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Title: Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions

Abstract

Recent advances in finite-difference time-domain (FDTD) modeling techniques allow plasma-surface interactions such as sheath formation and sputtering to be modeled concurrently with the physics of antenna near- and far-field behavior and ICRF power flow. Although typical sheath length scales (micrometers) are much smaller than the wavelengths of fast (tens of cm) and slow (millimeter) waves excited by the antenna, sheath behavior near plasma-facing antenna components can be represented by a sub-grid kinetic sheath boundary condition, from which RF-rectified sheath potential variation over the surface is computed as a function of current flow and local plasma parameters near the wall. These local time-varying sheath potentials can then be used, in tandem with particle-in-cell (PIC) models of the edge plasma, to study sputtering effects. Particle strike energies at the wall can be computed more accurately, consistent with their passage through the known potential of the sheath, such that correspondingly increased accuracy of sputtering yields and heat/particle fluxes to antenna surfaces is obtained. The new simulation capabilities enable time-domain modeling of plasma-surface interactions and ICRF physics in realistic experimental configurations at unprecedented spatial resolution. We will present results/animations from high-performance (10k-100k core) FDTD/PIC simulations of Alcator C-Mod antenna operation.

Authors:
 [1];  [1]
  1. Tech-X Corporation, Boulder, CO (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1567551
Resource Type:
Accepted Manuscript
Journal Name:
EPJ Web of Conferences
Additional Journal Information:
[ Journal Volume: 157]; Journal ID: ISSN 2100-014X
Publisher:
EDP Sciences
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

Jenkins, Thomas G., and Smithe, David N. Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions. United States: N. p., 2017. Web. doi:10.1051/epjconf/201715703021.
Jenkins, Thomas G., & Smithe, David N. Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions. United States. doi:10.1051/epjconf/201715703021.
Jenkins, Thomas G., and Smithe, David N. Mon . "Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions". United States. doi:10.1051/epjconf/201715703021. https://www.osti.gov/servlets/purl/1567551.
@article{osti_1567551,
title = {Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions},
author = {Jenkins, Thomas G. and Smithe, David N.},
abstractNote = {Recent advances in finite-difference time-domain (FDTD) modeling techniques allow plasma-surface interactions such as sheath formation and sputtering to be modeled concurrently with the physics of antenna near- and far-field behavior and ICRF power flow. Although typical sheath length scales (micrometers) are much smaller than the wavelengths of fast (tens of cm) and slow (millimeter) waves excited by the antenna, sheath behavior near plasma-facing antenna components can be represented by a sub-grid kinetic sheath boundary condition, from which RF-rectified sheath potential variation over the surface is computed as a function of current flow and local plasma parameters near the wall. These local time-varying sheath potentials can then be used, in tandem with particle-in-cell (PIC) models of the edge plasma, to study sputtering effects. Particle strike energies at the wall can be computed more accurately, consistent with their passage through the known potential of the sheath, such that correspondingly increased accuracy of sputtering yields and heat/particle fluxes to antenna surfaces is obtained. The new simulation capabilities enable time-domain modeling of plasma-surface interactions and ICRF physics in realistic experimental configurations at unprecedented spatial resolution. We will present results/animations from high-performance (10k-100k core) FDTD/PIC simulations of Alcator C-Mod antenna operation.},
doi = {10.1051/epjconf/201715703021},
journal = {EPJ Web of Conferences},
number = ,
volume = [157],
place = {United States},
year = {2017},
month = {10}
}

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Works referenced in this record:

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