Excitation of the plasma and upper hybrid resonances in a warm magnetoplasma by an alternating electric dipole

Abstract

The potential created by an alternating dipole in a warm magnetoplasma is calculated analytically, in the approximation of the full adiabatic theory, for excitation frequencies ω close either to the upper hybrid frequency ωT or to the plasma frequency ωp The potential is finite at these frequencies. For ω ˜ ωp, the equipotential surfaces can be considered roughly as planes perpendicular to the static magnetic field B. For ω ˜ ωT and ω2p ≪3ω2b (where ωb is the electron gyrofrequency), the equipotential surfaces are cylinders of axis B. On the other hand, if ω2p ≪3ω2b, the potential is the sum of a cylindrical wave and of a wave for which the equipotential surfaces are paraboloids of axis B. These results are used to calculate the mutual impedance ζ of a quadrupole probe, and it is shown that the measurement of Zγ atω = ωT provides a new method for determining the electron temperature.