Influence of the electric field perpendicular to the current sheet on ion beamlets in the magnetotail

2010 ◽  
Vol 115 (A2) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. S. Dolgonosov ◽  
G. Zimbardo ◽  
A. Greco
Keyword(s):  
Electric Field ◽  
Current Sheet

Antarctic polar plateau vertical electric field variations across heliocentric current sheet crossings

2006 ◽  
Vol 68 (6) ◽  
pp. 639-654 ◽  
Author(s):  
G.B. Burns ◽  
B.A. Tinsley ◽  
A.R. Klekociuk ◽  
O.A. Troshichev ◽  
A.V. Frank-Kamenetsky ◽  
...  
Keyword(s):  
Electric Field ◽  
Current Sheet ◽  
Vertical Electric Field

scholarly journals Particle acceleration in a reconnecting current sheet: PIC simulation

2009 ◽  
Vol 75 (5) ◽  
pp. 619-636 ◽  
Author(s):  
TARAS V. SIVERSKY ◽  
VALENTINA V. ZHARKOVA
Keyword(s):  
Electric Field ◽  
Energy Distribution ◽  
Current Sheet ◽  
Plasma Density ◽  
Three Dimensional ◽  
Polarization Field ◽  
Electron Mass ◽  
Langmuir Waves ◽  
Particle In Cell ◽  
Reconnecting Current Sheet

AbstractThe acceleration of protons and electrons in a reconnecting current sheet (RCS) is simulated with a particle-in-cell (PIC) 2D3V (two-dimensional in space and three-dimensional in velocity space) code for the proton-to-electron mass ratio of 100. The electromagnetic configuration forming the RCS incorporates all three components of the magnetic field (including the guiding field) and a drifted electric field. PIC simulations reveal that there is a polarization electric field that appears during acceleration owing to a separation of electrons from protons towards the midplane of the RCS. If the plasma density is low, the polarization field is weak and the particle trajectories in the PIC simulations are similar to those in the test particle (TP) approach. For the higher plasma density the polarization field is stronger and it affects the trajectories of protons by increasing their orbits during acceleration. This field also leads to a less asymmetrical abundance of ejected protons towards the midplane in comparison with the TP approach. For a given magnetic topology electrons in PIC simulations are ejected to the same semispace as protons, in contrast to the TP results. This happens because the polarization field extends far beyond the thickness of a current sheet. This field decelerates the electrons, which are initially ejected into the semispace opposite to the protons, returns them back to the RCS, and, eventually, leads to the electron ejection into the same semispace as protons. The energy distribution of the ejected electrons is rather wide and single-peaked, in contrast to the two-peak narrow-energy distribution obtained in the TP approach. In the case of a strong guiding field, the mean energy of the ejected electrons is found to be smaller than it is predicted analytically and by the TP simulations. The beam of accelerated electrons is also found to generate turbulent electric field in the form of Langmuir waves.

scholarly journals Effects on magnetic reconnection of a density asymmetry across the current sheet

2008 ◽  
Vol 26 (8) ◽  
pp. 2471-2483 ◽  
Author(s):  
K. G. Tanaka ◽  
A. Retinò ◽  
Y. Asano ◽  
M. Fujimoto ◽  
I. Shinohara ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Three Dimensional ◽  
Flow Region ◽  
Electron Acceleration ◽  
Particle In Cell ◽  
Line Structure ◽  
Simulation Results

Abstract. The magnetopause (MP) reconnection is characterized by a density asymmetry across the current sheet. The asymmetry is expected to produce characteristic features in the reconnection layer. Here we present a comparison between the Cluster MP crossing reported by Retinò et al. (2006) and virtual observations in two-dimensional particle-in-cell simulation results. The simulation, which includes the density asymmetry but has zero guide field in the initial condition, has reproduced well the observed features as follows: (1) The prominent density dip region is detected at the separatrix region (SR) on the magnetospheric (MSP) side of the MP. (2) The intense electric field normal to the MP is pointing to the center of the MP at the location where the density dip is detected. (3) The ion bulk outflow due to the magnetic reconnection is seen to be biased towards the MSP side. (4) The out-of-plane magnetic field (the Hall magnetic field) has bipolar rather than quadrupolar structure, the latter of which is seen for a density symmetric case. The simulation also showed rich electron dynamics (formation of field-aligned beams) in the proximity of the separatrices, which was not fully resolved in the observations. Stepping beyond the simulation-observation comparison, we have also analyzed the electron acceleration and the field line structure in the simulation results. It is found that the bipolar Hall magnetic field structure is produced by the substantial drift of the reconnected field lines at the MSP SR due to the enhanced normal electric field. The field-aligned electrons at the same MSP SR are identified as the gun smokes of the electron acceleration in the close proximity of the X-line. We have also analyzed the X-line structure obtained in the simulation to find that the density asymmetry leads to a steep density gradient in the in-flow region, which may lead to a non-stationary behavior of the X-line when three-dimensional freedom is taken into account.

scholarly journals Electron scale structures of thin current sheets in magnetic reconnection

2012 ◽  
Vol 30 (4) ◽  
pp. 661-666 ◽  
Author(s):  
N. Jain ◽  
A. S. Sharma ◽  
L. M. Zelenyi ◽  
H. V. Malova
Keyword(s):  
Electric Field ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Time Scales ◽  
Early Phase ◽  
Out Of Plane ◽  
Scale Structures ◽  
Magnetohydrodynamic Model ◽  
The Individual ◽  
Secondary Instabilities

Abstract. An electron-magnetohydrodynamic model is used to simulate the structure of an electron scale current sheet during early phase of collisionless magnetic reconnection. The current sheet develops structures, viz. bifurcated, filamented and triple-peak structures at different locations in the current sheet. The reversal of the net out-of-plane electric field seen by electrons bifurcates the current sheet in the outflow regions, the individual peaks having scale sizes of a few electron skin depths. Secondary instabilities of the bifurcated CS lead to its filamentation in the outflow and separatrix regions while triple-peak structures form at reconnection sites. These structures have implications for the forthcoming NASA/MMS mission designed to resolve electron space and time scales in the magnetosphere.

scholarly journals The evolution of electron current sheet and formation of secondary islands in guide field reconnection

2011 ◽  
Vol 18 (5) ◽  
pp. 727-733 ◽  
Author(s):  
C. Huang ◽  
Q. Lu ◽  
Z. Yang ◽  
M. Wu ◽  
Q. Dong ◽  
...  
Keyword(s):  
Electric Field ◽  
Current Sheet ◽  
Diffusion Region ◽  
Two Dimensional ◽  
Electron Current ◽  
Particle In Cell ◽  
Field Force ◽  
Guide Field ◽  
Tearing Instability ◽  
Electric Field Force

Abstract. Two-dimensional (2-D) particle-in-cell (PIC) simulations are performed to investigate the evolution of the electron current sheet (ECS) in guide field reconnection. The ECS is formed by electrons accelerated by the inductive electric field in the vicinity of the X line, which is then extended along the x direction due to the imbalance between the electric field force and Ampere force. The tearing instability is unstable when the ECS becomes sufficiently long and thin, and several seed islands are formed in the ECS. These tiny islands may coalesce and form a larger secondary island in the center of the diffusion region.

Nonideal Electric Field Observed in the Separatrix Region of a Magnetotail Reconnection Event

2020 ◽  
Author(s):  
Xiancai Yu ◽  
Rongsheng Wang ◽  
Quanming Lu
Keyword(s):  
Energy Dissipation ◽  
Electric Field ◽  
Current Sheet ◽  
Thermal Energy ◽  
Electrostatic Potential ◽  
Electron Distribution ◽  
Diffusion Region ◽  
Pressure Tensor ◽  
Magnetospheric Multiscale ◽  
Magnetotail Reconnection

<p>The microphysics in the separatrix region (SR) plays an important role for the energy conversion in reconnection. Based on the Magnetospheric Multiscale observations in the magnetotail, we present a complete crossing of the current sheet with ongoing magnetic reconnection. The field‐aligned inflowing electrons were observed in both separatrix regions (SRs) and their energy extended up to several times of the thermal energy. Along the SR, a net parallel electrostatic potential was estimated and could be the reason for the inflowing electron streaming. In the northern SR, the electron frozen‐in condition was violated and nonideal electric field was inferred to be caused by the gradient of the electron pressure tensor. The nongyrotropic electron distribution and significant energy dissipation were observed at the same region. The observations indicate that the inner electron diffusion region can extend along the separatrices or some electron‐scale instability can be destabilized in the SR. </p>

scholarly journals Electron Acceleration by Strong DC Electric Fields in Extragalactic Jets

2000 ◽  
Vol 195 ◽  
pp. 311-312
Author(s):  
Y. E. Litvinenko
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Electric Fields ◽  
Electron Acceleration ◽  
Acceleration Time ◽  
Extragalactic Jets ◽  
Dc Electric Field ◽  
The Magnetic Field

Fast magnetic reconnection in extragalactic jets leads to electron acceleration by the DC electric field in the reconnecting current sheet. The maximum electron energy (γ > 106) and the acceleration time (< 106 s) are determined by the magnetic field dynamics in the sheet.

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