title: Mechanism of stabilization of ballooning modes by toroidal rotation shear in tokamaks.
abstract: A ballooning perturbation in a toroidally rotating tokamak is expanded by square-integrable eigenfunctions of an eigenvalue problem associated with ballooning modes in a static plasma. Especially a weight function is chosen such that the eigenvalue problem has only the discrete spectrum. The eigenvalues evolve in time owing to toroidal rotation shear, resulting in a countably infinite number of crossings among them. The crossings cause energy transfer from an unstable mode to the infinite number of stable modes; such transfer works as the stabilization mechanism of the ballooning mode.
authors.affiliation: Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka, Ibaraki 311-0193, Japan. furukawa@ppl.k.u-tokyo.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Furukawa
authors.forename: S
authors.initials: S
authors.lastname: Tokuda