Kinetic Simulations of the Self-Focusing and Dissipation of Finite-Width Electron Plasma Waves

Journal Article · Sun Sep 01 04:00:00 EDT 2013 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.111.105002· OSTI ID:1165748

Winjum, B. J. ^[1]; Berger, R. L. ^[2]; Chapman, T. ^[2]; Banks, J. W. ^[2]; Brunner, S. ^[3]

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1. Univ. of California, Los Angeles, CA (United States)
2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
3. Federal Inst. of Technology, Lausanne (Switzerland)

Two-dimensional simulations, both Vlasov and particle-in-cell, are presented that show the evolution of the field and electron distribution of finite-width, nonlinear electron plasma waves. The intrinsically intertwined effects of self-focusing and dissipation of field energy caused by electron trapping are studied in simulated systems that are hundreds of wavelengths long in the transverse direction but only one wavelength long and periodic in the propagation direction. From various initial wave states, both the width at focus Δm relative to the initial width Δ0 and the maximum field amplitude at focus are shown to be a function of the growth rate of the transverse modulational instability γ_TPMI divided by the loss rate of field energy ν_E to electrons escaping the trapping region. With dissipation included, an amplitude threshold for self-focusing γ_TPMI/ν_E~1 is found that supports the analysis of Rose [Phys. Plasmas 12, 012318 (2005)].

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1165748
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 10 Vol. 111; ISSN 0031-9007; ISSN PRLTAO
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON PLASMA WAVES
VLASOV