Electron Kinetic Instability Driven by Electron Temperature Anisotropy and Electron Beam in the Solar Wind

2020 ◽  
Author(s):  
Jinsong Zhao ◽  
Heyu Sun ◽  
Wen Liu ◽  
Huasheng Xie ◽  
Dejin Wu
Keyword(s):  
Solar Wind ◽  
Electron Beam ◽  
Electron Temperature ◽  
Electron Dynamics ◽  
Temperature Anisotropy ◽  
Acoustic Instability ◽  
Beam Velocity ◽  
Kinetic Instability ◽  
Electron Acoustic ◽  
Beam Component

<p>Electron temperature anisotropy instabilities are believed to constrain the distributions of the electron parallel and perpendicular temperatures in the solar wind. When the electron perpendicular temperature is larger than the parallel temperature, the whistler instability is normally stronger than the electron mirror instability. While the electron parallel temperature is larger than the perpendicular temperature, the electron oblique firehose instability dominates the parallel firehose instability. Therefore, previous studies proposed the whistler and electron oblique firehose instabilities constraint on the electron dynamics in the solar wind. Based on the fact that there always exists the differential drift velocity among different electron populations, we consider the electron kinetic instability in the plasmas containing the electron anisotropic component and the electron beam component. Consequently, we give a comprehensive electron kinetic instability analysis in the solar wind. Furthermore, we propose that the electron acoustic/magneto-acoustic instability can arise in the low electron beta regime, and the whistler electron beam instability can be triggered in a wide beta regime. These two instabilities can provide a constraint on the electron beam velocity. Moreover, we find a new instability in the regime of the electron beta ~ 1, and this instability produces obliquely-propagating fast-magnetosonic/whistler waves. These results would be helpful for distinguishing the electron instability and for analyzing the constraint mechanism on the electron temperature distribution in the solar wind.</p>

scholarly journals Electron Temperature Anisotropy and Electron Beam Constraints from Electron Kinetic Instabilities in the Solar Wind

2020 ◽  
Vol 902 (1) ◽  
pp. 59
Author(s):  
Heyu Sun ◽  
Jinsong Zhao ◽  
Wen Liu ◽  
Huasheng Xie ◽  
Dejin Wu
Keyword(s):  
Solar Wind ◽  
Electron Beam ◽  
Electron Temperature ◽  
Temperature Anisotropy ◽  
Kinetic Instabilities

The ion-ion acoustic instability

1987 ◽  
Vol 37 (1) ◽  
pp. 45-61 ◽  
Author(s):  
S. Peter Gary ◽  
Nojan Omidi
Keyword(s):  
Numerical Solutions ◽  
Temperature Anisotropy ◽  
Acoustic Instability ◽  
The Core ◽  
Ion Acoustic ◽  
Earth’S Bow Shock ◽  
Kinetic Instability ◽  
Electrostatic Dispersion ◽  
Effective Beam ◽  
Vlasov Plasma

This paper considers the linear theory of ion-acoustic-like instabilities in a homogeneous Vlasov plasma with two ion components, a less dense beam and a more dense core, with a relative drift velocity. Numerical solutions of the full electrostatic dispersion equation are presented, and the properties of the ion–ion acoustic instability are studied in detail. The following properties are demonstrated: (i) At relatively cold beam temperatures, the instability is fluid-like, but it becomes a beam resonant kinetic instability as the beam temperature becomes of the order of the core temperature; (ii) if the mode is unstable, its threshold lies well below the threshold of the electron–ion acoustic instability; (iii) an electron temperature anisotropy T⊥/T‖e > 1 enhances the instability and (iv) at sufficiently large beam-core relative drift speeds, electron magnetization can either detract from or enhance the instability. If field-aligned ion beams are to drive the ion-acoustic-like enhanced fluctuations observed upstream of the Earth's bow shock, the effective beam temperature must be much smaller than values quoted in the literature.

scholarly journals Simulation of Electron-Electron Two Stream Instability (ETSI)

2019 ◽  
Vol 1 ◽  
pp. 265-273
Author(s):  
F Gbaorun ◽  
E S John ◽  
T M Aper ◽  
T Daniel ◽  
F Eriba-Idoko
Keyword(s):  
Solar Wind ◽  
Electron Beam ◽  
Kinetic Energy ◽  
Electron Density ◽  
High Velocity ◽  
Electron Beams ◽  
Field Energy ◽  
Beam Velocity ◽  
Fixed Beam ◽  
Stream Instability

Stream instabilities are widely studied due to their importance in understanding astrophysical phenomena such as acceleration of high velocity of solar wind. In this work, the simulation of electron two stream instability was performed using Vorpal Simulation (VSim) code to explore the kinetic energy of plasma that arises due to the interaction between two counter-streaming electron beams at different velocities as well as different electron densities. The electron beam velocity was varied in the range of 3.58 × 106 m/s - 7.98 × 106 m/s and the resulting kinetic energy of plasma increased from 19 × 10−6J - 210 × 10−6J respectively. Also, increasing the electron density at fixed beam velocity from 1.05 × 1014m−3 - 5.84 × 1014m−3, the kinetic energy was observed to increase from 100 × 10−6J - 200 × 10−6J .However, the kinetic energy of the electron increases more with increasing beam velocity than with increasing electron density. The electric field energy which arose due to the interaction of the streaming beams did not exceed the energy of the beams.

scholarly journals Particle-in-cell Simulations of the Parallel Proton Firehose Instability Influenced by the Electron Temperature Anisotropy in Solar Wind Conditions

2020 ◽  
Vol 893 (2) ◽  
pp. 130 ◽  
Author(s):  
A. Micera ◽  
E. Boella ◽  
A. N. Zhukov ◽  
S. M. Shaaban ◽  
R. A. López ◽  
...  
Keyword(s):  
Solar Wind ◽  
Electron Temperature ◽  
Temperature Anisotropy ◽  
Particle In Cell

scholarly journals Spontaneous Magnetic Fluctuations and Collisionless Regulation of Turbulence in the Earth’s Magnetotail

2022 ◽  
Vol 924 (1) ◽  
pp. 8
Author(s):  
C. M. Espinoza ◽  
P. S. Moya ◽  
M. Stepanova ◽  
J. A. Valdivia ◽  
R. E. Navarro
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
Relaxation Processes ◽  
Magnetic Fluctuations ◽  
Temperature Anisotropy ◽  
Satellite Mission ◽  
Astrophysical Plasmas ◽  
Fluctuation Dissipation ◽  
Collisionless Plasmas ◽  
Kinetic Instability

Abstract Among the fundamental and most challenging problems of laboratory, space, and astrophysical plasma physics is to understand the relaxation processes of nearly collisionless plasmas toward quasi-stationary states and the resultant states of electromagnetic plasma turbulence. Recently, it has been argued that solar wind plasma β and temperature anisotropy observations may be regulated by kinetic instabilities such as the ion cyclotron, mirror, electron cyclotron, and firehose instabilities; and it has been argued that magnetic fluctuation observations are consistent with the predictions of the fluctuation–dissipation theorem, even far below the kinetic instability thresholds. Here, using in situ magnetic field and plasma measurements by the THEMIS satellite mission, we show that such regulation seems to occur also in the Earth’s magnetotail plasma sheet at the ion and electron scales. Regardless of the clear differences between the solar wind and the magnetotail environments, our results indicate that spontaneous fluctuations and their collisionless regulation are fundamental features of space and astrophysical plasmas, thereby suggesting the processes is universal.

Electron-acoustic instability driven by a field-aligned hot electron beam

1991 ◽  
Vol 46 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R. Bharuthram
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Electron Beam ◽  
Hot Electron ◽  
Plasma Parameters ◽  
Acoustic Instability ◽  
Electrons And Ions ◽  
Component Plasma ◽  
Instability Growth ◽  
Electron Acoustic

Using kinetic theory, the electron-acoustic instability is investigated in a three-component plasma consisting of a hot electron beam and stationary cool electrons and ions. In the model considered here both the electrons and ions are magnetized, with the beam drift along the external magnetic field. The dependence of the growth rate on plasma parameters, such as electron-beam density, electron-beam speed, magnetic field strength and propagation angle, is studied. In addition, the effects of anisotropies in the velocity distributions of the hot electron beam and the cool electrons on the instability growth rate are examined.

Electron temperature anisotropy constraints in the solar wind

2008 ◽  
Vol 113 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Štěpán Štverák ◽  
Pavel Trávníček ◽  
Milan Maksimovic ◽  
Eckart Marsch ◽  
Andrew N. Fazakerley ◽  
...  
Keyword(s):  
Solar Wind ◽  
Electron Temperature ◽  
Temperature Anisotropy

scholarly journals Effects of Electron Temperature Anisotropy on Proton-beam Instability in the Solar Wind

2020 ◽  
Vol 899 (1) ◽  
pp. 61
Author(s):  
L. Xiang ◽  
K. H. Lee ◽  
D. J. Wu ◽  
L. C. Lee
Keyword(s):  
Solar Wind ◽  
Electron Temperature ◽  
Proton Beam ◽  
Beam Instability ◽  
Temperature Anisotropy

The magnetized electron-acoustic instability driven by a warm, field-aligned electron beam

2004 ◽  
Vol 11 (5) ◽  
pp. 1996-2008 ◽  
Author(s):  
A. Sooklal ◽  
R. L. Mace
Keyword(s):  
Electron Beam ◽  
Acoustic Instability ◽  
Electron Acoustic
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