scholarly journals Energy Conversion and Electron Acceleration in the Magnetopause Reconnection Diffusion Region

2019 ◽  
Vol 46 (17-18) ◽  
pp. 10274-10282 ◽  
Author(s):  
K. R. Pritchard ◽  
J. L. Burch ◽  
S. A. Fuselier ◽  
J. M. Webster ◽  
R. B. Torbert ◽  
...  
2021 ◽  
Author(s):  
Takuma Nakamura ◽  
Hiroshi Hasegawa ◽  
Tai Phan ◽  
Kevin Genestreti ◽  
Richard Denton ◽  
...  

<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>


2012 ◽  
Vol 39 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. Y. Huang ◽  
A. Vaivads ◽  
Y. V. Khotyaintsev ◽  
M. Zhou ◽  
H. S. Fu ◽  
...  

2016 ◽  
Vol 43 (12) ◽  
pp. 5935-5942 ◽  
Author(s):  
Daniel J. Gershman ◽  
John C. Dorelli ◽  
Gina A. DiBraccio ◽  
Jim M. Raines ◽  
James A. Slavin ◽  
...  

2020 ◽  
Author(s):  
Hiroshi Hasegawa ◽  
Richard Denton ◽  
Kevin Genestreti ◽  
Takuma Nakamura ◽  
Tai Phan ◽  
...  

Abstract Establishing the mechanism of magnetic-to-particle energy conversion through magnetic reconnection in current sheets1 is the key to understanding the impact of fast release of magnetic energy in many space and astrophysical plasma systems, such as during magnetospheric substorms2,3. It is generally believed that an electron-scale diffusion region (EDR), where a magnetic-to-electron energy conversion occurs, has an X-type magnetic-field geometry4 around which the energy of anti-parallel magnetic fields injected is mostly converted to the bulk-flow energy of electrons by magnetic tension of reconnected field-lines5,6. However, it is at present unknown exactly how this energy conversion occurs in EDRs, because there has been no observational method to fully address this problem. Here we present state-of-the-art analysis of multi-spacecraft observations in Earth’s magnetotail of an electron-scale current sheet, which demonstrates that contrary to the standard model of reconnection with an X-type EDR geometry, the fast energy conversion in the detected EDR was caused mostly by magnetic-field annihilation, rather than reconnection. Furthermore, we detected a magnetic island forming in the EDR itself, implying that the EDR had an elongated shape ideal for island generation7 and magnetic-field annihilation. The experimental discovery of the annihilation-dominated EDR reveals a new form of energy conversion in the reconnection process that can occur when the EDR has evolved from the X-type to planar geometry.


2019 ◽  
Vol 99 (4) ◽  
Author(s):  
Giulia Cozzani ◽  
A. Retinò ◽  
F. Califano ◽  
A. Alexandrova ◽  
O. Le Contel ◽  
...  

2016 ◽  
Vol 43 (12) ◽  
pp. 6036-6043 ◽  
Author(s):  
Li-Jen Chen ◽  
Michael Hesse ◽  
Shan Wang ◽  
Daniel Gershman ◽  
Robert Ergun ◽  
...  

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