Observations of Nonlinear Landau Damping

Gentle, K. W.; Malein, A.

doi:10.1103/physrevlett.26.625

Cited by 41 publications

(12 citation statements)

References 10 publications

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“…In Fig. 3 we show the results of Roberson et al (1971). As the beam current (density) is increased, saturation occurs in increasingly shorter distances.…”

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confidence: 99%

“…Only recently have experimental tests of these theories become available (Cano et a/. , 1967;Ellis and Porkolab, 1968;Porkolab and Chang, 1969;Chang and Porkolab, 19VO(a), 1970(b); Gentle and Malein, 1971;Gentle and Roberson, 1971; Roberson et a/. , 1971; Franklin et al , 1971; .…”

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confidence: 99%

“…The first quantitative test of quasilinear theory was carried out by Roberson et al , (1971) and Arunasalam et al (1971). These authors studied the saturation of an unstable spectrum of electron plasma waves excited by a "gentle bump" on the tail of the electron distribution function.…”

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confidence: 99%

“…, nonline3r Landau damping and/or growth Porkolab, 1970, 1972;Gentle and Malein, 1971;fkezi and Kiwamoto, 1971). While…”

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confidence: 99%

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Nonlinear wave effects in laboratory plasmas: A comparison between theory and experiment

Porkoláb

Chang²

1978

Rev. Mod. Phys.

124

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The rich nonlinear phenomena that occur in plasmas are reviewed in a systematic way. The foundations of turbulence theory (both weak and strong) and-experiments performed in the past decade to verify such theories are presented. The aim is to emphasize those experiments that demonstrate clearly the validity (or failure) of' some of the theories. In particular, we discuss experiments that demonstrate the validity and/or limits of weak turbulence theory, strong turbulence theory, parametric instabilities, echoes, trapping of particles in large-amplitude waves, and electrostatic ion acoustic shocks. We present concluding remarks in each section regarding the present status of each of these phenomenon. CONTENTSimproving weak-turbulence theory by "renormalization, " namely, orbit diffusion and the concept of "clumps. " In Sec. VI we present results concerning large-amplitude waves and trapping, and in Sec. VII we discuss some experiments on ion acoustic shocks. We have deliberately avoided or discuss only briefly experiments that (in our opinion) are not yet well understood in terms of quantitative comparison with theories (e.g. , nonlinear drift waves, turbulent resistivity experiments, nonlinear tearing modes, magnetic reconnection, etc. ). II. WEAK-TURBULENCE THEORY AND EXP ER IMENTSA. Foundations of weak-turbulence theoryThe first comprehensive theory of plasma turbulence, what we today call "weak-turbulence theory, " was devel-Rev.

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“…In Fig. 3 we show the results of Roberson et al (1971). As the beam current (density) is increased, saturation occurs in increasingly shorter distances.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…, nonline3r Landau damping and/or growth Porkolab, 1970, 1972;Gentle and Malein, 1971;fkezi and Kiwamoto, 1971). While…”

mentioning

confidence: 99%

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Nonlinear wave effects in laboratory plasmas: A comparison between theory and experiment

Porkoláb

Chang²

1978

Rev. Mod. Phys.

124

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“…Nonlinear Landau damping (NLD), which transfers energy from an incoming wave to a daughter wave through resonance of particles with the beat wave, was extensively studied theoretically as well as experimentally near four decades ago. [8][9][10] However, the plasma density and temperature in those experiments were very low, and so was the incident wave power. In future EBW heating and current drive experiments, the incident wave power could be up to a couple of megawatts, 11 thus increasing the importance of understanding nonlinear effects.…”

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confidence: 95%

Decays of electron Bernstein waves near plasma edge

Xiang

Cary

2011

Physics of Plasmas

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Nonlinear wave-wave couplings near the upper hybrid resonance are studied via particle-in-cell simulations. It is found that the decay of an electron Bernstein wave (EBW) depends on the ratio of the incident frequency and electron cyclotron frequency. For ratios less than two, parametric decay into a lower hybrid wave (or an ion Bernstein wave) and EBWs at a lower frequency is observed. For ratios larger than two, the daughter waves could be an electron cyclotron quasi-mode and another EBW or an ion wave and EBW. For sufficiently high incident power, the former process may dominate. Because of the electron cyclotron quasi-mode, electrons can be strongly heated by nonlinear Landau damping. As a result, the bulk of the incident power can be absorbed near plasma edge at high power. The increase in number of decay channels with frequency implies that the allowable power into the plasma must decrease with frequency.

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