EXCITATION OF HIGH-N TOROIDAL SHEAR ALFVEN MODE DUE TO ALPHA-PARTICLE RIPPLE LOSSES IN TOKAMAKS

The alpha-particle effects on high-n toroidal shear Alfven mode are investigated analytically. The mode can be driven to unstable when the alpha-particles have a n anisotropic distribution function due to ripple losses in tokamaks. The growth rates of the instability in both “fast” and “slow ” plasma heating cases are calculated, and the conditions for the excitation of the modes are also studied.