A5035540674- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- GNSS positioning and interference
- Meteorological Phenomena and Simulations
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Semiconductor materials and devices
- Sentiment Analysis and Opinion Mining
- EU Law and Policy Analysis
- Topic Modeling
- Geophysics and Gravity Measurements
- Material Properties and Processing
- Electrostatic Discharge in Electronics
- Geomagnetism and Paleomagnetism Studies
- Reservoir Engineering and Simulation Methods
- Atomic and Molecular Physics
- Modeling, Simulation, and Optimization
- Electromagnetic Compatibility and Noise Suppression
Max Planck Institute for Plasma Physics
2018-2025
Max Planck Institute for Plasma Physics - Greifswald
2022
Max Planck Society
2018-2021
University of Southern Queensland
2021
University of York
2018-2019
Australian National University
2018
The University of Queensland
2015
Abstract The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is high-confinement mode. In this regime, however, periodic relaxations of plasma edge can occur. These edge-localized modes pose a threat to integrity fusion device. Here we reveal strong impact energetic ions on spatio-temporal structure in tokamaks using nonlinear hybrid kinetic–magnetohydrodynamic simulations. A resonant interaction between fast at electromagnetic...
Self-consistent full-size turbulent-transport simulations of the divertor and SOL existing tokamaks have recently become feasible. This enables direct comparison turbulence against experimental measurements. In this work, we perform a series diverted Ohmic L-mode discharges on TCV tokamak, building first-of-a-kind dataset for validation edge models. dataset, referred to as TCV-X21, contains measurements from 5 diagnostic systems -- giving total 45 1- 2-D observables in two toroidal magnetic...
This work characterizes the core transport physics of SPARC early-campaign plasmas using PORTALS-CGYRO framework. Empirical modeling with L-mode confinement indicates an ample window breakeven (Q > 1) without need H-mode operation. Extensive multi-channel (electron energy, ion and electron particle) flux-matched conditions nonlinear CGYRO code for turbulent coupled to macroscopic plasma evolution PORTALS reveals that maximum fusion performance be attained will highly dependent on...
Turbulent dynamics in the scrape-off layer (SOL) of magnetic fusion devices is intermittent with large fluctuations density and pressure. Therefore, a model required that allows perturbations similar or even larger magnitude to time-averaged background value. The fluid-turbulence code GRILLIX extended such global model, which consistently accounts for variation plasma parameters. Derived from drift reduced Braginskii equations, new includes electromagnetic electron-thermal dynamics, retains...
Abstract Turbulence simulations in diverted geometry across the edge and scrape-off layer (SOL) of ASDEX Upgrade are performed with GRILLIX code (Stegmeir et al 2019 Phys. Plasmas 26 052517). The underlying global (full- f ) drift-reduced Braginskii model allows to concurrently study self-consistent dynamics turbulence background as well evolution toroidal zonal flows. Different contributions radial electric field identified. dominant contribution on closed flux surfaces comes from ion...
To make predictions for and design fusion reactors, a multitude of physical processes must be considered. In the edge scrape-off layer (SOL), turbulent fluctuations intertwine with plasma background, which is largely determined by neutral gas, magnetic geometry plays an important role. A diffusive neutrals model has now been implemented in global Braginskii turbulence code GRILLIX. The based on flux-coordinate independent (FCI) approach, allows efficient simulations diverted equilibria. We...
A physics and engineering analysis of alternative divertor configurations is carried out by examining benefits problems comparing the baseline single null solution with a Snowflake, an X- Super-X divertor. It observed that can provide margin resilience against large power fluctuations, but their has intrinsic difficulties, especially in balance between structural solidity accessibility components when specific poloidal field coil positioning poses further constraints. hybrid proposed as...
Abstract Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER EU DEMO. A major objective the AUG programme is to shed light underlying physics confinement, stability, plasma exhaust order allow reliable extrapolation results obtained present day machines these reactor-grade devices. Concerning pedestal physics, mitigation edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found be consistent with reduction linear...
The Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on ASDEX-Upgrade tokamak, as demonstrated experimentally. mechanism of excitation and nonlinear evolution is not yet fully understood. In present work, a first-principles simulation using MEGA code investigated properties in both linear growth saturated phases. Here we show that successfully reproduced coexistence these two modes, agreed with experimental results well. Conclusive evidence showed...
Abstract On the basis of several recent breakthroughs in fusion research, many activities have been launched around world to develop power plants on fastest possible time scale. In this context, high-fidelity simulations plasma behavior large supercomputers provide one main pathways accelerating progress by guiding crucial design decisions. When it comes determining energy confinement a magnetic device, which is key quantity interest, gyrokinetic turbulence are considered approach choice –...
Abstract The separatrix operational space (SepOS) model [Eich \& Manz, \emph{Nuclear Fusion} (2021)] is shown to predict the L-H transition, L-mode density limit, and ideal MHD ballooning limit in terms of parameters for a wide range Alcator C-Mod plasmas. tested using Thomson scattering measurements across operating conditions on C-Mod, spanning $\overline{n}_{e} = 0.3 - 5.5 \times 10^{20}$m$^{-3}$, $B_{t} 2.5 8.0$ T, $B_{p} 0.1 1.2$ T. An empirical regression electron pressure gradient...
Abstract An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling AUG discharges was established which able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In center, theoretical predictions current redistribution by a dynamo effect were confirmed experimentally. For core transport, stabilizing fast ion distributions turbulent transport shown be important explain isotope and...
Understanding and predicting turbulence in the edge scrape-off layer (SOL) is critical for optimization of magnetic confinement fusion devices. While there has been progress along these lines, especially with help fluid codes, development full-f electromagnetic gyrokinetic codes SOL, general, diverted geometries, remains crucial. In this work, we present simulations SOL ASDEX Upgrade tokamak novel grid-based (continuum) code GENE-X. The presented are performed at both reduced realistic...
Abstract A recently developed reduced model of H-mode sustainment based on interchange-drift-Alfvén turbulence description in the vicinity separatrix matching experimental observations ASDEX Upgrade has been extended to experiments with unfavorable <?CDATA $\nabla B$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi mathvariant="normal">∇</mml:mi> <mml:mi>B</mml:mi> </mml:mrow> </mml:math> drift. The combination theory magnetic-shear-induced...
A new 1D divertor plasma code, SD1D, has been used to examine the role of recombination, radiation, and momentum exchange in detachment. Neither or power losses by themselves are found be sufficient produce a reduction target ion flux detachment (flux rollover); radiative required (a) limit reduce ionisation source (b) access low-target temperature, Ttarget, conditions for volumetric losses. Recombination is play small at rollover, but as Ttarget drops temperatures around 1 eV, it becomes...
Transport processes around the magnetic X-point of tokamaks, such as turbulence and mean-field drifts, are scarcely understood. The assessment capability codes to quantitatively reproduce these dynamics has been hampered by limitations in computational power available experimental data. In this paper, we present a rigorous validation full-scale simulations newly developed scenario basic toroidal plasma device TORPEX, performed with four state-of-the-art FELTOR, GBS, GRILLIX, STORM....
Nitrogen impurity seeding is a promising technique for increasing the radiative power dissipation rate in edge plasma of fusion device. It will be required future devices such as ITER to reduce directed heat flux on divertor strike-points within erosion limits. However, chemical reactions between nitrogen and fuel isotopes may complicate tritium control measures by in-vessel retention impacting gas-handling plant. To gain insight into nitrogen–hydrogen chemistry volume-averaged (global)...
Understanding and predicting turbulent transport in the edge scrape-off-layer (SOL) of magnetic confinement fusion devices is crucial for developing feasible power plants. In this work, we present latest improvements to gyrokinetic turbulence code GENE-X validate extended model against experimental results TCV tokamak (“TCV-X21”). features a full-f electromagnetic specifically targeted SOL simulations diverted geometries. can effect collisions using either basic Bhatnagar–Gross–Krook (BGK)...
Abstract In tokamaks, a leading platform for fusion energy, periodic filamentary plasma eruptions known as edge-localized modes occur in plasmas with high-energy confinement and steep pressure profiles at the edge. These could damage tokamak wall but can be suppressed using small three-dimensional magnetic perturbations. Here we demonstrate that these perturbations change topology just inside gradient region of We identify signatures island, their observation is linked to suppression modes....
The understanding and the predictive capability for turbulence in plasma edge scrape-off layer (SOL) are crucial development of magnetic confinement fusion reactors. To this end, we characterise turbulent transport across SOL diverted ASDEX Upgrade tokamak attached L-mode conditions by means validated, global simulations. collisionality is controlled divertor neutrals density, as their ionisation increases density decreases temperature. radial E×B particle heat transport, quantified...
Abstract GRILLIX employs the flux‐coordinate independent approach (FCI), which allows us to study boundary plasma turbulence in realistic diverted configurations. Recently, physical model has been extended a global drift‐reduced Braginskii model, without any separation between background and fluctuations. It includes electromagnetic thermal dynamics with hot ions, relaxation of Boussinesq approximation non‐linear parametric dependencies. This contribution presents solutions associated...
Abstract Advanced divertor configurations modify the magnetic geometry of to achieve a combination strong flux expansion, increased connection length and higher volume—to improve detachment stability, neutral/impurity confinement heat‐channel broadening. In this paper, we discuss modification flux‐coordinate independent (FCI) turbulence code GRILLIX treat generalized geometry, allow for investigation effect on turbulent structures in edge scrape‐off layer (SOL). The development grids...