The relation between reconnected flux, the parallel electric field, and the reconnection rate in a three-dimensional kinetic simulation of magnetic reconnection

2013 ◽  
Vol 20 (12) ◽  
pp. 122105 ◽  
Author(s):  
D. E. Wendel ◽  
D. K. Olson ◽  
M. Hesse ◽  
N. Aunai ◽  
M. Kuznetsova ◽  
...  
Keyword(s):  
Electric Field ◽  
Magnetic Reconnection ◽  
Three Dimensional ◽  
Kinetic Simulation ◽  
Parallel Electric Field ◽  
Reconnection Rate

scholarly journals Global MHD Simulation of the Weak Southward IMF Condition for Different Time Resolutions

2021 ◽  
Vol 8 ◽  
Author(s):  
Kyung Sun Park
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Three Dimensional ◽  
Slow Solar Wind ◽  
Polar Cap ◽  
Plasma Properties ◽  
Simulation Results ◽  
Field Lines ◽  
The Impact

We performed high-resolution three-dimensional global MHD simulations to determine the impact of weak southward interplanetary magnetic field (IMF) (Bz = −2 nT) and slow solar wind to the Earth’s magnetosphere and ionosphere. We considered two cases of differing, uniform time resolution with the same grid spacing simulation to find any possible differences in the simulation results. The simulation results show that dayside magnetic reconnection and tail reconnection continuously occur even during the weak and steady southward IMF conditions. A plasmoid is generated on closed plasma sheet field lines. Vortices are formed in the inner side of the magnetopause due to the viscous-like interaction, which is strengthened by dayside magnetic reconnection. We estimated the dayside magnetic reconnection which occurred in relation to the electric field at the magnetopause and confirmed that the enhanced electric field is caused by the reconnection and the twisted structure of the electric field is due to the vortex. The simulation results of the magnetic field and the plasma properties show quasi-periodic variations with a period of 9–11 min between the appearances of vortices. Also the peak values of the cross-polar cap potential are both approximately 50 kV, the occurrence time of dayside reconnections are the same, and the polar cap potential patterns are the same in both cases. Thus, there are no significant differences in outcome between the two cases.

Fast Magnetic Reconnection by Turbulence with High Landquist Number

2020 ◽  
Author(s):  
Liping Yang ◽  
Hui Li ◽  
Fan Guo ◽  
Xiancan Li ◽  
Shengtai Li ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Energy Release ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Turbulent Plasma ◽  
Turbulence Level ◽  
Reconnection Rate ◽  
Numerical Studies ◽  
Large Opening ◽  
Magnetic Energy Release

<p>We report detailed numerical studies of magnetic reconnection in high-Lundquist-number, turbulent plasma by means of a three-dimensional (3D) resistive magnetohydrodynamics model. It is found that although turbulence is pre-existing, magnetic fields still restructure themselves to shape many X-points with evident mean inflow/outflow as well as the hierarchically generated magnetic flux ropes (plasmoids in 2D) with twist field lines. Moreover, the turbulence facilitates magnetic reconnections, and makes the normalized global reconnection rate reach ∼ 0.02 − 0.1, corresponding to turbulence level from very low to high and magnetic energy release from feeble to violent. The rate is nearly independent on the Lundquist number, and thus the fast turbulent reconnection occurs. A stochastic separation of the reconnected magnetic field lines with large opening angles follows a super-diffusion, indicating the broadening of outflow regions owing to the turbulence. These findings manifest that with the high Lundquist numbers (S ≥ 10^4), the 3D reconnection is turbulent and fast.</p>

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.

On ion temperature dependence of symmetric magnetic reconnection

2021 ◽  
Author(s):  
Ivan Zaitsev ◽  
Andrey Divin ◽  
Vladimir Semenov ◽  
Daniil Korovinskiy ◽  
Jan Deca ◽  
...  
Keyword(s):  
Electric Field ◽  
Temperature Dependence ◽  
Magnetic Reconnection ◽  
Observational Studies ◽  
Ion Temperature ◽  
Reconnection Rate ◽  
Outflow Velocity ◽  
Steady Stage ◽  
Plasma Compression ◽  
Thermal Speed

<p>Various simulations of collisionless magnetic reconnection reveal that the process is typically fast, with the reconnection rate being of the order of 0.1. Systematic numerical and observational studies of upstream parameters dependence (density, magnetic field) concord the basic Sweet-Parker-like predictions that the dynamical properties scale globally with the Alfven speed, with particle heating scaling as the Alfven speed squared. In this study, we perform a set of symmetric 2D PIC simulations starting from Harris current sheet but differ in upstream background plasma ion temperature. The exhaust velocity in such a setup is known to have explicit temperature dependence, leading to a reduction of the jet velocity at high temperatures. We suggest that the global reconnection rate is controlled by this outflow velocity since the reconnection electric field in the quasi-steady stage is the motional (convective) electric field of the ion bulk flow within the exhaust. Consequently, if the upstream thermal speed is above the Alfven velocity, then the reconnection rate drops. On top of that, the electron-ion temperature partition in the exhaust depends strongly on the upstream ion temperature, which we attribute to the scaling in plasma compression and development of the parallel electrostatic potential in the exhaust. </p>

The Effect of Roughness Features on Mos Surface Electric Field and Fowler-Nordheim Tunneling Behavior

1997 ◽  
Vol 473 ◽  
Author(s):  
Heng-Chih Lin ◽  
Edwin C. Kan ◽  
Toshiaki Yamanaka ◽  
Simon J. Fang ◽  
Kwame N. Eason ◽  
...  
Keyword(s):  
Electric Field ◽  
Three Dimensional ◽  
Tunneling Current ◽  
Gate Oxide ◽  
Oxide Thickness ◽  
Interface Roughness ◽  
Normal Electric Field ◽  
Surface Electric Field ◽  
Tunneling Behavior ◽  
Nordheim Tunneling

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.

Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate

2003 ◽  
Author(s):  
C.Z. Cheng ◽  
Y. Ren ◽  
G.S. Choe ◽  
Y.-J. Moon
Keyword(s):  
Magnetic Reconnection ◽  
Flux Rope ◽  
Reconnection Rate

scholarly journals Simulation of Thermal and Electric Field Distribution in Packaged Sausages Heated in a Stationary Versus a Rotating Microwave Oven

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1622
Author(s):  
Wipawee Tepnatim ◽  
Witchuda Daud ◽  
Pitiya Kamonpatana
Keyword(s):  
Temperature Distribution ◽  
Electric Field ◽  
Three Dimensional ◽  
Development Stage ◽  
Microwave Oven ◽  
Computational Time ◽  
Plastic Package ◽  
Heating Uniformity ◽  
The Cost ◽  
Good Agreement

The microwave oven has become a standard appliance to reheat or cook meals in households and convenience stores. However, the main problem of microwave heating is the non-uniform temperature distribution, which may affect food quality and health safety. A three-dimensional mathematical model was developed to simulate the temperature distribution of four ready-to-eat sausages in a plastic package in a stationary versus a rotating microwave oven, and the model was validated experimentally. COMSOL software was applied to predict sausage temperatures at different orientations for the stationary microwave model, whereas COMSOL and COMSOL in combination with MATLAB software were used for a rotating microwave model. A sausage orientation at 135° with the waveguide was similar to that using the rotating microwave model regarding uniform thermal and electric field distributions. Both rotating models provided good agreement between the predicted and actual values and had greater precision than the stationary model. In addition, the computational time using COMSOL in combination with MATLAB was reduced by 60% compared to COMSOL alone. Consequently, the models could assist food producers and associations in designing packaging materials to prevent leakage of the packaging compound, developing new products and applications to improve product heating uniformity, and reducing the cost and time of the research and development stage.

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