Publications by Falk Hans Braunmüller

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

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

Simulation and experimental study of proton bunch self-modulation in plasma with linear density gradients

Ambrogio Fasoli, Ivo Furno, Patrick Blanchard, Yanis Andrebe, Riccardo Agnello, Falk Hans Braunmüller, Christine Stollberg, Sun Hee Kim, Alban Sublet

We present numerical simulations and experimental results of the self-modulation of a long proton bunch in a plasma with linear density gradients along the beam path. Simulation results agree with the experimental results reported [F. Braunmller, T. Nechae ...

2021

A Variable Structure Control Scheme Proposal for the Tokamak a Configuration Variable

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Ivo Furno, Duccio Testa

Fusion power is the most significant prospects in the long-term future of energy in the sense that it composes a potentially clean, cheap, and unlimited power source that would substitute the widespread traditional nonrenewable energies, reducing the geogr ...

2019

Sliding Surface Based Schemes for the Tokamak a Configuration Variable

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Stefano Alberti, Ivo Furno

Fusion power may be seen as the energy of the future in the sense that it composes a potentially clean, cheap and unlimited power source that would reduce the worldwide dependency on non-renewable energies. Nevertheless, while nowadays the fusion reaction ...

IEEE2018

Conceptual design of the EU DEMO EC-system: main developments and R&D achievements

Stefano Alberti, Minh Quang Tran, Falk Hans Braunmüller, Ioannis Pagonakis, Emanuele Poli, Konstantinos Avramidis

For the development of a DEMOnstration Fusion Power Plant the design of auxiliary heating systems is a key activity in order to achieve controlled burning plasma. The present heating mix considers electron cyclotron resonance heating (ECRH), neutral beam i ...

IOP Publishing Ltd2017

Overview of the TCV tokamak program: scientific progress and facility upgrades

Stefano Coda, Olivier Sauter, Ambrogio Fasoli, Basil Duval, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Stefano Alberti, Ivo Furno

IOP Publishing Ltd2017

Dynamic nuclear polarization by frequency modulation of a tunable gyrotron of 260 GHz

Stefano Alberti, Jean-Philippe Ansermet, Falk Hans Braunmüller, Philippe Cuanillon, Murari Soundararajan, Dongyoung Yoon

An increase in Dynamic Nuclear Polarization (DNP) signal intensity is obtained with a tunable gyrotronproducing frequency modulation around 260 GHz at power levels less than 1W. The sweep rate of frequency modulation can reach 14 kHz, and its amplitude is ...

Academic Press2016

Gyrotron physics from linear to chaotic regimes: experiment and numerical modeling

Falk Hans Braunmüller

Gyrotrons belong to the family of high-power coherent radiation sources known as Electron Cyclotron Masers (ECMs) and are based on the physical mechanism of the ECM-instability, converting electron rotational kinetic energy into coherent electromagnetic ra ...

EPFL2016

Experimental results on a modular-gyrotron operating at 0.26THz for 400MHz DNP/NMR spectroscopy application

Stefano Alberti, Minh Quang Tran, Jean-Philippe Ansermet, Jean-Philippe Hogge, Damien Fasel, Jérémie Dubray, Falk Hans Braunmüller, Philippe Cuanillon, Trach-Minh Tran, Emile Jacques de Rijk

2012