Stabilizing Effect of Mode Coupling in Collisionless Plasma

Abstract

Plasma instabilities produce fluctuating electric and magnetic fields in a limited mode spectrum of frequency and wave number. It is shown that under many circumstances mode coupling can lead to a saturated wave spectrum which turns off the instability. This process can take place in a time shorter than the time required for quasilinear relaxation of the plasma distribution function, and the saturated wave spectrum can be quite unrelated to linear growth characteristics. The low-frequency electromagnetic drift wave is given as an example.