title: Existence of metastable kinetic modes.
abstract: The nonlinear evolution of resonantly driven systems, such as suprathermal particle driven modes in magnetically confined plasmas, is shown to strongly depend on the existence and nature of an underlying damping mechanism. When background resonant damping is present, subcritical states can take place. In particular, purely nonlinear steady-state regimes are found, whose destabilization threshold and saturation levels are calculated and validated using numerical simulations. This nonlinear behavior can be of relevance for acoustic modes in magnetically confined plasmas.
authors.affiliation: Centre de Physique Théorique, CNRS-Ecole Polytechnique, Palaiseau, France. christine.nguyen@cpht.polytechnique.fr
authors.forename: C
authors.initials: C
authors.lastname: Nguyen
authors.forename: H
authors.initials: H
authors.lastname: Lütjens
authors.forename: X
authors.initials: X
authors.lastname: Garbet
authors.forename: V
authors.initials: V
authors.lastname: Grandgirard
authors.forename: M
authors.initials: M
authors.lastname: Lesur