title: Chaotic regime of Alfvén Eigenmode wave-particle interaction.
abstract: The chaotic regime in Alfvén eigenmode wave-particle interaction is identified for the first time in the tokamak plasma of the Joint European Torus. The Alfvén modes are driven by energetic hydrogen minority ions produced by ion cyclotron resonance heating. The experimental signatures of the chaotic regime include spectral broadening, phase flips, and nonperiodic amplitude variations. These phenomena are found to be consistent with a general nonlinear theory of kinetic instabilities near stability threshold developed by Berk, Breizman, and Pekker.
authors.affiliation: Princeton Plasma Physics Lab and JET Joint Undertaking, P.O. Box 451, Princeton, New Jersey 08543, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Heeter
authors.forename: A F
authors.initials: AF
authors.lastname: Fasoli
authors.forename: S E
authors.initials: SE
authors.lastname: Sharapov