A5004021890- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Fluid Dynamics and Turbulent Flows
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Quantum chaos and dynamical systems
- Laser-induced spectroscopy and plasma
- Theoretical and Computational Physics
- Gas Dynamics and Kinetic Theory
- Meteorological Phenomena and Simulations
- Geomagnetism and Paleomagnetism Studies
- Physics of Superconductivity and Magnetism
- Computational Fluid Dynamics and Aerodynamics
- High-Energy Particle Collisions Research
- Statistical Mechanics and Entropy
- Particle Dynamics in Fluid Flows
- Dust and Plasma Wave Phenomena
- earthquake and tectonic studies
- Advanced Data Storage Technologies
- High-pressure geophysics and materials
CEA Cadarache
2016-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2025
Institut de Recherche sur la Fusion par Confinement Magnétique
2015-2025
Centre National de la Recherche Scientifique
2008-2024
Centrale Marseille
2024
Institut national de recherche en informatique et en automatique
2024
Université Paris-Sud
2022
Université Paris-Saclay
2022
CEA Grenoble
2021
Japan External Trade Organization
2015
Progress, since the ITER Physics Basis publication (ITER Editors et al 1999 Nucl. Fusion 39 2137–2664), in understanding processes that will determine properties of plasma edge and its interaction with material elements is described. Experimental areas where significant progress has taken place are energy transport scrape-off layer (SOL) particular anomalous scaling, particle SOL plays a major role diverted plasmas main-chamber elements, localized mode (ELM) deposition on mechanism for ELM...
Interchange turbulence in two dimensions is investigated the scrape-off layer (SOL) of fusion devices, when driven by a constant core particle influx. Contrary to standard gradient-driven approach, density allowed fluctuate around its average profile. Transverse transport exhibits some features self-organized critical systems, namely inward and outward avalanches, together with frequency spectrum decrease 1/f f−2 at intermediate high frequencies, respectively. An avalanche occurs local...
This review paper addresses the physics of stochastic boundaries. Although it is focused on tokamak configuration many features are common to boundaries stellarators. The properties magnetic field lines recalled and related spectrum radial perturbation. region, referred as divertor volume, shown be bounded edge plasma. Furthermore, discriminate two regions. On short scales, stochasticity not effective parallel transport dominates, this defines laminar region. long scales one recovers proper...
A systematic, constructive and self-consistent procedure to quantify nonlocal, nondiffusive action at a distance in plasma turbulence is exposed applied turbulent heat fluxes computed from the state-of-the-art full-$f$, flux-driven gyrokinetic GYSELA XGC1 codes. striking commonality found: transport below dynamically selected mesoscale has structure of L\'evy distribution, strongly nondiffusive, scale-free, avalanche mediated; larger scales, we report observation self-organized flow which...
Recent research in scrape-off layer (SOL) and divertor physics is reviewed; new existing data from a variety of experiments have been used to make cross-experiment comparisons with implications for further ITER. Studies the region near separatrix addressed relationship profiles turbulence as well scaling parallel power flow. Enhanced low-field side radial transport implicated driving flows inboard side. The medium-n nature edge localized modes (ELMs) has elucidated measurements determined...
In the perspective of operating tungsten monoblocks in WEST, ongoing major upgrade Tore Supra tokamak, a dedicated modelling effort has been carried out to simulate interaction between edge plasma and wall. A new transport code, SolEdge2D–EIRENE, developed with ability up first This is especially important for steady state operation, where thermal loads on all facing components, even remote from plasma, are interest. Moreover, main chamber sources thought dominate contamination core. We...
With WEST (Tungsten Environment in Steady State Tokamak) (Bucalossi et al 2014 Fusion Eng. Des. 89 907–12), the Tore Supra facility and team expertise (Dumont Plasma Phys. Control. 56 075020) is used to pave way towards ITER divertor procurement operation. It consists implementing a configuration installing ITER-like actively cooled tungsten monoblocks tokamak, taking full benefit of its unique long-pulse capability. user platform, open all partners. This paper describes physics basis WEST:...
The turbulent transport governed by the toroidal ion temperature gradient driven instability is analysed with full- f global gyrokinetic code GYSELA (Grandgirard et al 2007 Plasma Phys. Control. Fusion 49 B173 ) when system a prescribed heat source. Weak, yet finite, collisionality governs neoclassical flux that can compete transport. In turn, ratio of to increases source magnitude, resulting in degradation confinement additional power. exhibits avalanche-like events, characterized...
The impact on turbulent transport of geodesic acoustic modes excited by energetic particles is evidenced for the first time in flux-driven 5D gyrokinetic simulations using Gysela code. Energetic (EGAMs) are a regime with barrier outer radial region. interaction between EGAMs and turbulence such that can be enhanced presence EGAMs, subsequent destruction barrier. This scenario could particularly critical those plasmas, as burning exhibiting rich population suprathermal capable exciting modes.
We show that a class of near-marginal and low-collisional magnetised plasmas naturally evolve into globally organised state dubbed the ' × E B staircase'.A key signature this self-organised is containment avalanche activity, detrimental for confinement, by series microbarriers transport, staircase steps, beneficial confinement.Conditions existence staircase, impact on transport confinement robustness in parameter space are discussed.
The effect of a sheared toroidal velocity on transport barrier is studied. This analysis done by using three-dimensional global fluid simulations electrostatic ion temperature gradient driven turbulence in tokamaks. produced with reversed magnetic shear. For flat density profile, and at low collisionality, co-rotation leads to an outward motion the barrier, whereas counter rotation inward displacement. However, displacement saturates when increasing torque fixed heat source. saturation...
Critical physical issues can be specifically tackled with the global full-f gyrokinetic code GYSELA. Three main results are presented. First, self-consistent treatment of equilibrium and fluctuations highlights competition between two compensation mechanisms for curvature driven vertical charge separation, namely, parallel flow polarization. The impact latter on turbulent transport is discussed. In non-linear regime, benchmark Particle-In-Cell ORB5 looks satisfactory. Second, scaling ρ*...
Flux-driven global gyrokinetic codes are now mature enough to make predictions in terms of turbulence and transport tokamak plasmas. Some the recent breakthroughs three such codes, namely GYSELA, ORB5 XGC1, reported compared wherever appropriate. In all turbulent appears be mediated by avalanche-like events, for a broad range ρ * = i / values, ratio gyro-radius over minor radius. Still, radial correlation length scales with , leading gyro-Bohm scaling effective coefficient below ≈ 1/300. The...
This contribution presents the recent effort at CEA and French federation for fusion to simulate edge plasma transport with new code SOLEDGE3X. The latter can be used both as a 2D or 3D turbulence code. It makes possible simulating up first wall including complex geometry. also includes neutral recycling impurity sputtering, seeding transport. In order improve description in simulation, reduced model intensity prediction has been derived implemented, based on 'k-epsilon' like models from...
Abstract Magnetic confinement fusion offers the promise of sustainable and safe energy production on Earth. Advanced experimental scenarios exploit fascinating yet uncommon ability confined plasmas to bifurcate into states enhanced performance upon application additional free sources. Self-regulation small-scale turbulent eddies is essential accessing these improved regimes. However, after several decades, basic principles for bifurcations are still largely debated clarifications from first...
Turbulence self-organization is studied in the flux-driven regime by means of reduced model Tokam1D. Derived electrostatic and isothermal limit but keeping finite electron ion temperatures, it features two instabilities that are suspected to dominate turbulent transport at edge L-mode tokamak plasmas: interchange (a version resistive ballooning modes) collisional drift waves, governed respectively an effective gravity parameter $g$ adiabaticity $C$ . The usual properties these recovered...
Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely high confinement that is, H-modes advanced scenarios.
Deuterium gas injected into ELMing H mode divertor discharges in the DIII-D tokamak typically reduced total power at target ~2 times and peak heat flux ~3 to 5 with modest (<10%) degradation plasma energy confinement. The parameter range for investigated was: Ip=1.0-2.0 MA, q95 approximately= 2.4-6.0 input (≲20 MW. Most of this reduction occurred sudden formation a high density, highly radiating region located between outboard separatrix strike point X point. This behaviour is associated...
The entropy production rate is calculated for an interchange driven turbulence both in fluid and kinetic regimes. This calculation provides a rigorous way to define thermodynamical forces fluxes. It found that the are gradients of density temperature normalized their “canonical” values, which Lagrangian invariants flow. formulation equivalent expressing fluxes terms “curvature pinches,” where curvature pinches proportional logarithmic gradient canonical profiles. Off diagonal transport...
Upgrade of the Tore Supra ergodic divertor (ED) has led to significant progress in ED physics. Pulse durations 30?s with LHCD have been achieved demonstrating heat exhaust capability both actively cooled technology at hand and this specific concept. The disruptive limit governed by stochastization outer magnetic surfaces is found occur for a value Chirikov parameter reaching two on surface q = 2+(3/12). This experimentally observed robustness allows one operate very low safety factor...
This paper analyzes the properties of a two-field critical gradient model that couples heat equation to an evolution for turbulence intensity. It is shown dynamics perturbation ballistic or diffusive depending on shape pulse and also distance temperature instability threshold. dual character appears in linear response this wave packet. recovered when investigating nonlinear solutions system. Both self-similar fronts are exist. When propagation ballistic, it found front velocity geometric...