Transport by intermittent convection in the boundary of the DIII-D tokamak
Boedo, J. A. ; Rudakov, D. ; Moyer, R. ; Krasheninnikov, S. ; Whyte, D. ; McKee, G. ; Tynan, G. ; Schaffer, M. ; Stangeby, P. ; West, P. ; Allen, S. ; Evans, T. ; Fonck, R. ; Hollmann, E. ; Leonard, A. ; Mahdavi, A. ; Porter, G. ; Tillack, M. ; Antar, G.
[S.l.] : American Institute of Physics (AIP)
Published 2001
[S.l.] : American Institute of Physics (AIP)
Published 2001
| ISSN: |
1089-7674
|
|---|---|
| Source: |
AIP Digital Archive
|
| Topics: |
Physics
|
| Notes: |
Intermittent plasma objects (IPOs) featuring higher pressure than the surrounding plasma, and responsible for ∼50% of the E×BT radial transport, are observed in the scrape off layer (SOL) and edge of the DIII-D tokamak [J. Watkins et al., Rev. Sci. Instrum. 63, 4728 (1992)]. Conditional averaging reveals that the IPOs, produced at a rate of ∼3×103 s−1, are positively charged and also polarized, featuring poloidal electric fields of up to 4000 V/m. The IPOs move poloidally at speeds of up to 5000 m/s and radially with E×BT/B2 velocities of ∼2600 m/s near the last closed flux surface (LCFS), and ∼330 m/s near the wall. The IPOs slow down as they shrink in radial size from 4 cm at the LCFS to 0.5 cm near the wall. The IPOs appear in the SOL of both L and H mode discharges and are responsible for nearly 50% of the SOL radial E×B transport at all radii; however, they are highly reduced in absolute amplitude in H-mode conditions. © 2001 American Institute of Physics.
|
| Type of Medium: |
Electronic Resource
|
| URL: |