Potential structure in a sheath formed in front of a metal wall

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:212843

Ikuta, H; Kimura, T; Ohe, K ^[1]

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1. Nagoya Institute of Technology, Nagoya (Japan)

In spite of many investigations since Langmuir`s pioneering works, there has still remained an essential ambiguity for a sheath formed in a plasma-wall region. The ambiguity is partially due to the difficulty in detection of the sheath structure by a Langmuir probe. Using an emissive probe has, however, provided a meaningful information on a potential in a pre-sheath region. The Bohm`s pre-sheath model is that ions should be accelerated within the sheath such that their density is larger than the electron one, deducing the well-known Bohm`s criterion. There have been some approaches to describe the plasma-sheath transition by a set of hydrodynamic equations and the Poisson one. Such an approach has, however, not overcome a distinct discrepancy between the analytical and experimental results. The aim of the present paper is to describe the potential structure detected in a plasma-sheath region formed near a metal wall immersed in a homogeneous low pressure Ar plasma. And an analysis using a set of the hydrodynamic and Poisson equations is described.

• OSTI ID: 212843
• Report Number(s): CONF-950749--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
66 PHYSICS
ARGON
GLOW DISCHARGES
HOMOGENEOUS PLASMA
LANGMUIR PROBE
PLASMA POTENTIAL
PLASMA SHEATH
WALL EFFECTS