Beta-induced Alfven-acoustic eigenmodes in National Spherical Torus Experiment and DIII-D driven by beam ions

Journal Article · Fri May 15 04:00:00 EDT 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3097920· OSTI ID:21277158

Gorelenkov, N N; Darrow, D; Fredrickson, E; Fu, G -Y; Menard, J; Nazikian, R ^[1]; Van Zeeland, M A ^[2]; Berk, H L ^[3]; Crocker, N A ^[4]; Heidbrink, W W ^[5]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2. General Atomics, San Diego, California 92186 (United States)
3. Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)
4. Institute of Plasma and Fusion Research, University of California, Los Angeles, California 90095 (United States)
5. University of California, Irvine, California 92697 (United States)

Kinetic theory and experimental observations of a special class of energetic particle driven instabilities called here beta-induced Alfven-acoustic eigenmodes (BAAEs) are reported confirming, previous results [N. N. Gorelenkov et al., Plasma Phys. Controlled Fusion 49, B371 (2007)]. The kinetic theory is based on the ballooning dispersion relation where the drift frequency effects are retained. BAAE gaps are recovered in kinetic theory. It is shown that the observed certain low-frequency instabilities on DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] and National Spherical Torus Experiment [M. Ono, S. M. Kaye, Y.-K. M. Peng et al., Nucl. Fusion 40, 557 (2000)] are consistent with their identification as BAAEs. BAAEs deteriorate the fast ion confinement in DIII-D and can have a similar effect in next-step fusion plasmas, especially if excited together with multiple global toroidicity-induced shear Alfven eigenmode instabilities. BAAEs can also be used to diagnose safety factor profiles, a technique known as magnetohydrodynamic spectroscopy.

• OSTI ID: 21277158
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DISPERSION RELATIONS
DOUBLET-3 DEVICE
EIGENFUNCTIONS
EIGENVALUES
IONS
PLASMA CONFINEMENT
PLASMA INSTABILITY