Parallel 3-D particle-in-cell modelling of charged ultrarelativistic beam dynamics

2015 ◽  
Vol 81 (6) ◽  
Author(s):  
Marina A. Boronina ◽  
Vitaly A. Vshivkov
Keyword(s):  
Distribution Function ◽  
Electromagnetic Fields ◽  
High Efficiency ◽  
Three Dimensional ◽  
The Self ◽  
Beam Dynamics ◽  
Particle In Cell ◽  
Self Consistent ◽  
Longitudinal Effects ◽  
Parallel Code

We present a three-dimensional (3-D) particle-in-cell (PIC) model and parallel code for the self-consistent motion of charged ultrarelativistic beams (${\it\gamma}\sim 10^{3}{-}10^{5}$) in supercolliders. We use the 3-D set of Maxwell’s equations for the electromagnetic fields, and the Vlasov equation for the distribution function of the beam particles. The model incorporates automatically the longitudinal effects, which can play a significant role in the cases of super-high densities. We present numerical results for the dynamics of two focused ultrarelativistic beams with a size ratio 10:1:100. The results demonstrate high efficiency of the proposed computational methods and algorithms, which are applicable to a variety of problems in relativistic plasma physics.

Protection Against Electromagnetic Fields by Means of Fractal Screen-Restructor

10.12737/2744 ◽  
2013 ◽  
Vol 20 (4) ◽  
pp. 116-120
Author(s):  
Хачапуридзе ◽  
N. Khachapuridze ◽  
Филиппов ◽  
Yu. Filippov ◽  
Соколовская ◽  
...  
Keyword(s):  
Electromagnetic Fields ◽  
High Efficiency ◽  
Three Dimensional ◽  
Small Diameter ◽  
Medical Personnel ◽  
Negative Influence ◽  
Electrically Conductive ◽  
Electromagnetic Screen ◽  
Biological Protection ◽  
Made In

To protect medical personnel and other institutions where used low- intensity electromagnetic fields the fractal electromagnetic screen-restructor was developed. This device contains a substrate of bioinert material and installation tool, which is made in the form of electromagnetic circuit, which includes overlapping concentric circles of big and small diameters and flat element located in the centre of the circle formed by the circles of the big diameter. A circle of small diameter located on six radial lines, circles of the big diameter equidistantly in relation to each other and relative to the center of the circles of the big diameter, and the flat element is made in the form of a regular hexagon. The screen was tested and has shown high efficiency. The developed fractal screen is the medical technique and is used to protect personnel from the negative influence of various fields of electro - and radio-technical installations, from unauthorized exposure, as well as for biological protection and correction of the functional state of operators industrially loaded productions. There are many devices designed for protection of an organism from the negative electromagnetic radiation, to maintain and enhance its bioenergetic potential, containing a variety of three-dimensional constructs and two-dimensional plate-a matrix, equipped with various geometric structures of electrically conductive materials, or diminutive volume elements - cylindrical or cone-shaped and their combinations.

Thermodynamically self-consistent theories of simple liquids. II. A perturbation scheme for systems with purely repulsive forces

1980 ◽  
Vol 58 (5) ◽  
pp. 713-717 ◽  
Author(s):  
Donald S. Hall ◽  
W. R. Conkie
Keyword(s):  
Monte Carlo ◽  
Free Energy ◽  
Distribution Function ◽  
The Self ◽  
Perturbation Scheme ◽  
Simple Liquids ◽  
Lennard Jones ◽  
Self Consistent ◽  
Repulsive Forces ◽  
Simple Systems

A parametrized perturbation scheme is derived for simple systems with purely repulsive forces. The parameter is chosen so that the pressure in the system found by differentiating the free energy is consistent with that found by integrating over the radial distribution function. Results of calculations for the equation of state of an inverse-12 fluid are presented and found to be in excellent agreement with Monte Carlo simulations. The use of the results of the self-consistent scheme as a reference system for the Lennard-Jones fluid is discussed.

scholarly journals Three-dimensional modelling of accretion columns: spatial asymmetry and self-consistent simulations

2020 ◽  
Vol 501 (1) ◽  
pp. 564-575
Author(s):  
M I Gornostaev
Keyword(s):  
Radiation Flux ◽  
Three Dimensional ◽  
3D Models ◽  
3D Modelling ◽  
The Self ◽  
Physical Parameters ◽  
Hydrodynamic Simulations ◽  
X Ray ◽  
Self Consistent ◽  
Column Base

ABSTRACT The paper presents the results of three-dimensional (3D) modelling of the structure and the emission of accretion columns formed above the surface of accreting strongly magnetized neutron stars under the circumstances when a pressure of the photons generated in the column base is enough to determine the dynamics of the plasma flow. On the foundation of numerical radiation hydrodynamic simulations, several 3D models of accretion column are constructed. The first group of the models contains spatially 3D columns. The corresponding calculations lead to the distributions of the radiation flux over the sidewalls of the columns which are not characterized by axial symmetry. The second group includes the self-consistent modelling of spectral radiative transfer and two-dimensional spatial structure of the column, with both thermal and bulk Comptonization taken into account. The changes in the structure of the column and the shape of X-ray continuum are investigated depending on physical parameters of the model.

scholarly journals Particle-in-cell Simulation Concerning Heat-flux Mitigation Using Electromagnetic Fields

2016 ◽  
Vol 3 (3) ◽  
pp. 110-115
Author(s):  
K. F. Lüskow ◽  
S. Kemnitz ◽  
G. Bandelow ◽  
J. Duras ◽  
D. Kahnfeld ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Electromagnetic Fields ◽  
Plasma Simulation ◽  
Particle In Cell ◽  
Self Consistent ◽  
Basic Understanding ◽  
Cell Simulation ◽  
Neutral Plasma ◽  
Pic Method

The Particle-in-Cell (PIC) method was used to study heat flux mitigation experiments with argon. In the experiment it was shown that a magnetic field allows to reduce the heat flux towards a target. PIC is well-suited for plasma simulation, giving the chance to get a better basic understanding of the underlying physics. The simulation demonstrates the importance of a self-consistent neutral-plasma description to understand the effect of heat flux reduction.

scholarly journals Three-Dimensional MHD Modeling of Interplanetary Solar Wind Using Self-Consistent Boundary Condition Obtained from Multiple Observations and Machine Learning

Universe ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 371
Author(s):  
Yi Yang ◽  
Fang Shen
Keyword(s):  
Magnetic Field ◽  
Machine Learning ◽  
Boundary Condition ◽  
Solar Wind ◽  
Three Dimensional ◽  
The Self ◽  
Multiple Observations ◽  
Self Consistent ◽  
Mhd Modeling ◽  
The Magnetic Field

Three-dimensional (3-d) magnetohydrodynamics (MHD) modeling is a key method for studying the interplanetary solar wind. In this paper, we introduce a new 3-d MHD solar wind model driven by the self-consistent boundary condition obtained from multiple observations and the Artificial Neural Network (ANN) machine learning technique. At the inner boundary, the magnetic field is derived using the magnetogram and potential field source surface extrapolation; the electron density is derived from the polarized brightness (pB) observations, the velocity can be deduced by an ANN using both the magnetogram and pB observations, and the temperature is derived from the magnetic field and electron density by a self-consistent method. Then, the 3-d interplanetary solar wind from CR2057 to CR2062 is modeled by the new model with the self-consistent boundary conditions. The modeling results present various observational characteristics at different latitudes, and are in better agreement with both the OMNI and Ulysses observations compared to our previous MHD model based only on photospheric magnetic field observations.

scholarly journals Dissipation measures in weakly-collisional plasmas

2021 ◽  
Author(s):  
Paul Cassak ◽  
Oreste Pezzi ◽  
Haoming Liang ◽  
Jimmy Juno ◽  
Christain Vasconez ◽  
...  
Keyword(s):  
Distribution Function ◽  
Energy Transfer ◽  
Coherent Structures ◽  
Particle Distribution ◽  
Velocity Distribution Function ◽  
Local Correlation ◽  
Particle Collisions ◽  
Particle In Cell ◽  
Self Consistent ◽  
Compare And Contrast

<p>The physical foundations of the dissipation of energy and the associated heating in weakly collisional plasmas are poorly understood. Here, we compare and contrast several measures that have been used to characterize energy dissipation and kinetic-scale conversion in plasmas by means of a suite of kinetic numerical simulations describing both magnetic reconnection and decaying plasma turbulence. We adopt three different numerical codes that can also include inter-particle collisions: the fully-kinetic particle-in-cell vpic, the fully-kinetic continuum Gkeyll, and the Eulerian Hybrid Vlasov-Maxwell (HVM) code. We differentiate between i) four energy-based parameters, whose definition is related to energy transfer in a fluid description of a plasma, and ii) four distribution function-based parameters, requiring knowledge of the particle velocity distribution function. There is overall agreement between the dissipation measures obtained in the PIC and continuum reconnection simulations, with slight differences due to the presence/absence of secondary islands in the two simulations. There are also many qualitative similarities between the signatures in the reconnection simulations and the self-consistent current sheets that form in turbulence, although the latter exhibits significant variations compared to the reconnection results. All the parameters confirm that dissipation occurs close to regions of intense magnetic stresses, thus exhibiting local correlation. The distribution function-based measures show a broader width compared to energy-based proxies, suggesting that energy transfer is co-localized at coherent structures, but can affect the particle distribution function in wider regions. The effect of inter-particle collisions on these parameters is finally discussed.</p>

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