Instability-Enhanced Collisional Friction Can Determine the Bohm Criterion in Multiple-Ion-Species Plasmas

Journal Article · Fri Nov 13 00:00:00 EST 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.205002· OSTI ID:21370836

Baalrud, S D; Hegna, C C; Callen, J D ^[1]

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1. Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706-1609 (United States)

A generalized Lenard-Balescu theory that accounts for instability-enhanced collective responses is used to calculate the collisional friction between ion species in the plasma-boundary transition region (presheath). Ion-ion streaming instabilities are shown to cause such a strong frictional force that the relative flow speed between ion species cannot significantly exceed the critical threshold value (DELTAV{sub c}) at which instability onset occurs. When combined with the Bohm criterion, this condition uniquely determines the flow speed of each ion species at the plasma-sheath boundary. For cold ions, DELTAV{sub c}->0 and each ion species leaves the plasma at a common system sound speed c{sub s}.

• OSTI ID: 21370836
• Journal Information: Physical Review Letters, Vol. 103, Issue 20; Other Information: DOI: 10.1103/PhysRevLett.103.205002; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOHM CRITERION
FRICTION
IONS
PLASMA
PLASMA INSTABILITY
PLASMA SHEATH
PRIGOGINE THEOREM
SOUND WAVES
VELOCITY
CHARGED PARTICLES
INSTABILITY