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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei
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Neutron-scattering evidence for a periodically modulated superconducting phase in the underdoped cuprate La 1.905 Ba 0.095 CuO 4
The role of antiferromagnetic spin correlations in high-temperature superconductors remains a matter of debate. We present inelastic neutron-scattering evidence that gapless spin fluctuations coexist with superconductivity in La 1.905 Ba 0.095 CuO 4 . Furthermore, we observe that both the low-energy magnetic spectral weight and the spin incommensurability are enhanced with the onset of superconducting correlations. We propose that the coexistence occurs through intertwining of spatial modulations of the pair wave function and the antiferromagnetic correlations. This proposal is also directly relevant to sufficiently underdoped La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 6+x .
Measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon at $\langle E_{\nu} \rangle $ = 3.6 GeV
The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q 2 are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q 2 for ν e with that of similarly selected ν μ -induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current νe interactions used by long-baseline neutrino oscillation experiments. Furthermore, the data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.
Nuclear Force Imprints Revealed on the Elastic Scattering of Protons with C 10
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Complex Structure of Molten FLiBe (2 Li F – Be F 2 ) Examined by Experimental Neutron Scattering, X-Ray Scattering, and Deep-Neural-Network Based Molecular Dynamics
The use of molten salts as coolants, fuels, and tritium breeding blankets in the next generation of fission and fusion nuclear reactors benefits from furthering the characterization of the molecular structure of molten halide salts, paving the way to predictive capability of the chemical and thermophysical properties of molten salts. Due to its neutronic, chemical, and thermochemical properties, 2 Li F - Be F 2 is a candidate molten salt for several fusion- and fission-reactor designs. We performed neutron and x-ray total-scattering measurements to determine the atomic structure of liquid 2 Li F - Be F 2 . We also performed and neural-network molecular-dynamics simulations to predict the structure obtained by neutron- and x-ray-diffraction experiments. The use of machine learning provides improvements to the efficiency in predicting the structure at a longer length scales than is achievable with simulations at significantly lower computational expense while retaining near accuracy. We found that the NNMD simulations accurately predicted the Be F 4 2 − oligomer formations seen in the experimental first-structure-factor peak. Our combination of high-resolution measurements with large-scale molecular dynamics provided an avenue to explore and experimentally verify the intermediate-range ordering beyond the first-nearest neighbor that has posed too many experimental and computational challenges in previous works. With a deeper understanding of the salt structure and ion ordering, the evolution of salt chemistry over the lifetime of a reactor can be better predicted, which is crucial to the licensing and operation of advanced fission and fusion reactors that employ molten salts. To this end, this work will serve as a reference for future studies of salt structure and macroscopic properties with and without the addition of solutes. Published by the American Physical Society 2024
Structure Prediction from Neutron Scattering Profiles: A Data Sciences Approach
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The omnidirectional scattering of acoustic waves from rough surfaces with application to electromagnetic scattering
Theoretical and experimental studies on acoustic and electromagnetic wave scattering from rough surfaces
Multiple scattering in a plane-parallel atmosphere. I - Successive scattering in a semi-infinite medium
Solar radiation reflection function for plane- parallel atmosphere with isotropic phase function calculated by successive scattering method, noting application to planetary atmospheres
Electron scattering by H2 with and without vibrational excitation. II - Experimental and theoretical study of elastic scattering
Elastic scattering of electrons by hydrogen as function of vibrational excitation, discussing intensities and cross sections
Electron scattering by H2 with and without vibrational excitation. III - Experimental and theoretical study of inelastic scattering
Differential cross sections for electron scattering by hydrogen with and without vibrational excitation, discussing inelastic processes
Method for the solution of electromagnetic scattering problems for inhomogeneous dielectrics as a power series in the ratio /dimension of scatterer//wavelength
Electromagnetic scattering solutions for inhomogeneous dielectrics as power series, using multipoles for far field determination
Comparison of exact and approximate evaluations of the single-scattering integral in nucleon-deuteron elastic scattering
The exact nucleon-deuteron elastic single scattering integral was calculated numerically in order to evaluate errors in sticking factor approximations. A similar analysis made by using S wave separable potentials concluded that errors for these approximations were negligible except near backward angles where they were found to be about 10 percent.
Scattering from nonspherical Chebyshev particles. III - Variability in angular scattering patterns
Shape-induced variability in the scattered intensity from randomly oriented nonspherical particles is studied. A comparison is made between bands of shape-induced variability for six size intervals within the size parameter range of 1 to 20 and corresponding spherical intensities. It is found that averaging spherical intensities over narrow size ranges produces effects that are qualitatively similar to a slightly distorted single sphere. The results also show that, for Chebyshev particles which are neither small nor large compared to the wavelength, shape-induced variability is often comparable to the mean.
Polarimetric Scattering from Layered Media with Multiple Species of Scatterers
Geophysical media are usually heterogeneous and contain multiple species of scatterers.
Quasireal Compton scattering measurement and e* scattering with DELCO at PEP
We report on a measurement of the elastic scattering of quasi-real photons generated by one beam with the particles of the other in e + e - interactions at $\sqrt{s}$ = 29 GeV performed using the DELCO detector at PEP. The events are characterized by coplanar and anti-tagged ey pairs with large visible energy where the charge of the electron is correlated with the acolinearity angle. We also use our result to search for the on-shell production of a hypothetical excited electron e*. We find that the data agree well with the predictions for the QED Compton process, and set upper limits on the e*eγ coupling parameter λ to be below 10 -2 (95% C.L.) in the range 15 ≲ M e* 27 GeV.
Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot)
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Small Angle Neutron Scattering Shows Nanoscale PMMA Distribution in Transparent Wood Biocomposites
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