Publications de Stefano Alberti

Electron trapping in gyrotron electron guns: Validation of the FENNECS code with the T-REX experiment

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge, Joaquim Loizu Cisquella, Mario Ludovico Podesta, Jérémy Genoud, Falk Hans Braunmüller, Francesco Romano, Guillaume Michel Le Bars

Gyrotrons are essential devices for the development of nuclear fusion, but their design and reliable operation still present numerous challenges. In particular, certain gyrotrons encounter issues related to trapped electron clouds in the magnetron injectio ...

AIP Publishing2025

Design and First Tests of the Trapped Electrons Experiment T-REX

Stefano Alberti, Joaquim Loizu Cisquella, Damien Fasel, Jérémy Genoud, Steve Couturier, Severino Antonioni, Francesco Romano

Gyrotrons are essential for electron cyclotron resonance heating (ECRH) in fusion reactors, making efficient operation crucial for advancing fusion energy. Past experiments revealed instability issues due to trapped electrons in the magnetron injection gun ...

AIP Publishing2024

Experimental research on the TCV tokamak

Olivier Sauter, Ambrogio Fasoli, Stefano Coda, Timothy Goodman, Yves Martin, Stefano Alberti, Ivo Furno, Duccio Testa, Patrick Blanchard, Holger Reimerdes

Tokamak à configuration variable (TCV), recently celebrating 30 years of near-continual operation, continues in its missions to advance outstanding key physics and operational scenario issues for ITER and the design of future power plants such as DEMO. The ...

IOP Publishing Ltd2024

FENNECS: a novel particle-in-cell code for simulating the formation of magnetized non-neutral plasmas trapped by electrodes of complex geometries

Stefano Alberti, Jean-Philippe Hogge, Joaquim Loizu Cisquella, Jérémy Genoud, Francesco Romano, Guillaume Michel Le Bars

This paper presents the new 2D electrostatic particle -in -cell code FENNECS developed to study the formation of magnetized non -neutral plasmas in geometries with azimuthal symmetry. This code has been developed in the domain of gyrotron electron gun desi ...

2024

Experimental characterization of the TCV dual-frequency gyrotron and validation of numerical codes including the effect of After Cavity Interaction

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge, Damien Fasel, Matthieu Toussaint, Ugo Siravo, Jérémy Genoud, Jérémie Dubray, Falk Hans Braunmüller

A dual-frequency gyrotron has been developed within the context of the recent Tokamak à Configuration Variable (TCV) upgrade. The gyrotron is designed to generate a 1 MW, 2 seconds RF wave at 84 or 126 GHz. Before integrating the gyrotrons in the TCV tokam ...

2024

Plasma sputtering of biased electrodes in an oblique magnetic field

Stefano Alberti, Ivo Furno, Alessandro Geraldini

The surface erosion of biased electrodes immersed in a radio frequency (RF) plasma was investigated in oblique magnetic fields ranging from 0.1 T to 3.5 T. The plasma potential and density in the vicinity of the biased electrode have been measured using an ...

IOP Publishing Ltd2023

First self-consistent simulations of trapped electron clouds in a gyrotron gun and comparison with experiments

Stefano Alberti, Jean-Philippe Hogge, Ioannis Pagonakis, Joaquim Loizu Cisquella, Jérémy Genoud, Francesco Romano

We report on the initial validation of the novel code FENNECS, which simulates the spontaneous formation of trapped electron clouds in coaxial geometries with strong externally applied azimuthal flows and in the presence of a residual neutral gas. For this ...

American Institute of Physics (AIP)2023

Homogenous power distribution along gyrotron collector walls

Stefano Alberti, Jean-Philippe Hogge, Damien Fasel, Ugo Siravo, Jérémie Dubray, Miguel Filipe Silva Füglister, Pierre-François Isoz

EC RF power sources will play a major role in the future operation of large scale tokamaks (ITER, DEMO). A 1MW/170GHz gyrotron is the standard RF power unit considered for ITER. Even though the efficiency of such devices has been significantly increased th ...

2023

Homogenous power distribution along gyrotron collector walls

Stefano Alberti, Jean-Philippe Hogge, Damien Fasel, Ugo Siravo, Jérémie Dubray, Miguel Filipe Silva Füglister, Pierre-François Isoz

2023

A new 3MW ECRH system at 105 GHz for WEST*

Stefano Alberti, Timothy Goodman, Jean-Philippe Hogge, Ioannis Pagonakis, Konstantinos Avramidis

The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m2. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an ...

2023