Particle‐in‐cell simulations of stochastic electron acceleration

1989 ◽  
Vol 1 (12) ◽  
pp. 2530-2532 ◽  
Author(s):  
K. Akimoto ◽  
H. Karimabadi
Keyword(s):  
Electron Acceleration ◽  
Particle In Cell

scholarly journals Electron acceleration in underdense plasmas described with a classical effective theory

2015 ◽  
Vol 33 (2) ◽  
pp. 307-313 ◽  
Author(s):  
M. A. Pocsai ◽  
S. Varró ◽  
I. F. Barna
Keyword(s):  
Experimental Data ◽  
Continuous Medium ◽  
Equations Of Motion ◽  
Electron Acceleration ◽  
Index Of Refraction ◽  
Effective Theory ◽  
Electron Motion ◽  
Particle In Cell ◽  
Underdense Plasmas ◽  
Relativistic Equations

AbstractAn effective theory of laser–plasma-based particle acceleration is presented. Here we treated the plasma as a continuous medium with an index of refraction nm in which a single electron propagates. Because of the simplicity of this model, we did not perform particle-in-cell (PIC) simulations in order to study the properties of the electron acceleration. We studied the properties of the electron motion due to the Lorentz force and the relativistic equations of motion were numerically solved and analyzed. We compared our results with PIC simulations and experimental data.

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 Stochastic Electron Acceleration by Temperature Anisotropy Instabilities under Solar Flare Plasma Conditions

2022 ◽  
Vol 924 (2) ◽  
pp. 52
Author(s):  
Mario Riquelme ◽  
Alvaro Osorio ◽  
Daniel Verscharen ◽  
Lorenzo Sironi
Keyword(s):  
Critical Role ◽  
Electron Acceleration ◽  
High Energy ◽  
Temperature Anisotropy ◽  
Particle In Cell ◽  
Long Term Effect ◽  
Spectral Break ◽  
Cell Plasma ◽  
Electron Magnetic Moment

Abstract Using 2D particle-in-cell plasma simulations, we study electron acceleration by temperature anisotropy instabilities, assuming conditions typical of above-the-loop-top sources in solar flares. We focus on the long-term effect of T e,⊥ > T e,∥ instabilities by driving the anisotropy growth during the entire simulation time through imposing a shearing or a compressing plasma velocity (T e,⊥ and T e,∥ are the temperatures perpendicular and parallel to the magnetic field). This magnetic growth makes T e,⊥/T e,∥ grow due to electron magnetic moment conservation, and amplifies the ratio ω ce/ω pe from ∼0.53 to ∼2 (ω ce and ω pe are the electron cyclotron and plasma frequencies, respectively). In the regime ω ce/ω pe ≲ 1.2–1.7, the instability is dominated by oblique, quasi-electrostatic modes, and the acceleration is inefficient. When ω ce/ω pe has grown to ω ce/ω pe ≳ 1.2–1.7, electrons are efficiently accelerated by the inelastic scattering provided by unstable parallel, electromagnetic z modes. After ω ce/ω pe reaches ∼2, the electron energy spectra show nonthermal tails that differ between the shearing and compressing cases. In the shearing case, the tail resembles a power law of index α s ∼ 2.9 plus a high-energy bump reaching ∼300 keV. In the compressing runs, α s ∼ 3.7 with a spectral break above ∼500 keV. This difference can be explained by the different temperature evolutions in these two types of simulations, suggesting that a critical role is played by the type of anisotropy driving, ω ce/ω pe, and the electron temperature in the efficiency of the acceleration.

scholarly journals Electron acceleration by high current-density relativistic electron bunch in plasmas

2007 ◽  
Vol 25 (2) ◽  
pp. 313-319 ◽  
Author(s):  
C.T. ZHOU ◽  
M.Y. YU ◽  
X.T. HE
Keyword(s):  
Relativistic Electron ◽  
Electron Bunch ◽  
High Current Density ◽  
Electron Acceleration ◽  
High Energy ◽  
Energy Gain ◽  
Small Scale ◽  
High Current ◽  
Particle In Cell ◽  
Very High Energy

Electron acceleration by a short high-current relativistic electron bunch (EB) in plasmas at three characteristic densities is studied by particle-in-cell simulation. It is found that if the EB is appropriately matched to the background plasma, the blowout space-charge field of the EB can accelerate the trailing bunch electrons at very high energy gain rate. This high energy gain, as well as the large-amplitude wakefield, the turbulent small-scale electron plasma waves, and the formation of large current peaks, are studied. The evolution of the EB, its blowout field, and other related parameters are shown to be self-similar.

scholarly journals Particle-in-cell simulations of electron acceleration from relativistic interaction of mid-infrared laser interactions with near solid density matter

2017 ◽  
Vol 24 (10) ◽  
pp. 103112 ◽  
Author(s):  
Gregory K. Ngirmang ◽  
Chris Orban ◽  
Scott Feister ◽  
John T. Morrison ◽  
Enam A. Chowdhury ◽  
...  
Keyword(s):  
Electron Acceleration ◽  
Infrared Laser ◽  
Mid Infrared ◽  
Particle In Cell ◽  
Solid Density ◽  
Relativistic Interaction ◽  
Density Matter ◽  
Laser Interactions
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