Scrape-off Layer Current Model for Filament Structure Observed during Edge Localized Modes (ELMs) in the DIII-D Tokamak
Authors: Hironori Takahashi, E. D. Fredrickson, and M.J. Schaffer
Abstract:
The plasma in tokamaks often exhibits a relaxation oscillation called the edge localized mode (ELM), which is generally attributed to MHD instability driven by strong gradients at the plasma boundary. It is shown here that field-aligned currents flowing just outside the boundary may also play a role in the ELM process. The poloidal perturbation magnetic field during ELMs in the DIII–D tokamak calculated from measured currents can reproduce prominent observed features, including a narrow magnetic structure at the outboard midplane similar to filaments observed earlier in DIII–D and NSTX.
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Accepted to: Physical Review Letters (October 2007) LK10983
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