The Evolution Of Alfven Wave 's Dynamics

In magnetic confinement fusion plasmas, Alfvén wave plays an extremely important role, and αTAE also exists in tokamak plasmas as a kind of Alfvén eigenmodes. Based on the high-n ballooning mode formalism and the(s, α) model equilibrium, the kinetic effect of the energetic particles in toroidal fusion plasmas on the discrete Alfvén eigenmodes is studied with linear Gyro-kinetic approximation. Here, =,=-2, is the safety factor, and R and r are, respectively, the major and minor radii of the toroidal plasma.Based on the simulation data of ITER(International Thermonuclear Experimental Reactor), the kinetic effect of the energetic particles on the evolution of αTAE is analyzed according to the mode structure and frequency. αTAE is found both in positive and reversed magnetic shear. These quasimarginally stable eigenmodes can be kinetically excited by magnetically trapped energetic particles via bounce–precessional drift resonances. The different kinetic features of energetic particles will change the frequency and growth rate of Alfvén instability.