Publications de Gabriele Merlo

First-principle based predictions of the effects of negative triangularity on DTT scenarios

Olivier Sauter, Gabriele Merlo, Alberto Mariani

Plasmas with negative triangularity (NT) shape have been recently shown to be able to achieve H-mode levels of confinement in L-mode, avoiding detrimental edge localised modes. Therefore, this plasma geometry is now studied as a possible viable option for ...

IOP Publishing Ltd2024

Global 'zero particle flux-driven' gyrokinetic analysis of the density profile for a TCV plasma

Olivier Sauter, Stephan Brunner, Gabriele Merlo, Alberto Mariani

The tokamak `a configuration variable (TCV) is a small-sized tokamak, where finite size effects (often called 'rho-star' or 'global' effects) could significantly impact the heat and particle fluxes, leading to discrepancies between gyrokinetic flux-tube re ...

IOP Publishing Ltd2023

A synthetic phase-contrast imaging diagnostic with spatial filtering for gyrokinetic simulations

Stefano Coda, Stephan Brunner, Justin Richard Ball, Gabriele Merlo, Aylwin Iantchenko

A Phase-contrast imaging (PCI) diagnostic provides measurements of line-integrated electron density fluctuations. Localisation along the laser beam path can be achieved with a spatial filter that selects the wave-vector directions of the fluctuations contr ...

2023

Nonlocal effects in negative triangularity TCV plasmas

Olivier Sauter, Stefano Coda, Laurent Villard, Stephan Brunner, Zhouji Huang, Gabriele Merlo, Claudio Marini

Global gradient driven gyrokinetic simulations performed with the Gyrokinetic Electromagnetic Numerical Experiment (GENE) code are used to investigate Tokamak a configuration variable (TCV) plasmas with negative triangularity. Considering limited L-mode pl ...

2021

How eigenmode self-interaction affects zonal flows and convergence of tokamak core turbulence with toroidal system size

Stephan Brunner, Justin Richard Ball, Gabriele Merlo, Ajay Chandrarajan Jayalekshmi, Julien Stanislas Pierre Dominski

Self-interaction is the process by which a microinstability eigenmode that is extended along the direction parallel to the magnetic field interacts non-linearly with itself. This effect is particularly significant in gyrokinetic simulations accounting for ...

Cambridge University Press2020

Direct gyrokinetic comparison of pedestal transport in JET with carbon and ITER-like walls

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Alessandro Pau, Henri Weisen

This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). Th ...

IOP Publishing Ltd2019

DIII-D research towards establishing the scientific basis for future fusion reactors

Olivier Sauter, Wilfred Anthony Cooper, Lorenzo Anton-Louis Talà, Terunobu Akiyama, Mario Ludovico Podesta, Dongbin Zhao, Zhixian Yan, Jeffrey Huang, Xin Yang, Richard Pitts

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary ...

IOP Publishing Ltd2019

Turbulent transport in TCV plasmas with positive and negative triangularity

Stefano Coda, Laurie Porte, Gabriele Merlo, Matteo Fontana

Local gyrokinetic simulations with the GENE code are used to investigate the turbulent transport for different levels of neutral beam injection heating power in the Tokamak a Configuration Variable (TCV) for plasmas with both positive and negative edge tri ...

2019

Gyrokinetic analysis of radial dependence and global effects on the zero particle flux condition in a TCV plasma

Olivier Sauter, Stephan Brunner, Gabriele Merlo, Alberto Mariani

In small-sized tokamaks, finite Larmor radius effects could lead to a significant discrepancy between gyrokinetic local flux-tube results and global ones. This has been highlighted by previous turbulent transport studies as in McMillan et al (2010 Phys. Re ...

IOP2019

Effects of collisionality and T e /T i on fluctuations in positive and negative δ tokamak plasmas

Olivier Sauter, Ambrogio Fasoli, Stefano Coda, Stephan Brunner, Laurie Porte, Gabriele Merlo, Matteo Fontana, Ajay Chandrarajan Jayalekshmi

The effects of negative triangularity () on confinement and fluctuations in plasmas covering a large range of parameters were investigated on the tokamak à configuration variable (TCV). The conditions explored in this paper include discharges where neutral ...

IOP Publishing Ltd2019