scholarly journals Fully kinetic Biermann battery and associated generation of pressure anisotropy

2018 ◽  
Vol 97 (3) ◽  
Author(s):  
K. M. Schoeffler ◽  
N. F. Loureiro ◽  
L. O. Silva
Keyword(s):  
Pressure Anisotropy ◽  
Biermann Battery

scholarly journals The generation of magnetic fields by the Biermann battery and the interplay with the Weibel instability

2016 ◽  
Vol 23 (5) ◽  
pp. 056304 ◽  
Author(s):  
K. M. Schoeffler ◽  
N. F. Loureiro ◽  
R. A. Fonseca ◽  
L. O. Silva
Keyword(s):  
Magnetic Fields ◽  
Weibel Instability ◽  
Biermann Battery

Effects of electron pressure anisotropy on current sheet configuration

2016 ◽  
Vol 23 (9) ◽  
pp. 092901 ◽  
Author(s):  
A. V. Artemyev ◽  
I. Y. Vasko ◽  
V. Angelopoulos ◽  
A. Runov
Keyword(s):  
Current Sheet ◽  
Electron Pressure ◽  
Pressure Anisotropy

Parametric instabilities of finite-amplitude, circularly polarized Alfvén waves in an anisotropic plasma

1993 ◽  
Vol 49 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Hiromitsu Hamabata
Keyword(s):  
Finite Amplitude ◽  
Alfven Waves ◽  
Mhd Equations ◽  
Alfvén Waves ◽  
Linear Perturbation ◽  
Plasma Parameters ◽  
Circularly Polarized ◽  
Pressure Anisotropy ◽  
Parametric Instabilities ◽  
Fifth Order

A class of parametric instabilities of finite-amplitude, circularly polarized Alfvén waves in a plasma with pressure anisotropy is studied by application of the CGL equations. A linear perturbation analysis is used to find the dispersion relation governing the instabilities, which is a fifth-order polynomial and is solved numerically. A large-amplitude, circularly polarized wave is unstable with respect to decay into three waves: one sound-like wave and two side-band Alfvén-like waves. It is found that, in addition to the decay instability, two new instabilities that are absent in the framework of the MHD equations can occur, depending on the plasma parameters.

Electron Pitch Angle Distributions in the Compressional Pc5 Waves

2021 ◽  
Author(s):  
Xiao Ma ◽  
Anmin Tian ◽  
Quanqi Shi ◽  
Shichen Bai ◽  
Ji Liu ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Interaction Effects ◽  
Plasma Pressure ◽  
Whistler Waves ◽  
Whistler Mode ◽  
Compressional Waves ◽  
The Earth ◽  
Pressure Anisotropy ◽  
Electron Distributions ◽  
Whistler Mode Waves

<p>In the two flanks of the Earth’s magnetosphere, the compressional Pc5 waves are often observed. Previous study suggests that these waves are usually excited by plasma pressure anisotropy such as drift mirror instability. Interestingly, whistler mode waves are often observed in the magnetic trough regions of the compressional Pc5 waves. In this study, we use 10 years (2007-2016) THEMIS A data to study the electron distributions in the compressional Pc5 waves associated with the whistler mode waves. We find three typical electron pitch angle distributions (PADs) in these compressional waves: cigar-shape, donut-shape and pancake-shape. They predominantly occur at tens to hundreds eV, several keV and >10 keV, respectively. The interaction effects between the electrons and whistler waves inside the magnetic troughs are stressed in understanding the formation of these PADs.</p>

Ion acoustic solitary waves in magnetized anisotropic nonextensive plasmas

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Khalid ◽  
Mohsin Khan ◽  
Ata ur-Rahman ◽  
Muhammad Irshad
Keyword(s):  
Solitary Waves ◽  
Type Equation ◽  
Reductive Perturbation Method ◽  
Nonlinear Propagation ◽  
Astrophysical Plasma ◽  
Parallel Component ◽  
Pressure Anisotropy ◽  
Ion Acoustic ◽  
Tsallis Distribution ◽  
Perpendicular Component

Abstract The nonlinear propagation of ion-acoustic (IA) electrostatic solitary waves (SWs) is studied in a magnetized electron–ion (e–i) plasma in the presence of pressure anisotropy with electrons following Tsallis distribution. The Korteweg–de Vries (KdV) type equation is derived by employing the reductive perturbation method (RPM) and its solitary wave (SW) solution is determined and analyzed. The effect of nonextensive parameter q, parallel component of anisotropic ion pressure p 1, perpendicular component of anisotropic ion pressure p 2, obliqueness angle θ, and magnetic field strength Ω on the characteristics of SW structures is investigated. The present investigation could be useful in space and astrophysical plasma systems.

scholarly journals Onset of magnetic reconnection in a collisionless, high- plasma

2019 ◽  
Vol 85 (1) ◽  
Author(s):  
Andrew Alt ◽  
Matthew W. Kunz
Keyword(s):  
Magnetic Reconnection ◽  
Collisionless Plasma ◽  
High Plasma ◽  
Tearing Modes ◽  
Associated Production ◽  
Pressure Anisotropy ◽  
Low Threshold ◽  
Collisionless Reconnection ◽  
Field Lines ◽  
The Impact

In a magnetized, collisionless plasma, the magnetic moment of the constituent particles is an adiabatic invariant. An increase in the magnetic-field strength in such a plasma thus leads to an increase in the thermal pressure perpendicular to the field lines. Above a$\unicode[STIX]{x1D6FD}$-dependent threshold (where$\unicode[STIX]{x1D6FD}$is the ratio of thermal to magnetic pressure), this pressure anisotropy drives the mirror instability, producing strong distortions in the field lines on ion-Larmor scales. The impact of this instability on magnetic reconnection is investigated using a simple analytical model for the formation of a current sheet (CS) and the associated production of pressure anisotropy. The difficulty in maintaining an isotropic, Maxwellian particle distribution during the formation and subsequent thinning of a CS in a collisionless plasma, coupled with the low threshold for the mirror instability in a high-$\unicode[STIX]{x1D6FD}$plasma, imply that the geometry of reconnecting magnetic fields can differ radically from the standard Harris-sheet profile often used in simulations of collisionless reconnection. As a result, depending on the rate of CS formation and the initial CS thickness, tearing modes whose growth rates and wavenumbers are boosted by this difference may disrupt the mirror-infested CS before standard tearing modes can develop. A quantitative theory is developed to illustrate this process, which may find application in the tearing-mediated disruption of kinetic magnetorotational ‘channel’ modes.

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