Influence of Ion Streaming Instabilities on Transport Near Plasma Boundaries

Abstract

Plasma boundary layers are susceptible to electrostatic instabilities driven by ion flows in presheaths and, when present, these instabilities can influence transport. In plasmas with a single species of positive ion, ion-acoustic instabilities are expected under conditions of low pressure and large electron-to-ion temperature ratio ($T_e/T_i\gg 1$). In plasmas with two species of positive ions, ion-ion two-stream instabilities can also be excited. The stability phase-space is characterized using the Penrose criterion and approximate linear dispersion relations. Predictions for how these instabilities affect ion and electron transport in presheaths, including rapid thermalization due to instability-enhanced collisions and an instability-enhanced ion-ion friction force, are also briefly reviewed. Recent experimental tests of these predictions are discussed along with research needs required for further validation. The calculated stability boundaries provide a guide to determine the experimental conditions at which these effects can be expected.

18 pages, 10 figures, International Conference on Phenomena in Ionized Gases 2015

References in corpus (5)

• Kinetic Theory of the Presheath and the Bohm Criterion
• Theory of the Electron Sheath and Presheath
• Instability-Enhanced Friction in the Presheath of Two-Ion-Species Plasmas
• Ion sound instability driven by ion beam
• Electron Preheaths: The Outsized Influence of Positive Boundaries on Plasmas

Cited by in corpus (4)

• Interaction of Biased Electrodes and Plasmas: Sheaths, Double Layers and Fireballs
• Simulations of ion heating due to ion-acoustic instabilities in the presheath
• Nonlinear interactions of ion acoustic waves explored using fast imaging decompositions
• Two-Stream Instability and Bernstein-Greene-Kruskal Mode Formation in Coulomb One Component Plasma