Relativistic electromagnetic instabilities near electron cyclotron frequency and harmonics

Electrons having highly anisotropic, relativistic distribution functions are frequentlu created in intensely heated plasmas using electron-cyclotron resonance heating, and characterize intense, relativistic electron beams used in devices for generating electromagnetic energy. In this paper the absolute versus convective nature and propagation characteristics of instabilities that are given by beam-type electron distributions representing such highly anisotropic electron plasmas are presented. Instabilities that propagate along and perpendicular to the steady, uniform magnetic field in which the plasma exists are also studied