Ion Heating by Fast Particle Induced Alfvén Turbulence
Authors: D. Gates, N. Gorelenkov, and R.B. White
Date of PPPL Report: May 2001
Published in: Physical Review Letters 87 (November 2001) pp. 205003-1 through 205003-4
A novel mechanism that directly transfers energy from Super-Alfvénic energetic ions to thermal ions in high-beta plasmas is described. The mechanism involves the excitation of compressional Alfvén eigenmodes (CAEs) in the frequency range with w less than or approximately equal to wci. The broadband turbulence resulting from the large number of excited modes causes stochastic diffusion in velocity space, which transfers wave energy to thermal ions. This effect may be important on National Spherical Torus Experiment (NSTX), and may scale up to reactor scenarios. This has important implications for low aspect ratio reactor concepts, since it potentially allows for the modification of the ignition criterion.