Electromagnetic Instabilities in a Strongly Inhomogeneous Plasma

This chapter examines finite–ß effects in the drift-cyclotron instability , the lower-hybrid-drift instability, the drift loss-cone instability, and the ion cyclotron excitation of the transverse drift waves . For a finite ratio of the Larmor radius of particles to the characteristic length of a plasma inhomogeneity, it is necessary to allow for the cyclotron and high-frequency instabilities . One of the main and experimentally verified methods of suppression of the drift loss-cone instability is the injection of a plasma of a relatively low density with slightly warm ions . With increasing β , the electromagnetic part of the perturbations and the electron magnetic drift become important. The broadening of the cyclotron resonance is also caused by ion magnetic drift . For a sufficiently large ion magnetic drift, that is, for sufficiently highβ , the frequency range of such a broadening can also be compared with the ion cyclotron frequency.