Cyclotron radiation in hot magnetoplasmas

Abstract

The effects of thermal motions on the cyclotron radiation from test particles gyrating in a homogeneous magnetoplasma are studied. These effects take care of all singularities that exist in the theory of cyclotron radiation in cold magneto- plasma, e.g. the divergence in energy loss for small particle energies. Around the hybrid frequencies thermal corrections become of dominant importance. At these frequencies cold-plasma theory breaks down. Thermal effects arise in two ways: by modifying the wave modes known from cold plasma theory, and by the introduction of a new longitudinal wave mode, known as the Bernstein mode. All wave modes are damped (in stable plasmas), the damping increasing rapidly with the product (V/v|) (ω - s), where the wave frequency ω is measured in units of the gyro frequency; V is the thermal velocity; v| the parallel component of the particle velocity, and s is an integer.