Ion acoustic wave radiation by a pulsating point source in a warm magnetoplasma

The scalar potential created by an oscillating point charge in a warm collisionless magnetoplasma is studied theoretically for extremely low frequencies in the band 300-500 Hz. The electron and ion velocity distribution functions are assumed to be Maxwellian. Only the directions perpendicular to the magnetic field are considered. Calculations are made using numerical integration. It is shown that up to several hundred electron Debye lengths from the source, the potential is essentially due to the excitation of ion acoustic waves. The damping of these waves is studied as a function of the distance and of the electron-ion temperature ratio.