Reconnection site and ion scale turbulence generation

2020 ◽  
Author(s):  
Andris Vaivads ◽  
Chengming Liu ◽  
Yuri V. Khotyaintsev ◽  
Daniel B. Graham ◽  
Per-Arne Lindqvist ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Electric Fields ◽  
Magnetic Island ◽  
Magnetospheric Multiscale ◽  
Strong Electric Fields ◽  
Scale Structures ◽  
Reconnection Site ◽  
Scale Turbulence ◽  
Turbulence Generation ◽  
Kinetic Alfvén Waves

<p><span>We analyze in detail a reconnection site observed by the Magnetospheric Multiscale (MMS) mission in the magnetotail.</span><span> The interval around the X-line is identified based on the ion jet reversal, Hall electric fields and other reconnection signatures. At the reconnection site strong electric fields with amplitudes above 100mV/m are observed. In addition, the region shows strong turbulent variations on ion scales, including magnetic island-like structures. We discuss the cause of strong electric fields, their relation to ion scale structures and associated particle acceleration in this region. </span><span>Of particular interest is the relation of the reconnection site to the generation of kinetic Alfven waves.</span></p>

scholarly journals Effects of plasma turbulence on the nonlinear evolution of magnetic island in tokamak

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Minjun J. Choi ◽  
Lāszlo Bardōczi ◽  
Jae-Min Kwon ◽  
T. S. Hahm ◽  
Hyeon K. Park ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nonlinear Evolution ◽  
Plasma Turbulence ◽  
Magnetized Plasmas ◽  
Tokamak Plasmas ◽  
Magnetic Islands ◽  
Magnetic Island ◽  
Reconnection Site ◽  
Ambient Turbulence

AbstractMagnetic islands (MIs), resulting from a magnetic field reconnection, are ubiquitous structures in magnetized plasmas. In tokamak plasmas, recent researches suggested that the interaction between an MI and ambient turbulence can be important for the nonlinear MI evolution, but a lack of detailed experimental observations and analyses has prevented further understanding. Here, we provide comprehensive observations such as turbulence spreading into an MI and turbulence enhancement at the reconnection site, elucidating intricate effects of plasma turbulence on the nonlinear MI evolution.

Calculation of the probability of optical transitions in strong electric fields

2000 ◽  
Vol 91 (5) ◽  
pp. 945-951 ◽  
Author(s):  
S. V. Bulyarskii ◽  
N. S. Grushko ◽  
A. V. Zhukov
Keyword(s):  
Electric Fields ◽  
Optical Transitions ◽  
Strong Electric Fields

Electrohydrodynamic rotation of drops at large electric Reynolds numbers

2016 ◽  
Vol 788 ◽  
Author(s):  
Ehud Yariv ◽  
Itzchak Frankel
Keyword(s):  
Electric Fields ◽  
Numerical Solutions ◽  
Fluid Velocity ◽  
Reynolds Numbers ◽  
Mirror Image ◽  
Liquid Drops ◽  
Weakly Conducting ◽  
Strong Electric Fields ◽  
Quincke Rotation ◽  
Asymmetric Solution

When subject to sufficiently strong electric fields, particles and drops suspended in a weakly conducting liquid exhibit spontaneous rotary motion. This so-called Quincke rotation is a fascinating example of nonlinear symmetry-breaking phenomena. To illuminate the rotation of liquid drops we here analyse the asymptotic limit of large electric Reynolds numbers, $\mathit{Re}\gg 1$, within the framework of a two-dimensional Taylor–Melcher electrohydrodynamic model. A non-trivial dominant balance in this singular limit results in both the fluid velocity and surface-charge density scaling as $\mathit{Re}^{-1/2}$. The flow is governed by a self-contained nonlinear boundary-value problem that does not admit a continuous fore–aft symmetric solution, thus necessitating drop rotation. Furthermore, thermodynamic arguments reveal that a fore–aft asymmetric solution exists only when charge relaxation within the suspending liquid is faster than that in the drop. The flow problem possesses both mirror-image (with respect to the direction of the external field) and flow-reversal symmetries; it is transformed into a universal one, independent of the ratios of electric conductivities and dielectric permittivities in the respective drop phase and suspending liquid phase. The rescaled angular velocity is found to depend weakly upon the viscosity ratio. The corresponding numerical solutions of the exact equations indeed collapse at large $\mathit{Re}$ upon the asymptotically calculated universal solution.

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