Personne
Stephan Brunner
Publications associées (131)
Gyrokinetic turbulence modeling of a high performance scenario in JT-60SA
Stefano Coda, Stephan Brunner, Aylwin Iantchenko
Local gyrokinetic simulations are used to model turbulent transport for the first time in a representative high-performance plasma discharge projected for the new JT-60SA tokamak. The discharge features a double-null separatrix, 41 MW of combined neutral b ...
Bristol2024Validation of short-pulse reflectometry turbulence measurements with a synthetic diagnostic
Stefano Coda, Stephan Brunner, Oleg Krutkin, Umesh Kumar, Mackenzie Peter-Fulford Van Rossem, Samuele Mazzi
Experimental measurements of the turbulence amplitude utilizing a short pulse reflectometry method are presented. Two discharges with shaped plasma possessing opposite signs of triangularity are considered and a higher turbulence amplitude is found in the ...
Bristol2024Verification of the Fourier-enhanced 3D finite element Poisson solver of the gyrokinetic full-f code PICLS
Laurent Villard, Stephan Brunner, Alberto Bottino, Moahan Murugappan
We introduce and derive the Fourier -enhanced 3D electrostatic field solver of the gyrokinetic full -f PIC code PICLS. The solver makes use of a Fourier representation in one periodic direction of the domain to make the solving of the system easily paralle ...
Elsevier2024Ultra long turbulent eddies, magnetic topology, and the triggering of internal transport barriers in tokamaks
Stephan Brunner, Justin Richard Ball, Arnas Volcokas
Local nonlinear gyrokinetic simulations of tokamak plasmas demonstrate that turbulent eddies can extend along magnetic field lines for hundreds of poloidal turns when the magnetic shear is very small. By accurately modeling different field line topologies ...
IOP Publishing Ltd2023Linear scattering theory of short-pulse reflectometry
Stefano Coda, Stephan Brunner, Oleg Krutkin
The linear scattering theory of short pulse reflectometry is presented. An expression for the scattering signal is obtained by applying the perturbation theory approach for solving the Helmholtz equation. Based on these analytical results, a method for mea ...
2023A 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 ...
IOP Publishing Ltd2023Local gyrokinetic simulations of tokamaks with non-uniform magnetic shear
Stephan Brunner, Justin Richard Ball
In this work, we modify the standard flux tube simulation domain to include arbitrary ion gyroradius-scale variation in the radial profile of the safety factor. To determine how to appropriately include such a modification, we add a strong ion gyroradius-s ...
IOP Publishing Ltd2023Global '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 Ltd2023The competing effects of wave amplitude and collisions on multi-ion species suppression of stimulated Brillouin scattering in inertial confinement fusion Hohlraums
Reduction in stimulated Brillouin scattering (SBS) from National Ignition Facility Hohlraums has been predicted through the use of multi-ion species materials on Hohlraum walls. This approach to controlling SBS is based upon introducing a lighter ion speci ...
AIP Publishing2023Study of fast-ion-driven toroidal Alfvén eigenmodes impacting on the global confinement in TCV L-mode plasmas
Stefano Coda, Laurent Villard, Stephan Brunner, Justin Richard Ball, Oleg Krutkin, Luke Simons, Umesh Kumar, Baruch Rofman, Jesús Poley Sanjuán, Javier García Hernández, Matteo Vallar, Aylwin Iantchenko, Samuele Mazzi
Following recent observations of unstable Toroidal Alfven Eigenmodes (TAEs) in a counter-current Neutral Beam Injection (NBI) scenario developed in TCV, an in-depth analysis of the impact of such modes on the global confinement and performance is carried o ...
2023