Electron cyclotron instability

The paper presents a study of the dependence of initiation and development of instability on the cyclotron frequency of electrons in a homogeneous plasma with cold ions and electrons forming two beams which move in the direction of, and opposite to, that of a constant magnetic field. It is demonstrated that for ^{2 2} , the instability can already arise at _pe ² _ce ² , and a brief comparison with the experimental results is carried out.The authors take this opportunity to thank Dr. M. Seidl for his valuable comments and stimulating discussions on this paper.