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Author Parke, E. ♦ Anderson, J. K. ♦ Den Hartog, D. J. ♦ Brower, D. L. ♦ Ding, W. X. ♦ Lin, L. ♦ Johnson, C. A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PLASMA PHYSICS AND FUSION TECHNOLOGY ♦ BEAM INJECTION ♦ CURRENT DENSITY ♦ EQUILIBRIUM ♦ FLUCTUATIONS ♦ ION DENSITY ♦ IONS ♦ ISLANDS ♦ LIMITING VALUES ♦ MODE RATIONAL SURFACES ♦ PLASMA ♦ REVERSED-FIELD PINCH DEVICES ♦ REVERSE-FIELD PINCH ♦ TEARING INSTABILITY
Abstract Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm with neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q{sub 0} by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].
ISSN 1070664X
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-05-15
Publisher Place United States
Journal Physics of Plasmas
Volume Number 23
Issue Number 5


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