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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Nanomechanical electric and electromagnetic field sensor

The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

47 OTHER INSTRUMENTATION↗
DOE OSTI2016

Detection of electromagnetic radiation using nonlinear materials

An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Generating a heated fluid using an electromagnetic radiation-absorbing complex

A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EM radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Quantum metrology of low frequency electromagnetic modes with frequency upconverters

We describe the RF Quantum Upconverter (RQU) and describe its application to quantum metrology of electromagnetic modes between dc and the Very High Frequency band (VHF) (≲300MHz). The RQU uses a Josephson interferometer made up of superconducting loops and Josephson junctions to implement a parametric interaction between a low-frequency electromagnetic mode (between dc and VHF) and a mode in the microwave C Band (~ 5GHz), analogous to the radiation pressure interaction between electromagnetic and mechanical modes in cavity optomechanics. The RQU can operate as a quantum-limited op-amp, or use protocols from optomechanics to implement non-classical measurement protocols equivalent to those used in cavity optomechanics, including back-action evading (BAE) measurements, sideband cooling, and two-mode squeezing. Furthermore, these protocols enable experiments using dc-VHF electromagnetic modes as quantum sensors.

Kuenstner, Stephen E.↗
DOE OSTI2013

The momentum of an electromagnetic wave inside a dielectric

The problem of assigning a momentum to an electromagnetic wave packet propagating inside an insulator has become known under the name of the Abraham–Minkowski controversy. In the present paper we re-examine this issue making the hypothesis that the forces exerted on an insulator by an electromagnetic field do not distinguish between polarization and free charges. Under this assumption we show that the Abraham expression for the radiation mechanical momentum is highly favored. -- Highlights: •We discuss an approximation to treat electrodynamics of a dielectric material. •We support the Abraham form for the electromagnetic momentum. •We deduce Snell’s law from the conservation of the Abraham momentum. •We show how to deal with the electric field discontinuity at the dielectric boundary.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Radiation of de-excited electrons at large times in a strong electromagnetic plane wave

The late time asymptotics of the physical solutions to the Lorentz–Dirac equation in the electromagnetic external fields of simple configurations–the constant homogeneous field, the linearly polarized plane wave (in particular, the constant uniform crossed field), and the circularly polarized plane wave–are found. The solutions to the Landau–Lifshitz equation for the external electromagnetic fields admitting a two-parametric symmetry group, which include as a particular case the above mentioned field configurations, are obtained. Some general properties of the total radiation power of a charged particle are established. In particular, for a circularly polarized wave and constant uniform crossed fields, the total radiation power in the asymptotic regime is independent of the charge and the external field strength, when expressed in terms of the proper-time, and equals a half the rest energy of a charged particle divided by its proper-time. The spectral densities of the radiation power formed on the late time asymptotics are derived for a charged particle moving in the external electromagnetic fields of the simple configurations pointed above. This provides a simple method to verify experimentally that the charged particle has reached the asymptotic regime. -- Highlights: •Late time asymptotics of the solutions to the Lorentz–Dirac equation are studied. •General properties of the total radiation power of electrons are established. •The total radiation power equals a half the rest energy divided by the proper-time. •Spectral densities of radiation formed on the late time asymptotics are derived. •Possible experimental verification of the results is proposed.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2012

Detection of electromagnetic waves using charged MEMS structures

We describe micromechanical structures that are capable of sensing both electrostatic fields and electromagnetic fields over a wide frequency range. Typically, sensing of electromagnetic waves is achieved with electrically conducting antennas, which despite the many advantages do not exhibit high sensitivity over a broad frequency range. An important aspect of our present work is that, in contrast to traditional antennas, the dimensions of micromechanical oscillators sensitive to electromagnetic waves can be much smaller than the wavelength. We characterized the micromechanical oscillators and measured responses to electric fields and estimated the performance limits by evaluating the signal-to-noise ratio theoretically and experimentally.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2014

Emergent spin electromagnetism induced by magnetization textures in the presence of spin-orbit interaction (invited)

Emergent electromagnetic field which couples to electron's spin in ferromagnetic metals is theoretically studied. Rashba spin-orbit interaction induces spin electromagnetic field which is in the linear order in gradient of magnetization texture. The Rashba-induced effective electric and magnetic fields satisfy in the absence of spin relaxation the Maxwell's equations as in the charge-based electromagnetism. When spin relaxation is taken into account besides spin dynamics, a monopole current emerges generating spin motive force via the Faraday's induction law. The monopole is expected to play an important role in spin-charge conversion and in the integration of spintronics into electronics.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2014

Interaction of a two-dimensional electromagnetic breather with an electron inhomogeneity in an array of carbon nanotubes

Propagation of ultrashort laser pulses through various nano-objects has recently became an attractive topic for both theoretical and experimental studies due to its promising perspectives in a variety of problems of modern nanoelectronics. Here, we study the propagation of extremely short two-dimensional bipolar electromagnetic pulses in a heterogeneous array of semiconductor carbon nanotubes. Heterogeneity is defined as a region of enhanced electron density. The electromagnetic field in an array of nanotubes is described by Maxwell's equations, reduced to a multidimensional wave equation. Our numerical analysis shows the possibility of stable propagation of an electromagnetic pulse in a heterogeneous array of nanotubes. Furthermore, we establish that, depending on its speed of propagation, the pulse can pass through the area of increased electron concentration or be reflected therefrom.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2011

Electrons in a relativistic-intensity laser field: generation of zeptosecond electromagnetic pulses and energy spectrum of the accelerated electrons

We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out. (superintense laser fields)

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Lorentz-Abraham-Dirac versus Landau-Lifshitz radiation friction force in the ultrarelativistic electron interaction with electromagnetic wave (exact solutions)

When the parameters of electron-extreme power laser interaction enter the regime of dominated radiation reaction, the electron dynamics changes qualitatively. The adequate theoretical description of this regime becomes crucially important with the use of the radiation friction force either in the Lorentz-Abraham-Dirac form, which possesses unphysical runaway solutions, or in the Landau-Lifshitz form, which is a perturbation valid for relatively low electromagnetic wave amplitude. The goal of the present paper is to find the limits of the Landau-Lifshitz radiation force applicability in terms of the electromagnetic wave amplitude and frequency. For this, a class of the exact solutions to the nonlinear problems of charged particle motion in the time-varying electromagnetic field is used.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2018

Models of the Dynamics of Spatially Separated Broadband Electromagnetic Fields Interacting with Resonant Atoms

The Markov model of spontaneous emission of an atom localized in a spatial region with a broadband electromagnetic field with zero photon density is considered in the conditions of coupling of the electromagnetic field with the broadband field of a neighboring space. The evolution operator of the system and the kinetic equation for the atom are obtained. It is shown that the field coupling constant affects the rate of spontaneous emission of the atom, but is not manifested in the atomic frequency shift. The analytic expression for the radiative decay constant for the atom is found to be analogous in a certain sense to the expression for the decay constant for a singly excited localized ensemble of identical atoms in the conditions when the effect of stabilization of its excited state by the Stark interaction with the vacuum broadband electromagnetic field is manifested. The model is formulated based on quantum stochastic differential equations of the non- Wiener type and the generalized algebra of the Ito differential of quantum random processes.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Beta decay and other processes in strong electromagnetic fields

We consider effects of the fields of strong electromagnetic waves on various characteristics of quantum processes. After a qualitative discussion of the effects of external fields on the energy spectra and angular distributions of the final-state particles as well as on the total probabilities of the processes (such as decay rates and total cross sections), we present a simple method of calculating the total probabilities of processes with production of nonrelativistic charged particles. Using nuclear {beta} decay as an example, we study the weak- and strong-field limits, as well as the field-induced {beta} decay of nuclei stable in the absence of the external fields, both in the tunneling and multiphoton regimes. We also consider the possibility of accelerating forbidden nuclear {beta} decays by lifting the forbiddeness due to the interaction of the parent or daughter nuclei with the field of a strong electromagnetic wave. It is shown that for currently attainable electromagnetic fields all effects on total {beta}-decay rates are unobservably small.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2012

Weak and electromagnetic mechanisms of neutrino-pair photoproduction in a strongly magnetized electron gas

Expressions for the power of neutrino radiation from a degenerate electron gas in a strong magnetic field are derived for the case of neutrino-pair photoproduction via the weak and electromagnetic interaction mechanisms (it is assumed that the neutrino possesses electromagnetic form factors). It is shown that the neutrino luminosity of a medium in the electromagnetic reaction channel may exceed substantially the luminosity in the weak channel. Relative upper bounds on the effective neutrino magnetic moment are obtained.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Wave Nature of the Transverse Doppler Effect and the “Red” and “Blue” Frequency Shift Anomaly in an Electromagnetic Wave from a Moving Radiation Source

The electromagnetic field of a harmonic oscillator moving at a constant velocity has been analyzed. The expression for calculating the Doppler frequency shift at relativistic velocities of its motion is derived using the classical electromagnetic theory. It is shown that the transverse Doppler effect is a special case and also differs from zero in the wave theory. With an increasing velocity of the radiation source, the “red” frequency shift in an electromagnetic wave prevails over the “blue” shift more strongly. The noncontradictory nature of the proposed model relative to the well-known experimental data has been demonstrated.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2025

Utah FORGE: LBNL Reports on VEMP Electromagnetic Data Collection and Processing - 2024

This archive contains reports related to Vertical Electromagnetic Profiling (VEMP) tool data collection and processing at Utah FORGE in 2024. The first report describes LBNL's effort to collect electromagnetic geophysical data with the tool in well 78-32B and a downhole electrode in well 16A. The second report describes the final data acquisition and processing of the VEMP electromagnetic data collected at the Utah FORGE site in May of 2024. Also included are a noise analysis as well as a comparison of the data to numerical models. This was originally presented as a paper at the 2025 Stanford Geothermal Workshop.

15 GEOTHERMAL ENERGY↗
DOE OSTI2017

Numerical Research on Magnetic Field, Temperature Field and Flow Field During Melting and Directionally Solidifying TiAl Alloys by Electromagnetic Cold Crucible

The electromagnetic cold crucible (EMCC) technique is an effective method to melt and directionally solidify reactive and high-temperature materials without contamination. The temperature field and fluid flow induced by the electromagnetic field are very important for melting and controlling the microstructure. In this article, a 3D EMCC model for calculating the magnetic field in the charges (TiAl alloys) using the T-Ω finite element method was established and verified. Magnetic fields in the charge under different electrical parameters, positions and dimensions of the charge were calculated and analyzed. The calculated results show that the magnetic field concentrates in the skin layer, and the magnetic flux density (B) increases with increasing of the frequency, charge diameter and current. The maximum B in the charge is affected by the position of the charge in EMCC (h{sub 1}) and the charge height (h{sub 2}), which emerges at the middle of coils (h{sub c}) when the relationship of h{sub c} < h{sub 1} + h{sub 2} < h{sub c} + δ is satisfied. Lower frequency and smaller charge diameter can improve the uniformity of the magnetic field in the charge. Consequently, the induced uniform electromagnetic stirring weakens the turbulence and improves temperature uniformity in the vicinity of the solid/liquid (S/L) interface, which is beneficial to forming a planar S/L interface during directional solidification. Based on the above conclusions, the TiAlNb alloy was successfully melted with lower power consumption and directionally solidified by the square EMCC.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Optimized Electromagnetic Fields Levitate Bulk Metallic Materials

The bulk metallic electromagnetic levitation technique has a promising application prospect in condensed physics and materials science. In order to resolve the problem of weak levitation force and the small size of samples, an optimized solution based on finite element analysis (FEA) is developed to seek the best electromagnetic field distribution in the levitation zone. The influence of material properties on the distribution of magnetic flux density, surface pressure, and the Lorentz force were studied by the FEA method with various sample sizes of titanium and copper balls. The levitation capability of cylindrical coil system which consists of a single-layer coil with an inner diameter of 30 mm and the levitated object with a diameter of 20 mm was analyzed. To keep a balance between the turn number and increment efficiency of force, the best number of 7 turns is confirmed. Then, two types of optimized coils were predicted by numerical simulations, and the levitation force is improved drastically. The double-layer coil displays an outstanding levitation capability owing to the strong electromagnetic field generated by multilayer turns. In addition, 5 to 50 g aluminum, titanium, copper, and nickel are levitated by the above three kinds of coils and the levitation capacities are validated from the recorded data of the minimum operating current that can levitate the samples. The experimental results show good agreements with the simulation results, and the minimum current for optimized coils is reduced efficiently.

36 MATERIALS SCIENCE↗