scholarly journals Resonance overlap and nonlinear features of the beam–plasma system

2020 ◽  
Vol 86 (4) ◽  
Author(s):  
N. Carlevaro ◽  
G. Montani ◽  
M. V. Falessi
Keyword(s):  
Velocity Spread ◽  
Linear Growth Rate ◽  
Fusion Plasma ◽  
Resonance Overlap ◽  
Beam Plasma ◽  
Transport Barriers ◽  
Nonlinear Features ◽  
Space Dynamics ◽  
Beam Plasma Instability

The beam–plasma instability can be addressed as a reduced model in several contexts of plasma physics, from space to fusion plasma. In this paper, we review and refine some nonlinear features of this model. Specifically, by analysing the dependence of the nonlinear velocity spread as a function of the linear growth rate, we discuss the effective size of the resonance in view of its role in the spectral overlap at saturation. The relevance of this characterization relies on the necessity of a quantitative determination of the overlap degree to discriminate among different transport regimes of the self-consistent dynamics. The analysis is enriched with a study of the phase-space dynamics by means of the Lagrangian coherent structure technique, in order to define the transport barriers of the system describing the relevant features of the overlap process. Finally, we discuss relevant features related to the mode saturation levels.

Nonlinear stabilization of cold beam-plasma instability

1972 ◽  
Vol 8 (2) ◽  
pp. 159-168 ◽  
Author(s):  
M. R. Gupta
Keyword(s):  
Plasma Instability ◽  
Linear Growth Rate ◽  
Nonlinear Frequency ◽  
Nonlinear Stabilization ◽  
Beam Plasma ◽  
Frequency Correction ◽  
Beam Plasma Instability ◽  
The Waves ◽  
Trapping Frequency ◽  
Cold Beam

Nonlinear stabilization of cold beam plasma instability are studied on the basis of Dupree's theory of strong plasma turbulence. Calculations are carried out to second order in the perturbed electric field, and it is found that, for a narrow spectrum satisfying δκ/κ≪1, stabilization occurs for the trapping frequency ωT ť ∣qeκΕk/me∣½ ť γL the linear growth rate. Nonlinear frequency correction, and also the changes in the kinetic and thermal energy densities of the beam, are calculated as the waves grow. Some points of difference between the resonant and non-resonant instabilities are discussed.

scholarly journals Electron beam relaxation in inhomogeneous plasmas

2013 ◽  
Vol 31 (8) ◽  
pp. 1379-1385 ◽  
Author(s):  
A. Voshchepynets ◽  
V. Krasnoselskikh
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Electron Beams ◽  
Inhomogeneous Plasma ◽  
Density Fluctuations ◽  
Langmuir Waves ◽  
Wave Trapping ◽  
Beam Plasma ◽  
Beam Plasma Instability ◽  
Accelerated Particles

Abstract. In this work, we studied the effects of background plasma density fluctuations on the relaxation of electron beams. For the study, we assumed that the level of fluctuations was so high that the majority of Langmuir waves generated as a result of beam-plasma instability were trapped inside density depletions. The system can be considered as a good model for describing beam-plasma interactions in the solar wind. Here we show that due to the effect of wave trapping, beam relaxation slows significantly. As a result, the length of relaxation for the electron beam in such an inhomogeneous plasma is much longer than in a homogeneous plasma. Additionally, for sufficiently narrow beams, the process of relaxation is accompanied by transformation of significant part of the beam kinetic energy to energy of accelerated particles. They form the tail of the distribution and can carry up to 50% of the initial beam energy flux.

Modulation of proton beams by relativistic electron beam-plasma instability

2018 ◽  
Vol 25 (10) ◽  
pp. 102104 ◽  
Author(s):  
Xiao-Juan Wang ◽  
Zhang-Hu Hu ◽  
Yong-Tao Zhao ◽  
You-Nian Wang
Keyword(s):  
Electron Beam ◽  
Relativistic Electron ◽  
Relativistic Electron Beam ◽  
Plasma Instability ◽  
Proton Beams ◽  
Beam Plasma ◽  
Beam Plasma Instability ◽  
Electron Beam Plasma

scholarly journals EFFECT OF A BOUNDARY ON THE BEAM PLASMA INSTABILITY

1969 ◽  
Author(s):  
Jr. Evans ◽  
Jackson Kenneth ◽  
E. A.
Keyword(s):  
Plasma Instability ◽  
Beam Plasma ◽  
Beam Plasma Instability

scholarly journals Nonlinear features of equatorial baroclinic Rossby waves detected in Topex altimeter observations

1996 ◽  
Vol 3 (2) ◽  
pp. 115-126 ◽  
Author(s):  
R. E. Glazman ◽  
A. Fabrikant ◽  
A. M. Greysukh
Keyword(s):  
Rossby Waves ◽  
Propagation Speed ◽  
Altimeter Data ◽  
Satellite Altimeter ◽  
Wave Regime ◽  
Nonlinear Features ◽  
Wavenumber Spectrum ◽  
Satellite Altimeter Data ◽  
Rule Out

Abstract. Using a recently proposed technique for statistical analysis of non-gridded satellite altimeter data, regime of long equatorially-trapped baroclinic Rossby waves is studied. One-dimensional spatial and spatiotemporal autocorrelation functions of sea surface height (SSH) variations yield a broad spectrum of baroclinic Rossby waves and permit determination of their propagation speed. The 1-d wavenumber spectrum of zonal variations is given by a power-law k-2 on scales from about 103 km to 104 km. We demonstrate that the observed wave regime exhibits features of soliton turbulence developing in the long baroclinic Rossby waves. However, being limited to second statistical moments, the present analysis does not allow us to rule out a possibility of weak wave turbulence.

Sign in / Sign up

Export Citation Format

Share Document