Abstract
Electromagnetic waves propagating transverse to an external magnetic field in a high-β (β being the ratio of the kinetic pressure to the magnetic pressure) plasma become unstable through purely growing modes when β∥e, (electron β parallel to the magnetic field) exceeds a certain minimum value β∥*. For J ≦ 2 (J being the distribution index), the region of instability consists of a single band of unstable wavenumbers k, whereas for J ≥ 3 more than one unstable wave number band may exist. The growth rates are largest for J = 0, and tend to decrease as J increases. The presence of hot ions increases the instability region by exciting a low-frequency instability. This instability gets excited at considerably lowered values of β‖e, and has growth rates of the order of ion cyclotron frequency. The effect of T‖i/T‖e and T‖e/T⊥e is destabilizing, whereas that of T⊥i/T⊥e is stabilizing.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have