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Title: Radio-frequency wave interactions with a plasma sheath in oblique-angle magnetic fields using a sheath impedance model

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.5054920· OSTI ID:1494126

Here, the physics of interactions between waves in plasmas and sheaths for background magnetic fields which make oblique angles with the sheath surfaces is studied with the use of the self-consistent finite element code rfSOL incorporating the recently developed sheath impedance model. The calculation based on this model employs the generalized sheath boundary condition (sheath BC), which surpasses the previously used capacitive sheath BC in reliability by taking into account the contributions of the ion and electron currents in the sheath as well as the displacement current. A series of numerical simulations is carried out in two-dimensional slab geometry with a flat or curved sheath surface as part of the boundary. It is shown that the sheath–plasma wave appears when the equilibrium magnetic field line angle with respect to the sheath surface is small, the absolute value of the radio-frequency (RF) sheath voltage is large, and the plasma density is slightly higher than the lower hybrid resonance density (LHR density), all of which bring the sheath property closer to being capacitive. It is also shown that the sharp variation of the magnetic field line angle along the sheath surface can sensitively affect the maximum absolute value of the RF sheath voltage at a plasma density slightly lower than the LHR density.

Research Organization:
Lodestar Research Corp., Boulder, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
FG02-97ER54392
OSTI ID:
1494126
Journal Information:
Physics of Plasmas, Vol. 26, Issue 2; Related Information: http://doi.org/10.5281/zenodo.1667247; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 11 works
Citation information provided by
Web of Science

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