A5042743621- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fluid Dynamics and Turbulent Flows
- Solar and Space Plasma Dynamics
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Astro and Planetary Science
- Fusion materials and technologies
- Geomagnetism and Paleomagnetism Studies
Laboratoire de Physique des Plasmas
2022-2025
CEA Cadarache
2021-2025
Institut de Recherche sur la Fusion par Confinement Magnétique
2023-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2021-2025
École Polytechnique
2022
Centre National de la Recherche Scientifique
2022
École Normale Supérieure de Lyon
2021
Université Claude Bernard Lyon 1
2021
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...
Abstract A Doppler backscattering (DBS) diagnostic has recently been installed on the Tokamak à Configuration Variable (TCV) to facilitate study of edge turbulence and flow shear in a versatile experimental environment. The dual channel V-band DBS system is coupled TCV’s quasi-optical launcher, providing access upper low-field side region plasma cross-section. Verifications measurements are presented. equilibrium v⊥ profiles found compare favorably with gas puff imaging (GPI) Er inferred...
A model of E × B staircases is proposed based on a wave kinetic equation coupled to poloidal momentum equation. staircase pattern idealized as periodic radial structure zonal shear layers that bound regions propagating packets, viewed avalanches. Wave packets are trapped in flow due refraction. In this model, an motif emerges the interaction between (avalanches) and waves presence instability drive. Amplitude, shape, spatial period predicted functions background fluctuation spectrum growth...
Abstract This paper presents a model for zonal flow generation based on wave kinetic equation coupled to poloidal momentum in regime where trapping matters. Several models of the collision operator have been tested: Krook, diffusion and plus an instability growth rate. Conditions identified. It is found that possible all cases. However force power law velocity, so different from quasi-linear case random phases produces linear velocity. Also may change sign, leading radial profiles are not sinusoidal.
The interplay between toroidal drift-wave turbulence and tokamak profiles is investigated using a wave-kinetic description. coupled system used to investigate the marginally stable geodesic acoustic modes (GAMs). found be unstable. Notably, most unstable mode corresponds resonance turbulent wave radial group velocity GAM phase velocity. For low-field-side ballooned growth, background flow shear breaks symmetry inwards- outwards-travelling instabilities. Although this turbulence–GAM coupling...
Abstract We complete the 2D 2-fields turbulence model previously used with an interchange-like instability by slightly modifying parallel loss terms to drive drift wave instabilities. show that driven temperature fluctuations of sheath losses is identical turbulence. The linear analysis performed and select control parameters yield maximum growth rates for interchange alone instability. Combining two instabilities doubles rate. non-linear simulations are analyse SOL width. allow one identify...
Relaxations of localized over-density in a plane transverse to the magnetic field are numericallyinvestigated under effect drift-wave and interchange drives SOL conditions. Such controlleddeparture from thermodynamic equilibrium allows investigation fundamental processesat play cross-field transport. Interchange instabilities generate ballistic outward radial flux withlow amplitude zonal flow patterns, whereas result symmetric fluxwith large patterns. When both considered, combinedeffects...
Abstract This study is motivated by experiments on Tore Supra and WEST tokamaks where a deepening of the E × B velocity—governed radial electric field r —near edge observed when safety factor decreases in L-mode plasmas. Flux-driven global simulations ion temperature gradient turbulence recover qualitatively trend experiments, i.e. velocity increases decreasing factor. From these simulations, multiple clues point out role establishment even though turbulent intensity with The proposed...