Formation of electron beams under the interaction of a whistler wave packet with the radiation belt electrons

• Published in: Advances in space research 1999-01, Vol.24 (8), p.1007-1010
• Main Authors: Hobara, Y., Trakhtengerts, V.Y., Demekhov, A.G., Hayakawa, M.
• Format: Article
• Language: English
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/S0273-1177(99)00558-X

The purpose of this paper is to discuss the properties of electron beams formed by cyclotron interaction between radiation belt electrons and a quasi-monochromatic whistler wave packet from a ground-based VLF transmitter. Those electron beams are thought to be the source of triggered ELF/VLF emissions as secondary whistler waves. The beams are formed due to trapping of electrons at the forward front of the wave packet, their acceleration inside the packet, escape of the accelerated electrons from the moving backward front of the packet, and their following free motion in an inhomogeneous magnetic field. Combination of these processes provides the main features of the spatial-temporal evolution of the beams which are investigated analytically and numerically. Movement of the pumping wave packet in the inhomogeneous magnetic field provides the variations of the initial velocity and position of the beam injection which change the spatial and temporal gradients of the parallel velocity of the beam opposite direction to a pure adiabatic motion. Such a behavior can be significant for the generation of secondary emissions.