Publications associées à EDGE2D code simulations of SOL flows and in-out divertor asymmetries in JET

Noise-induced transitions past the onset of a steady symmetry-breaking bifurcation: The case of the sudden expansion

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière

We consider fluid flows, governed by the Navier-Stokes equations, subject to a steady symmetry-breaking bifurcation and forced by a weak noise acting on a slow timescale. By generalizing the multiple-scale weakly nonlinear expansion technique employed in t ...

2024

Iterative removal of sources to model the turbulent electromotive force

Jennifer Waltraud Schober, Abhijit Bhausaheb Bendre

We describe a novel method to compute the components of dynamo tensors from direct magnetohydrodynamic (MHD) simulations. Our method relies upon an extension and generalization of the standard H & ouml;gbom CLEAN algorithm widely used in radio astronomy to ...

Oxford Univ Press2024

The effect of pressure-anisotropy-driven kinetic instabilities on magnetic field amplification in galaxy clusters

Yoan Rappaz, Jennifer Waltraud Schober

Context. The intracluster medium (ICM) is the low-density diffuse gas that fills the space between galaxies within galaxy clusters. It is primarily composed of magnetized plasma, which reaches virial temperatures of up to 10(8) K, probably due to mergers o ...

Edp Sciences S A2024

Shedding light on the MRI-driven dynamo in a stratified shearing box

Abhijit Bhausaheb Bendre

We study the magneto-rotational instability (MRI) dynamo in a geometrically thin disc (H/R < 1) using stratified zero net (vertical) flux shearing box simulations. We find that mean fields and electromotive forces (EMFs) oscillate with a primary frequency ...

2024

Divertor turbulence characterisation using Gas Puff Imaging in the TCV tokamak

Curdin Tobias Wüthrich

The performance of magnetic confinement fusion devices, such as tokamaks, is strongly correlated to the phenomena that occur in the boundary region of the plasma core that faces the wall of the device. The dominant cross-field transport mechanisms from the ...

EPFL2024

Chiral magnetohydrodynamics with zero total chirality

Kohei Kamada, Jennifer Waltraud Schober

We study the evolution of magnetic fields coupled with chiral fermion asymmetry in the framework of chiral magnetohydrodynamics with zero initial total chirality. The initial magnetic field has a turbulent spectrum peaking at a certain characteristic scale ...

American Physical Society2023

Production of a Chiral Magnetic Anomaly with Emerging Turbulence and Mean-Field Dynamo Action

Jennifer Waltraud Schober

In relativistic magnetized plasmas, asymmetry in the number densities of left-and right-handed fermions, i.e., a nonzero chiral chemical potential mu(5), leads to an electric current along the magnetic field. This causes a chiral dynamo instability for a u ...

AMER PHYSICAL SOC2022

Effects of velocity-dependent apparent toughness on the pre- and post-shut-in growth of a hydraulic fracture

Dong Liu, Guanyi Lu

We investigate the growth of a plane-strain/radial hydraulic fracture in an infinite impermeable medium driven by a constant injection rate assuming that the apparent toughness scales with the decreasing fracture growth rate in a power-law relation. The vi ...

ELSEVIER SCI LTD2022

Reentrant magic-angle phenomena in twisted bilayer graphene in integer magnetic fluxes

Oleg Yazyev, Yifei Guan

In this Letter we address the reentrance of magic-angle phenomena (band flatness and quantum-geometric transport) in twisted bilayer graphene (TBG) subjected to strong magnetic fluxes +/-(1)0, +/- 200, +/- 3(p0 ... ((D0 = h/e is the flux quantum per moire ...

AMER PHYSICAL SOC2022

Global fluid simulation of plasma turbulence in a stellarator with an island divertor

Joaquim Loizu Cisquella, Paolo Ricci, Maurizio Giacomin, António João Caeiro Heitor Coelho

Results of a three-dimensional, flux-driven, electrostatic, global, two-fluid turbulence simulation for a five-field period stellarator with an island divertor are presented. The numerical simulation is carried out with the GBS code, recently extended to s ...

IOP Publishing Ltd2022

Parallel convection and E × B drifts in the TCV snowflake divertor and their effects on target heat-fluxes

Basil Duval, Holger Reimerdes, Joaquim Loizu Cisquella, Cedric Kar-Wai Tsui, Roberto Maurizio, Mirko Wensing, Davide Galassi

Parallel convection and E × B drifts act together to redistribute heat between the strike-points mechanisms is enhanced near the secondary X-point and is shown to dominate over heat in the low field side snowflake minus (LFS SF−). The cumulative heat conve ...

IOP Publishing Ltd2021

CO2-Driven diffusiophoresis and water cleaning: similarity solutions for predicting the exclusion zone in a channel flow

Mrudhula Baskaran

We investigate experimentally and theoretically diffusiophoretic separation of negatively charged particles in a rectangular channel flow, driven by CO2 dissolution from one side-wall. Since the negatively charged particles create an exclusion zone near th ...

ROYAL SOC CHEMISTRY2021

Forces on buildings with openings and orientation in a steady post-tsunami free-surface flow

Anton Schleiss, Michael Pfister, Davide Wüthrich

Steady free-surface flows around buildings occurring during flood or tsunami events can produce major damages and a quantification of the post-peak forces is essential for safety and resilience of coastal structures. The loading process is highly affected ...

2020

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

Deformation of porous flexible strip in low and moderate Reynolds number flows

François Gallaire, Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla

We present results from a combined experimental and numerical investigation of the fluid-structure interaction of cantilevered porous flexible strips, towed through a fluid bath. We characterize the steady-state deformation of the strips and their associat ...

AMER PHYSICAL SOC2020

Chiral fermion asymmetry in high-energy plasma simulations

Jennifer Waltraud Schober

The chiral magnetic effect (CME) is a quantum relativistic effect that describes the appearance of an additional electric current along a magnetic field. It is caused by an asymmetry between the number densities of left- and right-handed fermions, which ca ...

2020

Energetics of turbulence generated by chiral MHD dynamos

Jennifer Waltraud Schober

An asymmetry in the number density of left- and right-handed fermions is known to give rise to a new term in the induction equation that can result in a dynamo instability. At high temperatures, when a chiral asymmetry can survive for long enough, this chi ...

TAYLOR & FRANCIS LTD2019

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

Eric Serre, Davide Galassi

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

Preferential Deposition of Snow and Dust Over Hills: Governing Processes and Relevant Scales

Marc Parlange, Michael Lehning, Marco Giovanni Giometto, Francesco Comola

Preferential deposition of snow and dust over complex terrain is responsible for a wide range of environmental processes and accounts for a significant source of uncertainty in the surface mass balances of cold and arid regions. Despite the growing body of ...

2019

LTCC magnetic sensors at EPFL and TCV: Lessons learnt for ITER

Thomas Maeder, Pierre Lavanchy, Jonathan Bryan Lister, Xavier Llobet, Blaise Marlétaz, Philippe Marmillod, Matthias Garcin, Ugo Siravo, Caroline Jacq, Christian Moura, Duccio Testa, Frédéric Dolizy, Severino Antonioni, Matthieu Toussaint, Steve Couturier, Adrien Aymeric Thibault Corne, Aylwin Iantchenko, Lorenzo Stipani

Innovative 3D high-frequency magnetic sensors have been designed and manufactured in-house for installation on the Tokamak a Configuration Variable (TCV), and are currently routinely operational. These sensors combine the Low Temperature Co-fired Ceramic ( ...

2019