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Proceedings/Recueil Des Communications Année : 2010

Nonlocal dynamics of Turbulence, Transport and Zonal Flows in Tokamak Plasmas

Résumé

The understanding of plasma turbulent transport in tokamaks used to rely on a local process, in the sense that locally excited fluctuations exhibit short radial correlation lengths only, ultimately leading to diffusive transport. We find here that the intrinsic nature of turbulent heat transport in tokamaks is nonlocal. This nonlocality is thoroughly defined and quantified. In the same vein, it is also found that the global structure of turbulence and transport results from a synergy between edge-driven inward propagation of turbulence intensity with outward heat transport. This synergy results in inward-outward pulse scattering leading to spontaneous production of strong internal shear layers in which the turbulent transport is almost suppressed over several radial correlation lengths. These two examples represent different sides of the same coin: the turbulence-generated self-organised processes which occur at mesoscales are central to our understanding of transport processes as they govern shear generation and flow pattern formation.
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Dates et versions

cea-01468375 , version 1 (15-02-2017)

Identifiants

  • HAL Id : cea-01468375 , version 1

Citer

Guilhem Dif-Pradalier, S Ku, P.H S Diamond, C.S. Chang, Yanick Sarazin, et al.. Nonlocal dynamics of Turbulence, Transport and Zonal Flows in Tokamak Plasmas. 23rd IAEA Fusion Energy Conference, Daejon, Rep. of Korea, France. 2010. ⟨cea-01468375⟩
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