Radiation From a Short Electric Dipole in a Hot Uniaxial Plasma

Abstract

The effects of electron temperature on the radiation fields and the resistance of a short electric dipole antenna embedded in a uniaxial plasma have been studied. The radiation condition for solving Maxwell's equations is discussed, and the phase and group velocities for propagation are given. It is found that for ω < ω_ρ the antenna excites two waves, a slow wave and a fast wave. These waves propagate only within a cone whose axis is parallel to the biasing magnetostatic field B₀ and whose half-cone angle is slightly less than sin⁻¹ (ω/ω_ρ). In the case of ω > ω_ρ the antenna excites two separate modes of radiation. One of the modes is the electromagnetic mode, while the other mode is of hot plasma origin. A characteristic interference structure is noted in the angular distribution of the field. The input and the radiation resistances are calculated and are shown to remain finite for nonzero electron thermal velocities. The effect of Landau damping and the antenna length on the input and the radiation resistances has been considered.

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