Neoclassical Tearing Mode Seeding by Nonlinear Three-Wave Interactions in Tokamaks
L. Bardóczi, N.C. Logan, E. J. Strait
Abstract
We report the experimental observation of seed magnetic island formation by nonlinear three-wave coupling of magnetic island triplets. In this experiment, disruptive 2,1 islands are seeded by the coupling of 4,3 and 3,2 tearing modes to a central 1,1 sawtooth precursor. Three-wave interactions between these modes are conclusively identified by bispectral analysis, indicating fixed phase relationships in agreement with theory. This new observation of this seeding mechanism has important implications for future reactors that must operate in stable plasma equilibria, free of disruptive 2,1 islands.
Topics & Concepts
TearingTokamakSeedingSawtooth waveCoupling (piping)Nonlinear systemPhysicsPlasmaMode (computer interface)ParthenocarpyPhase (matter)MagnetohydrodynamicsNuclear physicsMaterials scienceQuantum mechanicsBiologyThermodynamicsComputer scienceTelecommunicationsOperating systemGeneticsMetallurgyMagnetic confinement fusion researchIonosphere and magnetosphere dynamicsLaser-Plasma Interactions and Diagnostics