Lower-hybrid drift and Buneman instabilities in current sheets with guide field

2008 ◽  
Vol 15 (11) ◽  
pp. 112105 ◽  
Author(s):  
P. H. Yoon ◽  
A. T. Y. Lui
Keyword(s):  
Lower Hybrid ◽  
Current Sheets ◽  
Guide Field

Drift instabilities in current sheets with guide field

2008 ◽  
Vol 15 (7) ◽  
pp. 072101 ◽  
Author(s):  
P. H. Yoon ◽  
A. T. Y. Lui
Keyword(s):  
Current Sheets ◽  
Guide Field

scholarly journals Anomalous Transport in Current Sheets

1985 ◽  
Vol 107 ◽  
pp. 315-328
Author(s):  
J. D. Huba
Keyword(s):  
Anomalous Transport ◽  
Lower Hybrid ◽  
Diffusion Region ◽  
Transport Mechanisms ◽  
Current Sheets ◽  
Nonlinear Properties ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Linear And Nonlinear ◽  
Drift Instability

A review of several microinstabilities that have been suggested as possible anomalous transport mechanisms in current sheets is presented. The specific application is to a ‘field reversed plasma’ which is relevant to the so-called ‘diffusion region’ of a reconnection process. The linear and nonlinear properties of the modes are discussed, and each mode is assessed as to its importance in reconnection processes based upon these properties. It is concluded that the two most relevant instabilities are the ion acoustic instability and the lower-hybrid-drift instability. However, each instability has limitations as far as reconnection is concerned, and more research is needed in this area.

Gyrokinetic theory of electrostatic lower-hybrid drift instabilities in a current sheet with guide field

2014 ◽  
Vol 21 (5) ◽  
pp. 052104 ◽  
Author(s):  
K. Tummel ◽  
L. Chen ◽  
Z. Wang ◽  
X. Y. Wang ◽  
Y. Lin
Keyword(s):  
Current Sheet ◽  
Lower Hybrid ◽  
Guide Field ◽  
A Current

scholarly journals Thin current sheets with strong bell-shape guide field: Cluster observations and models with beams

2014 ◽  
Vol 32 (10) ◽  
pp. 1349-1360 ◽  
Author(s):  
I. Y. Vasko ◽  
A. V. Artemyev ◽  
A. A. Petrukovich ◽  
H. V. Malova
Keyword(s):  
Electron Beam ◽  
Current Sheet ◽  
Electron Beams ◽  
Ion Beam ◽  
Distribution Functions ◽  
Electron Velocity ◽  
Electron Current ◽  
Electron Velocity Distribution ◽  
Current Sheets ◽  
Guide Field

Abstract. We study the kinetic structure of intense ion-scale current sheets with strong electron currents and the guide field having a bell-shape profile. We consider four crossings of the Earth magnetotail current sheet by the Cluster mission in 2003. The thickness of these current sheets is about the ion inertial length and significantly smaller than the characteristic ion gyroradius. We analyze the asymmetry of the electron velocity distribution functions and show that the electron current is provided by the small electron subpopulation interpreted as an electron beam or two counter-streaming electron beams. The beam (counter-streaming beams) has a bulk velocity of the order of the electron thermal velocity and a density (difference of beam densities) of about 1–5% of the plasma density. To describe the observed current sheets we develop a kinetic model with particle beams. The model predicts different thickness of the current sheet for different types of current carriers (one electron beam or two counter-streaming electron beams). The observed ion-scale current sheets can be explained assuming that the current is carried by one electron beam and a co-streaming ion beam. Although the ion beam does not carry a significant current, this beam is required to balance the electron current perpendicular to the current sheet neutral plane. The developed model explains the dominance of the electron current and the ion scales of the current sheets.

scholarly journals Lower Hybrid Drift Waves During Guide Field Reconnection

2020 ◽  
Vol 47 (21) ◽  
Author(s):  
Jongsoo Yoo ◽  
Jeong‐Young Ji ◽  
M. V. Ambat ◽  
Shan Wang ◽  
Hantao Ji ◽  
...  
Keyword(s):  
Drift Waves ◽  
Lower Hybrid ◽  
Guide Field

scholarly journals Distinctive features of the structure of current sheets formed in plasma in three-dimensional magnetic configurations with an X line (a review)

2021 ◽  
Vol 9 (6) ◽  
pp. 464-478
Author(s):  
Anna Frank
Keyword(s):  
Longitudinal Magnetic Field ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Limited Range ◽  
Transverse Plane ◽  
Plasma Current ◽  
Initial Value ◽  
Distinctive Features ◽  
Current Sheets ◽  
Guide Field

A review is presented on experimental results related to investigation of distinctive features of the structure and evolution of plasma current sheets formed in three dimensional (3D) magnetic configurations with an X line, in the presence of a longitudinal magnetic field component (guide field) directed along the X line. It is shown that formation of a plasma current sheet results in enhancement of the guide field within the sheet. The excessive guide field is maintained by plasma currents that flow in the transverse plane relative to the main current in the sheet. As a result, the structure of the currents becomes three-dimensional. Increasing the initial value of the guide field brings about a decrease of compression into the sheet of both the electric current and plasma. This effect is caused by changing the pres- sure balance in the sheet when an excessive guide field appears in it. Deformation of plasma current sheets in 3D magnetic configurations, namely, an appearance of asymmetric and tilted sheets, results from excitation of the Hall currents and their interaction with the guide field. It is shown that the formation of current sheets in 3D magnetic configurations with an X line is possible in a relatively wide, but limited range of initial conditions

Lower hybrid waves at the magnetosheath separatrix region

2020 ◽  
Author(s):  
Binbin Tang ◽  
Wenya Li ◽  
Daniel Graham ◽  
Chi Wang ◽  
Yuri Khotyaintsev ◽  
...  
Keyword(s):  
Lower Hybrid ◽  
Particle Diffusion ◽  
Limited Region ◽  
Guide Field ◽  
Out Of Plane ◽  
Hybrid Waves ◽  
Drift Instability ◽  
The Waves ◽  
Lower Hybrid Waves ◽  
Drift Direction

<div>Lower hybrid waves are investigated at the magnetosheath separatrix region in asymmetric guide-field reconnection at Earth’s magnetopause by using MMS observations. These waves are found in a limited region, depending on the density gradient across the separatrix, and they are driven by the lower hybrid drift instability. Properties of these waves are presented: (1) the waves propagate towards the x-line due to the out-of-plane magnetic field, consistent with the electron drift direction; (2) the wave potential is about 20% of the electron temperature. These drift waves effectively produce cross-field particle diffusion, enabling the entry of magnetosheath electrons into the exhaust region.</div>

scholarly journals Lower-hybrid drift waves and their interaction with plasmas in a 3D symmetric reconnection simulation with zero guide field

2021 ◽  
Vol 28 (7) ◽  
pp. 072102
Author(s):  
Shan Wang ◽  
Li-Jen Chen ◽  
Jonathan Ng ◽  
Naoki Bessho ◽  
Michael Hesse
Keyword(s):  
Drift Waves ◽  
Lower Hybrid ◽  
Guide Field

scholarly journals Bifurcated Current Sheet Observed on the Boundary of Kelvin-Helmholtz Vortices

2021 ◽  
Vol 8 ◽  
Author(s):  
K-J. Hwang ◽  
K. Dokgo ◽  
E. Choi ◽  
J. L. Burch ◽  
D. G. Sibeck ◽  
...  
Keyword(s):  
Current Sheet ◽  
Layer Structure ◽  
Velocity Shear ◽  
Current Layer ◽  
Combined Effects ◽  
Slow Mode ◽  
Flow Shear ◽  
Current Sheets ◽  
Guide Field ◽  
Line Region

On May 5, 2017 MMS observed a bifurcated current sheet at the boundary of Kelvin-Helmholtz vortices (KHVs) developed on the dawnside tailward magnetopause. We use the event to enhance our understanding of the formation and structure of asymmetric current sheets in the presence of density asymmetry, flow shear, and guide field, which have been rarely studied. The entire current layer comprises three separate current sheets, each corresponding to magnetosphere-side sunward separatrix region, central near-X-line region, and magnetosheath-side tailward separatrix region. Two off-center structures are identified as slow-mode discontinuities. All three current sheets have a thickness of ∼0.2 ion inertial length, demonstrating the sub-ion-scale current layer, where electrons mainly carry the current. We find that both the diamagnetic and electron anisotropy currents substantially support the bifurcated currents in the presence of density asymmetry and weak velocity shear. The combined effects of strong guide field, low density asymmetry, and weak flow shear appear to lead to asymmetries in the streamlines and the current-layer structure of the quadrupolar reconnection geometry. We also investigate intense electrostatics waves observed on the magnetosheath side of the KHV boundary. These waves may pre-heat a magnetosheath population that is to participate into the reconnection process, leading to two-step energization of the magnetosheath plasma entering into the magnetosphere via KHV-driven reconnection.

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