Radial interchange motions of plasma filaments
Top Cited Papers
- 1 August 2006
- journal article
- research article
- Published by AIP Publishing in Physics of Plasmas
- Vol. 13 (8), 082309
- https://doi.org/10.1063/1.2336422
Abstract
Radial convection of isolated filamentary structures due to interchange motions in magnetized plasmas is investigated. Following a basic discussion of vorticity generation, ballooning, and the role of sheaths, a two-field interchange model is studied by means of numerical simulations on a biperiodic domain perpendicular to the magnetic field. It is demonstrated that a blob-like plasma structure develops dipolar vorticity and electrostatic potential fields, resulting in rapid radial acceleration and formation of a steep front and a trailing wake. While the dynamical evolution strongly depends on the amount of collisional diffusion and viscosity, the structure travels a radial distance many times its initial size in all parameter regimes in the absence of sheath dissipation. In the ideal limit, there is an inertial scaling for the maximum radial velocity of isolated filaments. This velocity scales as the acoustic speed times the square root of the structure size relative to the length scale of the magnetic field. The plasma filament eventually decelerates due to mixing and collisional dissipation. Finally, the role of sheath dissipation is investigated. When included in the simulations, it significantly reduces the radial velocity of isolated filaments. The results are discussed in the context of convective transport in scrape-off layer plasmas, comprising both blob-like structures in low confinement modes and edge localized mode filaments in unstable high confinement regimes.Keywords
This publication has 82 references indexed in Scilit:
- On the scaling of avaloids and turbulence with the average density approaching the density limitPhysics of Plasmas, 2005
- Overview of edge electrostatic turbulence experiments on TCVCzechoslovak Journal of Physics, 2005
- Self-similar density turbulence in the TCV tokamak scrape-off layerPlasma Physics and Controlled Fusion, 2005
- Intermittent transport in the plasma periphery of the T-10 tokamakPlasma Physics and Controlled Fusion, 2004
- Transport by intermittency in the boundary of the DIII-D tokamakPhysics of Plasmas, 2003
- Universality of intermittent convective transport in the scrape-off layer of magnetically confined devicesPhysics of Plasmas, 2003
- Transport by intermittent convection in the boundary of the DIII-D tokamakPhysics of Plasmas, 2001
- Experimental Evidence of Intermittent Convection in the Edge of Magnetic Confinement DevicesPhysical Review Letters, 2001
- Turbulence intermittency and burst properties in tokamak scrape-off layerPhysics of Plasmas, 2001
- Statistical characterization of fluctuation wave forms in the boundary region of fusion and nonfusion plasmasPhysics of Plasmas, 2000