KINETIC THEORY OF PLASMA-WAVE MOTION IN PRESENCE OF COLLISIONS

Utilizing a Krook-type collision integral, we carry out a systematic analysis of electrostatic waves and instabilities in a fully ionized, low β, inhomogeneous plasma (where β is the ratio of particle pressure to magnetic pressure). The model employed is that of a plasma slab supported by magnetic and gravitational fields. In particular, the dispersion relations for drift waves, appropriate to a short system, and for ion cyclotron waves are derived and discussed. Thus, for drift waves it is found that in the presence of collisions, ion motion parallel to the magnetic field can provide a strong stabilizing effect for sufficiently large values of the axial wave vector. For the two-stream ion cyclotron instability we find that ion-ion collisions can provide strong damping even for collision frequencies well below the ion cyclotron frequency.