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Title: Radio frequency sheaths in an oblique magnetic field

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4922848· OSTI ID:1187967
 [1];  [1]
  1. Lodestar Research Corp., Boulder, CO (United States)

The physics of radio-frequency (rf) sheaths near a conducting surface is studied for plasmas immersed in a magnetic field that makes an oblique angle θ with the surface. A set of one-dimensional equations is developed that describe the dynamics of the time-dependent magnetic presheath and non-neutral Debye sheath. The model employs Maxwell-Boltzmann electrons, and the magnetization and mobility of the ions is determined by the magnetic field strength, and wave frequency, respectively. The angle, θ assumed to be large enough to insure an electron-poor sheath, is otherwise arbitrary. Concentrating on the ion-cyclotron range of frequencies, the equations are solved numerically to obtain the rectified (dc) voltage, the rf voltage across the sheath and the rf current flowing through the sheath. As an application of this model, the sheath voltage-current relation is used to obtain the rf sheath impedance, which in turn gives an rf sheath boundary condition for the electric field at the sheath-plasma interface that can be used in rf wave codes. In general the impedance has both resistive and capacitive contributions, and generalizes previous sheath boundary condition models. The resistive part contributes to parasitic power dissipation at the wall.

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:
1187967
Alternate ID(s):
OSTI ID: 1228643
Report Number(s):
LRC-15-161; PHPAEN
Journal Information:
Physics of Plasmas, Vol. 22, Issue 6; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 32 works
Citation information provided by
Web of Science

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Cited By (13)

Physics-Based Parametrization Of The Surface Impedance For Radio Frequency Sheaths [Supplemental Data] dataset April 2017
Numerical investigation of fast-wave propagation and radio-frequency sheath interaction with a shaped tokamak wall journal July 2015
Physics-based parametrization of the surface impedance for radio frequency sheaths journal July 2017
Collisional RF sheath in capacitive discharge in strong oblique magnetic field journal January 2019
Radio-frequency wave interactions with a plasma sheath in oblique-angle magnetic fields using a sheath impedance model journal February 2019
Radio frequency wave interactions with a plasma sheath: The role of wave and plasma sheath impedances journal May 2019
Numerical model of the radio-frequency magnetic presheath including wall impurities journal September 2019
Numerical solutions of Maxwell's equations in 3D in frequency domain with linear sheath boundary conditions journal August 2019
The effect of energetic electrons on the collisionless fusion plasma sheath in ion cyclotron range of frequencies heating journal December 2019
Modelling of radio frequency sheath and fast wave coupling on the realistic ion cyclotron resonant antenna surroundings and the outer wall journal January 2018
Calculation of RF sheath properties from surface wave-fields: a post-processing method journal July 2019
Radio-frequency wave interactions with a plasma sheath in oblique-angle magnetic fields using a sheath impedance model text January 2018
Radio frequency wave interactions with a plasma sheath: the role of wave and plasma sheath impedances text January 2018

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