Publications associées à Axisymmetric oscillations at L-H transitions in JET: M-mode

Energy-Efficient Particle Accelerators for Research

Particle accelerators are the drivers for large-scale research infrastructures for particle physics but also for many branches of condensed matter research. The types of accelerator-driven research infrastructures include particle colliders, neutron, muon ...

2024

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation

Farhad Rachidi-Haeri, Marcos Rubinstein

In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to ...

2024

Re-design of EU DEMO with a low aspect ratio

Hartmut Zohm

The design point that had been chosen for EU DEMO in 2016 is reviewed here and a modification is proposed with a lower aspect ratio. Previously the same aspect ratio, A, was chosen for EU DEMO as in major tokamak experiments including ITER (A = 3.1), and, ...

2024

Self-sustained dynamics and forced resonant oscillations in flows: cross-junction jets and sloshing liquids

Alessandro Bongarzone

In engineering, oscillatory instabilities and resonances are often considered undesirable flow features and measures are taken to avoid them. This may include avoiding certain parametric regions or implementing control and mitigation strategies. However, t ...

EPFL2023

First characterization of the SPIDER beam AC component with the Beamlet Current Monitor

SPIDER is the full scale prototype for the ITER Heating Neutral Beam source, hosted at the Neutral Beam Test Facility in Padova, Italy. The behavior of the beam must be thoroughly investigated to bring the machine's performance in line with ITER's requirem ...

2023

A model of non-Maxwellian electron distribution function for the analysis of ECE data in JET discharges

Mikhail Maslov, Javier García Hernández, Samuele Mazzi

Recent experiments performed in JET at high level of plasma heating, in preparation of, and during the DT campaign have shown significant discrepancies between electron temperature measurements by Thomson Scattering (TS) and Electron Cyclotron Emission (EC ...

E D P SCIENCES2023

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part I—Analysis Based on Time Domain Electromagnetic Radiation

Farhad Rachidi-Haeri, Marcos Rubinstein

In this paper, an inequality satisfied by the vacuum energy density of the universe is derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant ...

2023

Vertical electron cyclotron emission diagnostic on the tokamak à configuration variable

Ambrogio Fasoli, Stefano Coda, Laurie Porte

In this paper, a diagnostic for the measurement of the electron cyclotron emission (ECE) from non-thermal electrons in magnetically confined fusion plasmas is presented. The diagnostic employs a vertical viewing line of sight that allows us to directly inf ...

2023

Excitation of toroidal Alfvén eigenmodes with counter-current NBI in the TCV tokamak

Alexander Karpushov, Laurie Porte, Matteo Vallar, Samuele Mazzi

In TCV, unstable modes excited by resonant interaction between the shear Alfvèn waves in con- tinuum gaps and energetic particles have been observed in scenarios with Neutral Beam Injection (NBI). TCV is a middle-size device (R 0 /a = 0.88/0.25) equipped w ...

IOP Publishing Ltd2023

Possible restoration of particle-hole symmetry in the 5/2-quantized Hall state at small magnetic field

Frédéric Mila, Loïc Jean Pierre Herviou

Motivated by the experimental observation of a quantized 5/2 thermal conductance at filling nu = 5/2, a result incompatible with both the Pfaffian and the anti-Pfaffian states, we have pushed the expansion of the effective Hamiltonian of the 5/2-quantized ...

AMER PHYSICAL SOC2023

A machine-learning-based tool for last closed-flux surface reconstruction on tokamaks

Olivier Sauter, Alessandro Pau, Chenguang Wan, Xiaojuan Liu

Tokamaks allow to confine fusion plasma with magnetic fields. The prediction/reconstruction of the last closed-flux surface (LCFS) is one of the primary challenges in the control of the magnetic configuration. The evolution in time of the LCFS is determine ...

IOP Publishing Ltd2023

Rock-Flow Cell Parameters Evaluation Using Ultrasound Doppler Velocimetry

Giovanni De Cesare, Javier Neves da Silva, Andre Luis Stakowian

This work presents a study of two-phase flow generated inside a rock-flow cell setup. It is characterized by a pipe section filled with fluid (oil in our studies) that is put into oscillation around its mass centre by an electric motor. This type of appara ...

2023

Characterisation of electron cyclotron wall conditioning plasma in ASDEX Upgrade

Richard Pitts

Electron cyclotron wall condition (ECWC) discharges are characterised in ASDEX Upgrade with full tungsten plasma facing components and X2 polarised waves launched from the equatorial ports, relevant to ECWC conditions in ITER Pre-Fusion Power Operation pha ...

IOP Publishing Ltd2023

Quantum engineering and detection of advanced radiation beams

Veronica Leccese

Controlling and shaping radiation beams is fundamental for a better understanding of radiation-matter interaction and advancing experimental techniques for material characterization at high spatial resolution. In particular, the current trend in the miniat ...

EPFL2023

Anisotropic and nonlinear transport in microstructured 3D topological semimetals

Xiangwei Huang

Topological semimetals are frequently discussed as materials platforms for future electronics that exploit the remarkable properties of their quasiparticles. These ideas are mostly based on dispersion relations that mimic relativistic particles, such as We ...

EPFL2022

New Capabilities of the FLUKA Multi-Purpose Code

Philippe Jean Schoofs, Nikolaos Charitonidis, Francesco Cerutti, André Donadon Servelle

FLUKA is a general purpose Monte Carlo code able to describe the transport and interaction of any particle and nucleus type in complex geometries over an energy range extending from thermal neutrons to ultrarelativistic hadron collisions. It has many diffe ...

FRONTIERS MEDIA SA2022

Controlling the magnetic and electric responses of dielectric nanoparticles via near-field coupling

Olivier Martin, Andrei Kiselev

Among the two materials families used in nanophotonics, the fundamental mode for metal nanostructures is electric, while that for dielectric nanostructures is magnetic. Consequently, the optical properties of hybrid dimers that incorporate both materials h ...

2022

Modeling of saturated external MHD instabilities in tokamaks: A comparison of 3D free boundary equilibria and nonlinear stability calculations

Jonathan Graves

3D free boundary equilibrium computations have recently been used to model external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD stability codes, and nonlinear analytic theory [Kleiner et al., Phys. Plasma Controlled Fusion 61, 08 ...

2022

Experimental and modeling-based analysis of reaction pathways on catalysts for natural gas engines under periodic lean/rich oscillations

Oliver Kröcher, Davide Ferri, Moyu Wang

Methane (CH4) has the prospective of becoming one of the major energy carriers for heavy-duty mobility, but its catalytic abatement remains a challenge. CH4 abatement reaction pathways were analyzed using targeted periodic lean/rich oscillations, which res ...

ELSEVIER SCIENCE SA2022

A novel measurement of marginal Alfven eigenmode stability during high power auxiliary heating in JET

Ambrogio Fasoli, Mario Ludovico Podesta, Paulo Giovane Paschoali Pereira Puglia

The interaction of Alfven eigenmodes (AEs) and energetic particles is one of many important factors determining the success of future tokamaks. In JET, eight in-vessel antennas were installed to actively probe stable AEs with frequencies ranging 25-250 kHz ...

IOP Publishing Ltd2022