Publications de Emmanuel Lanti

Gyrokinetic transport driven by ubiquitous modes in LTX-like tokamak with ‘flat’ temperature

A global, gyro-kinetic nonlinear study of the ubiquitous mode (UM) for Lithium Tokamak eXperiment (LTX)-like profiles, under flat electron and ion temperature scenarios is conducted using a global gyrokinetic model. Exact MHD equilibria with circular shape ...

2025

Magnetic shaping effects on turbulence in ADITYA-U tokamak

Laurent Villard, Emmanuel Lanti

The work reported in this paper addresses two aspects. In the first part, numerical simulations are conducted to examine the impact of magnetic equilibrium shaping (elongation and triangularity), on both conventional Ion Temperature Gradient (ITG) modes an ...

IOP Publishing Ltd2024

Gyrokinetic simulation of short wavelength ion temperature gradient instabilities in the ADITYA-U tokamak

Laurent Villard, Emmanuel Lanti

In this work, linear and nonlinear collisionless electrostatic simulation studies of the standard and short wavelength ion temperature gradient mode (SWITG) for experimental profiles and parameters of ADITYA-U tokamak are performed using the linear global ...

IOP Publishing Ltd2023

Numerical tools for burning plasmas

Laurent Villard, Alberto Bottino, Jonathan Graves, Ben McMillan, Emmanuel Lanti, Emanuele Poli, Xiao Wang, Baruch Rofman

The software stack under development within a European coordinated effort on tools for burning plasma modelling is presented. The project is organised as a Task (TSVV Task 10) under the new E-TASC initiative (Litaudon et al 2022 Plasma Phys. Control. Fusio ...

IOP Publishing Ltd2023

Linear and nonlinear excitation of TAE modes by external electromagnetic perturbations using ORB5

Laurent Villard, Alberto Bottino, Emmanuel Lanti, Mohsen Sadr

The excitation of toroidicity-induced Alfven eigenmodes (TAEs) using prescribed external electromagnetic perturbations (hereafter 'antenna') acting on a confined toroidal plasma, as well as its nonlinear couplings to other modes in the system, is studied. ...

IOP Publishing Ltd2022

The GBS code for the self-consistent simulation of plasma turbulence and kinetic neutral dynamics in the tokamak boundary

Gilles Fourestey, Paolo Ricci, Emmanuel Lanti, Nicolas Richart, Louis Nicolas Stenger, André Calado Coroado, Maurizio Giacomin, Davide Galassi, Davide Mancini

A new version of GBS (Ricci et al. (2012) [27]; Halpern et al. J. Comput. Phys. 315 (2016) 388-408; Paruta et al. (2018) [11]) is described. GBS is a three-dimensional, fluxdriven, global, two-fluid turbulence code developed for the self-consistent simulat ...

2022

Gyrokinetic particle-in-cell simulations of electromagnetic turbulence in the presence of fast particles and global modes

Laurent Villard, Emmanuel Lanti

Global simulations of electromagnetic turbulence in circular-flux-surface tokamak and ASDEX-Upgrade geometry, tearing instabilities and their combination with the electromagnetic turbulence, nonlinear Alfvenic modes in the presence of fast particles and th ...

2022

Moment approach of the multi-species non-linear Coulomb collision operator adapted to particle-in-cell codes

Stephan Brunner, Laurent Villard, Emmanuel Lanti, Noé Thomas Elie Ohana, Moahan Murugappan, Claudio Gheller

In this article an approximated version of the multi-species, non-linear Coulomb collision operator is derived via the use of a truncated moment expansion of the distribution function to compute the Rosenbluth potentials. The evolution of the distribution ...

2021

Implementation of energy transfer technique in ORB5 to study collisionless wave-particle interactions in phase-space

Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana, Emanuele Poli

A new diagnostic has been developed to investigate the wave-particle interaction in the phase-space in gyrokinetic particle-in-cell codes. Keeping information about energy transfer terms in the velocity space, the technique has been implemented and tested ...

2021

Numerics and computation in gyrokinetic simulations of electromagnetic turbulence with global particle-in-cell codes

Laurent Villard, Alberto Bottino, Emmanuel Lanti

Electromagnetic turbulence is addressed in tokamak and stellarator plasmas with the global gyrokinetic particle-in-cell codes ORB5 (E Lanti et al, Comp. Phys. Comm., 251, 107072 (2020)) and EUTERPE (V Kornilov et al, Phys. Plasmas, 11, 3196 (2004)). The la ...

2021

An optimisation of allreduce communication in message-passing systems

Laurent Villard, Emmanuel Lanti, Noé Thomas Elie Ohana

Collective communication, namely the pattern allreduce in message-passing systems, is optimised based on measurements at the installation time of the library. The algorithms used are set up in an initialisation phase of the communication, as so-called pers ...

2021

Gyrokinetic simulations on many- and multi-core architectures with the global electromagnetic Particle-In-Cell Code ORB5

Stephan Brunner, Laurent Villard, Emmanuel Lanti, Noé Thomas Elie Ohana, Claudio Gheller

Gyrokinetic codes in plasma physics need outstanding computational resources to solve increasingly complex problems, requiring the effective exploitation of cutting-edge HPC architectures. This paper focuses on the enabling of ORB5, a state-of-the-art, fir ...

2021

Nonlinear dynamics of energetic-particle driven geodesic acoustic modes in ASDEX Upgrade

Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana, Emanuele Poli

Turbulence in tokamaks generates radially sheared zonal flows. Their oscillatory counterparts, geodesic acoustic modes (GAMs), appear due to the action of the magnetic field curvature. The GAMs can be driven unstable by an anisotropic energetic particle (E ...

AMER INST PHYSICS2020

Global turbulence features across marginality and non-local pedestal-core interactions

Stephan Brunner, Olivier Sauter, Laurent Villard, Alberto Bottino, Ben McMillan, Emmanuel Lanti, Noé Thomas Elie Ohana

Spatially non-local aspects of turbulent transport in tokamak plasmas are examined with global gyrokinetic simulations using the ORB5 code. Inspired by very accurate measurements in the TCV tokamak in L-mode, we initialise plasma profiles with constant log ...

2019

First principles gyrokinetic analysis of electromagnetic plasma instabilities

Stephan Brunner, Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana

A two-fold analysis of electromagnetic core tokamak instabilities in the framework of the gyrokinetic theory is presented. First principle theoretical foundations of the gyrokinetic theory are used to explain and justify the numerical results obtained with ...

2019

Orb5: A global electromagnetic gyrokinetic code using the PIC approach in toroidal geometry

Stephan Brunner, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan, Emmanuel Lanti, Julien Stanislas Pierre Dominski, Noé Thomas Elie Ohana, Aaron Lewis Scheinberg, Claudio Gheller

This paper presents the current state of the global gyrokinetic code Orb5 as an update of the previous reference (Jolliet et al., 2007). The Orb5 code solves the electromagnetic Vlasov–Maxwell system of equations using a PIC scheme and also includes collis ...

2019

Gyrokinetic full-f particle-in-cell simulations on open field lines with PICLS

Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana

While in recent years gyrokinetic simulations have become the workhorse for theoretical turbulence and transport studies in the plasma core, their application to the edge and scrape-off layer (SOL) region presents significant challenges. In particular, ste ...

2019

Pullback Scheme Implementation in ORB5

Stephan Brunner, Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana

The pullback scheme is implemented in the global gyrokinetic particle-in-cell code ORB5 (Jolliet et al., 2007[1]) to mitigate the cancellation problem in electromagnetic simulations. The equations and the discretisation used by the code are described. Nume ...

Elsevier2019

Global Flux-Driven Simulations of Ion Temperature-Gradient and Trapped-Electron Modes Driven Turbulence with an Improved Multithreaded Gyrokinetic PIC Code

Emmanuel Lanti

Performance of tokamak fusion plasmas is heavily linked to the radial heat and particle transport, which is known to be mainly produced by turbulence driven by micro-instabilities. Understanding such processes is thus of key importance for the design and o ...

EPFL2019

Mode excitation by an antenna in global gyrokinetic simulations

Stephan Brunner, Laurent Villard, Alberto Bottino, Ben McMillan, Emmanuel Lanti, Noé Thomas Elie Ohana

In order to get a better understanding of the linear and non-linear plasma interaction of microinstabilities and associated turbulence with different specific modes, an antenna is implemented in the global gyrokinetic code ORB5. It consists in applying an ...

2018