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Fluid reductions of the Vlasov-Amp{\`e}re equations that preserve the Hamiltonian structure of the parent kinetic model are investigated. Hamiltonian closures using the first four moments of the Vlasov distribution are obtained, and all…

Chaotic Dynamics · Physics 2015-02-17 M Perin , C Chandre , P. J. Morrison , E Tassi

Moment closures of the Vlasov-Amp{\`e}re system, whereby higher moments are represented as functions of lower moments with the constraint that the resulting fluid system remains Hamiltonian, are investigated by using water-bag theory. The…

Plasma Physics · Physics 2015-09-30 M. Perin , Cristel Chandre , P. J. Morrison , E. Tassi

Energetic particles interact with the plasma surrounding them, resonating with certain plasma waves to stabilize them while destabilizing others, and changing the character of the background turbulence in ways that have not been fully…

High Energy Astrophysical Phenomena · Physics 2026-01-27 J. Pratt

We present a new method for formulating closures that learn from kinetic simulation data. We apply this method to phase mixing in a simple gyrokinetic turbulent system - temperature gradient driven turbulence in an unsheared slab. The…

Plasma Physics · Physics 2021-10-08 A. Shukla , D. R. Hatch , W. Dorland , C. Michoski

This review presents an upgraded wave theory adapted to the high fluctuation level of driven realistic i.e. non-idealized plasmas. Above all, this means giving up the well-known concept of a linear wave theory in favor of a thoroughly…

Plasma Physics · Physics 2022-05-18 Hans Schamel

We use a set of simple angular moments to solve the Boltzmann equation in the relaxation time approximation for a boost invariant longitudinally expanding gluonic plasma. The transition from the free streaming regime at early time to the…

Nuclear Theory · Physics 2020-01-08 Jean-Paul Blaizot , Li Yan

We investigate the dynamics of plasma-based acceleration processes with collisionless particle dynamics and non negligible thermal effects. We aim at assessing the applicability of fluid-like models, obtained by suitable closure assumptions…

We consider the Hamiltonian structure of reduced fluid models obtained from a kinetic description of collisionless plasmas by Vlasov-Maxwell equations. We investigate the possibility of finding Poisson subalgebras associated with fluid…

Plasma Physics · Physics 2012-10-31 Loïc De Guillebon , Cristel Chandre

We present a novel flow-based kinetic approach, inspired by continuous normalizing flows, for plasma simulation that unifies the complementary strengths of direct Vlasov solvers and particle-based methods. By tracking the distribution…

Plasma Physics · Physics 2025-01-29 Bowen Zhu , Jian Wu , Yuanbo Lu

The velocity-space moments of the often troublesome nonlinear Landau collision operator are expressed exactly in terms of multi-index Hermite-polynomial moments of the distribution functions. The collisional moments are shown to be…

Plasma Physics · Physics 2017-05-24 David Pfefferlé , Eero Hirvijoki , Manasvi Lingam

This paper presents a grid-free simulation algorithm for the fully three-dimensional Vlasov--Poisson system for collisionless electron plasmas. We employ a standard particle method for the numerical approximation of the distribution…

Numerical Analysis · Mathematics 2020-03-06 Torsten Keßler , Sergej Rjasanow , Steffen Weißer

We propose a well-posed Maxwell-type boundary condition for the linear moment system in half-space. As a reduction of the Boltzmann equation, the moment equations are available to model Knudsen layers near a solid wall, where proper…

Analysis of PDEs · Mathematics 2023-01-31 Ruo Li , Yichen Yang

Without access to the full quantum state, modeling dissipation in an open system requires approximations. The physical soundness of such approximations relies on using realistic microscopic models of dissipation that satisfy completely…

Quantum Physics · Physics 2017-09-06 E. Colomés , Z. Zhan , D. Marian , X. Oriols

In this paper, we propose a moment method to numerically solve the Vlasov equations using the framework of the NRxx method developed in [6, 8, 7] for the Boltzmann equation. Due to the same convection term of the Boltzmann equation and the…

Mathematical Physics · Physics 2012-09-05 Zhenning Cai , Ruo Li , Yanli Wang

A discontinuous Galerkin method for approximating the Vlasov-Poisson system of equations describing the time evolution of a collisionless plasma is proposed. The method is mass conservative and, in the case that piecewise constant functions…

Plasma Physics · Physics 2011-10-04 R. E. Heath , I. M. Gamba , P. J. Morrison , C. Michler

The kinetic study of plasma sheaths is critical, among other things, to understand the deposition of heat on walls, the effect of sputtering, and contamination of the plasma with detrimental impurities. The plasma sheath also provides a…

Plasma Physics · Physics 2017-02-22 Petr Cagas , Ammar Hakim , James Juno , Bhuvana Srinivasan

A fluid description for collisionless magnetized plasmas that takes into account the effect of cyclotron resonance has been developed. Following the same approach as the Landau fluid closure, the heat flux components associated with…

Plasma Physics · Physics 2021-04-13 Taiki Jikei , Takanobu Amano

KEEN waves are nonlinear, non-stationary, self-organized asymptotic states in Vlasov plasmas outside the scope or purview of linear theory constructs such as electron plasma waves or ion acoustic waves. Nonlinear stationary mode theories…

Controlling instability in plasma is one of the central challenges in fusion energy research. Among the various sources of instability, kinetic effects play a significant role. In this work, we aim to suppress the instability induced by…

Numerical Analysis · Mathematics 2025-08-27 Jingcheng Lu , Li Wang , Jeff Calder

A Landau fluid model for a collisionless electron-proton magnetized plasma, that accurately reproduces the dispersion relation and the Landau damping rate of all the magnetohydrodynamic waves, is presented. It is obtained by an accurate…

Plasma Physics · Physics 2010-04-02 P. Goswami , T. Passot , P. L. Sulem