Trapping Instabilities in a Slightly Inhomogeneous Plasma

Publisher Website
Google Scholar
Abstract
The stability of an infinite collisionless plasma with a small density gradient in the x direction (using the collisionless Boltzmann equation and Maxwell's equations) confined by a static magnetic field in the z direction, is studied. Unstable modes are found at frequencies near multiples of the ion‐cyclotron frequency Ωi. These modes are electrostatic oscillations transverse to the magnetic field, and have very short wavelengths λ ∼ vd/Ωi, where vd is the (small) drift occasioned by the magnetic‐field inhomogeneity. The phase velocity of the wave is comparable to vd, and resonant interaction leads to the growth. Typical growth rates are large, α ∼ (me/mi) Ωi, but the effect of the instability is minimized by the extremely short wavelength.

This publication has 5 references indexed in Scilit: