Existence of subsonic plasma sheaths

Journal Article · Sat Jan 15 04:00:00 EST 2011 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.83.016406· OSTI ID:21560008

Loizu, Joaquim; Ricci, Paolo; Theiler, Christian ^[1]

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1. Centre de Recherches en Physique des Plasmas-Ecole Polytechnique Federale de Lausanne, Association EURATOM-Confederation Suisse, CH-1015 Lausanne (Switzerland)

The location of the plasma sheath edge, where quasineutrality is broken, is rigorously derived by using a kinetic description of the plasma. It is shown that sheaths can exist with arbitrarily small ion velocity at the sheath edge, thus violating the Bohm criterion, V{sub i}=c{sub s} at the sheath edge. Bohm's criterion is recovered in the case of large enough ion current through the wall, and it is found to be a reasonable approximation in floating potential conditions. However, in the case of a predominant electron current through the wall, Bohm's criterion is not able to describe the sheath-edge transition. The analytical results are supported by numerical simulations performed with a fully kinetic particle-in-cell code modeling a source-driven, weakly collisional plasma, bound between two absorbing walls.

• OSTI ID: 21560008
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Journal Name: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print) Journal Issue: 1 Vol. 83; ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
APPROXIMATIONS
BOHM CRITERION
CALCULATION METHODS
CHARGED PARTICLES
COLLISIONAL PLASMA
COMPUTERIZED SIMULATION
CURRENTS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
IONS
LEPTONS
PARTICLES
PLASMA
PLASMA SHEATH
POTENTIALS
SIMULATION
WALLS