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Author DIppolito, D. A. ♦ Myra, J. R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PLASMA PHYSICS AND FUSION ♦ PLASMA INSTABILITY ♦ TOKAMAK DEVICES ♦ PLASMA SCRAPE-OFF LAYER ♦ DIVERTORS ♦ ELASTIC SCATTERING ♦ CHARGE EXCHANGE ♦ BALLOONING INSTABILITY
Abstract The influence of ion{endash}neutral interactions (charge exchange, elastic scattering) on scrape-off-layer (SOL) stability is studied in the eikonal limit for a single-null X-point geometry typical of tokamak divertors. Instability drives due to curvature and to the ion{endash}neutral drag effect are included in the model. The ion{endash}neutral interaction terms are highly localized near the divertor plates; these terms are stabilizing for typical parameters and large enough to affect the SOL ballooning-interchange stability in the absence of resistivity. It is shown that the growth rate of ideal curvature-driven modes is significantly reduced by the ion{endash}neutral interaction terms; the growth rate of resistive ballooning modes is not affected much by the neutrals, because resistivity allows the mode to disconnect from the divertor region. In both cases, the X-point geometry significantly affects the stability. An ion{endash}neutral drag instability localized near the plates is only found in a small region of parameter space. Conditions for the existence of this instability in X-point geometry are discussed. {copyright} {ital 1999 American Institute of Physics.}
ISSN 1070664X
Educational Use Research
Learning Resource Type Article
Publisher Date 1999-02-01
Publisher Place United States
Journal Physics of Plasmas
Volume Number 6
Issue Number 2


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