The interaction of quasiperpendicular shock waves in a collisionless plasma

1987 ◽  
Vol 30 (8) ◽  
pp. 2504 ◽  
Author(s):  
P. J. Cargill ◽  
C. C. Goodrich
Keyword(s):  
Shock Waves ◽  
Collisionless Plasma

scholarly journals Formation of dispersive shock waves in evolution of a two-temperature collisionless plasma

2020 ◽  
Vol 32 (12) ◽  
pp. 126115
Author(s):  
Sergey K. Ivanov ◽  
Anatoly M. Kamchatnov
Keyword(s):  
Shock Waves ◽  
Collisionless Plasma ◽  
Two Temperature

Existence conditions for collisionless hydromagnetic shock waves along the magnetic field

1971 ◽  
Vol 6 (3) ◽  
pp. 467-493 ◽  
Author(s):  
Yusuke Kato† ◽  
Masayoshi Tajiri ◽  
Tosiya Taniuti
Keyword(s):  
Magnetic Field ◽  
Shock Waves ◽  
Flow Velocity ◽  
Maxwell Equations ◽  
Collisionless Plasma ◽  
Electrostatic Waves ◽  
Pressure Anisotropy ◽  
Existence Conditions ◽  
Upstream Flow ◽  
The Magnetic Field

This paper is concerned with existence conditions for steady hydromagnetic shock waves propagating in a collisionless plasma along an applied magnetic field. The electrostatic waves are excluded. The conditions are based on the requirement that solutions of the Vlasov-Maxwell equations deviate from a uniform state ahead of a wave. They are given as the conditions on the upstream flow velocity in the wave frame (i.e. in the form of inequalities among the upstream flow velocity and some critical velocities). The conditions crucially depend on the pressure anisotropy, and demonstrate possibilities of exacting collisionless shock waves for high β plasmas.

Dust acoustic shock waves in dusty plasma of opposite polarity with non-extensive electron and ion distributions

2014 ◽  
Vol 80 (3) ◽  
pp. 517-528 ◽  
Author(s):  
S. K. Zaghbeer ◽  
H. H. Salah ◽  
N. H. Sheta ◽  
E. K. El-Shewy ◽  
A. Elgarayhi
Keyword(s):  
Shock Waves ◽  
Dusty Plasma ◽  
Collisionless Plasma ◽  
Homogeneous System ◽  
Opposite Polarity ◽  
Reductive Perturbation Method ◽  
Ion Distributions ◽  
Electrons And Ions ◽  
Dust Acoustic ◽  
Space Environments

A theoretical investigation has been made of obliquely propagating nonlinear electrostatic shock structures. The reductive perturbation method has been used to derive the Korteweg-de Vries-Burger (KdV-Burger) equation for dust acoustic shock waves in a homogeneous system of a magnetized collisionless plasma comprising a four-component dusty plasma with massive, micron-sized, positively, negatively dust grains and non-extensive electrons and ions. The effect of dust viscosity coefficients of charged dusty plasma of opposite polarity and the non-extensive parameters of electrons and ions have been studied. The behavior of the oscillatory and monotonic shock waves in dusty plasma has been investigated. It has been found that the presence of non-extensive parameters significantly modified the basic properties of shock structures in space environments.

Inverse Energy Cascade of Fast Magnetosonic Turbulence in the Heliosheath

2020 ◽  
Author(s):  
Bertalan Zieger
Keyword(s):  
Solar Wind ◽  
High Resolution ◽  
Shock Waves ◽  
High Frequency ◽  
Collisionless Plasma ◽  
Energy Cascade ◽  
Fast Mode ◽  
Turbulence Spectrum ◽  
Inverse Energy Cascade ◽  
Voyager 2

<p>The solar wind in the heliosheath beyond the termination shock (TS) is a non-equilibrium collisionless plasma consisting of thermal solar wind ions, suprathermal pickup ions (PUI) and electrons. In such multi-ion plasma, two fast magnetosonic wave modes exist: the low-frequency fast mode that propagates in the thermal ion component and the high-frequency fast mode that propagates in the suprathermal PUI component [<em>Zieger et al.</em>, 2015]. Both fast modes are dispersive on fluid and ion scales, which results in nonlinear dispersive shock waves. In this talk, we briefly review the theory of dispersive shock waves in multi-ion collisionless plasma. We present high-resolution three-fluid simulations of the TS and the heliosheath up to 2.2 AU downstream of the TS. We show that downstream propagating nonlinear magnetosonic waves grow until they steepen into shocklets (thin current sheets), overturn, and start to propagate backward in the frame of the downstream propagating wave, as predicted by theory <em>[McKenzie et al</em>., 1993; <em>Dubinin et al.</em>, 2006]. The counter-propagating nonlinear waves result in fast magnetosonic turbulence far downstream of the shock. Since the high-frequency fast mode is positive dispersive on fluid scale, energy is transferred from small scales to large scales (inverse energy cascade). Thermal solar wind ions are preferentially heated by the turbulence. Forward and reverse shocklets in the heliosheath can efficiently accelerate both ions and electrons to high energies through the shock drift acceleration mechanism. We validate our three-fluid simulations with in-situ high-resolution Voyager 2 magnetic field and plasma observations at the TS and in the heliosheath. Our simulations reproduce the magnetic turbulence spectrum with a spectral slope of -5/3 observed by Voyager 2 in frequency domain [<em>Fraternale et al</em>., 2019]. However, since Taylor’s hypothesis is not true for fast magnetosonic perturbations in the heliosheath, the inertial range of the turbulence spectrum is not a Kolmogorov spectrum in wave number domain. </p>

scholarly journals On the formation and properties of fluid shocks and collisionless shock waves in astrophysical plasmas

2018 ◽  
Vol 84 (3) ◽  
Author(s):  
Antoine Bret ◽  
Asaf Pe’er
Keyword(s):  
Shock Waves ◽  
Initial Density ◽  
Collisionless Plasma ◽  
Critical Density ◽  
Strong Shock ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Plasma Instabilities ◽  
Astrophysical Plasmas ◽  
Binary Collisions

When two plasmas collide, their interaction can be mediated by collisionless plasma instabilities or binary collisions between particles of each shell. By comparing the maximum growth rate of the collisionless instabilities with the collision frequency between particles of the shells, we determine the critical density separating the collisionless formation from the collisional formation of the resulting shock waves. This critical density is also the density beyond which the shock downstream is field free, as plasma instabilities do not have time to develop electromagnetic patterns. We further determine the conditions on the shells initial density and velocity for the downstream to be collisional. If these quantities fulfil the determined conditions, the collisionality of the downstream also prevents the shock from accelerating particles or generating strong magnetic fields. We compare the speed of sound with the relative speed of collision between the two shells, thus determining the portion of the parameter space where strong shock formation is possible for both classical and degenerate plasmas. Finally, we discuss the observational consequences in several astrophysical settings.

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