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Related papers: Non-Maxwellian fast particle effects in gyrokineti…

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The transport of heat out of tokamak plasmas by turbulence is the dominant mechanism limiting the performance of fusion reactors. Turbulence can be driven by the ion temperature gradient (ITG) and suppressed by toroidal sheared flows.…

Plasma Physics · Physics 2017-03-20 Ferdinand van Wyk

For plasma velocity space instabilities driven by particle distributions significantly deviated from a Maxwellian, weak collisions can damp the instabilities by an amount that is significantly beyond the collisional rate itself. This is…

Plasma Physics · Physics 2023-03-15 Yanzeng Zhang , Xian-Zhu Tang

High-energy astrophysical systems frequently contain collisionless relativistic plasmas that are heated by turbulent cascades and cooled by emission of radiation. Understanding the nature of this radiative turbulence is a frontier of…

High Energy Astrophysical Phenomena · Physics 2020-02-05 Vladimir Zhdankin , Dmitri A. Uzdensky , Gregory R. Werner , Mitchell C. Begelman

Simulations of plasma turbulence in a linear plasma device configuration are presented. These simulations are based on a simplified version of the gyrokinetic (GK) model proposed by B. J. Frei et al. [J. Plasma Phys. 86, 905860205 (2020)]…

Plasma Physics · Physics 2024-01-12 B. J. Frei , J. Mencke , P. Ricci

The past decade has seen a dramatic increase of practical applications of the microwave gyrosynchrotron emission for plasma diagnostics and three-dimensional modeling of solar flares and other astrophysical objects. This break-through…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Alexey A. Kuznetsov , Gregory D. Fleishman

The results of a comprehensive investigation into the effects of toroidicity-induced Alfv\'{e}n eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due…

The solar wind plasma is a fully ionized and turbulent gas ejected by the outer layers of the solar corona at very high speed, mainly composed by protons and electrons, with a small percentage of helium nuclei and a significantly lower…

The dynamics of low-x partons in the transverse plane of a high-energy nuclear collision is classical, and therefore admits a fully non--perturbative numerical treatment. We report results of a recent study estimating the initial energy…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alex Krasnitz , Raju Venugopalan

An argon-xenon (Ar/Xe) plasma is used as a model system for complex plasmas. Based on this system, symmetric low-pressure capacitively coupled radio-frequency discharges are examined utilizing Particle-In-Cell/Monte Carlo Collisions…

Plasma Physics · Physics 2021-08-11 M. Klich , S. Wilczek , J. F. J. Janssen , R. P. Brinkmann , T. Mussenbrock , J. Trieschmann

This paper describes a conceptual framework for understanding kinetic plasma turbulence as a generalized form of energy cascade in phase space. It is emphasized that conversion of turbulent energy into thermodynamic heat is only achievable…

In the present paper, the evolution of the Alfv\'en modes is studied in a realistic ASDEX Upgrade equilibrium by analysing the results of simulations with the global, electromagnetic, gyrokinetic particle-in-cell code ORB5. The energetic…

In this work, we study the impact of aspect ratio A = R0 /r (the ratio of major radius R0 to minor radius r) on the confinement benefits of Negative Triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE…

The ion drag force arising from plasma flow past an embedded spherical grain is calculated self-consistently and non-linearly using particle in cell codes, accounting for ion-neutral collisions. Using ion velocity distribution appropriate…

Plasma Physics · Physics 2013-10-18 I. H. Hutchinson , C. B. Haakonsen

A study of turbulent impurity transport by means of quasilinear and nonlinear gyrokinetic simulations is presented for Wendelstein 7-X (W7-X). The calculations have been carried out with the recently developed gyrokinetic code stella.…

We study the approximation and stability properties of a recently popularized discretization strategy for the speed variable in kinetic equations, based on pseudo spectral collocation on a grid defined by the zeros of a non-standard family…

Plasma Physics · Physics 2018-04-23 Tonatiuh Sanchez-Vizuet , Antoine J. Cerfon

Impacts of isotope ion mass on trapped electron mode (TEM) driven turbulence and zonal flows in magnetically confined fusion plasmas are investigated. Gyrokinetic simulations of TEM-driven turbulence in three-dimensional magnetic…

Plasma Physics · Physics 2026-02-27 Motoki Nakata , Masanori Nunami , Hideo Sugama , Tomo-Hiko Watanabe

We present iGENE, a fully-differentiable TensorFlow implementation of the electromagnetic local nonlinear gyrokinetic model, which allows us to compute gradients of any simulation output with respect to any input via automatic…

Plasma Physics · Physics 2026-05-06 Victor Artigues , Gabriele Merlo , Frank Jenko

A crucial issue in relativistic plasma, particularly relevant in the astrophysical context, is the description of highly magnetized plasmas based on a covariant formulation of gyrokinetic dynamics. An interesting case in question is that in…

Plasma Physics · Physics 2007-05-23 Massimo Tessarotto , Claudio Cremaschini , Piero Nicolini , Alexei Beklemishev

Nonlinear simulations of Alfv\'en modes (AM) driven by energetic particles (EP) in the presence of turbulence are performed with the gyrokinetic particle-in-cell code ORB5. The AMs carry a heat flux, and consequently they nonlinearly modify…

The phenomenon of redistribution of neutral beam fast-ions due to MHD activity in plasma has been observed on many tokamaks and more recently has been a focus of research on MAST (Turnyanskiy M. et al, 2011 Nucl. Fusion 53 053016). n=1…