Bifurcation Theory of the Transition to Collisionless Ion-temperature-gradient-driven Plasma Turbulence

Kolesnikov, R.A. ; Krommes, J.A.

Princeton University. Plasma Physics Laboratory.

关键词: Drift Waves;    Excitation;    70 Plasma Physics And Fusion Technology;    Bifurcation;    Turbulence Drift Waves;   

DOI  :  10.1063/1.2116887
RP-ID  :  PPPL-4102
RP-ID  :  DE-AC02-76CH03073
RP-ID  :  878299

美国|英语

来源: UNT Digital Library

【 摘 要 】

The collisionless limit of the transition to ion-temperature-gradient-driven plasma turbulence is considered with a dynamical-systems approach. The importance of systematic analysis for understanding the differences in the bifurcations and dynamics of linearly damped and undamped systems is emphasized. A model with ten degrees of freedom is studied as a concrete example. A four-dimensional center manifold (CM) is analyzed, and fixed points of its dynamics are identified and used to predict a ''Dimits shift'' of the threshold for turbulence due to the excitation of zonal flows. The exact value of that shift in terms of physical parameters is established for the model; the effects of higher-order truncations on the dynamics are noted. Multiple-scale analysis of the CM equations is used to discuss possible effects of modulational instability on scenarios for the transition to turbulence in both collisional and collisionless cases.