Improved Unlike-Particle Collision Operator for delta-f Drift-Kinetic Particle Simulations

AbstractPlasmas in modern tokamak experiments contain a significant fraction of impurity ion species in addition to main deuterium background. A new unlike-particle collision operator for δf particle simulation has been developed to study the nonlocal effects of impurities due to finite ion orbits on neoclassical transport in toroidal plasmas. A new algorithm for simulation of cross-collisions between different ion species includes test-particle and conserving field-particle operators. An improved field-particle operator is designed to exactly enforce conservation of number, momentum and energy.

Download Full-text

Unlike-particle collision operator for gyrokinetic particle simulations

Journal of Computational Physics ◽

10.1016/j.jcp.2010.04.018 ◽

2010 ◽

Vol 229 (15) ◽

pp. 5564-5572 ◽

Cited By ~ 5

Author(s):

R.A. Kolesnikov ◽

W.X. Wang ◽

F.L. Hinton

Keyword(s):

Collision Operator ◽

Particle Collision ◽

Particle Simulations

Download Full-text

Benchmark of a new multi-ion-species collision operator for δf Monte Carlo neoclassical simulation

Computer Physics Communications ◽

10.1016/j.cpc.2020.107249 ◽

2020 ◽

Vol 255 ◽

pp. 107249 ◽

Cited By ~ 1

Author(s):

Shinsuke Satake ◽

Motoki Nataka ◽

Theerasarn Pianpanit ◽

Hideo Sugama ◽

Masanori Nunami ◽

...

Keyword(s):

Monte Carlo ◽

Collision Operator ◽

Ion Species

Download Full-text

Particle simulation of plasmons

Nanophotonics ◽

10.1515/nanoph-2020-0067 ◽

2020 ◽

Vol 9 (10) ◽

pp. 3303-3313 ◽

Cited By ~ 1

Author(s):

Wen Jun Ding ◽

Jeremy Zhen Jie Lim ◽

Hue Thi Bich Do ◽

Xiao Xiong ◽

Zackaria Mahfoud ◽

...

Keyword(s):

Simulation Method ◽

Electron Excitation ◽

Particle Simulation ◽

Quantum Limit ◽

Free Electrons ◽

Theoretical Approaches ◽

Electromagnetic Responses ◽

Electric And Magnetic Fields ◽

Particle Simulations ◽

Collective Oscillations

AbstractParticle simulation has been widely used in studying plasmas. The technique follows the motion of a large assembly of charged particles in their self-consistent electric and magnetic fields. Plasmons, collective oscillations of the free electrons in conducting media such as metals, are connected to plasmas by very similar physics, in particular, the notion of collective charge oscillations. In many cases of interest, plasmons are theoretically characterized by solving the classical Maxwell’s equations, where the electromagnetic responses can be described by bulk permittivity. That approach pays more attention to fields rather than motion of electrons. In this work, however, we apply the particle simulation method to model the kinetics of plasmons, by updating both particle position and momentum (Newton–Lorentz equation) and electromagnetic fields (Ampere and Faraday laws) that are connected by current. Particle simulation of plasmons can offer insights and information that supplement those gained by traditional experimental and theoretical approaches. Specifically, we present two case studies to show its capabilities of modeling single-electron excitation of plasmons, tracing instantaneous movements of electrons to elucidate the physical dynamics of plasmons, and revealing electron spill-out effects of ultrasmall nanoparticles approaching the quantum limit. These preliminary demonstrations open the door to realistic particle simulations of plasmons.

Download Full-text

Guiding center particle simulation of wide-orbit neoclassical transport

Physics of Plasmas ◽

10.1063/1.1416486 ◽

2001 ◽

Vol 8 (12) ◽

pp. 5192-5198 ◽

Cited By ~ 40

Author(s):

A. Bergmann ◽

A. G. Peeters ◽

S. D. Pinches

Keyword(s):

Particle Simulation ◽

Neoclassical Transport ◽

Center Particle

Download Full-text

Gyrokinetic particle simulation of neoclassical transport

Physics of Plasmas ◽

10.1063/1.871196 ◽

1995 ◽

Vol 2 (8) ◽

pp. 2975-2988 ◽

Cited By ~ 111

Author(s):

Z. Lin ◽

W. M. Tang ◽

W. W. Lee

Keyword(s):

Particle Simulation ◽

Neoclassical Transport

Download Full-text

Ion Dynamics in the Meso-scale 3-D Kelvin–Helmholtz Instability: Perspectives From Test Particle Simulations

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.758442 ◽

2021 ◽

Vol 8 ◽

Author(s):

Xuanye Ma ◽

Peter Delamere ◽

Katariina Nykyri ◽

Brandon Burkholder ◽

Stefan Eriksson ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Reconnection ◽

Test Particle ◽

Acoustic Waves ◽

Particle Simulation ◽

Three Dimensions ◽

Small Scale ◽

Physical Processes ◽

Length Scales ◽

Ion Species

Over three decades of in-situ observations illustrate that the Kelvin–Helmholtz (KH) instability driven by the sheared flow between the magnetosheath and magnetospheric plasma often occurs on the magnetopause of Earth and other planets under various interplanetary magnetic field (IMF) conditions. It has been well demonstrated that the KH instability plays an important role for energy, momentum, and mass transport during the solar-wind-magnetosphere coupling process. Particularly, the KH instability is an important mechanism to trigger secondary small scale (i.e., often kinetic-scale) physical processes, such as magnetic reconnection, kinetic Alfvén waves, ion-acoustic waves, and turbulence, providing the bridge for the coupling of cross scale physical processes. From the simulation perspective, to fully investigate the role of the KH instability on the cross-scale process requires a numerical modeling that can describe the physical scales from a few Earth radii to a few ion (even electron) inertial lengths in three dimensions, which is often computationally expensive. Thus, different simulation methods are required to explore physical processes on different length scales, and cross validate the physical processes which occur on the overlapping length scales. Test particle simulation provides such a bridge to connect the MHD scale to the kinetic scale. This study applies different test particle approaches and cross validates the different results against one another to investigate the behavior of different ion species (i.e., H+ and O+), which include particle distributions, mixing and heating. It shows that the ion transport rate is about 1025 particles/s, and mixing diffusion coefficient is about 1010 m2 s−1 regardless of the ion species. Magnetic field lines change their topology via the magnetic reconnection process driven by the three-dimensional KH instability, connecting two flux tubes with different temperature, which eventually causes anisotropic temperature in the newly reconnected flux.

Download Full-text