Magnetic Components of Geodesic Acoustic Modes in Plasmas with Anisotropic Ion Distribution

The existence of magnetic components in geodesic acoustic modes is investigated for a weakly anisotropic tokamak plasma with dual-temperature Maxwellian distributions for ions. An m = 1 perpendicular magnetic perturbation is discovered to be proportional to the relative difference between the two temperatures in addition to an m = 2 perpendicular magnetic perturbation which always exists due to the m = 2 parallel return current, with m the poloidal mode number. The dispersion relation and the mode frequency are also modified by the anisotropic distribution.