Low frequency solitons and double layers in a magnetized plasma with two temperature electrons

2012 ◽  
Vol 19 (12) ◽  
pp. 122308 ◽  
Author(s):  
O. R. Rufai ◽  
R. Bharuthram ◽  
S. V. Singh ◽  
G. S. Lakhina
Keyword(s):  
Low Frequency ◽  
Magnetized Plasma ◽  
Double Layers ◽  
Two Temperature

scholarly journals Electron acoustic solitons in the Earth's magnetotail

2004 ◽  
Vol 11 (2) ◽  
pp. 215-218 ◽  
Author(s):  
S. G. Tagare ◽  
S. V. Singh ◽  
R. V. Reddy ◽  
G. S. Lakhina
Keyword(s):  
Electron Beam ◽  
Small Amplitude ◽  
Low Frequency ◽  
Frequency Component ◽  
Magnetized Plasma ◽  
Cold Electron ◽  
Ion Plasma ◽  
Electron Acoustic ◽  
Two Temperature ◽  
Perpendicular Polarization

Abstract. Small amplitude electron - acoustic solitons are studied in a magnetized plasma consisting of two types of electrons, namely cold electron beam and background plasma electrons and two temperature ion plasma. The analysis predicts rarefactive solitons. The model may provide a possible explanation for the perpendicular polarization of the low-frequency component of the broadband electrostatic noise observed in the Earth's magnetotail.

scholarly journals Sheaths and Double Layers with Instabilities

2021 ◽  
Vol 2 (1) ◽  
pp. 70-92
Author(s):  
Reiner L Stenzel ◽  
Johannes Grünwald ◽  
Codrina Ionita ◽  
Roman Schrittwieser ◽  
Manuel Urrutia
Keyword(s):  
Double Layer ◽  
Secondary Electron Emission ◽  
Low Frequency ◽  
Negative Electrode ◽  
Density Perturbation ◽  
Magnetized Plasma ◽  
Double Layers ◽  
Electrode Current ◽  
Neutral Gas ◽  
The Impact

The properties of sheaths and associated potential structures and instabilities cover a broad field which even a review cannot cover everything. Thus, the focus will be on about a dozen examples, describe their observations and focus on the basic physical explanations for the effects, while further details are found in the references. Due to familiarity the review focuses mainly on the authors work but compared and referenced related work. The topics start with a high frequency oscillations near the electron plasma frequency. Low frequency instabilities also occur at the ion plasma frequency.The injection of ions into an electron-rich sheath widens the sheath and forms a double layer. Likewise, the injection of electrons into an ion rich sheath widens and establishes a double layer which occurs in free plasma injection into vacuum. The sheath widens and forms a double layer by ionization in an electron rich sheath. When particle fluxes in "fireballs" gets out of balance the double layer performs relaxation instabilities which has been studied extensively. Fireballs inside spherical electrodes create a new instability due to the transit time of trapped electrons. On cylindrical and spherical electrodes the electron rich sheath rotates in magnetized plasmas. Electrons rotate due to $\mathbf E \times \mathbf B_0$ which excites electron drift waves with azimuthal eigenmodes. Conversely a permanent magnetic dipole has been used as a negative electrode. The impact of energetic ions produces secondary electron emission, forming a ring of plasma around the magnetic equator. Such "magnetrons" are subject to various instabilities. Finally, the current to a positively biased electrode in a uniformly magnetized plasma is unstable to relaxation oscillations, which shows an example of global effects. The sheath at the electrode raises the potential in the flux tube of the electrode thereby creating a radial sheath which moves unmagnetized ions radially. The ion motion creates a density perturbation which affects the electrode current. If the electrode draws large currents the current disruptions create large inductive voltages on the electrode, which again produce double layers. This phenomenon has been seen in reconnection currents. Many examples of sheath properties will be explained. Although the focus is on the physics some examples of applications will be suggested such as neutral gas heating and accelerating, sputtering of plasma magnetrons and rf oscillators.

Ion-acoustic solitary structures at the acoustic speed in a collisionless magnetized nonthermal dusty plasma

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Debdatta Debnath ◽  
Anup Bandyopadhyay
Keyword(s):  
Double Layer ◽  
Negative Polarity ◽  
Critical Value ◽  
Magnetized Plasma ◽  
Double Layers ◽  
Nonthermal Electrons ◽  
Solitary Structures ◽  
Ion Acoustic ◽  
Density Of Electrons ◽  
Acoustic Speed

Abstract At the acoustic speed, we have investigated the existence of ion-acoustic solitary structures including double layers and supersolitons in a collisionless magnetized plasma consisting of negatively charged static dust grains, adiabatic warm ions, and nonthermal electrons. At the acoustic speed, for negative polarity, the system supports solitons, double layers, supersoliton structures after the formation of double layer, supersoliton structures without the formation of double layer, solitons after the formation of double layer whereas the system supports solitons and supersolitons without the formation of double layer for the case of positive polarity. But it is not possible to get the coexistence of solitary structures (including double layers and supersolitons) of opposite polarities. For negative polarity, we have observed an important transformation viz., soliton before the formation of double layer → double layer → supersoliton → soliton after the formation of double layer whereas for both positive and negative polarities, we have observed the transformation from solitons to supersolitons without the formation of double layer. There does not exist any negative (positive) potential solitary structures within 0 < μ < μ c (μ c < μ < 1) and the amplitude of the positive (negative) potential solitary structure decreases for increasing (decreasing) μ and the solitary structures of both polarities collapse at μ = μ c, where μ c is a critical value of μ, the ratio of the unperturbed number density of electrons to that of ions. Similarly there exists a critical value β e2 of the nonthermal parameter β e such that the solitons of both polarities collapse at β e = β e2.

scholarly journals Comparative study of dust acoustic solitons in two-temperature ion homogeneous and inhomogeneous plasmas

2020 ◽  
Vol 14 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Rashmi Srivastava ◽  
Hitendra K. Malik ◽  
Devi Singh
Keyword(s):  
Solitary Waves ◽  
Inhomogeneous Plasma ◽  
Low Frequency ◽  
Soliton Solutions ◽  
Dusty Plasmas ◽  
Number Density ◽  
Dust Charge ◽  
Plasma Species ◽  
Dust Acoustic ◽  
Two Temperature

AbstractThe dust acoustic solitary waves are theoretically investigated in dusty plasmas for different cases of with and without density gradients. These low-frequency solitary waves are studied using appropriate Korteweg–de Vries equations obtained using relevant stretched coordinates. The soliton solutions in homogeneous plasma, weakly inhomogeneous plasma and strongly inhomogeneous plasma, are thoroughly investigated for studying the effect of different parameters like dust charge and density of all the plasma species on the soliton profiles. The combination of the dust charge with its number density changes the dynamics of the solitons and that is further affected by the number density of the hot ion with respect to the cold ions.

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