119 citations · 476 across the 22 of their papers we have counts for
22 papers
A Weakly Nonlinear Theory of Zonal-Flow Forcing in Gyrokinetic Turbulence
Georgia Acton, Eduardo Rodrìguez, Gareth Roberg-Clark +1
The forced generation of zonal flows by microinstability-driven turbulence is investigated within the framework of local gyrokinetic theory far from marginality. We use a numerical…
The Kinetic Ion-Temperature-Gradient-driven instability and its localisation
Eduardo Rodriguez, Alessandro Zocco
We construct a description of Ion Temperature Gradient (ITG) driven localised linear modes which retains both wave-particle and magnetic drift resonant effects while capturing the…
Ion temperature and density gradient driven instabilities and turbulence in Wendelstein 7-X close to the stability threshold
L. Podavini, A. Zocco, J. M. García-Regaña +4
Electrostatic gyrokinetic instabilities and turbulence in the Wendelstein 7-X stellarator are studied. Particular attention is paid to the ion-temperature-gradient (ITG) instabilit…
Testing of the new JOREK stellarator-capable model in the tokamak limit
Nikita Nikulsin, Matthias Hoelzl, Alessandro Zocco +2
In preparation for extending the JOREK nonlinear MHD code to stellarators, a hierarchy of stellarator-capable reduced and full MHD models has been derived and tested. The derivatio…
Gyrokinetic investigation of Alfvén instabilities in the presence of turbulence
A. Biancalani, A. Bottino, A. Di Siena +10
The nonlinear dynamics of beta-induced Alfvén Eigenmodes (BAE) driven by energetic particles (EP) in the presence of ion-temperature-gradient (ITG) turbulence is investigated, by m…
Turbulent impurity transport simulations in Wendelstein 7-X plasmas
J. M. García-Regaña, M. Barnes, I. Calvo +8
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 ou…
A three-dimensional reduced MHD model consistent with full MHD
Nikita Nikulsin, Matthias Hoelzl, Alessandro Zocco +2
Within the context of a viscoresistive magnetohydrodynamic (MHD) model with anisotropic heat transport and cross-field mass diffusion, we introduce novel three-term representations…
Quasilinear particle transport from gyrokinetic instabilities in general magnetic geometry
Per Helander, Alessandro Zocco
The quasilinear particle flux arising from gyrokinetic instabilities is calculated in the electrostatic and collisionless approximation, keeping the geometry of the magnetic field…
Gyrokinetic Stability of Electron-Positron-Ion Plasmas
Alexey Mishchenko, Alessandro Zocco, Per Helander +1
The gyrokinetic stability of electron-positron plasmas contaminated by ion (proton) admixture is studied in slab geometry. The appropriate dispersion relation is derived and solved…
Viriato: a Fourier-Hermite spectral code for strongly magnetised fluid-kinetic plasma dynamics
N. F. Loureiro, W. Dorland, L. Fazendeiro +4
We report on the algorithms and numerical methods used in Viriato, a novel fluid-kinetic code that solves two distinct sets of equations: (i) the Kinetic Reduced Electron Heating M…
Magnetic compressibility and ion-temperature-gradient-driven microinstabilities in magnetically confined plasmas
A. Zocco, P. Helander, J. W. Connor
The electromagnetic theory of the strongly driven ion-temperature-gradient (ITG) instability in magnetically confined toroidal plasmas is developed. Stabilizing and destabilizing e…
Linear Collisionless Landau Damping in Hilbert Space
Alessandro Zocco
The equivalence between the Laplace transform [Landau L., J. Phys. USSR, 10 (1946), 25] and Hermite transform [Zocco and Schekochihin, Phys. Plasmas, 18, 102309 (2011)] solutions o…
Kinetic microtearing modes and reconnecting modes in strongly magnetised slab plasmas
A Zocco, N F Loureiro, D Dickinson +2
The problem of the linear microtearing mode in a slab magnetised plasma, and its connection to kinetic reconnecting modes, is addressed. Electrons are described using a novel hybri…
The Stochastic Field Transport associated with the Slab ITG Modes
J W Connor, R J Hastie, A Zocco
Many models for anomalous transport consider the turbulent ExB transport arising from electrostatic micro-instabilities. In this paper we investigate whether the perturbed magnetic…
Fast collisionless reconnection and electron heating in strongly magnetized plasmas
N. F. Loureiro, A. A. Schekochihin, A. Zocco
Magnetic reconnection in strongly magnetized (low-beta), weakly collisional plasmas is investigated using a novel fluid-kinetic model [Zocco & Schekochihin, Phys. Plasmas 18, 10230…
Global gyrokinetic particle-in-cell simulations of internal kink instabilities
Alexey Mishchenko, Alessandro Zocco
Internal kink instabilities have been studied in straight tokamak geometry employing an electromagnetic gyrokinetic particle-in-cell (PIC) code. The ideal-MHD internal kink mode an…
Improved Criterion for Sawtooth Trigger and Modelling
A. Zocco, J. W. Connor, C. G. Gimblett +1
We discuss the role of neoclassical resistivity and local magnetic shear in the triggering of the sawtooth in tokamaks. When collisional detrapping of electrons is considered the v…
Ion Landau Damping on Drift Tearing Modes
J. W. Connor, R. J. Hastie, A. Zocco
Kinetic treatments of drift-tearing modes that match an inner resonant layer solution to an external MHD region solution, characterised by , fail to properly match the…
Unified theory of the semi-collisional tearing mode and internal kink mode in a hot tokamak: implications for sawtooth modelling
J. W. Connor, R. J. Hastie, A. Zocco
In large hot tokamaks like JET, the width of the reconnecting layer for resistive modes is determined by semi-collisional electron dynamics and is much less than the ion Larmor rad…
Reduced fluid-kinetic equations for low-frequency dynamics, magnetic reconnection and electron heating in low-beta plasmas
Alessandro Zocco, Alexander Schekochihin
A minimal model for magnetic reconnection and, generally, low-frequency dynamics in low-beta plasmas is proposed. The model combines analytical and computational simplicity with ph…
Analytical Model of Fast Magnetic Reconnection with a Large Guide Field
Andrei N. Simakov, L. Chacón, A. Zocco
Analytical theory of fast magnetic reconnection with a large guide field is presented for the first time. We confirm that two distinct reconnection regimes are possible depending o…
Current sheet bifurcation and collapse in electron magnetohydrodynamics
A. Zocco, L. Chacon, Andrei N. Simakov
Inertial effects in nonlinear magnetic reconnection are studied within the context of 2D electron magnetohydrodynamics (EMHD) with resistive and viscous dissipation. Families of no…