Vlf wave propagation and its interaction with the magnetoplasma

Abstract

Propagation of low frequency electromagnetic waves in the magnetoplasma is discussed. Dispersion relations for cold, collisional plasmas as well as for a cold beam-plasma system are derived. With the help of refractive index surfaces we show that the focusing mechanism fails to yield the required strength of VLF waves if collisional and temperature effects in the ambient plasma are taken into account. An alternative mechanism is proposed in terms of wave-particle interactions. It is shown that the VLF signal is amplified by a few orders of magnitude due to resonance interactions. The total amplification of the waves depends on the interaction time. Finally we outline a possible theory for the Cerenkov radiation from a beam of charged particles. The detectibility of VLF waves is also discussed. © 1972, IOP Publishing Ltd.