2015/01/08 by Haijun Ren, Ren, Haijun, Jintao Cao +1
Physics and Astronomy · #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.1501.01750
openalex publication_date 2015/01/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Geodesic acoustic mode (GAM) is analyzed by using modified gyro-kinetic (MGK) equation applicable to low-frequency microinstabilities in a rotating axisymmetric plasma. Dispersion relation of GAM in the presence of arbitrary Mach number is analytically derived. Toroidal rotation plays the same effects on the GAM regardless of the orientation of equilibrium flow. It is shown that the toroidal Mach number M increases the GAM frequency and dramatically decreases the Landau damping rate. The valid of classical gyro-kinetic (CGK) equation is also examined. For zero electron temperature, CGK is identical with MGK. For non-zero electron temperature, CGK gives the same real frequency of GAM as MGK but induces an instability with a growth rate proportional to M3/q, where q is the safety factor.