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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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Dipole antenna radiation in compressible anisotropic electron plasma overlying imperfectly conducting half space, solving for lunar environment
Dipole antenna radiation in compressible anisotropic electron plasma overlying imperfectly conducting half space, evaluating Fourier- Bessel integrals for lunar environment
Computer program transforming spherical harmonic coefficients into arbitrarily tilted coordinate systems, tabulating coefficients of International Geomagnetic Reference Field 1965 in dipole coordinate system
Calculation method for large numbers of dipole and quadrupole transition probabilities
Dipole relaxation and molecular arrangements in liquid crystals
Field measurements by rotating spacecraft for dipole moment determination
Rotational and vibration effects in ion dipole collisions demonstrated in color motion picture
Radiation patterns of dipole antenna in stratified medium representing lunar surface
Vibrational degrees of freedom effects on capture cross sections and ion-molecule complexes formation in ion-dipole collisions
Interatomic electric dipole moment coefficient derivation by approximation involving accessible atomic properties, noting application to H atoms
Short dipole antenna impedance in warm isotropic plasma using Vlasov theory
International geomagnetic reference field 1965 geomagnetic potential rate of change and transformation to dipole coordinates
Vibrational effects on capture cross sections and ion-molecule complexes formation based on ion- dipole collisions, noting multiple reflection probabilities and collision lifetimes
Three dimensional fields excited by arbitrarily oriented dipole in cylindrically inhomogeneous isotropic plasma, deriving closed form solution
Rotational and vibrational effects in ion dipole collisions
Expressions for the excitation cross section of the highly excited states of the hydrogenlike atoms by fast charged particles have been derived in the dipole approximation of the semiclassical impact parameter and the Born approximations, making use of a formula for the asymptotic expansion of the oscillator strength of the hydrogenlike atoms given by Menzel. When only the leading term in the asymptotic expansion is retained, the expression for the cross section becomes identical to the expression obtained by the method of the classical collision and correspondence principle given by Percival and Richards. Comparisons are made between the Bethe coefficients obtained here and the Bethe coefficients of the Born approximation for transitions where the Born calculation is available. Satisfactory agreement is obtained only for n yields n + 1 transitions, with n the principal quantum number of the excited state.
Data from the auroral particles experiment on OGO-4 were used to study effects of substorm activity, interplanetary magnetic field latitutde, and dipole tilt angle on high-latitude precipitation of 700 eV electrons. It was found that: (1) The high-latitude zone of 700 eV electron precipitation in late evening and early morning hours moves equatorward by 5 to 10 deg during substorms. (2) The low-latitude boundary of polar cusp electron precipitation at 9 to 15 hours MLT also moves equatorward by several degrees during substorms and, in the absence of significant substorm activity, after a period of southward interplanetary magnetic field. (3) With times containing substorm activity or a southward interplanetary magnetic field eliminated, the low-latitude boundary of polar cusp electron precipitation is found to move by approximately 4 deg over the total yearly range of tilt angles. At maximum winter and summer conditions the invariant latitude of the boundary is shown to shift by approximately -3 deg and +1 deg respectively from its equinox location.
A method for determining the magnetic moment of a spacecraft from magnetic field data taken in a limited region of space close to the spacecraft. The spacecraft's magnetic field equations are derived from first principles. With measurements of this field restricted to certain points in space, the near-field equations for the spacecraft are derived. These equations are solved for the dipole moment by a least squares procedure. A method by which one can estimate the magnitude of the error in the calculations is also presented. This technique was thoroughly tested on a computer. The test program is described and evaluated, and partial results are presented.