Evaluation of the Landau damping based on the Hamiltonian structure of MHD continuous spectrum

Hirota, Makoto; Tokuda, Shinji

Resonant damping (e.g. continuum damping, Landau damping) of MHD wave is a key issue in various stability problems. In fact, accurate estimation of the damping (or growth) rate is needed for the resistive wall mode and the toroidicity-induced Alfvn eigenmode. Recently, we have formulated wave action not only for eigenmodes but also for continuum mode, and found that the wave action is conserved among these modes in the process of resonant coupling. This fact can provide another approach to the estimation of resonant damping.