Reconstruction of the electron diffusion region

2016 ◽  
Vol 121 (5) ◽  
pp. 4279-4290 ◽  
Author(s):  
B. U. Ö. Sonnerup ◽  
H. Hasegawa ◽  
R. E. Denton ◽  
T. K. M. Nakamura
Keyword(s):  
Diffusion Region ◽  
Electron Diffusion

scholarly journals Identification of the Electron-Diffusion Region during Magnetic Reconnection in a Laboratory Plasma

2008 ◽  
Vol 101 (8) ◽  
Author(s):  
Yang Ren ◽  
Masaaki Yamada ◽  
Hantao Ji ◽  
Stefan P. Gerhardt ◽  
Russell Kulsrud
Keyword(s):  
Magnetic Reconnection ◽  
Diffusion Region ◽  
Laboratory Plasma ◽  
Electron Diffusion

Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection

2021 ◽  
Author(s):  
Takuma Nakamura ◽  
Hiroshi Hasegawa ◽  
Tai Phan ◽  
Kevin Genestreti ◽  
Richard Denton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Efficient Energy ◽  
Micro Scale ◽  
Island Evolution ◽  
Macro Scale ◽  
Scale Evolution

<p>Magnetic reconnection is a key fundamental process in collisionless plasmas that explosively converts magnetic energy to plasma kinetic and thermal energies through a change of magnetic field topology in an electron-scale central region called the electron diffusion region. Past simulations and observations demonstrated that this process causes efficient energy conversion through the formation of multiple macro-scale or micro-scale magnetic islands/flux ropes. However, how these different spatiotemporal scale phenomena are coupled is still poorly understood. In this study, to investigate the turbulent evolution of magnetic reconnection, we perform a new large-scale fully kinetic simulation of a thin current sheet considering a power-law spectrum of initial fluctuations in the magnetic field as frequently observed in the Earth’s magnetotail. The simulation demonstrates that during a macro-scale evolution of turbulent reconnection, the merging of macro-scale islands results in reduction of the rate of reconnection as well as the aspect ratio of the electron diffusion region. This allows the repeated, quick formation of new electron-scale islands within the electron diffusion region, leading to an efficient energy cascade between macro- and micro-scales. The simulation also demonstrates that a strong electron acceleration/heating occurs during the micro-scale island evolution within the EDR. These new findings indicate the importance of non-steady features of the EDR to comprehensively understand the energy conversion and cascade processes in collisionless reconnection.</p>

Electron‐Scale Magnetic Structure Observed Adjacent to an Electron Diffusion Region at the Dayside Magnetopause

2019 ◽  
Vol 124 (12) ◽  
pp. 10153-10169
Author(s):  
S. Hoilijoki ◽  
R. E. Ergun ◽  
S. J. Schwartz ◽  
S. Eriksson ◽  
F. D. Wilder ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Dayside Magnetopause

scholarly journals Spatial dimensions of the electron diffusion region in anti-parallel magnetic reconnection

2016 ◽  
Vol 34 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Takuma Nakamura ◽  
Rumi Nakamura ◽  
Hiroshi Haseagwa
Keyword(s):  
Electric Field ◽  
Magnetic Reconnection ◽  
Real Space ◽  
Diffusion Region ◽  
Electron Mass ◽  
Plasma Parameters ◽  
Electron Diffusion ◽  
Background Density ◽  
Spatial Dimensions ◽  
Inner Region

Abstract. Spatial dimensions of the detailed structures of the electron diffusion region in anti-parallel magnetic reconnection were analyzed based on two-dimensional fully kinetic particle-in-cell simulations. The electron diffusion region in this study is defined as the region where the positive reconnection electric field is sustained by the electron inertial and non-gyrotropic pressure components. Past kinetic studies demonstrated that the dimensions of the whole electron diffusion region and the inner non-gyrotropic region are scaled by the electron inertial length de and the width of the electron meandering motion, respectively. In this study, we successfully obtained more precise scalings of the dimensions of these two regions than the previous studies by performing simulations with sufficiently small grid spacing (1∕16–1∕8 de) and a sufficient number of particles (800 particles cell−1 on average) under different conditions changing the ion-to-electron mass ratio, the background density and the electron βe (temperature). The obtained scalings are adequately supported by some theories considering spatial variations of field and plasma parameters within the diffusion region. In the reconnection inflow direction, the dimensions of both regions are proportional to de based on the background density. Both dimensions also depend on βe based on the background values, but the dependence in the inner region ( ∼ 0.375th power) is larger than the whole region (0.125th power) reflecting the orbits of meandering and accelerated electrons within the inner region. In the outflow direction, almost only the non-gyrotropic component sustains the positive reconnection electric field. The dimension of this single-scale diffusion region is proportional to the ion-electron hybrid inertial length (dide)1∕2 based on the background density and weakly depends on the background βe with the 0.25th power. These firm scalings allow us to predict observable dimensions in real space which are indeed in reasonable agreement with past in situ spacecraft observations in the Earth's magnetotail and have important implications for future observations with higher resolutions such as the NASA Magnetospheric Multiscale (MMS) mission.

scholarly journals Electron Bernstein waves driven by electron crescents near the electron diffusion region

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
W. Y. Li ◽  
D. B. Graham ◽  
Yu. V. Khotyaintsev ◽  
A. Vaivads ◽  
M. André ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Hall Current ◽  
Neutral Line ◽  
Electron Velocity ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Field Diffusion ◽  
Bernstein Waves ◽  
Electron Distributions ◽  
Current Reversal

AbstractThe Magnetospheric Multiscale (MMS) spacecraft encounter an electron diffusion region (EDR) of asymmetric magnetic reconnection at Earth’s magnetopause. The EDR is characterized by agyrotropic electron velocity distributions on both sides of the neutral line. Various types of plasma waves are produced by the magnetic reconnection in and near the EDR. Here we report large-amplitude electron Bernstein waves (EBWs) at the electron-scale boundary of the Hall current reversal. The finite gyroradius effect of the outflow electrons generates the crescent-shaped agyrotropic electron distributions, which drive the EBWs. The EBWs propagate toward the central EDR. The amplitude of the EBWs is sufficiently large to thermalize and diffuse electrons around the EDR. The EBWs contribute to the cross-field diffusion of the electron-scale boundary of the Hall current reversal near the EDR.

scholarly journals Evidence of Magnetic Nulls in Electron Diffusion Region

2019 ◽  
Vol 46 (1) ◽  
pp. 48-54 ◽  
Author(s):  
H. S. Fu ◽  
J. B. Cao ◽  
D. Cao ◽  
Z. Wang ◽  
A. Vaivads ◽  
...  
Keyword(s):  
Diffusion Region ◽  
Electron Diffusion

scholarly journals Electron diffusion region and thermal demagnetization

2008 ◽  
Vol 113 (A10) ◽  
Author(s):  
J. D. Scudder ◽  
R. D. Holdaway ◽  
R. Glassberg ◽  
S. L. Rodriguez
Keyword(s):  
Diffusion Region ◽  
Electron Diffusion ◽  
Thermal Demagnetization
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