Transport by intermittent convection in the boundary of the DIII-D tokamak

摘要: Intermittent plasma objects (IPOs) featuring higher pressure than the surrounding plasma, and responsible for ∼50% of E×BT radial transport, are observed in scrape off layer (SOL) edge DIII-D tokamak [J. Watkins et al., Rev. Sci. Instrum. 63, 4728 (1992)]. Conditional averaging reveals that IPOs, produced at a rate ∼3×103 s−1, positively charged also polarized, poloidal electric fields up to 4000 V/m. The IPOs move poloidally speeds 5000 m/s radially with E×BT/B2 velocities ∼2600 near last closed flux surface (LCFS), ∼330 wall. slow down as they shrink size from 4 cm LCFS 0.5 appear SOL both L H mode discharges nearly 50% E×B transport all radii; however, highly reduced absolute amplitude H-mode conditions.