Paper detail

Geodesic Acoustic Mode in Toroidally Rotating Anisotropic Tokamaks

Effects of anisotropy on the geodesic acoustic mode (GAM) is analyzed by using gyro-kinetic equations applicable to low-frequency microinstabilities in a toroidally rotating tokamak plasma. Dispersion relation in the presence of arbitrary Mach number $M$, anisotropy strength $σ$, and the temperature ration $τ$ is analytically derived. It is shown that when $σ$ is less than $ 3 + 2 τ$, the increased electron temperature with fixed ion parallel temperature increases the normalized GAM frequency. When $σ$ is larger than $ 3 + 2 τ$, the increasing of electron temperature decreases the GAM frequency. The anisotropy $σ$ always tends to enlarge the GAM frequency. The Landau damping rate is dramatically decreased by the increasing $τ$ or $σ$.