Note on Maxwell's field equations and the constitutive equations.
Maxwell field equations and constitutive equations, discussing best pedagogical formulation for electrodynamics
VELOCITY DISTRIBUTION↗
SEARCH · Search NASA
Results for “ELECTRODYNAMICS”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Structural and electromechanical interaction in the multiple-exciter technique for random vibration testing.
Random vibration testing by multiple electrodynamic exciter technique, analyzing electromechanics and structural feedback
POWER SPECTRUM↗
Moessbauer diffraction. I - Quantum theory of gamma-ray and X-ray optics.
X rays and gamma rays interaction with crystals analyzed by quantum electrodynamics Green function methods, emphasizing Mossbauer gamma ray diffraction optics
Hannon, J. P.↗
Ion mass spectrometer for special uses
Prototype of curved-electrode, Paul-type, quadrupole, electrodynamic mass filter has the mass-resolution and transmission-factor properties expected from both theoretical considerations and results of experiments using linear quadrupole features.
Abramson, R. H.↗
On the general correspondence between field theories and the theories of direct interparticle action.
Field theories and direct interparticle action theories of classical electrodynamics, establishing general correspondence between formalisms
Narlikar, J. V.↗
A review of the theories concerning the equatorial F2 region ionosphere.
Causal and semiphenomenological theories concerning equatorial F 2 region, discussing electrodynamic drift theory and transequatorial winds
Goldberg, R. A.↗
Intrinsic transport theorem.
Intrinsic transport theorem for electrodynamics of continuous media, using Cartan method of exterior differential forms
Kiehn, R. M.↗
Propagation and confinement of light beams Final report, 15 Mar. 1968 - 1 Aug. 1970
Laser optics and quantum electrodynamics
Rexroad, H. N.↗
Review on ionosphere
Ionospheric research covering electron and ion distributions, ion chemistry, neutral atmosphere interactions, thermal structure, electrodynamics, etc
Bowhill, S. A.↗
The feasibility of electrohydrodynamic heat pipes
The effect of a nonuniform electrostatic field on insulating dielectric liquids in heat pipes was studied. Topics discussed include the theory of operation, design criteria, and evaluation of optimal design features. It is concluded that the electrodynamic heat pipes offer advantages that must be weighed against the disadvantages in order to arrive at a proper assessment of their value in solving heat transfer problems.
Jones, T. B.↗
Interaction of the solar wind with a planetary ionosphere
An electrodynamic model for an ionosphere-solar wind interaction is developed based on the existence of a low beta plasma below the anemopause. The currents for the interaction are driven by the solar wind motional electric field and induce a stagnation magnetic field at the anemopause. For Venus and Mars the lower region of the ionosphere near the electron density peak has the highest conductivity, and therefore the tangential component of the induction current flows substantially in this region. The current paths close in the anemopause, which is a solar wind current sheath analogous to the magnetopause. Both the fraction of the undisturbed solar wind motional electric field, which drives the induction current, and the required fraction of incident solar wind particles, crossing the anemopause to produce this current, are shown to be small.
Blank, J. L.↗
Kinematic distributions for electron pair production by muons
Cross sections and kinematic distributions for the trident production process plus or negative muon plus charge yields plus or minus muon plus electron plus positron plus charge (with charge = dipion moment and Fe) are given for beam energies of 100 to 300 GeV at fixed (electron positron) masses from 5 to 15 GeV. This process is interesting as a test of quantum electrodynamics at high energies, and in particular as a test of the form of the photon propagator at large timelike (four-momentum) squared. For this purpose, it is desirable to impose kinematic cuts that favor those Bethe-Heitler graphs which contain a timelike photon propagator. It is found that there are substantial differences between the kinematic distributions for the full Bethe-Heitler matrix element and the distributions for the two timelike-photon graphs alone; these differences can be exploited in the selection of appropriate kinematic cuts.
Linsker, R.↗
Energy straggling and radiation reaction for magnetic bremsstrahlung.
Using the method of quantum electrodynamics, the energy distribution of particles and emitted photons is calculated for the case when increases in the average energy of the photon emitted by synchrotron radiation to values appreciable compared to the energy of the particle give rise to particle energy straggling and radiation spectrum broadening. The classical radiative reaction effects which may be tested in this type of experiment are outlined, and a detailed quantum mechanical calculation is presented. The significance of energy straggling in astrophysics is discussed briefly.
Shen, C. S.↗
Testing techniques and comparisons between theory and test for vibration modes of ring stiffened truncated-cone shells.
Vibration tests were carried out on truncated-cone shells with widely spaced ring stiffeners. The models were excited by an air shaker for LF modes and by small electrodynamic shakers for HF modes. The Novozhilov thin shell theory according to which a ring is an assembly of an arbitrary number of segments, each being a short truncated-cone shell of uniform thickness, is used in the analysis of the results. A mobile, noncontacting, displacement-sensitive sensor system developed by the author was used in the tests. Tests results are given for a free-free 60-deg cone and for a clamped-free 60-deg cone. The tests are characterized as having considerable value for the classification of prevalent multimode responses in shells of this type.
Naumann, E. C.↗
Oxygen and hydrogen ion densities above Millstone Hill.
Measurements of the vertical flux of oxygen ions, when combined with simultaneous measurements of electron density and of electron and ion temperatures, present a unique opportunity to examine conditions in the topside ionosphere. The measured fluxes and densities may be used directly to evaluate terms in the O+ continuity equation without requiring any assumptions to be made about neutral winds, electric fields, or the ambipolar diffusion coefficient. From observations at Millstone Hill we have, in this way, derived the rate of loss of O+ in the charge-exchange reaction with hydrogen, the rate of photoionization of atomic oxygen, and the rate of loss of O+ in reactions with N2 and O2. In combination with laboratory and theoretical results, these rates can be interpreted to yield number densities of the corresponding neutral species. When the measured fluxes are examined for consistency with measured density gradients and temperature profiles, we find clear evidence of wind-induced or electrodynamic vertical drifts larger than 60 m/sec.
Schunk, R. W.↗
Source and identification of heavy ions in the equatorial F layer.
Further evidence is presented to show that the interpretation of some Ogo 6 retarding potential analyzer (RPA) results in terms of ambient Fe+ ions is correct. The Fe+ ions are observed only within dip latitudes of plus or minus 30 deg, and the reason for this latitudinal specificity is discussed in terms of a low-altitude source region and F region diffusion and electrodynamic drift. It is shown that the polarization field associated with the equatorial electrojet will raise ions to 160 km out of a chemical source region below 100 km but it will do so only in a narrow region centered on the dip equator. Subsequent vertical ExB drift, coupled with motions along the magnetic fields, can move the ions to greater heights and greater latitudes. There should be a resultant fountain of metallic ions rising near the equator that subsequently descends back to the E and D layers at tropical latitudes.
Hanson, W. B.↗
Dynamic testing of complex structures
Response of structure is determined under impulses large enough to create severe strains. Electrodynamic shaker can provide impulses to nearly any point on structure and can deliver repeated pulses of varying force and duration.
Birs, C.↗
Avalanche diodes for the generation of coherent radiation
Solid state devices and characterization, and optimum imbedding networks for realizing best performance were investigated along with a barrier injection transit time diode. These diodes were investigated for possible application as microwave amplifiers and oscillators. Measurements were made of diode noise figures in the frequency ranges of 4 - 6 GHz. Initial results indicate that a noise figure of 6 - 8 db may be possible. Optimum device structure and fabrication techniques necessary for low noise performance were investigated. Previously published documents on electrodynamics are included.
Penfield, P., Jr.↗