Publications associées à Déclinaison magnétique terrestre

Impact of microwave beam scattering by density fluctuations on the electron-cyclotron power deposition profile in tokamaks

Stefano Coda, Joan Decker, Oleg Krutkin, Umesh Kumar, Jean Arthur Cazabonne

Electron-cyclotron waves are a tool commonly used in tokamaks, in particular to drive current. Their ability to drive current in a very localized manner renders them an optimal tool for MHD mode mitigation. However, such applications require high accuracy ...

IOP Publishing Ltd2024

Hybridization driving distortions and multiferroicity in rare-earth nickelates

Nicola Marzari, Iurii Timrov, Michele Kotiuga, Luca Binci

For decades transition-metal oxides have generated a huge interest due to the multitude of physical phenomena they exhibit. In this class of materials, the rare-earth nickelates, RNiO3, stand out for their rich phase diagram stemming from complex couplings ...

Amer Physical Soc2023

Equilibrium pressure limits in stellarators

Antoine Baillod

This thesis delves into the potential of magnetic fusion energy, and in particular focuses on the stellarator concept. Stellarators use external coils to produce 3-dimensional (3D) magnetic fields that confine a thermonuclear plasma in a topologically toro ...

EPFL2023

Equilibrium β-limits dependence on bootstrap current in classical stellarators

Jonathan Graves, Joaquim Loizu Cisquella, Antoine Baillod

While it is important to design stellarators with high magnetohydrodynamic stability β-limit, it is also crucial to ensure that good magnetic surfaces exist in a large range of β values. As β increases, pressure-driven currents perturb the vacuum magnetic ...

Cambridge University Press2023

Ultra 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 Ltd2023

Magnetic regulation of the luminescence of hybrid lanthanide-doped nanoparticles

Jean-Claude Bünzli

The unique optical properties of lanthanide-doped nanomaterials have made them broadly attractive to a wide range of applications in chemical, physical, and biomedical fields. As an external and real-time reg-ulation tool, the magnetic field is highly usef ...

ELSEVIER SCIENCE SA2022

Three-dimensional Fermi surfaces from charge order in layered CsV3Sb5

Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo, Yi-Chiang Sun, Xiangwei Huang

The cascade of electronic phases in CsV3Sb5 raises the prospect to disentangle their mutual interactions in a clean, strongly interacting kagome lattice. When the kagome planes are stacked into a crystal, its electronic dimensionality encodes how much of t ...

AMER PHYSICAL SOC2022

Intercalant-mediated Kitaev exchange in Ag3LiIr2O6

Oleg Yazyev, Ravi Yadav

The recently synthesized Ag3LiIr2O6 has been proposed as a Kitaev magnet in proximity to the quantum spin liquid phase. We explore its microscopic Hamiltonian and magnetic ground state using many-body quantum chemistry methods and exact diagonalization tec ...

AMER PHYSICAL SOC2022

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

Paolo Ricci, Joaquim Loizu Cisquella, 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

Sheath collapse at critical shallow angle due to kinetic effects

Alessandro Geraldini

The Debye sheath is known to vanish completely in magnetised plasmas for a sufficiently small electron gyroradius and small angle between the magnetic field and the wall. This angle depends on the current onto the wall. When the Debye sheath vanishes, ther ...

IOP Publishing Ltd2022

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

Performance and Micro-Vibrations in Magnetic Bearings for Space Actuators

Guzmán Borque Gallego

The development of new space missions with novel high-performance and very sensitive payloads for Earth observation or scientific missions has imposed considerably tougher requirements in terms of the satellite's pointing accuracy and stability, and thus o ...

EPFL2021

Model for current drive induced crash cycles in W7-X

Joaquim Loizu Cisquella, Ajay Kumar

In the Wendelstein 7-X (W7-X) stellarator, the vacuum rotational transform, ι, has a flat radial profile and does not cross any major rational resonance. Nevertheless, during plasma operation the ι‐profile can be strongly modified by electron cyclotron cur ...

IOP Publishing Ltd2021

Effect of periodic gas-puffs on drift-tearing modes in ADITYA/ADITYA-U tokamak discharges

Harshita Raj, Abhijit Sen

The effect of a periodic train of short gas-puff pulses on the rotation frequency and amplitude of drift-tearing modes has been studied in ADITYA/ADITYA-U tokamak. The short gas puffs, injecting approximately similar to 10(17)-10(18) molecules of fuel gas ...

IOP Publishing Ltd2020

Persistent random walks of charged particles across magnetic field lines

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Marcelo Baquero Ruiz, Fabian Manke

We investigate the time evolution of the mean location and variance of a charged particle subject to random collisions that are Poisson distributed. The particle moves on a plane and is subject to a magnetic field applied perpendicular to the plane, so it ...

2020

A system for planning and/or providing neurostimulation for a patient

Grégoire Courtine, Vincent Delattre, Tomislav Milekovic, Marco Capogrosso, Fabien Bertrand Paul Wagner, Flavio Raschella

The present invention relates to a system (10) for planning and/or providing neurostimulation for a patient, comprising: - a pathological spinal cord map storage module (48) for storing at least one pathological spinal cord map (49) describing the activati ...

2019

A Magnetic Continuum Device with Variable Stiffness for Minimally Invasive Surgery

Dario Floreano, Alice Tonazzini

One of the challenges of minimally invasive surgery is the dexterous manipulation and precise control of small diameter continuum surgical instruments. In this paper, a magnetic continuum device with variable stiffness (VS) is presented, whose tip can be p ...

2019

Tuning the structure, reactivity and magnetic communication of nitride-bridged uranium complexes with the ancillary ligands

Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Anne-Clémence Corminboeuf, Alberto Fabrizio, Luciano Barluzzi

Molecular uranium nitride complexes were prepared to relate their small molecule reactivity to the nature of the U & xe001;N & xe001;U bonding imposed by the supporting ligand. The U4+-U4+ nitride complexes, [NBu4][{(((BuO)-Bu-t)(3)SiO)(3)U}(2)(mu-N)], [NB ...

2019

Progress in disruption prevention for ITER

Olivier Sauter, Mengdi Kong, Alessandro Pau, Francesca Maria Poli, Umar Sheikh, Ji Hyun Kim

Key plasma physics and real-time control elements needed for robustly stable operation of high fusion power discharges in ITER have been demonstrated in recent research worldwide. Recent analysis has identified the current density profile as the main drive ...

IOP Publishing Ltd2019

Direct observation of coherent magnons with suboptical wavelengths in a single-crystalline ferrimagnetic insulator

Joe Martin Bailey

Spin-wave dynamics were studied in an extended thin film of single-crystalline yttrium iron garnet using time-resolved scanning transmission x-ray microscopy. A combination of mechanical grinding and focused ion beam milling has been utilized to achieve a ...

2019