scholarly journals δf simulation studies of the ion–electron two-stream instability in heavy ion fusion beams

2003 ◽  
Vol 21 (1) ◽  
pp. 21-26 ◽  
Author(s):  
HONG QIN ◽  
RONALD C. DAVIDSON ◽  
EDWARD A. STARTSEV ◽  
W. WEI-LI LEE
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Simulation Method ◽  
Heavy Ion ◽  
Particle Simulation ◽  
Linear Growth Rate ◽  
Momentum Spread ◽  
Heavy Ion Fusion ◽  
Stream Instability

Ion–electron two-stream instabilities in high intensity heavy ion fusion beams, described self-consistently by the nonlinear Vlasov–Maxwell equations, are studied using a three-dimensional multispecies perturbative particle simulation method. Large-scale parallel particle simulations are carried out using the recently developed Beam Equilibrium, Stability, and Transport (BEST) code. For a parameter regime characteristic of heavy ion fusion drivers, simulation results show that the most unstable mode of the ion–electron two-stream instability has a dipole-mode structure, and the linear growth rate decreases with increasing axial momentum spread of the beam particles due to Landau damping by the axial momentum spread of the beam ions in the longitudinal direction.

Thermo-mechanical coupling particle simulation of three-dimensional large-scale non-isothermal problems

2017 ◽  
Vol 34 (5) ◽  
pp. 1551-1571 ◽  
Author(s):  
Ming Xia
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Particle Simulation ◽  
Similarity Criteria ◽  
Particle Model ◽  
Length Scale ◽  
Content Type ◽  
Mechanical Coupling ◽  
Particle Simulation Method

Purpose The main purpose of this paper is to present a comprehensive upscale theory of the thermo-mechanical coupling particle simulation for three-dimensional (3D) large-scale non-isothermal problems, so that a small 3D length-scale particle model can exactly reproduce the same mechanical and thermal results with that of a large 3D length-scale one. Design/methodology/approach The objective is achieved by following the scaling methodology proposed by Feng and Owen (2014). Findings After four basic physical quantities and their similarity-ratios are chosen, the derived quantities and its similarity-ratios can be derived from its dimensions. As the proposed comprehensive 3D upscale theory contains five similarity criteria, it reveals the intrinsic relationship between the particle-simulation solution obtained from a small 3D length-scale (e.g. a laboratory length-scale) model and that obtained from a large 3D length-scale (e.g. a geological length-scale) one. The scale invariance of the 3D interaction law in the thermo-mechanical coupled particle model is examined. The proposed 3D upscale theory is tested through two typical examples. Finally, a practical application example of 3D transient heat flow in a solid with constant heat flux is given to illustrate the performance of the proposed 3D upscale theory in the thermo-mechanical coupling particle simulation of 3D large-scale non-isothermal problems. Both the benchmark tests and application example are provided to demonstrate the correctness and usefulness of the proposed 3D upscale theory for simulating 3D non-isothermal problems using the particle simulation method. Originality/value The paper provides some important theoretical guidance to modeling 3D large-scale non-isothermal problems at both the engineering length-scale (i.e. the meter-scale) and the geological length-scale (i.e. the kilometer-scale) using the particle simulation method directly.

Three‐dimensional particle simulation of heavy‐ion fusion beams*

1992 ◽  
Vol 4 (7) ◽  
pp. 2203-2210 ◽  
Author(s):  
Alex Friedman ◽  
David P. Grote ◽  
Irving Haber
Keyword(s):  
Three Dimensional ◽  
Heavy Ion ◽  
Particle Simulation ◽  
Heavy Ion Fusion

scholarly journals Wavelength dependence of the linear growth rate of the <I>E<sub>s</sub></I> layer instability

2007 ◽  
Vol 25 (6) ◽  
pp. 1311-1322 ◽  
Author(s):  
R. B. Cosgrove
Keyword(s):  
Growth Rate ◽  
Electric Fields ◽  
Large Scale ◽  
Linear Growth ◽  
Three Dimensional ◽  
Generalized Derivation ◽  
Wavelength Dependence ◽  
Meridional Wind ◽  
Linear Growth Rate ◽  
Significant Wavelength

Abstract. It has recently been shown, by computation of the linear growth rate, that midlatitude sporadic-E (Es) layers are subject to a large scale electrodynamic instability. This instability is a logical candidate to explain certain frontal structuring events, and polarization electric fields, which have been observed in Es layers by ionosondes, by coherent scatter radars, and by rockets. However, the original growth rate derivation assumed an infinitely thin Es layer, and therefore did not address the short wavelength cutoff. Also, the same derivation ignored the effects of F region loading, which is a significant wavelength dependent effect. Herein is given a generalized derivation that remedies both these short comings, and thereby allows a computation of the wavelength dependence of the linear growth rate, as well as computations of various threshold conditions. The wavelength dependence of the linear growth rate is compared with observed periodicities, and the role of the zeroth order meridional wind is explored. A three-dimensional paper model is used to explain the instability geometry, which has been defined formally in previous works.

scholarly journals Study on Fluorine Pollution in a Slag Yard

2019 ◽  
Vol 9 (5) ◽  
pp. 847
Author(s):  
Lide Wei ◽  
Changfu Wei ◽  
Sugang Sui
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Solute Transport ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Laboratory Studies ◽  
Survey Results ◽  
Simulation Results

This paper suggests a large-scale three-dimensional numerical simulation method to investigate the fluorine pollution near a slag yard. The large-scale three-dimensional numerical simulation method included an experimental investigation, laboratory studies of solute transport during absorption of water by soil, and large-scale three-dimensional numerical simulations of solute transport. The experimental results showed that the concentrations of fluorine from smelting slag and construction waste soil were well over the discharge limit of 0.1 kg/m3 recommended by Chinese guidelines. The key parameters of the materials used for large-scale three-dimensional numerical simulations were determined based on an experimental investigation, laboratory studies, and soil saturation of survey results and back analyses. A large-scale three-dimensional numerical simulation of solute transport was performed, and its results were compared to the experiment results. The simulation results showed that the clay near the slag had a high saturation of approximately 0.9, consistent with the survey results. Comparison of the results showed that the results of the numerical simulation of solute transport and the test results were nearly identical, and that the numerical simulation results could be used as the basis for groundwater environmental evaluation.

scholarly journals ELBA (electron beams in accelerators) particle simulation code

1994 ◽  
Vol 12 (2) ◽  
pp. 273-282 ◽  
Author(s):  
Glenn Joyce ◽  
Jonathan Krall ◽  
Steven Slinker
Keyword(s):  
Large Scale ◽  
Electron Beams ◽  
Three Dimensional ◽  
Forward Direction ◽  
Laboratory Frame ◽  
Particle Simulation ◽  
Simulation Code ◽  
Particle In Cell ◽  
Charged Particle Beams ◽  
Cell Simulation

ELBA is a three-dimensional, particle-in-cell, simulation code that has been developed to study the propagation and transport of relativistic charged particle beams. The code is particularly suited to the simulation of relativistic electron beams propagating through collisionless or slightly collisional plasmas or through external electric or magnetic fields. Particle motion is followed via a coordinate “window” in the laboratory frame that moves at the speed of light. This scheme allows us to model only the immediate vicinity of the beam. Because no information can move in the forward direction in these coordinates, particle and field data can be handled in a simple way that allows for very large scale simulations. A mapping scheme has been implemented that, with corrections to Maxwell's equations, allows the inclusion of bends in the simulation system.

scholarly journals Electric Propulsion Plume Simulations Using Parallel Computer

2007 ◽  
Vol 15 (2) ◽  
pp. 83-94 ◽  
Author(s):  
Joseph Wang ◽  
Yong Cao ◽  
Raed Kafafy ◽  
Viktor Decyk
Keyword(s):  
Electric Propulsion ◽  
Large Scale ◽  
Three Dimensional ◽  
Particle Simulation ◽  
Parallel Computer ◽  
Solar Array ◽  
Electron Mass ◽  
Ion Thruster ◽  
Particle In Cell ◽  
Pic Code

A parallel, three-dimensional electrostatic PIC code is developed for large-scale electric propulsion simulations using parallel supercomputers. This code uses a newly developed immersed-finite-element particle-in-cell (IFE-PIC) algorithm designed to handle complex boundary conditions accurately while maintaining the computational speed of the standard PIC code. Domain decomposition is used in both field solve and particle push to divide the computation among processors. Two simulations studies are presented to demonstrate the capability of the code. The first is a full particle simulation of near-thruster plume using real ion to electron mass ratio. The second is a high-resolution simulation of multiple ion thruster plume interactions for a realistic spacecraft using a domain enclosing the entire solar array panel. Performance benchmarks show that the IFE-PIC achieves a high parallel efficiency of ≥ 90%

Analysis on Three-Dimensional Virtual Simulation for Rationality of Large-Scale Commercial and Residential Space

2014 ◽  
Vol 513-517 ◽  
pp. 2307-2310
Author(s):  
Jing Liu
Keyword(s):  
Virtual Reality ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Calculation Model ◽  
Virtual Simulation ◽  
Spatial Distance ◽  
Interior Space ◽  
Design Data ◽  
Residential Space

As an emerging industry, large-scale commercial and residential interior rational planning is related to the comfort of living. This paper proposes a virtual simulation method to design and plan large-scale commercial and residential interior space. The paper uses least squares image matching method in virtual reality to construct spatial distance calculation model, calculate the straight-line distance of key parts in large-scale commercial and residential space, and make up the shortcomings in traditional design. The design can be adjusted to the specific circumstances to reduce the cost of the actual design. Finally, simulation is conducted on basis of design data to prove the advantages of virtual reality.

scholarly journals Particle-in-cell simulations of the dynamic aperture of the HCX

2002 ◽  
Vol 20 (4) ◽  
pp. 577-579 ◽  
Author(s):  
C.M. CELATA ◽  
D.P. GROTE ◽  
I. HABER
Keyword(s):  
National Laboratory ◽  
Three Dimensional ◽  
Heavy Ion ◽  
High Current ◽  
Current Experiment ◽  
Particle Loss ◽  
Particle In Cell ◽  
Dynamic Aperture ◽  
Heavy Ion Fusion ◽  
Three Dimensional Simulations

The Heavy Ion Fusion Virtual National Laboratory High Current Experiment (HCX) is exploring transport issues such as dynamic aperture, effects of quadrupole rotation, and the effects on the beam of nonideal distribution function, mismatch, and electrons, using one driver-scale 0.2 μC/m, 2–10 μs coasting K+ beam. Two- and three-dimensional simulations are being done, using the particle-in-cell code WARP to study these phenomena. We present results which predict that the dynamic aperture in the electrostatic focusing transport section will be set by particle loss.

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