Nonlinear dynamics of driven relativistic electron plasma waves

Journal Article · Thu Oct 15 00:00:00 EDT 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.46.5112· OSTI ID:7173882

Leemans, W P; Joshi, C; Mori, W B; Clayton, C E ^[1]; Johnston, T W ^[2]

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1. Electrical Engineering Department, University of California, Los Angeles, Los Angeles, California 90024 (United States)
2. Institut National de Recherche Scientifique enEnergie Case Postale 1020, Varennes Quebec, J3X1S2 (Canada)

We have examined the nonlinear dynamics associated with beat-wave ([Delta][omega],[Delta][ital k]) generation of long-wavelength plasma waves ([Delta][ital k][le][omega][sub [ital p]]/[ital c]) in the presence of a strong ([delta][ital n]/[ital n][minus]0.15 to 0.75) short-wavelength density ripple [[ital k][sub [ital i]][minus](5 to 130) [Delta][ital k]] using the relativistic Lagrangian-oscillator model. Two cases are considered: time-varying detuning ratio ([omega][sub [ital p]]/[Delta][omega]) and time-varying laser intensity [ital I]. In the absence of the plasma ripple, it is found that the Lagrangian-oscillator motion contains half-harmonic components in an Arnold tonguelike parameter space ([omega][sub [ital p]]/[Delta][omega],[ital v][sub osc]/[ital c]) centered around [omega][sub [ital p]]/[Delta][omega][approx]0.5. The effect of the ripple is twofold: (a) It lowers the minimum driver strength needed to access the half-harmonic parameter region around [omega][sub [ital p]]/[Delta][omega][approx]0.5, and (b) it makes a second parameter region available, centered around [omega][sub [ital p]]/[Delta][omega][approx]2.0. Although the Lagrangian model exhibits further period doubling followed by a transition to chaos when a time-varying laser intensity is used, wave breaking sets in after the first bifurcation, thereby limiting the validity of the model. The origin of the first period doubling, however, is found to be linked to the stability of an equivalent Mathieu equation to 1/2 subharmonic resonances. Finally, a particle-in-cell-code simulation shows spatial wave-number peaks displaced by [Delta][ital k]/2 on both sides of the driver frequencies, giving support to the idea that the first bifurcation behavior may be observable in an experiment.

• DOE Contract Number: AS03-83ER40120; FG03-88ER40474
• OSTI ID: 7173882
• Journal Information: Physical Review A. General Physics; (United States), Vol. 46:8; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PLASMA WAVES
NONLINEAR PROBLEMS
COMPUTERIZED SIMULATION
ELECTRONS
OSCILLATORS
PERTURBATION THEORY
RELATIVISTIC RANGE
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
ENERGY RANGE
EQUIPMENT
FERMIONS
LEPTONS
SIMULATION
700340* - Plasma Waves
Oscillations
& Instabilities- (1992-)