  This paper summarizes the studies of plasma kinetic instabilities in the
electron cyclotron frequency range carried out over the last decade at the
Institute of Applied Physics of Russian Academy of Sciences. We investigate the
nonequilibrium plasma created and sustained by high-power microwave radiation
of a gyrotron under the electron cyclotron resonance condition. Resonant plasma
heating results in the formation of at least two electron components, one of
which, more dense and cold, determines the dispersion properties of the
high-frequency waves, and the second, a small group of energetic electrons with
a highly anisotropic velocity distribution, is responsible for the excitation
of unstable waves. Dynamic spectra and the intensity of stimulated
electromagnetic emission are studied with high temporal resolution.
Interpretation of observed data is based on the cyclotron maser paradigm, in
this context, a laboratory modeling of non-stationary wave-particle interaction
processes have much in common with similar processes occurring in the
magnetosphere of the Earth, planets, and in solar coronal loops.
