Kinetic instabilities in a mirror-confined plasma sustained by high-power microwave radiation

TL;DR

This paper reviews a decade of research on plasma kinetic instabilities in a mirror-confined plasma driven by high-power microwave radiation, highlighting wave-particle interactions and their relevance to space phenomena.

Contribution

It provides a comprehensive analysis of electron cyclotron resonance plasma instabilities and models non-stationary wave-particle interactions relevant to both laboratory and space plasmas.

Findings

Identification of two electron components affecting wave dispersion.

Observation of unstable wave excitation due to energetic electrons.

Correlation of laboratory plasma behavior with space plasma processes.

Abstract

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.