy-dependent distortions such as beam hardening, metal artifacts due starvation effects are still present, especially low-energy channels where attenuation coefficients...
Non-destructive characterization methods to observe phase transformations and thus, gain insights transformation mechanisms in representative volumes are key for the development of advanced materials manufacturing. Conventional constrained surface small sizes, access bulk often implies tedious destructive approaches hinders in-situ observations evolution. In this work, we introduce a non-destructive technique that overcomes limitations prevailing today mapping spatial distribution magnetic...
Spatially resolved studies of crystalline structures, e.g. lattice spacings, are enabled by recording the transmitted spectra in neutron Bragg edge imaging. The recorded signals are, however, a result through-thickness averaging probed specimen beam direction. Therefore, it is challenging to extract strain distribution when varies across thickness, which applies for on different materials or material states along beam. Here we introduce approach disentangle contributions signals, i.e....
The attenuation coefficient of textured materials presents a complex dependence on the preferred orientation with respect to neutron beam. Presented here is an model describe polycrystalline materials, based single-crystal approach, aiming towards use in full-pattern least-squares refinements wavelength-resolved transmission experiments. evaluates Bragg contribution as combination Bragg-reflected component discrete number imperfect single crystals different orientations, weighted by volume...
The advancement of laser-based metal additive manufacturing has enabled the production near net shape complex geometries. Understanding microstructural features materials is crucial for accurate modeling their mechanical behavior, particularly with regard to strain- or thermal-induced martensitic phase transformations in ferrous alloys and steels. For example, formation BCC α′-martensite can strengthen while preserving ductility dominating austenitic phase. However, components where memory...
Abstract Laser powder bed fusion is an additive manufacturing technique extensively used for the production of metallic components. Despite this process has reached a status at which parts are produced with mechanical properties comparable to those from conventional production, it still prone introduce detrimental tensile residual stresses towards surfaces along building direction, implying negative consequences on fatigue life and resistance crack formations. shock peening (LSP) promising...
The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world’s most powerful pulsed neutron source. Supported by 3 million Euro Research and Innovation Action within EU Horizon 2020 program, design study (HighNESS) has been develop second source located below spallation target. Compared first source, designed for high cold thermal brightness, new optimized...
Hierarchical biomaterials embody nature's intricate design principles, offering advanced functionalities through the complex, multi-level organization of their molecular and nanosized building blocks. However, comprehensive characterization 3D structure remains a challenge, particularly due to radiation damage caused by conventional X-ray- electron-based imaging techniques, as well length scale limitations scattering-based investigation methods. Here, we present study utilizing...
Hydrogen embrittlement in zirconium alloys is a highly relevant research topic, important for ensuring the integrity of nuclear fuel clads. While presence hydrides zirconium-based clad well-known risk factor due to their brittleness, effect hydrogen solid solution unclear. According Enhanced Localized Plasticity (HELP) model, may affect mechanical performance metal by increasing dislocation mobility shielding that has on interaction dislocations with other types defects. In presented work,...
Spectral computed tomography is an emerging imaging method that involves using recently developed energy discriminating photon-counting detectors (PCDs). This technique enables measurements at isolated high-energy ranges, in which the dominating undergoing interaction between x-ray and sample incoherent scattering. The scattered radiation causes a loss of contrast results, its correction has proven to be complex problem, due dependence on energy, material composition, geometry. Monte Carlo...
The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world's most powerful pulsed neutron source. Supported by 3 million Euro Research and Innovation Action within EU Horizon 2020 program, design study (HighNESS) has been develop second source located below spallation target. Compared first source, designed for high cold thermal brightness, new optimized...
We present Spectral X-ray Computed Tomography (SCT) estimations of material properties directly from energy-dependent measurements linear attenuation coefficients (LAC). (CT) is commonly utilized to characterize the internal an object interest. Dual-Energy CT allows characterization into energy-independent physical such as <i>Z</i><sub>e</sub> and electron density ρ<sub>e</sub>. However, it not robust in presence dense materials metal artifacts. report on performance a method for...