scholarly journals Beam-plasma interaction in randomly inhomogeneous plasmas and statistical properties of small-amplitude Langmuir waves in the solar wind and electron foreshock

2007 ◽  
Vol 112 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
V. V. Krasnoselskikh ◽  
V. V. Lobzin ◽  
K. Musatenko ◽  
J. Soucek ◽  
J. S. Pickett ◽  
...  
Keyword(s):  
Solar Wind ◽  
Small Amplitude ◽  
Statistical Properties ◽  
Langmuir Waves ◽  
Plasma Interaction ◽  
Beam Plasma

Statistical properties of small-amplitude Langmuir waves in the Earth's electron foreshock

2007 ◽  
Vol 55 (15) ◽  
pp. 2273-2280 ◽  
Author(s):  
K. Musatenko ◽  
V. Lobzin ◽  
J. Soucek ◽  
V.V. Krasnoselskikh ◽  
P. Décréau
Keyword(s):  
Small Amplitude ◽  
Statistical Properties ◽  
Langmuir Waves

scholarly journals A linear model for amplitude modulation of Langmuir waves in weak electron-beam plasma interaction

2013 ◽  
Vol 31 (1) ◽  
pp. 31-38 ◽  
Author(s):  
K. Baumgärtel
Keyword(s):  
Amplitude Modulation ◽  
Langmuir Wave ◽  
Langmuir Waves ◽  
Plasma Interaction ◽  
Temporal Representation ◽  
Weak Beam ◽  
Beam Plasma ◽  
The Waves ◽  
Electron Beam Plasma ◽  
Weak Electron

Abstract. A simple linear approach to the phenomenon of amplitude modulation of Langmuir waves in weak beam plasma interaction is presented. During the short growth phase of the instability and within the longer period after saturation, the waves are described by their linear kinetic dispersion properties.The amplitude modulation appears as result of the beating of waves with different wavelengths and amplitudes that have grown from noise in the initial phase. The Langmuir wave fields are calculated via FFT (fast Fourier transform) technique. The resulting waveforms in temporal representation are quite similar to those observed by spacecraft.

scholarly journals Particle-in-cell simulations of the relaxation of electron beams in inhomogeneous solar wind plasmas

2016 ◽  
Vol 82 (6) ◽  
Author(s):  
Jonathan O. Thurgood ◽  
David Tsiklauri
Keyword(s):  
Solar Wind ◽  
Electron Beam ◽  
Linear Theory ◽  
Langmuir Wave ◽  
High Energy ◽  
Density Fluctuations ◽  
Langmuir Waves ◽  
Particle In Cell ◽  
Hamiltonian Models ◽  
Beam Plasma

Previous theoretical considerations of electron beam relaxation in inhomogeneous plasmas have indicated that the effects of the irregular solar wind may account for the poor agreement of homogeneous modelling with the observations. Quasi-linear theory and Hamiltonian models based on Zakharov’s equations have indicated that when the level of density fluctuations is above a given threshold, density irregularities act to de-resonate the beam–plasma interaction, restricting Langmuir wave growth on the expense of beam energy. This work presents the first fully kinetic particle-in-cell (PIC) simulations of beam relaxation under the influence of density irregularities. We aim to independently determine the influence of background inhomogeneity on the beam–plasma system, and to test theoretical predictions and alternative models using a fully kinetic treatment. We carry out one-dimensional (1-D) PIC simulations of a bump-on-tail unstable electron beam in the presence of increasing levels of background inhomogeneity using the fully electromagnetic, relativistic EPOCH PIC code. We find that in the case of homogeneous background plasma density, Langmuir wave packets are generated at the resonant condition and then quasi-linear relaxation leads to a dynamic increase of wavenumbers generated. No electron acceleration is seen – unlike in the inhomogeneous experiments, all of which produce high-energy electrons. For the inhomogeneous experiments we also observe the generation of backwards-propagating Langmuir waves, which is shown directly to be due to the refraction of the packets off the density gradients. In the case of higher-amplitude density fluctuations, similar features to the weaker cases are found, but also packets can also deviate from the expected dispersion curve in $(k,\unicode[STIX]{x1D714})$-space due to nonlinearity. Our fully kinetic PIC simulations broadly confirm the findings of quasi-linear theory and the Hamiltonian model based on Zakharov’s equations. Strong density fluctuations modify properties of excited Langmuir waves altering their dispersion properties.

Interplanetary field enhancements in the solar wind: Statistical properties at 0.72 AU

Icarus ◽  
1984 ◽  
Vol 60 (2) ◽  
pp. 332-350 ◽  
Author(s):  
C.T. Russell ◽  
M.R. Arghavani ◽  
J.G. Luhmann
Keyword(s):  
Solar Wind ◽  
Statistical Properties ◽  
Field Enhancements

scholarly journals Electron beam—plasma interaction in a dusty plasma with excess suprathermal electrons

2011 ◽  
Author(s):  
A. Danehkar ◽  
N. S. Saini ◽  
M. A. Hellberg ◽  
I. Kourakis ◽  
Vladimir Yu. Nosenko ◽  
...  
Keyword(s):  
Electron Beam ◽  
Dusty Plasma ◽  
Plasma Interaction ◽  
Suprathermal Electrons ◽  
Beam Plasma ◽  
Electron Beam Plasma

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.

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