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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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At least 1,207 records · Page 67
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Magnetism in Non-Traditional Materials

We performed a systematic microscopic investigation of two completely dissimilar materials (namely, ZnO and rhombohedral-C 60 polymers) exhibiting ferromagnetism in the presence of defects, and showed that this new phenomena has a common origin and the mechanism responsible can be used as a powerful tool for inducing and tailoring magnetic features in systems which are not magnetic otherwise. Based on our findings we proposed a general recipe for developing ferromagnetism in new materials of great technological interest. Our results support the role of complimentary pairs of defects in inducing magnetism in otherwise non-magnetic materials belonging to two widely differing classes with no apparent correlation between them. In both classes, ferromagnetism is found to be enhanced when the two kinds of defects form structures (pathways) of alternating effective donor and acceptor crystal sites leading to the development of electron charge and spin density like waves.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2014

USU Alternative and Unconventional Energy Research and Development

The purpose and rationale of this project has been to develop enduring research capabilities at Utah State University (USU) and the Utah State University Research Foundation (USURF) in a number of energy efficient and renewable energy areas including primarily a) algae energy systems, b) solar lighting, c) intuitive buildings, d) electric transportation, 3) unconventional energy environmental monitoring and beneficial reuse technologies (water and CO 2 ), f) wind energy profiling, and g) land use impacts. The long-term goal of this initiative has been to create high-wage jobs in Utah and a platform for sustained faculty and student engagement in energy research. The program’s objective has been to provide a balanced portfolio of R&D conducted by faculty, students, and permanent staff. This objective has been met. While some of the project’s tasks met with more success than others, as with any research project of this scope, overall the research has contributed valuable technical insight and broader understanding in key energy related areas. The algae energy systems research resulted in a highly productive workforce development enterprise as it graduated a large number of well prepared students entering alternative energy development fields and scholarship. Moreover, research in this area has demonstrated both the technological and economic limitations and tremendous potential of algae feedstock-based energy and co-products. Research conducted in electric transportation, specifically in both stationary and dynamic wireless inductive coupling charging technologies, has resulted in impactful advances. The project initiated the annual Conference on Electric Roads and Vehicles (http://www.cervconference.org/), which is growing and attracts more than 100 industry experts and scholars. As a direct result of the research, the USU/USURF spin-out startup, WAVE (Wireless Advanced Vehicle Electrification), continues work in wirelessly charged bus transit systems and is poised to quickly become a multi-million dollar company with clients around the globe. Moreover, USU students and researchers alike are now on the leading edge of the electrified transportation workforce. Finally, the legacy of this DOE investment in electric transportation is continuing at USU with the formation in progress of an industry sponsored research center built around the Electric Roadway and Vehicle (EVR) research facility and test track (http://evr.usu.edu). The research conducted in unconventional energy environmental monitoring and beneficial reuse technologies experienced broad success developing experimental and modeling tools and implementing those tools to better understand environmental impacts of industrial processes used in unconventional energy development in the Utah’s Uintah Basin. Before this project began the USU Uintah Basin branch campus had minimal capability to perform this regionally critical environmental research. This research investment enabled monitoring and modeling equipment and expertise to assess impacts of energy development to all aspects of environmental quality. Laboratory capability for environmental analysis has been developed and engaged along with field testing at multiple locations. Successful campaigns to measure greenhouse gas and hydrocarbon emissions from produced water surface impoundments and leakage from subsurface oil and gas infrastructure were executed. A computer model of meteorological conditions during winter inversion episodes was created, and commercialization efforts are underway for those models. Finally, in the past 24 months, nearly $2 million in non- DOE external funding from state, local, federal and private entities has been awarded to USU Uintah Basin to continue and add to work and capability established by this task. The preceding examples represent a few highlights resulting from the USU Alternative and Unconventional Energy Research and Development project. The following report provides further detail.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Final Report: Advanced Detector Technologies for Precision Measurement of Inflation, Dark Energy, and Neutrino Masses with the Cosmic Microwave Background

Precision measurements of the Cosmic Microwave Background (CMB) provide unparalleled op- portunities to probe the conditions in the early universe and thereby explore particle physics and gravity at the highest energies yet; measure the number of neutrino species and the sum of the neutrino masses with sensitivity beyond what is achievable with planned terrestrial experiments; improve our knowledge of dark energy; and search for other forms of new physics. The P-5 panel recognized the importance and potential of future CMB observations and recommended the DOE fund a stage four CMB experiment (CMB-S4) under all budget scenarios with construction commencing near the end of this decade. The objective of this proposal is to develop and demonstrate new technologies in time to maximize the science return of CMB-S4. The proposed technologies include: (i) broad band metamaterial antireflection coatings on relevant lenses with negligible absorptive and reflective losses; (ii) filters that reduce out of band optical loading with near perfect in band transmission; (iii) broad-band continuously spinning metamaterial half wave plates that boost the sensitivity to inflationary gravitational waves on large angular scales and mitigate systematics with minimal penalty to the instantaneous sensitivity; and (iv) broad band detectors that will enable excellent foreground discrimination while simultaneously maximizing the sensitivity to the signals from inflation and neutrinos. Together these technologies can realize significant improvements in instrumental sensitivity and control of systematic effects. This improvement in raw sensitivity could be used to reduce costs without sacrificing science by deploying a smaller number of more sensitive detectors, or to improve the sensitivity of CMB-S4 to physics parameters including reducing the error bar on r by the inverse of the mapping speed improvement. Beyond raw sensitivity these technologies address key systematics including polarization mixing and galactic foregrounds and enable CMB-S4 to test the shape of the polarization power spectrum out to larger angular scales further boosting measurements of inflation. In this report we detail the progress that has been made in these technical areas. This includes: (i) a demonstration of 4:1 bandwidth AR coating technology and a detailed understanding of the production challenges, (ii) prototype filters that incorporate absorptive and reflective components into silicon, (iii) a prototype broad band HWP fabricated from metamaterial silicon, and (iv) detector designs spanning 20-350 GHz with an understanding of the difficulties associated with bandwidths greater than one octave.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS1975

The propagation of plane waves and higher order acoustic modes in multisectioned ducts

A theoretical and experimental study of acoustic propagation in an anechoically terminated multisectioned duct was performed. A unique source array consisting of two concentric rings of sources, providing phase and amplitude control in the radial as well as circumferential direction, was developed to generate plane waves and both spinning and non-spinning higher order modes. Measurement of attenuation and radial mode shapes were taken with various finite length liners inserted between the hard wall sections of a duct with an anechoic termination. A search technique was developed to find the complex eigenvalues for a liner under the assumption of a locally reacting boundary condition. The experimental results were compared with a theoretical analysis which includes the modal transmission and reflection at the interface of each duct section, and this indicated that the local reaction boundary condition is valid for three liner configurations.

Wyerman, B. R.↗
NASA NTRS1976

A Theoretical and Experimental Study of Acoustic Propagation in Multisectioned Circular Ducts

The propagation of plane waves and higher order acoustic modes in a circular multisectioned duct was studied. A unique source array consisting of two concentric rings of sources, providing phase and amplitude control in the radial, as well as circumferential direction, was developed to generate plane waves and both spinning and nonspinning higher order modes. Measurements of attenuation and radial mode shapes were taken with finite length liners inserted between the hard wall sections of an anechoically terminated duct. Materials tested as liners included a glass fiber material and both sintered fiber metals and perforated sheet metals with a honeycomb backing. The fundamental acoustic properties of these materials were studied with emphasis on the attenuation of sound by the liners and the determination of local versus extended reaction behavior for the boundary condition. A search technique was developed to find the complex eigenvalues for a liner under the assumption of a locally reacting boundary condition.

Wyerman, B. R.↗
NASA NTRS1976

The propagation and attenuation of complex acoustic waves in treated circular and annular ducts

The propagation of plane waves and higher order acoustic modes in a circular multisectioned duct was studied. A unique source array consisting of two concentric rings of sources, providing phase and amplitude control in the radial, as well as circumferential direction, was developed to generate plane waves and both spinning and nonspinning higher order modes. Measurements of attenuation and radial mode shapes were taken with finite length liners between the hard wall sections of an anechoically terminated duct. Materials tested as liners included a glass fiber material and both sintered fiber metals and perforated sheet metals with a honeycomb backing. The fundamental acoustic properties of these materials were studied with emphasis on the attenuation of sound by the liners and the determination of local versus extended reaction behavior for the boundary condition. The experimental results were compared with a mathematical model for the multisectioned duct.

Reethof, G.↗
DOE OSTI2015

Hydrodynamic and kinetic models for spin-1/2 electron-positron quantum plasmas: Annihilation interaction, helicity conservation, and wave dispersion in magnetized plasmas

We discuss the complete theory of spin-1/2 electron-positron quantum plasmas, when electrons and positrons move with velocities mach smaller than the speed of light. We derive a set of two fluid quantum hydrodynamic equations consisting of the continuity, Euler, spin (magnetic moment) evolution equations for each species. We explicitly include the Coulomb, spin-spin, Darwin and annihilation interactions. The annihilation interaction is the main topic of the paper. We consider the contribution of the annihilation interaction in the quantum hydrodynamic equations and in the spectrum of waves in magnetized electron-positron plasmas. We consider the propagation of waves parallel and perpendicular to an external magnetic field. We also consider the oblique propagation of longitudinal waves. We derive the set of quantum kinetic equations for electron-positron plasmas with the Darwin and annihilation interactions. We apply the kinetic theory to the linear wave behavior in absence of external fields. We calculate the contribution of the Darwin and annihilation interactions in the Landau damping of the Langmuir waves. We should mention that the annihilation interaction does not change number of particles in the system. It does not related to annihilation itself, but it exists as a result of interaction of an electron-positron pair via conversion of the pair into virtual photon. A pair of the non-linear Schrodinger equations for the electron-positron plasmas including the Darwin and annihilation interactions is derived. Existence of the conserving helicity in electron-positron quantum plasmas of spinning particles with the Darwin and annihilation interactions is demonstrated. We show that the annihilation interaction plays an important role in the quantum electron-positron plasmas giving the contribution of the same magnitude as the spin-spin interaction.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

Coherent Gate Operations in Hybrid Magnonics

Electromagnonics-the hybridization of spin excitations and electromagnetic waves-has been recognized as a promising candidate for coherent information processing in recent years. Among its various implementations, the lack of available approaches for real-time manipulation on the system dynamics has become a common and urgent limitation. In this work, by introducing a fast and uniform modulation technique, we successfully demonstrate a series of benchmark coherent gate operations in hybrid magnonics, including semiclassical analogies of Landau-Zener transitions, Rabi oscillations, Ramsey interference, and controlled mode swap operations. Finally, our approach lays the groundwork for dynamical manipulation of coherent signals in hybrid magnonics and can be generalized to a broad range of applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Massive spinning bosons on the celestial sphere

A natural extension of the Pasterski-Shao-Strominger (PSS) prescription is described, enabling the map of Minkowski space amplitudes with massive spinning external legs to the celestial sphere to be performed. An integral representation for the conformal primary wave function (CPW) of massive spinning bosons on the celestial sphere is derived explicitly for spin-one and -two. By analogy with the spin-zero case, the spinning bulk-to-boundary propagator on Euclidean AdS is employed to extend the massive CPW integral representation to arbitrary integer spin, and to describe the appropriate inverse transform of massive spinning CPWs back to the plane wave basis in Minkowski space. Subsequently, a massive spin-s momentum operator representation on the celestial sphere is determined, and used in conjunction with known Lorentz generators to derive Poincaré symmetry constraints on generic massive spinning two-, three- and four-point celestial amplitude structures. Finally, as a consistency check, three-point Minkowski space amplitudes of two massless scalars and a spin-one or -two massive boson are explicitly mapped to the celestial sphere, and the resulting three-point function coefficients are confirmed to be in exact agreement with the results obtained from Poincaré symmetry constraints.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2025

Symmetry-projected spin-AGP methods applied to spin systems

Symmetry-projected wave function methods capture static correlation by breaking and restoring the symmetries of a system. In this article, we present the symmetry-projected spin antisymmetrized geminal power (spin-AGP) state projected onto space group symmetry as well as complex conjugation, spin-flip, and time-reversal symmetries. The method is benchmarked on the 1D XXZ model and the 2D J 1 − J 2 model with square and triangular lattices. Our results indicate that symmetry projection methods provide a powerful tool for frustrated spin systems.

Antisymmetrized geminal power↗
DOE OSTI2019

Tensor optimized Fermi sphere method for nuclear matter—Power series correlated wave function and a cluster expansion

A new formalism, called “tensor optimized Fermi sphere (TOFS) method”, is developed to treat the nuclear matter using a bare interaction among nucleons. In this method, the correlated nuclear matter wave function is taken to be a power series type, Ψ{sub N}=[∑{sub n=0}{sup N}(1∕n!)F{sup n}]Φ{sub 0} and an exponential type, Ψ{sub ex}=exp(F)Φ{sub 0}, with the uncorrelated Fermi-gas wave function Φ{sub 0}, where the correlation operator F can induce central, spin–isospin, tensor, etc. correlations, and Ψ{sub ex} corresponds to a limiting case of Ψ{sub N} (N→∞). In the TOFS formalism based on Hermitian form, it is shown that the energy per particle in nuclear matter with Ψ{sub ex} can be expressed in terms of a linked-cluster expansion. On the basis of these results, we present the formula of the energy per particle in nuclear matter with Ψ{sub N}. We call the Nth-order TOFS calculation for evaluating the energy with Ψ{sub N}, where the correlation functions are optimally determined in the variation of the energy. The TOFS theory is applied for the study of symmetric nuclear matter using a central NN potential with short-range repulsion. The calculated results are fairly consistent to those of other theories such as the Brueckner–Hartree–Fock approach etc.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2025

Quantum Information for Fusion Energy Sciences (Final Technical Report)

The simulation of plasma dynamics is a critical area of Fusion Energy Sciences (FES) due to it’s usefulness in predicting, controlling, and confining plasmas in the context of potential fusion reactors. The simulation of plasmas is a computationally difficult problem in both classical and quantum physics, motivating investigation into the potential of quantum computers to simulate these systems. This project took several concrete steps towards this goal by developing tools for improving the control, characterization, and calibration of quantum gates on a superconducting quantum computer, developing error suppression and mitigation tools to reduce errors on the quantum computer, and utilizing these advancements to simulate reduced models of plasma dynamics on the quantum computer. In order to efficiently simulate plasma physics, an optimal control method which synthesizes, directly at the pulse level, any quantum gate on qubit and qutrit systems was developed. Using four superconducting transmon quantum processors at Rigetti and LLNL, it was demonstrated that any arbitrary quantum gate on qubits and qutrits could be implemented with high fidelity, leading to a significantly reduced length of a gate sequence. A problem of interest in FES is the nonlinear optical process of laser pulse compression within a plasma. Since quantum physics is linear, simulating nonlinear operations is not naturally feasible on a quantum computer, however it is possible to simulated a quantized version of the nonlinear process. A quantization approach to convert nonlinear wave-wave interaction problems to Hamiltonian simulation problems was developed and demonstrated using two qubits on a Rigetti device. In this experiment, a number of error suppression and mitigation techniques were investigated to determine how best to utilize the finite quantum resources. This study provides an example of how plasma problems may be solved on near-term, noisy quantum computing platforms and identified a promising set of techniques. Building on the insights of these experiments, the investigation turned to linear electron-plasma wave physics. A connection was identified between a local one-dimensional lattice spin model and linear wave phenomena, allowing a plasma physics problem to be efficiently mapped to the quantum computer. In this framework, reflection and transmission of plasma waves at a sharp boundary was studied, as well as the propagation of waves through an inhomogeneous plasma medium. In addition to the suite of error suppression and mitigation techniques developed, this experiment introduced the use of a digital-analog gate scheme designed to efficiently simulate the plasma Hamiltonian. With hardware available at the conclusion of the project, simulation at the scale of 9 qubits and 15 timesteps (60 entangling layers) was achieved.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1994

Probing the antiferromagnetic long-range order with Glauber spin states

It is well known that the ground state of low-dimensional antiferromagnets deviates from Neel states due to strong quantum fluctuations. Even in the presence of long-range order, those fluctuations produce a substantial reduction of the magnetic moment from its saturation value. Numerical simulations in anisotropic antiferromagnetic chains suggest that quantum fluctuations over Neel order appear in the form of localized reversal of pairs of neighboring spins. In this paper, we propose a coherent state representation for the ground state to describe the above situation. In the one-dimensional case, our wave function corresponds to a two-mode Glauber state, when the Neel state is used as a reference, while the boson fields are associated to coherent flip of spin pairs. The coherence manifests itself through the antiferromagnetic long-range order that survives the action of quantum fluctuations. The present representation is different from the standard zero-point spin wave state, and is asymptotically exact in the limit of strong anisotropy. The fermionic version of the theory, obtained through the Jordan-Wigner transformation, is also investigated.

Cabrera, Guillermo G.↗
DOE OSTI2026

Simulating plasma wave propagation on a superconducting quantum chip

Quantum computers may one day enable the efficient simulation of strongly coupled plasmas that lie beyond the reach of classical computation in regimes where quantum effects are important and the scale separation is large. Here, in this article, we take a first step toward efficient simulation of quantum plasmas by demonstrating linear plasma wave propagation on a superconducting quantum chip. Using high-fidelity and highly expressive device-native gates, combined with an error-mitigation technique, we simulate the scattering of laser pulses from inhomogeneous plasmas. Our approach is made feasible by the identification of a suitable local spin model whose excitations mimic plasma waves, and whose circuit implementation requires a lower gate count than other proposed approaches that would require a future fault-tolerant quantum computer. This work opens avenues to study more complicated phenomena that cannot be simulated efficiently on classical computers, such as nonlinear quantum dynamics when strongly coupled plasmas are driven out of equilibrium.

general physics↗
DOE OSTI2018

Effect of Configuration Interaction of Rare-Earth Ion States on the Intensity of Intermultiplet Transitions

We present the analysis of wave functions and the effect of configuration interaction on the intensity of absorption bands for Pr{sup 3+}, Tm{sup 3+}, and Er{sup 3+} ions. It is shown that due to the strong spin–orbit interaction the wave functions of rare-earth ions are multicomponent superpositions of ″pure″ {sup 2S+1}L{sub J} multiplets with different values of S and L and the same values of the angular momentum J. For this reason, the effect of configurational interaction depends not only on the energy gap up to excited configurations, but also on the presence of high-energy {sup 2S+1}L{sub J} components. The presence of such components yields a strong influence on the configuration interaction even at the deep layers. Another consequence of the multicomponent composition of the wave functions is the formation of groups of strongly interrelated states. When the configuration interaction is not fully taken into account, the error in describing the oscillator strengths is distributed among all the states of the group, and the low overall accuracy of the description is not perceived as a contradiction to the theory. To confirm the proposed assumptions, the oscillator strengths of the absorption transitions of laser materials activated by Pr{sup 3+}, Tm{sup 3+}, and Er{sup 3+} ions are described using the modified Judd–Ofelt theory.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Half-metallic Ferromagnetism in Novel Rh{sub 2}-based Full-Heusler Alloys Rh{sub 2}FeZ (Z = Ga and In)

In this approach, we have employed the ab initio method of full-potential linearized plane waves plus local orbital based on the framework of density functional theory, within the spin generalized gradient approximation plus U (GGA+U), where U is the Hubbard correlation term for exchange-correlation potential. This method is used to predict the equilibrium structural parameters, the electronic structure, and the magnetic properties of Rh{sub 2}FeGa and Rh{sub 2}FeIn full-Heusler alloys. The structural properties result show that both Rh{sub 2}FeGa and Rh{sub 2}FeIn compounds are stable in ferromagnetic states. The spin-polarized electronic structure demonstrate that both full-Heusler compounds are half-metals with half-metallic band gap (E{sub HM}) of 0.326 eV for Rh{sub 2}FeGa alloy and 0.245 eV for Rh{sub 2}FeIn alloy, where the apparition of an indirect gap from Γ to X in minority spin is shown by these Heusler alloys. Furthermore, calculations of total magnetic moment give the value of 5 µ{sub B}, which agrees with Slater-Pauling rule; also, the atomic magnetic moment of both Rh and Fe transition metals have the same sign which depicts the ferromagnetic behavior.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Spin-Density Matrix Elements in K∗(892) Photoproduction with Recoiling Λ at GlueX

We report on the measurement of spin-density matrix elements for the K∗(892) → K+π0 photoproduction process with a recoiling Λ hyperon. The measurement used high-statistics GlueX data from photoproduction off a proton target at photon energies between 8.2 and 8.8 GeV, in a kinematic regime dominated by t-channel exchange processes. GlueX is a fixed-target experiment with a linearly polarized photon beam and a nearly 4π hermetic detector, allowing extraction of the full spin observ- ables from both the K+π0 and Λ → π−p systems. The GlueX data show clear evidence of the K∗(892) resonance in the K+π0 mass spectrum, along with additional structures at higher masses that may correspond to K∗0 or K∗2 resonances. The precise measurement of the spin-density matrix elements of the K∗(892) could serve as a standard candle for con- tinuing studies of higher-mass excited K∗ states. In addition, t-channel K∗ photoproduction differs from previous measurements of non-strange vector meson photoproduction, as it is free from Pomeron exchange and is virtually unexplored in this energy regime. Furthermore, the unprece- dented data collected by GlueX allow for investigations of correlations between the Λ polarization and the spin-density matrix elements of K∗ production, paving the way for future partial-wave analyses with full spin information involving the recoil hyperon.

Li, Hao [College of William and Mary, Williamsburg↗