Coupling of Neutral-beam-driven Compressional 
Alfven Eigenmodes to Kinetic Alfven Waves 
in NSTX and Energy Channelling

Authors:  E. V. Belova, N. N. Gorelenkov, E. D. Fredrickson, K. Tritz, N. A. Crocker

Abstract:  An energy channelling mechanism is proposed to explain flattening of the electron temperature profiles at high beam power in beam-heated National Spherical Torus Experiment (NSTX). Results of self-consistent simulations of neutral-beam-driven compressional Alfven eigenmodes (CAEs) in NSTX are presented that demonstrate strong coupling of CAE to kinetic Alfven wave at the Alfven resonance location. It is suggested that CAE can channel energy from the beam ions to the location of the resonant mode conversion at the edge of the beam density profile, modifying the energy deposition profile.
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Submitted to:  Physical Review Letters
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Download PPPL-5142 (pdf 2 MD 14 pp)

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