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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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Radiation and propagation problems related to antennas and probes in magnetoionic plasma
Antenna impedance behavior in plasma related to radio astronomy, emphasizing electrically small antennas used in space vehicles
Antenna admittance in an ionospheric plasma with emphasis on electron density
Antenna impedance behavior in plasma, related to radio astronomy, emphasizing electrically small antennas used in space vehicles
Admittance of infinite cylindrical antenna in lossy plasma with axis parallel to static magnetic field
Effects of plasma sheath in near zone field of antennas
Numerical values for cylindrical antenna admittance in uniaxial plasma, considering plasma compressibility and vacuum sheath
Experimental studies of antennas and acoustic waves in plasma
Equatorial patterns measurement of plasma covered axially slotted cylindrical antenna, describing discharge tube, facility and Langmuir probe survey of tube electron density
Impedance and radiation field in surrounding hot plasma interacting with electrically short antenna
Research in antennas and waves in plasma
The electrostatic plasma response to a small pulsed antenna in a magnetic field is analyzed. The ringing of the plasma at three discrete frequencies--the upper-hybrid frequency and two resonance cone branch frequencies--is evidenced, and the amplitudes of these frequency responses is determined as a function of the characteristic plasma frequencies, the angle of observation with respect to the magnetic field, and the pulse length. Applications to plasma diagnostics are discussed. It is shown that the upper hybrid response and the response at either of the resonance cone branch frequencies is adequate information to determine the plasma density, and the magnetic field magnitude and angle.
Antennas impedances in warm isotropic plasma, using hydrodynamic and kinetic /Vlasov/ equations
Plasma compressibility, plasma anisotropy, and vacuum sheath effects on antenna admittance in ionosphere
Admittance of infinite cylindrical antenna immersed in lossy compressible plasma
Cylindrical dipole antenna field in compressible isotropic plasma, assuming triangular current distribution and deriving input impedance formula
Dielectric medium space-time modulated by two pump waves, cylindrical probe impedance behavior in magnetoplasma, and other studies related to antennas and waves in plasmas
The effect of plasma produced by an arc-jet thruster on the performance of on-board reflector antennas was investigated using a configuration in which the arc-jet plume is modeled as an inhomogeneous scatterer with a smoothly varying refractive index. On the basis of laws of geometrical optics, used to calculate the wave propagation, the trajectory, phase, amplitude, and polarization of the high-frequency ray field are computed numerically. The experiments performed to validate the calculated results experimentally are described.