Abstract
A general mechanism of large-amplitude stabilization of the drift instability is investigated. For slab geometry, a drift-wave potential of the form φ = Φ cos(kxx) cos(kyy+kzz−ωt) is used where x is the direction of plasma density inhomogeneity and z is the direction of a uniform field. It is assumed that kx∼ky≫kz and υi≪ω/kz≪υe. Studies of the exact guiding-center particle trajectories in the drift-wave potential show the existence of time-average, y-direction velocities whose magnitudes increase with the amplitude of the drift wave. As the wave grows, these velocities shift parts of the resonance region away from υz = ω/kz and finally into the bulk of the ion distribution. Thus, the original instability is stabilized by strong ion Landau damping. Stabilization will occur around the wave amplitude satisfying the condition, ckxΦ/B=ω/ky.
Published Version
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