Effects of static magnetic fields on rf-driven plasma sheaths

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871969· OSTI ID:288965

Riyopoulos, S ^[1]

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1. Science Applications International Corporation, McLean, Virginia 22102 (United States)

The physics of sheath formation during rf capacitor discharges in magnetized plasmas is examined, for arbitrary angle between the dc magnetic field and the oscillating rf electric field. Observations from particle simulations show that the induced dc sheath potential under given rf drive increases with increasing angle between the electric and magnetic fields, reaching a maximum nearly twice the unmagnetized dc potential for nearly perpendicular {bold E} and {bold B}. Analytic study of the ion dynamics in the time-averaged sheath field reveals that the ion motion is unstable, yielding unbound ion transport across the magnetic lines. The effective ion mass {ital m}{asterisk}, employed for the acceleration along the electric field, is obtained as a function of the magnetic angle and the relative magnetic strength. The magnetized presheath ions are partially demagnetized inside the sheath. The ratio of the effective masses {ital m}{sub {ital B}}/{ital m}{asterisk}, where {ital m}{sub {ital B}} stands for fully magnetized ions, parametrizes the sheath potential and sheath thickness. The sheaths behave as unmagnetized in the limit of parallel {bold E} and {bold B}. {copyright} {ital 1996 American Institute of Physics.}

• DOE Contract Number: FG05-93ER54201
• OSTI ID: 288965
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BOUNDARY LAYERS
CAPACITORS
ELECTRIC DISCHARGES
MAGNETIC FIELDS
PLASMA DRIFT
PLASMA POTENTIAL
PLASMA SHEATH
PLASMA SIMULATION
RADIOWAVE RADIATION
WALL EFFECTS