Effects of electrostatic confinement fields and finite gyroradius on an instability of hollow electron columns

Abstract

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Destabilization of them=1Diocotron Mode in Non-neutral Plasmas

“…(7) and (6) for m 3, r p 0.59. The growth rate g scales as k 2͞3 for k small, similar to the scaling obtained in [6]. The fractional power and zero instability threshold in k are associated with a boundary layer near r r V related to the singularity in the neutral mode of Eq.…”

“…This growth is inconsistent with the exponential growth measured in the experiment. Smith [6] has shown that a modification to (1) can lead to exponential growth for m 1. However, because of the phenomenological nature of the model, it has not been possible to compare these results with the experiments.…”

Motion of extended vortices in an inhomogeneous pure electron plasma

“…͑iii͒ The isomorphism neglects effects arising in a pure electron plasma from the finite length of the confinement system, finite gyroradius effects, 14,15 long time viscous effects and small spatial scale effects. 16,17 A modified model has been recently proposed in order to account for the radial variation of the equilibrium length of the system.…”

Simulations of the instability of the m=1 self-shielding diocotron mode in finite-length nonneutral plasmas

“…Several theoretical attempts have been made to understand the origin of the instability [7,8,9,10], but have failed to account for the exponential character of the stability and/or the size of the growth rate. In particular, Smith [8] has drawn attention to finite length effects and Finn et al [11] have drawn attention to the importance of the shape of the ends of the plasma based on an analogy to vortex stretching from topography variations in shallow fluid dynamics for geophysical flows.…”

“…In particular, Smith [8] has drawn attention to finite length effects and Finn et al [11] have drawn attention to the importance of the shape of the ends of the plasma based on an analogy to vortex stretching from topography variations in shallow fluid dynamics for geophysical flows. Hilsabeck and O'Neil [13] develop a Zero Debye Length Reduced Description, but also fail to predict large enough growth rates based on end shape and length alone.…”