Nonlinear evolution of two fast-particle-driven modes near the linear stability threshold
- West Pomeranian University of Technology, Szczecin (Poland)
- Chalmers University of Technology, Goeteborg (Sweden)
- Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland)
A system of two coupled integro-differential equations is derived and solved for the non-linear evolution of two waves excited by the resonant interaction with fast ions just above the linear instability threshold. The effects of a resonant particle source and classical relaxation processes represented by the Krook, diffusion, and dynamical friction collision operators are included in the model, which exhibits different nonlinear evolution regimes, mainly depending on the type of relaxation process that restores the unstable distribution function of fast ions. When the Krook collisions or diffusion dominate, the wave amplitude evolution is characterized by modulation and saturation. However, when the dynamical friction dominates, the wave amplitude is in the explosive regime. In addition, it is found that the finite separation in the phase velocities of the two modes weakens the interaction strength between the modes.
- OSTI ID:
- 21546939
- Journal Information:
- Physics of Plasmas, Vol. 18, Issue 6; Other Information: DOI: 10.1063/1.3601136; (c) 2011 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLITUDES
DISTRIBUTION FUNCTIONS
EVOLUTION
INTEGRO-DIFFERENTIAL EQUATIONS
IONS
NONLINEAR PROBLEMS
PLASMA
PLASMA INSTABILITY
PLASMA SIMULATION
PLASMA WAVES
RELAXATION
CHARGED PARTICLES
EQUATIONS
FUNCTIONS
INSTABILITY
SIMULATION