Eigenmode analysis of geodesic acoustic modes

  title={Eigenmode analysis of geodesic acoustic modes},
  author={Zhe Gao and Kimitaka Itoh and Heiji Sanuki and Jiaqi Dong},
Geodesic acoustic modes (GAMs) are studied as plasma eigenmodes when an electrostatic potential nearly constant around a magnetic surface is applied to collisionless toroidal plasmas. Besides the standard GAM, a branch of low frequency mode and an infinite series of ion sound wavelike modes are identified. Eigenfrequencies of these modes are obtained analytically and numerically from a linear gyrokinetic model. The finite gyroradius effect is found to enhance the collisionless damping of the… CONTINUE READING