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 ω T or to the plasma frequency ω p The potential is finite at these frequencies. For ω ˜ ω p , the equipotential surfaces can be considered roughly as planes perpendicular to the static magnetic field B. For ω ˜ ω T and ω 2 p ≪3ω 2 b (where ω b is the electron gyrofrequency), the equipotential surfaces are cylinders of axis B. On the other hand, if ω 2 p ≪3ω 2 b , 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 = ω T provides a new method for determining the electron temperature.