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The linear gyrokinetic stability properties of magnetically confined electron-positron plasmas are investigated in the parameter regime most likely to be relevant for the first laboratory experiments involving such plasmas, where the…

Plasma Physics · Physics 2016-06-16 Per Helander , J. W. Connor

Magnetohydrodynamic (MHD) turbulence is encountered in a wide variety of astrophysical plasmas, including accretion disks, the solar wind, and the interstellar and intracluster medium. On small scales, this turbulence is often expected to…

In this paper the global mode structures of linear ion-temperature-gradient (ITG) modes in tokamak plasmas are obtained by combining results from the local gyrokinetic code GS2 with analytical theory. Local gyrokinetic calculations, using…

Plasma Physics · Physics 2015-10-08 P. A. Abdoul , D. Dickinson , C. M. Roach , H. R. Wilson

Curvature-driven instabilities are ubiquitous in magnetised fusion plasmas. By analysing the conservation laws of the gyrokinetic system of equations, we demonstrate that the well-known spatial localisation of these instabilities to regions…

Plasma Physics · Physics 2025-10-23 P. G. Ivanov , P. Luhadiya , T. Adkins , A. A. Schekochihin

Recent gyrokinetic stability calculations have revealed that the spherical tokamak is susceptible to tearing parity instabilities with length scales of a few ion Larmor radii perpendicular to the magnetic field lines. Here we investigate…

Plasma Physics · Physics 2012-05-15 D J Applegate , C M Roach , J W Connor , S C Cowley , W Dorland , R J Hastie , N. Joiner

Predicting the dynamics of a thermonuclear plasma during a magnetic confinement experiment is fundamental in order to make nuclear fusion a reliable source of energy. The development of a set of equations describing the plasma evolution on…

Plasma Physics · Physics 2017-01-10 Matteo Valerio Falessi

Spherical tokamaks (STs) have been shown to possess properties desirable for a fusion power plant such as achieving high plasma ? and having increased vertical stability. To understand the confinement properties that might be expected in…

Plasma Physics · Physics 2021-12-22 B. S. Patel , D. Dickinson , C. M. Roach , H. R. Wilson

The kinetic effects of electrons are important to long wavelength magnetohydrodynamic(MHD)instabilities and short wavelength drift-Alfvenic instabilities responsible for turbulence transport in magnetized plasmas, since the non-adiabatic…

Plasma Physics · Physics 2017-02-07 J. Bao , D. Liu , Z. Lin

Gyrokinetic theory is arguably the most important tool for numerical studies of transport physics in magnetized plasmas. However, exact local energy-momentum conservation law for the electromagnetic gyrokinetic system has not been found…

Plasma Physics · Physics 2021-09-22 Peifeng Fan , Hong Qin , Jianyuan Xiao

Two-dimensional gyrokinetics is a simple paradigm for the study of kinetic magnetised plasma turbulence. In this paper, we present a comprehensive theoretical framework for this turbulence. We study both the inverse and direct cascades (the…

Plasma Physics · Physics 2015-05-13 G. G. Plunk , S. C. Cowley , A. A. Schekochihin , T. Tatsuno

The gyrokinetic paradigm in the long wavelength regime is reviewed from the perspective of variational averaging (VA). The VA-method represents a third pillar for averaging kinetic equations with highly-oscillatory characteristics, besides…

Mathematical Physics · Physics 2018-08-29 Stefan Possanner

Accurate modeling of core instabilities in tokamak plasmas is essential to understand the underlying physical mechanisms and their impact on plasma confinement. The ideal stability of the internal kink mode and the m = 1 collisionless…

This work reports on the development and numerical implementation of the linear electromagnetic gyrokinetic (GK) model in a tokamak flux-tube geometry using a moment approach based on the expansion of the perturbed distribution function on…

Plasma Physics · Physics 2022-10-13 B. J. Frei , A. C. D. Hoffmann , P. Ricci , S. Brunner , Z. Tecchiolli

The properties of the boundary plasma in a tokamak are now recognized to play a key role in determining the achievable fusion power and the lifetimes of plasma-facing components. Accurate quantitative modeling and improved qualitative…

Plasma Physics · Physics 2017-08-25 E. L. Shi

The induced electric field in a tokamak drives a parallel electron current flow. In an inhomogeneous, finite beta plasma, when this electron flow is comparable to the ion thermal speed, the Alfven mode wave solutions of the electromagnetic…

Plasma Physics · Physics 2014-03-05 István Pusztai , Peter J. Catto , Felix I. Parra , Michael Barnes

A new magnetohydrodynamics (MHD) code based on initial value approach, GMEC_I, has been developed for simulating various MHD physics in tokamak plasmas, as the MHD foundation of the gyrokinetic-MHD energetic particle simulation code (GMEC)…

Plasma Physics · Physics 2024-02-15 P. Y. Jiang , Z. Y. Liu , S. Y. Liu , J. Bao , G. Y. Fu

First-principles simulations of tokamak turbulence have proven to be of great value in recent decades. We develop a pseudo-spectral velocity formulation of the turbulence equations that smoothly interpolates between the highly efficient but…

Plasma Physics · Physics 2018-03-14 N. R. Mandell , W. Dorland , M. Landreman

The gyrokinetics formulation of plasmas in strong magnetic fields aims at the elimination of the angle associated with the Larmor rotation of charged particles around the magnetic field lines. In a perturbative treatment or as a…

Plasma Physics · Physics 2010-08-31 Philippe Ghendrih , Ricardo Lima , R. Vilela Mendes

With the increase in computational capabilities over the last years it becomes possible to simulate more and more complex and accurate physical models. Gyrokinetic theory has been introduced in the 1960s and 1970s in the need of describing…

Plasma Physics · Physics 2024-02-12 Mario Raeth , Klaus Hallatschek , Katharina Kormann

Small-scale turbulence originating from microinstabilities limits the energy confinement time in magnetic confinement fusion. Here we develop a semi-analytical dispersion relation based on lowest-order solutions to the gyrokinetic equations…