Averaged variational principle for autoresonant Bernstein-Greene-Kruskal modes

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3500246· OSTI ID:21421249

Khain, P; Friedland, L ^[1]

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1. Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

Whitham's averaged variational principle is applied in studying dynamics of formation of autoresonant (continuously phase-locked) Bernstein-Greene-Kruskal (BGK) modes in a plasma driven by a chirped frequency ponderomotive wave. A flat-top electron velocity distribution is used as a model allowing a variational formulation within the water bag theory. The corresponding Lagrangian, averaged over the fast phase variable yields evolution equations for the slow field variables, allows uniform description of all stages of excitation of driven-chirped BGK modes, and predicts modulational stability of these nonlinear phase-space structures. Numerical solutions of the system of slow variational equations are in good agreement with Vlasov-Poisson simulations.

• OSTI ID: 21421249
• Journal Information: Physics of Plasmas, Vol. 17, Issue 10; Other Information: DOI: 10.1063/1.3500246; (c) 2010 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BERNSTEIN MODE
ELECTRONS
LAGRANGIAN FUNCTION
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
PHASE SPACE
PLASMA
PLASMA INSTABILITY
PLASMA WAVES
PONDEROMOTIVE FORCE
VARIATIONAL METHODS
CALCULATION METHODS
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
INSTABILITY
LEPTONS
MATHEMATICAL SOLUTIONS
MATHEMATICAL SPACE
OSCILLATION MODES
SPACE