Double layer formation in a two-region electronegative plasma

Journal Article · Tue Dec 15 04:00:00 EST 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3276155· OSTI ID:21371313

Kawamura, E; Lichtenberg, A J; Lieberman, M A ^[1]; Verboncoeur, J P ^[2]

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1. Department of Electrical Engineering, University of California, Berkeley, California 94720-1770 (United States)
2. Department of Nuclear Engineering, University of California, Berkeley, California 94720-1730 (United States)

The formation of a double layer (DL) in a two-dimensional (2D) electronegative plasma with a source (heating) section connected to a larger downstream section is described. A 2D particle-in-cell (PIC) code is used to exhibit the DL, which appears near the transition between the source and downstream chambers, over a range of pressures and electronegativities. Diagnostics of the PIC code allow the calculation of various plasma parameters, not easily measured in experiments, to be compared with an analytic theory. The theory consists of a collisionless one-dimensional model of a DL connected to 2D source and downstream global models. The conditions of positive and negative ion balance upstream and downstream, and the downstream energy balance determine the DL potential, electron temperatures, and other plasma parameters. A rescaled oxygen reaction set is used both for the simulation and for the analytic comparison. The PIC simulations exhibit a Maxwellian electron distribution in the source region at temperature T{sub h}, and a bi-Maxwellian distribution downstream, with a low energy population at temperature T{sub c}<T{sub h} and with a hotter tail also having temperature T{sub h}. At the upstream DL edge, an accelerated electron component is observed. Using these results in the model, a DL is found in reasonable agreement with that obtained in the simulation.

• OSTI ID: 21371313
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
HEATING
LAYERS
PLASMA
PLASMA DIAGNOSTICS
PLASMA HEATING
PLASMA SIMULATION
SIMULATION