Cone resonance excited by an alternating point charge in a warm magnetoplasma

Using the quasi-static approximation, the potential created by an alternating point charge in a warm magnetoplasma is studied theoretically. The excitation frequency is assumed to be less than both the plasma frequency and the electron gyrofrequency. An approximate expression for the dispersion relation enables us to obtain an analytical result for the potential, which remains finite on the resonance cone, while an interference structure appears either inside or outside the cone, depending on the excitation frequency