Publications related to Avalanche-like bursts in global gyrokinetic simulations

Related publications (49)

X-point radiation: From discovery to potential application in a future reactor

Holger Reimerdes, Christian Gabriel Theiler, Umar Sheikh, Olivier Claude Martin Février

Power exhaust is a crucial issue for future fusion reactors. Divertor detachment and the required power dissipation fractions of about 95% are foreseen to be achieved by impurity seeding. In a tokamak, at high seeding levels the radiation often concentrate ...

Elsevier2025

Impurity-seeded detachment in conventional and optimized TCV divertor geometry

Guang-Yu Sun

Nuclear fusion provides a potentially unlimited and clean energy source which motivates the development of fusion power plants. The tokamak is one of the most promising concepts for a future reactor, confining the fusion plasmas in a torus using strong mag ...

EPFL2025

Neutral pressure measurement in TCV tokamak using ASDEX-type pressure gauges

Holger Reimerdes, Marcelo Baquero Ruiz, Guang-Yu Sun, Elena Tonello, Marc Noël, Mateusz Gospodarczyk, Hammam Elaian

Probing the neutral gas distribution at the edge of magnetic confinement fusion devices is critical for plasma exhaust studies. In the TCV tokamak, a set of ASDEX-type hot ionization pressure gauges (APGs) has been installed for fast, in situ measurements ...

2025

Plasma state monitoring and disruption characterization using multimodal VAEs

Giulio Romanelli, Olivier Sauter, Alessandro Pau, Yoeri Renier Johannes Poels, Cristina Venturini

When a plasma disrupts in a tokamak, significant heat and electromagnetic loads are deposited onto the surrounding device components. These forces scale with plasma current and magnetic field strength, making disruptions one of the key challenges for futur ...

IOP Publishing Ltd2025

Generalised Kerr Microcomb Physics in Synchronously Driven Systems

Miles Henry Anderson

In this thesis, the generation of microcombs under complex, non-trivial, and/or higher-order cavity conditions is explored, both in theory & simulation, and in practical experimentation. Pulse-driving of microresonators is investigated for the generation ...

EPFL2023

Validation of GBS plasma turbulence simulation of the TJ-K stellarator

Paolo Ricci, Joaquim Loizu Cisquella

We present a validation of a three-dimensional, two-fluid simulation of plasma turbulence in the TJ-K stellarator, a low temperature plasma experiment ideally suited for turbulence measurements. The simulation is carried out by the GBS code, recently adapt ...

IOP Publishing Ltd2023

Global gyrokinetic study of density gradient driven instability in tokamaks: the ubiquitous mode

Laurent Villard

The ubiquitous mode is investigated in the linear regime for the first time using a global gyrokinetic model. These modes are driven by the density gradient in trapped electron population but with mode frequency in the ion diamagnetic drift direction, in c ...

2024

Scalable angular spectrum propagation

Felix Wechsler

Coherent field propagation is an essential computational tool in optics with applications ranging from computational optics and optical design to iterative field reconstructions. An improvement in the computational speed of current propagation methods is t ...

Optica Publishing Group2023

Optimizing the ITER NBI ion source by dedicated RF driver test stand

Riccardo Agnello

The experimental fusion reactor ITER will feature two (or three) heating neutral beam injectors (NBI) capable of delivering 33(or 50) MW of power into the plasma. A NBI consists of a plasma source for production of negative ions (extracted negative ion cur ...

Institute of Physics2024

Impact of the turbulence wavenumber spectrum and probing beam geometry on Doppler reflectometry perpendicular velocity measurements

Frank Nüesch

The perpendicular propagation velocity of turbulent density fluctuations is an important parameter in fusion plasmas, since sheared plasma flows are crucial for reducing turbulence, and thus an essential input parameter for turbulent transport simulations. ...

IOP Publishing Ltd2023

Experimental validation of momentum transport theory in the core of H-mode plasmas in the ASDEX Upgrade tokamak

Basil Duval

This study employs the established momentum transport analysis at ASDEX Upgrade [Zimmermann et al., Nucl. Fusion 63, 124003 (2023)] to investigate the parametric variations of the momentum transport coefficients in the core of H-mode plasmas. These experim ...

Aip Publishing2024

Study of impurity C transport and plasma rotation in negative triangularity on the TCV tokamak

Olivier Sauter, Basil Duval, Stefano Coda, Benoît Labit, Laurie Porte, Alexander Karpushov, Antoine Pierre Emmanuel Alexis Merle, Alessandro Pau, Justin Richard Ball, Filippo Bagnato, Dmytry Mykytchuk

Carbon impurity transport is studied in the TCV tokamak using a charge exchange recombination diagnostic. TCVs flexible shaping capabilities were exploited to extend previous impurity transport studies to negative triangularity (delta < 0). A practical way ...

Iop Publishing Ltd2024

Infrared-active phonons in one-dimensional materials and their spectroscopic signatures

Nicola Marzari, Thibault Daniel Pierre Sohier, Norma Rivano

Dimensionality provides a clear fingerprint on the dispersion of infrared-active, polar-optical phonons. For these phonons, the local dipoles parametrized by the Born effective charges drive the LO-TO splitting of bulk materials; this splitting actually br ...

Nature Portfolio2023

Investigation of scrape-off layer and divertor transport using infrared thermography and SOLPS-ITER simulations

Claudia Colandrea

Nuclear fusion, with its potential to provide a nearly unlimited energy source, has inspired scientists to work on the development of fusion power plants. Among the various devices designed to harness nuclear fusion, the tokamak confines the fusion fuel, w ...

EPFL2024

Symmetry-reduced low-dimensional representation of large-scale dynamics in the asymptotic suction boundary layer

Omid Ashtari

An important feature of turbulent boundary layers are persistent large-scale coherent structures in the flow. Here, we use Dynamic Mode Decomposition (DMD), a data-driven technique designed to detect spatio-temporal coherence, to construct optimal low-dime ...

Elsevier2023

Validating reduced models for detachment onset and reattachment times on MAST-U

Holger Reimerdes

Two reduced models for predicting detachment onset and divertor reattachment times are validated on MAST Upgrade (MAST-U). These models are essential for future tokamak reactor design, providing rapid calculations based primarily on engineering parameters. ...

Elsevier2024

Mean flow modeling in high-order nonlinear Schrodinger equations

Debbie Eeltink

The evaluation and consideration of the mean flow in wave evolution equations are necessary for the accurate prediction of fluid particle trajectories under wave groups, with relevant implications in several domains, from the transport of pollutants in the ...

2023

Overview of physics results from MAST upgrade towards core-pedestal-exhaust integration

Olivier Sauter, Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Matteo Vallar, Samuele Mazzi

Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening understanding of key physics issues for the operation of ITER and the design of future fusion power plants. The impact of MHD instab ...

IOP Publishing Ltd2024

The dynamics of unsteady frictional slip pulses

Fabian Barras, Thibault Didier Roch

Self-healing slip pulses are major spatiotemporal failure modes of frictional systems, featuring a characteristic size L(t) and a propagation velocity c(p)(t) (t is time). Here, we develop a theory of slip pulses in realistic rate- and state-dependent fric ...

National Academy of Sciences2023

Scenario optimization for the tokamak ramp-down phase in RAPTOR. Part B: safe termination of DEMO plasmas

Olivier Sauter, Federico Alberto Alfredo Felici, Emiliano Fable, Anna Teplukhina, Simon Van Mulders, Cassandre Ekta Contré

An optimized plasma current ramp-down strategy is critical for safe and fast termination of plasma discharges in a tokamak demonstration fusion reactor (DEMO), both in planned and emergency scenarios, avoiding plasma disruptions and excessive heat loads to ...

Iop Publishing Ltd2024