Publications related to Alfvén's theorem

How accurate are flux-tube (local) gyrokinetic codes in modeling energetic particle effects on core turbulence?

Olivier Sauter, Alberto Bottino, Emanuele Poli

Flux-tube (local) gyrokinetic codes are widely used to simulate drift-wave turbulence in magnetic confinement devices. While a large number of studies show that flux-tube codes provide an excellent approximation for turbulent transport in medium-large devi ...

IOP Publishing Ltd2023

Validation of GBS plasma turbulence simulation of the TJ-K stellarator

Paolo Ricci, Joaquim Loizu Cisquella

We present a validation of a three-dimensional, two-fluid simulation of plasma turbulence in the TJ-K stellarator, a low temperature plasma experiment ideally suited for turbulence measurements. The simulation is carried out by the GBS code, recently adapt ...

IOP Publishing Ltd2023

Numerical study of delta-function current sheets arising from resonant magnetic perturbations

Joaquim Loizu Cisquella, Yao Zhou

General three-dimensional toroidal ideal magnetohydrodynamic equilibria with a continuum of nested flux surfaces are susceptible to forming singular current sheets when resonant perturbations are applied. The presence of singular current sheets indicates t ...

2022

The Alfvenic nature of chromospheric swirls

Aleksi Antoine Bossart, Andrea Francesco Battaglia

Context. Observations show that small-scale vortical plasma motions are ubiquitous in the quiet solar atmosphere. They have received increasing attention in recent years because they are a viable candidate mechanism for the heating of the outer solar atmos ...

EDP SCIENCES S A2021

Neural network surrogate of QuaLiKiz using JET experimental data to populate training space

Henri Weisen, Yann Camenen

Within integrated tokamak plasma modeling, turbulent transport codes are typically the computational bottleneck limiting their routine use outside of post-discharge analysis. Neural network (NN) surrogates have been used to accelerate these calculations wh ...

AMER INST PHYSICS2021

Generation of chiral asymmetry via helical magnetic fields

Ruth Durrer, Jennifer Waltraud Schober

It is well known that helical magnetic fields undergo a so-called inverse cascade by which their correlation length grows due to the conservation of magnetic helicity in classical ideal magnetohydro-dynamics (MHD). At high energies above approximately 10 M ...

American Physical Society2020

Properties of a new quasi-axisymmetric configuration

Joaquim Loizu Cisquella

A novel, compact, quasi-axisymmetric configuration is presented which exhibits low fast-particle losses and is stable to ideal magnetohydrodynamic (MHD) instabilities. The design has fast-particle loss rates below 8% for flux surfaces within the half-radiu ...

IOP Publishing Ltd2019

Singular global components and frequency shift of the geodesic acoustic continuum modes in shaped tokamaks

Jonathan Graves

Within the ideal magnetohydrodynamic (MHD) model, the geodesic acoustic modes (GAMs) in tokamaks derived by Winsor et al (1968 Phys. Fluids 11 2448) belong to the continuous spectrum, characterised by unbounded non-square integrable eigenfunctions (delta f ...

2019

Tokamak Edge Plasma Turbulence Interaction with Magnetic X-Point in 3D Global Simulations

Davide Galassi, Eric Serre

Turbulence in the edge plasma of a tokamak is a key actor in the determination of the confinement properties. The divertor configuration seems to be beneficial for confinement, suggesting an effect on turbulence of the particular magnetic geometry introduc ...

2019

Magnetohydrodynamic theory of the global structure and magnetic components of geodesic acoustic modes in tokamaks

Jonathan Graves

Ideal magnetohydrodynamic (MHD) theory is used to investigate some of the fundamental properties of the geodesic acoustic continuum modes (GAMs) in tokamaks, including their global structure, their associated magnetic components both inside and outside the ...

IOP2016

Axisymmetric Tokamak Equilibria computed with a Predefined Safety Factor Profile as CHEASE input

Olivier Sauter, Antoine Pierre Emmanuel Alexis Merle

The CHEASE code, which has been developed at the Swiss Plasma Center, generates an accurate reconstruction of toroidal magnetohydrodynamics equilibria by numerically solving the Grad-Shafranov equation. Having demonstrated its ability to achieve good conve ...

2016

An advection-diffusion model for cross-field runaway electron transport in perturbed magnetic fields

Joan Decker

Disruption-generated runaway electrons (RE) present an outstanding issue for ITER. The predictive computational studies of RE generation rely on orbit-averaged computations and, as such, they lack the effects from the magnetic field stochasticity. Since st ...

Iop Publishing Ltd2016

Comparative studies of electrostatic turbulence induced transport in presence of resonant magnetic perturbations in RFX-mod

Nicola Vianello

Three-dimensional non-axisymmetric magnetic fields are purposely applied to toroidally symmetric fusion plasmas in order to modify transport of heat and particle fluxes to the plasma-facing components (PFCs), and specifically to control and suppress edge l ...

IOP Publishing Ltd2015

Recent ASDEX Upgrade research in support of ITER and DEMO

Olivier Sauter, Basil Duval, Stefano Coda, Timothy Goodman, Alessandro Pau, Federico Alberto Alfredo Felici, Laurie Porte, Haomin Sun, Yann Camenen, Marco Wischmeier, Nicola Vianello, Alberto Bottino, Emiliano Fable, Andrea Scarabosio, Doohyun Kim, Dávid Wágner, Thomas Binderup Jensen, Heinz Mueller, Donghyun Kim, Xiao Wang, Bernhard Sieglin, Otto Asunta, Hartmut Zohm, Emanuele Poli, Gergely Papp, Giovanni Tardini

Recent experiments on the ASDEX Upgrade tokamak aim at improving the physics base for ITER and DEMO to aid the machine design and prepare efficient operation. Type I edge localized mode (ELM) mitigation using resonant magnetic perturbations (RMPs) has been ...

Iop Publishing Ltd2015

The European Integrated Tokamak Modelling (ITM) effort: achievements and first physics results

Olivier Sauter, Antonio José Pereira de Figueiredo, Emanuele Poli

A selection of achievements and first physics results are presented of the European Integrated Tokamak Modelling Task Force (EFDA ITM-TF) simulation framework, which aims to provide a standardized platform and an integrated modelling suite of validated num ...

IOP Publishing Ltd2014

The new TORPEX in-vessel toroidal conductor for the generation of a poloidal magnetic field

Ambrogio Fasoli, Ivo Furno, Fabio Avino

TORoidal Plasma EXperiment (TORPEX) is a Simple Magnetized Torus featuring open helical magnetic field lines obtained from the superposition of a small vertical component on the main toroidal field. This work introduces the experimental setup developed to ...

Amer Inst Physics2014

New insights into the decay of ion waves to turbulence, ion heating, and soliton generation

Stephan Brunner

The decay of a single-frequency, propagating ion acoustic wave (IAW) via two-ion wave decay to a continuum of IAW modes is found to result in a highly turbulent plasma, ion soliton production, and rapid ion heating. Instability growth rates, thresholds, an ...

Amer Inst Physics2014

Turbulent regimes in the tokamak scrape-off layer

Paolo Ricci, Joaquim Loizu Cisquella, Sébastien Jolliet, Federico David Halpern, Annamaria Mosetto

The non-linear turbulent regimes in the tokamak scrape-off layer (SOL) are identified according to the linear instability responsible for the perpendicular transport. Four regions of the SOL operational parameters are determined where turbulence is driven ...

American Institute of Physics2013

Ideal ballooning modes in the tokamak scrape-off layer

Paolo Ricci, Joaquim Loizu Cisquella, Sébastien Jolliet, Federico David Halpern, Annamaria Mosetto

A drift-reduced Braginskii fluid model is used to carry out a linear and non-linear study of ideal ballooning modes in the tokamak scrape-off layer. First, it is shown that the scrape-off layer finite connection length and boundary conditions modify the id ...

American Institute of Physics2013

Measurements of interactions between waves and energetic ions in basic plasma experiments

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Yi Zhang, Kyle Gustafson, Alexandre Dominique Bovet

To measure the transport of fast ions by various types of waves, complementary experiments are conducted in linear and toroidal magnetic fields in the large plasma device and the toroidal plasma experiment. Lithium sources that are immersed in the plasma p ...

Iop Publishing Ltd2012